Utility of Panoramic Radiographs in the Screening of Individuals with Edentulous Arches: A Need-Analysis Study

Abstract Objective: To evaluate the utility of panoramic radiographs in pre-prosthetic screening of edentulous arches. Material and Methods: Panoramic radiographs taken for three years were retrospectively analyzed. Observations from the radiographs shall be categorized and classified into either of the two categories, namely: 'findings with minimal impact on denture fabrication' and 'findings which affect denture fabrication and require further evaluation.' Anatomic variations, jaw pathologies, and residual ridge resorption patterns were assessed. Results: This study included the initial screening of 23,020 panoramic radiographs, out of which 505 (showing either one or both edentulous arches) were included for the study purpose. The age range of the subjects was from 21 to 94 years. 52.6% of the radiographs showed positive findings. More than half of the radiographs belonged to the males (52.5%). Hyperpneumatization of the maxillary sinus, crestal position of the mental foramen, and retained root fragments were the most common entities noted in the radiographs. Changes in the mental foramen were significantly higher in males than females (p=0.002). Conclusion: Observations from this study showed that panoramic radiographs have high utility for screening edentulous arches, and they should be used in routine clinical practice before denture fabrication.

Is scanning under rubber dam isolation a feasible approach for the execution of indirect restorations? / O escaneamento sob isolamento absoluto é uma técnica viável para execução de restaurações indiretas?

Objective: The aim of the study was to report the aplicability of intraoral scanning while rubber dam isolation is in place. Material and Methods: Female patient, 50 years old, required restorative procedures on teeth 35 and 37. An intraoral scan was initially performed on both arches. Isolation was carried out from 33 to 37, tooth preparation and immediate dentin sealing were carried out. A new scan with the rubber dam in place was performed and a CAD/CAM lithium disilicate hybrid block was digitally designed, milled, crystallized and cemented under the tooth surface with the rubber dam still in position. After completing this stage, the rubber dam was removed, the occlusion was verified, presenting excellent aesthetic and functional results. Results: The absolute isolation process used in the present study works as an excellent device for gingival retraction. Conclusion: The absolute isolation can be recommended in clinical activities of intraoral scanning favoring the quality of the final result of treatments (AU)

Objetivo: O objetivo do estudo foi relatar a aplicabilidade do escaneamento intraoral sob isolamento absoluto. Material e Métodos: Paciente do sexo feminino, 50 anos, necessitou de procedimentos restauradores nos dentes 35 e 37. Uma varredura intraoral foi inicialmente realizada em ambos os arcos. O isolamento absoluto foi feito de 33 a 37, permitindo a realização do preparo dentário e selamento imediato da dentina. Um novo escaneamento com o dique de borracha colocado foi realizado e um bloco híbrido de dissilicato de lítio CAD/CAM foi projetado digitalmente, fresado, cristalizado e cimentado sob a superfície dentária ainda com o dique de borracha em posição. Após a finalização dessa etapa, o dique de borracha foi removido, a oclusão foi verificada apresentando ótimos resultados estéticos e funcionais. Resultados: O isolamento absoluto utilizado no presente estudo funciona como um excelente dispositivo para retração gengival. Conclusão: O isolamento absoluto pode ser recomendado em atividades clínicas de escaneamento intraoral favorecendo a qualidade do resultado final dos tratamentos (AU)

Sobrevivência em fadiga de coroas bioinspiradas bilaminadas: estudo in vitro / Fatigue survival rate of bioinspired bilaminar crowns: in vitro study

O objetivo deste estudo foi avaliar o comportamento biomecânico através da resistência à fadiga e análise por elementos finitos de coroas bioinspiradas bilaminadas com infraestruturas modificadas na superfície vestibular (Estudo A) e utilizando diferentes materiais cerâmicos com módulos elásticos distintos (Estudo B). Para isso, foram confeccionados 90 preparos para coroa total em resina epóxi G10, sobre os quais foram preparadas coroas bioinspiradas de acordo com os seguintes grupos: Estudo A - IC (infraestrutura convencional), IME (infraestrutura modificada estratificada) e IMC (infraestrutura modificada cimentada), todas confeccionadas em dissilicato de lítio (infraestrutura) + porcelana (recobrimento); Estudo B ­ DL+LEU (dissilicato de lítio + leucita), LEU+DL (leucita + dissilicato de lítio), CH+DL (cerâmica híbrida + dissilicato de lítio) e CH+LEU (cerâmica híbrida + leucita). Para o Estudo A, todas as infraestruturas foram usinadas; os recobrimentos dos grupos IC e IME foram confeccionados através da estratificação, e os recobrimentos do grupo IMC foram usinados. Já para o Estudo B, todas as peças foram usinadas, de acordo com o material cerâmico de cada grupo. Em seguida, foi realizada a cimentação adesiva dos recobrimentos sobre as infraestruturas (a depender do grupo) e das coroas sobre os preparos utilizando cimento resinoso fotopolimerizável (Variolink Esthetic LC). Após a cimentação, os espécimes foram submetidos ao teste de fadiga cíclica (10.000 ciclos, 20Hz), e como desfecho foram considerados dois eventos, em que o primeiro foi a ocorrência de trinca e/ou lascamento (evento 1) e o segundo foi a falha catastrófica do conjunto (evento 2). Os valores de carga e número de ciclos para falha em que foram observados os eventos 1 e 2 foram utilizados para realizar a análise de sobrevivência de acordo com Kaplan-Meier e Log-Rank (Mantel-Cox; 95%). As marcas de fratura e o modo de falha das coroas foram avaliados e classificados por estereomicroscópio óptico e microscópio eletrônico de varredura. Por fim, foi realizada análise por elementos finitos (FEA) para ambos os estudos, a fim de avaliar a distribuição de tensões sobre as coroas e interface adesiva. Para o Estudo A, os resultados do teste de fadiga mostraram que, considerando o evento 1 (trinca/lascamento), os grupos IC e IMC apresentaram médias de carga fadiga estatisticamente significantes entre si (733,33 N e 913,33 N, respectivamente), enquanto o grupo IME apresentou média superior (1.020 N). O mesmo foi observado para o número de ciclos em fadiga para todos os grupos. Ao considerar o evento 2 (falha catastrófica), os três grupos apresentaram médias estatisticamente semelhantes entre si (~1.028 N). Os resultados de FEA mostraram que o grupo IC concentrou maior tensão de tração do que os grupos IME e IMC. Para o Estudo B, no teste de fadiga, o grupo DL+LEU apresentou a maior média de resistência à fadiga (evento 1: 913,33 N e evento 2: 1033,33 N), enquanto todas as outras combinações de materiais cerâmicos analisadas foram estatisticamente semelhantes entre si, considerando carga e número de ciclos. Com relação ao FEA, os grupos com cerâmica híbrida (CH+DL e CH+LEU) apresentaram menores picos de concentração de tensão na infraestrutura do que os grupos com cerâmicas vítreas (DL+LEU e LEU+DL), porém, em contrapartida, concentraram maior tensão na interface adesiva. Com isso, conclui-se que a utilização da infraestrutura modificada é uma alternativa viável e promissora para tratamentos reabilitadores, apresentando sobrevivência em fadiga e distribuição de tensões satisfatórias. Além disso, a combinação entre uma infraestrutura de dissilicato de lítio e recobrimento de cerâmica a base de leucita corresponde a melhor abordagem considerando a infraestrutura modificada.(AU)

The objective of this study was to evaluate the biomechanical behavior through fatigue resistance and finite element analysis of bilaminar bioinspired crowns with modified infrastructures on the buccal surface (Study A) and using different ceramic materials with different elastic moduli (Study B). For this, 90 preparations were made for a full crown in G10 epoxy resin, on which bioinspired crowns were prepared according to the following groups: Study A - CI (conventional infrastructure), SMI (stratified modified infrastructure) and CMI (cemented modified infrastructure ), all made of lithium disilicate (infrastructure) + porcelain (veneer); Study B ­ LD+LEU (lithium disilicate + leucite), LEU+LD (leucite + lithium disilicate), HC+LD (hybrid ceramic + lithium disilicate) and HC+LEU (hybrid ceramic + leucite). For Study A, all infrastructures were machined; the coverings of the CI and SMI groups were made through stratification technique, and the veneers of the SMI group were machined. For Study B, all pieces were machined, according to the ceramic material of each group. Then, the veneers were cemented into their infrastructures (depending on the group) and crowns were cemented into preparations using light-cured resin cement (Variolink Esthetic LC). After cementing, the specimens were subjected to the cyclic fatigue test (10,000 cycles, 20Hz), and as an outcome two events were considered: the occurrence of cracking and/or chipping (event 1) and catastrophic failure (event 2). The load (N) and number of cycles to failure in which events 1 and 2 were observed were used to perform the survival analysis according to Kaplan-Meier and Log-Rank (Mantel- Cox; 95%). The fracture marks and failure mode of the crowns were evaluated and classified by optical stereomicroscope and scanning electron microscope. Finally, finite element analysis (FEA) was performed for both studies in order to evaluate the stress distribution over the crowns and adhesive interface. For Study A, the results of the fatigue test showed that, considering event 1 (cracking/chipping), the CI and CMI groups presented average to failure that were statistically significant compared to each other (733.33 N and 913.33 N, respectively), while the SMI group showed higher averages (1,020 N). Same pattern was observed for the number of cycles under fatigue for both groups. When considering event 2 (catastrophic failure), the three groups presented statistically similar means (~1,028 N). The FEA results showed that the CI group concentrated greater tensile stress than the CMI and SMI groups. For Study B, in the fatigue test, the LC+LEU group presented the highest average fatigue resistance (event 1: 913.33 N and event 2: 1033.33 N), while all other combinations of ceramic materials analyzed were statistically similar to each other, considering load and number of cycles. Regarding FEA, the groups with hybrid ceramics (HC+LC and HC+LEU) showed lower stress concentration peaks in the infrastructure than the groups with glass ceramics (LC+LEU and LEU+LC), however, on the other hand, concentrated greater tension at the adhesive interface. With this, it is concluded that the use of modified infrastructure is a viable and promising alternative for oral rehabilitation treatments, presenting satisfactory fatigue survival and adequate stress distribution. Furthermore, the combination of a lithium disilicate infrastructure and a leucite-based ceramic coating corresponds to the best approach considering the modified infrastructure.(AU)

Anti-biofilm effectiveness of protocols for cleaning complete dentures in hospitalized patients: a randomized controlled trial

Abstract Denture biofilm acts as a potential reservoir for respiratory pathogens, considerably increasing the risk of lung infections, specifically aspiration pneumonia, mainly 48h after hospital admission. The establishment of a straightforward, affordable, and applicable hygiene protocol in a hospital environment for the effective control of denture biofilm can be particularly useful to prevent respiratory infections or reduce the course of established lung disease. Objectives To evaluate the anti-biofilm effectiveness of denture cleaning protocols in hospitalized patients. Methodology The maxillary complete dentures (MCDs) of 340 hospitalized participants were randomly cleaned once using one of the following 17 protocols (n=20): brushing with distilled water, toothpaste, or neutral liquid soap (controls); immersion in chemical solutions (1% sodium hypochlorite, alkaline peroxide, 0.12% or 2% chlorhexidine digluconate), or microwave irradiation (650 W for 3 min) combined or not with brushing. Before and after the application of the protocols, the biofilm of the intaglio surface of the MCDs was evaluated using two methods: denture biofilm coverage area (%) and microbiological quantitative cultures on blood agar and Sabouraud Dextrose Agar (CFU/mL). Data were subjected to the Wilcoxon and Kruskal-Wallis tests (α=0.05). Results All 17 protocols significantly reduced the percentage area of denture biofilm and microbial and fungal load (P<0.05). The highest percentage reductions in the area of denture biofilm were observed for 1% hypochlorite solution with or without brushing and for 2% chlorhexidine solution and microwave irradiation only in association with brushing (P<0.05). The greatest reductions in microbial and fungal load were found for the groups that used solutions of 2% chlorhexidine and 1% hypochlorite and microwave irradiation, regardless of the association with brushing (P<0.05). Conclusions A single immersion for 10 min in 1% sodium hypochlorite, even in the absence of brushing, proved to be a straightforward, rapid, low-cost, and effective protocol for cleaning the dentures of hospitalized patients.

Oral Manifestations in Hospitalized and Non-Hospitalized Cuban Patients with COVID-19: A Cross-Sectional Analysis through a Survey

Introduction: COVID-19 continues to drive research aimed at elucidating the disease's behavior and clinical aspects for improved diagnosis. Objective: To describe oral manifestations reported through a survey by dentate and denture-wearing Cuban individuals hospitalized due to confirmed COVID-19 infection. Methods: A cross-sectional descriptive study was conducted through a survey, involving Cuban individuals aged 18 years and above, confirmed COVID-19 positive by PCR. Exclusions encompassed smokers, alcoholics, regular medication users, those with poor oral hygiene, and individuals with pre-existing oral manifestations. A questionnaire was administered to over a thousand individuals, of which 264 met the criteria. Variables related to COVID-19 infection and oral hygiene were assessed. Data were processed using SPSS, adhering to ethical principles. Results: The study comprised 264 participants with an average age of 39.96 years. Xerostomia emerged as the most prevalent oral manifestation (40.2%), followed by mandibular pain, TMJ, or bone pain (18.9%), and non-dental mouth pain (12.5%). Xerostomia was more prevalent in the 35 to 39 age group, while mandibular pain predominated in the 50 to 54 age group. No statistically significant evidence was found for dentate individuals or denture wearers, but significance was observed for those requiring hospitalization, exhibiting painless tongue lesions, single ulcers, and painful tongue lesions. Conclusions: Xerostomia was the most prevalent oral manifestation, followed by mandibular pain, TMJ or bone pain, and non-dental mouth pain. A statistically significant association was noted between the need for hospitalization and certain oral manifestations. The use of dentures was not significantly related to the studied manifestations.

Introducción: La COVID-19 continúa generando interés en investigaciones que buscan esclarecer el comportamiento de la enfermedad y sus aspectos clínicos para facilitar el diagnóstico. Objetivo: Describir las manifestaciones orales informadas por individuos cubanos dentados, con prótesis, que fueron hospitalizados al dar positivo por COVID-19. Métodos: Se llevó a cabo un estudio descriptivo transversal a través de una encuesta con una muestra de individuos cubanos mayores de 18 años, infectados por COVID-19 y confirmados mediante PCR. Se excluyeron fumadores, alcohólicos, usuarios regulares de medicamentos, personas con mala higiene bucal y aquellos con manifestaciones bucales previas a la infección. Se aplicó un cuestionario a más de mil individuos, de los cuales 264 cumplieron con los criterios. Se utilizaron variables relacionadas con la infección por COVID-19 y la higiene bucal. Los datos se procesaron con SPSS, respetando los principios éticos. Resultados: El estudio incluyó a 264 participantes con una edad promedio de 39,96 años. La xerostomía fue la manifestación bucal más prevalente (40,2 %), seguida por el dolor mandibular, ATM o hueso (18,9 %) y el dolor de boca no dental (12,5 %). La xerostomía fue más frecuente en el grupo de 35 a 39 años, mientras que el dolor mandibular predominó en el grupo de 50 a 54 años. No se encontró evidencia estadística significativa para pacientes dentados o portadores de prótesis, pero sí para aquellos que necesitaron hospitalización, con lesiones en la lengua sin dolor, úlceras únicas y lesiones en la lengua con dolor. Conclusiones: La xerostomía fue la manifestación bucal más prevalente, seguida por el dolor mandibular, ATM o hueso, y el dolor de boca no dental. Se observó una asociación estadísticamente significativa entre la necesidad de hospitalización y ciertas manifestaciones bucales. No se encontró significativo el uso de prótesis en relación con las manifestaciones estudiadas.

Atividade antifúngica de nanofibras de policaprolactona/nistatina: estudo in vitro e in vivo / Antifungal activity of polycaprolactone/nystatin nanofibers: in vitro and in vivo study

Este estudo avaliou a eficácia in vitro e in vivo de mantas de nanofibras (NF) de policaprolactona (PCL) incorporadas com nistatina (NIS) no tratamento da estomatite protética (EP) em modelos animais. NF foram sintetizadas com diferentes concentrações de NIS, totalizando quatro soluções: PCL puro, PCL/NIS 0,045 g, PCL/NIS 0,090 g e PCL/NIS 0,225 g. A liberação da NIS foi analisada por espectroscopia Ultravioleta-Visível. A capacidade das mantas de inibirem o biofilme de Candida albicans, principal fator etiológico da EP, dividindo-se cinco grupos (N=5) compostos por um grupo com controle de células de C. albicans e com PCL puro, além das três concentrações de NIS. A seguir, foi analisada a viabilidade celular em queratinócitos humanos (HaCat) por meio do teste colorimétrico de resazurina. Cinco grupos foram divididos (N=10): controle celular, PCL puro e as três concentrações de NIS. Em modelos animais de ratos Wistar albinos (N=18), dispositivos palatinos (DP) de resina acrílica foram confeccionados simulando próteses totais e utilizados para a indução da EP. Para isso, DP contaminados com C. albicans foram cimentados na região molar da cavidade bucal dos animais e permaneceram em boca por 48 h. Após esse período, os DP foram removidos e os animais foram divididos em três grupos: (C) controle; (B1) com tratamento por mantas de PCL/NIS 0,045 g e (B2) PCL/NIS 0,225 g, com N=6. Então novos DP, livres de contaminação, foram cimentados na cavidade oral dos animais e permaneceu por mais 48 h. Após esse período, os animais foram eutanasiados, a contagem de UFC/ mL foi realizada e os palatos foram coletados para a análise histológica. A curva padrão de NIS obtida apresentou R2 de 0,99. As três concentrações de NF apresentaram liberação de NIS, com pico no tempo de 6 h e valores de 66,26 µg/ mL para PCL/NIS 0,045 g, de 333,87 µg/ mL para PCL/NIS 0,090 g e 436,51 µg/ mL para PCL/NIS 0,225 g, constantes até o fim do experimento. Os grupos com NIS reduziram em 2,5 log10 de crescimento do biofilme fúngico em relação aos grupos sem tratamento, Controle e PCL, sem diferença estatística significativa. Não foi observada citotoxicidade nas células HaCat, com viabilidade celular de 93,7% para PCL/NIS 0,045 g, 72,6% para PCL/NIS 0,090 g e 72,4% para PCL/NIS 0,225 g. A indução da EP nos três grupos foi possível e, porém, sem redução significativa na contagem de UFC/ mL de C. albicans nos grupos B1 e B2. Na análise histológica do grupo C pôde-se observar infiltração de hifas de Candida na camada queratinizada, presença de células inflamatórias formando micro abscessos e um discreto infiltrado inflamatório no tecido conjuntivo subjacente ao epitélio infectado. Nos grupos B1 e B2 não foram encontradas alterações epiteliais, concluindo-se que as NF demonstraram atividade antifúngica in vitro e foram efetivas na prevenção da penetração de hifas no tecido palatino de animais com DP (AU)

This study evaluated the in vitro and in vivo efficacy of nanofiber (NF) mats of polycaprolactone (PCL) incorporated with nystatin (NIS) in the treatment of denture stomatitis (DS) in animal models. NFs were synthesized with different concentrations of NIS, totaling four solutions: pure PCL, PCL/NIS 0.045 g, PCL/NIS 0.090 g, and PCL/NIS 0.225 g. The release of NIS was analyzed by Ultraviolet-Visible spectroscopy. The ability of the mats to inhibit Candida albicans biofilm, the main etiological factor of DS, was assessed by dividing five groups (N=5) composed of a group with C. albicans cell control and with pure PCL, in addition to the three concentrations of NIS. Next, cell viability in human keratinocytes (HaCat) was analyzed using the resazurin colorimetric test. Five groups were divided (N=10): cell control, pure PCL, and the three concentrations of NIS. In albino Wistar rat animal models (N=18), palatal devices (PD) made of acrylic resin were fabricated to simulate total prostheses and used to induce DS. For this, PD contaminated with C. albicans were cemented in the molar region of the animals' oral cavity and remained in the mouth for 48 hours. After this period, the PDs were removed, and the animals were divided into three groups: (C) control; (B1) treated with PCL/NIS 0.045 g mats, and (B2) PCL/NIS 0.225 g, with N=6. Then new, uncontaminated PDs were cemented in the animals' oral cavity and remained for another 48 hours. After this period, the animals were euthanized, UFC/ mL counts were performed, and the palates were collected for histological analysis. The standard NIS curve obtained showed an R2 of 0.99. The three concentrations of NF showed NIS release, with a peak at 6 h and values of 66.26 µg/ mL for PCL/NIS 0.045 g, 333.87 µg/ mL for PCL/NIS 0.090 g, and 436.51 µg/ mL for PCL/NIS 0.225 g, remaining constant until the end of the experiment. The groups with NIS reduced fungal biofilm growth by 2.5 log10 compared to the untreated groups, Control and PCL, with no significant statistical difference. No cytotoxicity was observed in HaCat cells, with cell viability of 93.7% for PCL/NIS 0.045 g, 72.6% for PCL/NIS 0.090 g, and 72.4% for PCL/NIS 0.225 g. Induction of DS in the three groups was possible; however, there was no significant reduction in UFC/ mL counts of C. albicans in groups B1 and B2. Histological analysis of group C revealed infiltration of Candida hyphae in the keratinized layer, presence of inflammatory cells forming micro abscesses, and a discreet inflammatory infiltrate in the connective tissue underlying the infected epithelium. No epithelial alterations were found in groups B1 and B2, concluding that NFs demonstrated in vitro antifungal activity and were effective in preventing hyphal penetration into palatal tissue in animals with PD.(AU)

Clinical application of lithium disilicate glass ceramic cantilever resin-bonded fixed partial denture in the restoration of single anterior tooth loss / 口腔疾病防治

Objective@#To investigate the clinical effect of lithium disilicate glass ceramic cantilever resin-bonded fixed partial dentures (CRBFPDs) on single anterior tooth loss to provide a reference for the selection of restoration methods for single anterior tooth loss.@*Methods@#This study was reviewed and approved by the Ethics Committee, and informed consent was obtained from the patients. Forty-two patients with less than two anterior teeth with monomaxillary loss were included in this study. After 6 months, 1 year, 2 years, and 3 years, the aesthetic and functional effects of the restorations and the periodontal health status were evaluated, and the visual analog scale (VAS) was used to assess patient satisfaction.@*Results@#During the observation period, the connector fractured in one case within 3 months. One case had debonded within 2 years. The aesthetic restoration effect of all lithium disilicate glass ceramic CRBFPDs was categorized as Class A. The periodontal health was good, there was no clinical absorption in the soft and hard tissues of the abutment or subbridge, periodontal status according to the evaluation indices was classified as class A, and the total satisfaction rate of the patient was 100%.@*Conclusion@#For single anterior tooth loss patients, lithium disilicate glass ceramic cantilever resin-bonded fixed partial denture can achieve the restoration effect of less invasion, better adhesion, aesthetics, comfort and good biocompatibility. With high patient satisfaction, it can be considered an ideal restoration method for replacing a single anterior tooth.

Reabilitação oral com próteses parciais removíveis após restabelecimento de dimensão vertical de oclusão e tratamento multidisciplinar: relato de caso / Oral rehabilitation with removable partial dentures after restoration of the vertical dimension of occlusion and multidisciplinary treatment: case report

As próteses parciais removíveis (PPRs) são uma alternativa de tratamento viável na prática clínica para reabilitar arcos parcialmente desdentados. Entretanto, o planejamento dessas próteses e preparo bucal prévio são frequentemente negligenciados. O presente artigo tem como objetivo relatar o caso clínico de uma reabilitação oral com PPRs superior e inferior após abordagem multidisciplinar, de modo a enfatizar as fases de um planejamento criterioso e de preparo prévio dos dentes pilares, visando o sucesso e a longevidade da reabilitação. Paciente do sexo masculino de 57 anos de idade compareceu à clínica da Faculdade de Odontologia de Bauru, Universidade de São Paulo, queixando-se da estética de seu sorriso e de algumas ausências dentárias. O indivíduo utilizava uma PPR provisória inferior insatisfatória e apresentava perda de dimensão vertical de oclusão (DVO). Após o exame clínico, radiográfico e estudo do caso em articulador semi-ajustável, realizou-se o planejamento com abordagens restauradoras, endodônticas, periodontais e protéticas. Após tratamento periodontal, foi realizada endodontia dos elementos 12, 15 e 47, confecção de núcleos e coroas nos dentes 12 e 15, restauração a nível gengival para apoio residual no dente 47, restaurações nos dentes 11, 13, 22, 24 e 44 e, por fim, a confecção das PPRs superior e inferior. A abordagem multidisciplinar utilizada neste caso clínico viabilizou o restabelecimento da DVO e possibilitou o sucesso da reabilitação protética(AU)

Removable partial dentures (RPDs) are a viable treatment alternative in clinical practice to rehabilitate partially edentulous arches. However, the planning of these dentures and prior oral preparation are often neglected. This article aims to report the clinical case of an oral rehabilitation with upper and lower RPDs after a multidisciplinary approach, to emphasize the phases of careful planning and prior preparation of the abutment teeth, aiming at the success and longevity of the rehabilitation. A 57-year-old male patient came to the clinic of the Bauru School of Dentistry, University of São Paulo, complaining about the esthetics of his smile and some missing teeth. The subject was using an unsatisfactory lower provisional prosthesis and had a loss of vertical dimension of occlusion (OVD). After the clinical and radiographic examination and the case study in a semi-adjustable articulator, planning was carried out with restorative, endodontic, periodontal and prosthetic approaches. After periodontal treatment, endodontics were performed on elements 12, 15 and 47, creation of cores and crowns on teeth 12 and 15, restoration at the gingival level for residual support on tooth 47, restorations on teeth 11, 13, 22, 24 and 44 and, finally, the making of the upper and lower PPRs. The multidisciplinary approach used in this clinical case enabled the restoration of the OVD and enabled the success of the oral rehabilitation(AU)

The bruxism paradigm in the absence of teeth: observational cross-sectional study in full denture users / O paradigma do bruxismo na ausência de dentes: estudo observacional de corte transversal em usuários de próteses totais

ABSTRACT BACKGROUND AND OBJECTIVES: Bruxism is defined as an activity of the masticatory muscles, which is independent of the teeth presence, so it can occur in total edentulous patients and users of dental prostheses. In this sense, It is therefore necessary to know the clinical manifestations of bruxism in this population. The objective of this study was to evaluate the clinical manifestation and the presence of probable sleep and awake bruxism in a sample of users of full dentures treated at a teaching dental clinic in the city of Ribeirão Preto/SP. METHODS: The adopted sample consisted of 30 patients (mean age 72 years, 18 women/12 men). The following questionnaires were used to assess probable bruxism: Oral Behavior Checklist (OBC), Questionnaire of the American Academy of Orofacial Pain (AADO) and the Depression Anxiety and Stress Scale (DASS-21). The clinical assessment included the identification of wear on the prostheses, tongue indentations, bitten cheek and sensitivity in the masticatory muscles and temporomandibular joints. The data was analyzed using descriptive statistics. RESULTS: The average of use of the dentures were nine years. Six patients (20%) reported self-perceived sleep bruxism, and 11 (36%) reported self-perceived awake bruxism. OBC showed an average total score of 9.8 ± 6.2, with "teeth clenching" being the most described symptom. DASS-21 presented an average of 16.5, and stress, anxiety and depression were within normal limits. The most commonly reported symptoms in the AADO were headache, neck pain, pain and/or difficulty during jaw function and recent trauma to the head, neck or jaws. In the clinical evaluation, 15 (50%) patients had wear on prosthesis, only 2 (6%) had bitten cheek, none had tongue indentations, 4 (13%) had pain during palpation. CONCLUSION: Despite the limitations of the study (cross-sectional, small sample and absence of instrumental evaluation of bruxism), it is possible to conclude that a significant portion of users of total dentures presented probable bruxism, with tooth clenching being the main report and wear on the prosthesis the main clinical manifestation.

RESUMO JUSTIFICATIVA E OBJETIVOS: O bruxismo é definido como uma atividade da musculatura mastigatória, que independe da presença de dentes, portanto pode ocorrer em pacientes desdentados totais e usuários de próteses dentárias. Assim, é preciso conhecer como o bruxismo se manifesta clinicamente nessa população. O objetivo deste estudo foi investigar a presença do provável bruxismo de sono e de vigília em usuários de prótese total atendidos em uma clínica odontológica de ensino em Ribeirão Preto/SP. MÉTODOS: Uma amostra de conveniência foi composta por 30 pacientes (média de 72 anos, 18 mulheres e 12 homens). Os seguintes questionários foram utilizados para avaliar o provável bruxismo: Oral Behavior Checklist (OBC), Questionário da Academia Americana de Dor Orofacial (AADO) e o Depression Anxiety and Stress Scale (DASS-21). A avaliação clínica incluiu a identificação de desgastes nas próteses, língua dentada, bochecha mordiscada e sensibilidade nos músculos mastigatórios e nas articulações temporomandibulares. Os dados foram analisados por meio de estatística descritiva. RESULTADOS: A média de uso das próteses foi de nove anos. Seis indivíduos (20%) relataram bruxismo do sono e 11 (36%) relataram bruxismo de vigília. O OBC apresentou média de escore total de 9,8 ± 6,2, sendo "apertar de dentes" o sintoma mais descrito. O DASS-21 apresentou média total de 16,5, com valores de estresse, ansiedade e depressão dentro da normalidade. Os sintomas mais relatados no AADO foram cefaleia, dores no pescoço, dor e/ou dificuldade durante a função mandibular e trauma recente na cabeça, pescoço ou maxilares. Na avaliação clínica, 15 (50%) dos pacientes apresentaram desgastes na prótese, 4 (13%) dor por palpação, 2 (6%) bochecha mordiscada e nenhum (0%) língua dentada. CONCLUSÃO: Apesar das limitações deste estudo (corte transversal, amostra reduzida e ausência de avaliação instrumental do bruxismo) foi possível concluir que uma parcela significativa de usuários de próteses totais apresentou provável bruxismo, sendo o apertamento dentário o principal relato e desgastes na prótese a principal manifestação clínica.

Invitro Comparative Analysis of the Flexural Strength of 4 Different Commercially Available Provisional Materials Used in Fixed Partial Dentures – An Original Research

Background: Provisional Prosthesis in fixed partial dentures are subjected to Flexure under stress. Selection of appropriate material for fabrication of Provisional is of utmost importance as the Provisional prosthesis has to remain in function till definitive prosthesis is delivered. Material & Methods: Bar type specimens of four different commercially available brands for provisional restorations fabricated according to ADA specification No. 27 and immersed in artificial saliva. The specimens were fractured under 3-point loading test. Results: The flexural strength ranged between 60 to 110 Mpa. BisGMA Auto polymerizing composite resin from Dentsply Caulk shows the highest flexural strength. Conclusion: Within the limitations of this study, the flexural strengths were material specific rather than category one. The BisGMA composite based resin shows significantly higher flexural strength over other materials

Stability of Denture Base Acrylic Resin to Tea, Coffe and Turmeric Solutions: An in Vitro Study

Background: The color stability of commercially available denture base acrylic resins (Lucitone-199, DPI and Travelon-HI) was studied in vitro. Material & Methods: The specimens were exposed to tea, coffee and turmeric solutions at 37 ± 1 °C. Colour measurement of the specimens from each brand of denture base acrylic resin recorded by spectrophotometer. The specimens were washed under distilled water and dried before measuring the colour on 0, 10, 20 and 30 days of immersion and color differences were calculated. Results: Statistically the colour change was significant between and within the groups of different heat cure denture base acrylic resins. Conclusion: Where as Lucitone-199 heat cure showed the highest colour variation in tea and coffee followed by DPI and Travelon-HI.

Desarrollo y aplicación de un software educativo bidimensional para el proceso de enseñanza del diseño de Prótesis Parcial Removible / Validation of a two-dimensional educational software for the learning process of the design of Removable Partial Dentures

Objetivo: El objetivo de este estudio fue desarrollar e implementar un software educativo bidimensional para el proceso de aprendizaje del diseño de Prótesis Parciales Removibles.Materiales y métodos: Se utilizó el método científico y procedimientos de evaluación educativa para abordar las necesidades de la asignatura de Prótesis Parcial Removible en la Facultad de Odontología de la UNMSM de Perú en el año 2022. Se utilizó análisis, síntesis y encuestas. Se examinó la aplicabilidad del software y el cumplimiento de los requerimientos de enseñanza y aprendizaje, no sólo en la UNMSM sino en cualquier universidad con requerimientos y características similares. Resultados: La aplicación in-terna del software arrojó un valor final del 96%, mientras que la evaluación de alumnos y docentes mostró un 90% de aceptación, al considerar que el SEDUPPR es sencillo para instalar, sencillo en su manejo y funcionamiento, y es muy útil para aprender diseño de PPR. Conclusiones: El software educativo bidimensional diseñado para el proceso de aprendizaje de Prótesis Parcial Removible es aplicable y puede ser implementado en diferentes ámbitos educativos.

Objective: The objective of this study was to develop and implement a two-dimensional educational software for the learning process of designing Removable Partial Prostheses.Materials and Methods: The scientific method and educational evaluation procedures were utilized to address the needs of the Removable Partial Prosthesis subject in the Fa-culty of Dentistry at the UNMSM in Peru in 2022. Analysis, synthesis, and surveys were used. The software's applicability and fulfillment of teaching and learning requirements were examined, not only at the UNMSM but also in any university with similar require-ments and characteristics. Results: The internal application of the software yielded a final value of 96%, while the evaluation of students and teachers showed a 90% acceptance rate, considering that SEDUPPR is simple to install, easy to use and operate, and is very useful for learn PPR design. Conclusion: The two-dimensional educational software designed for the learning process of Removable Partial Prosthesis is applicable and can be implemented in different educational settings.

Relationship between the occlusal plane and three different levels of ala-tragus line in a sample of sudanese adults / Relación entre el plano oclusal y tres niveles diferentes de la línea ala-trago en una muestra de adultos sudaneses

Aim: Correct orientation of the occlusal plane plays a vital role in achieving the perfect occlusal balance and function of complete dentures. This study aimed to evaluate the most reliable posterior reference point of the ala-tragus line (ATL) concerning occlusal plane (OP) in a sample of the dentate Sudanese population. Materials and Methods: A total of 150 subjects with healthy and well-aligned permanent teeth were randomly selected. Right lateral profile photographs were taken with subjects having a fox plane placed intra-orally, contacting the occlusal plane. Reference points corresponding to inferior, middle, and superior borders of the tragus and inferior border of the ala of the nose were marked on photographs. The angles between the lines were measured using the Auto-CAD software program, and the most parallel relationship was determined. Descriptive statistics in terms of means and standard deviations were presented. Independent t-test and one-way ANOVA tests were used to compare as appropriate. A p-value < 0.05 was considered significant. Results: The mean angle formed by the OP and ATL was 8.5±3.69º for the superior level, 4.68±3.13º for the middle line, and 2.89±2.57º for the inferior line. A significant difference was found between the means of the three angles (p< 0.001), while no significant difference (p> 0.05) was found between both genders regarding the measured angles. Conclusions: The line joining the inferior border of the ala of the nose with the inferior border of the tragus of the ear was the most reliable line in terms of parallelism to determine the occlusal plane orientation.

Antecedentes: La orientación correcta del plano oclusal juega un papel vital para lograr el equilibrio oclusal perfecto y la función de las prótesis completas. Este estudio tuvo como objetivo evaluar el punto de referencia posterior más confiable de la línea ala-trago (ATL) con respecto al plano oclusal (OP) en una muestra de la población dentada de Sudán. Materiales y Métodos: Se seleccionaron aleatoriamente un total de 150 sujetos con dientes permanentes sanos y bien alineados. Se tomaron fotografías de perfil lateral derecho de sujetos a los que se les colocó un plano de zorro intraoralmente, en contacto con el plano oclusal. En las fotografías se marcaron los puntos de referencia correspondientes a los bordes inferior, medio y superior del trago y al borde inferior del ala de la nariz. Los ángulos entre las líneas se midieron utilizando el programa de software Auto-CAD y se determinó la relación más paralela. Se presentaron estadísticas descriptivas en términos de medias y desviaciones estándar. Se utilizaron prueba-t independiente y prueba ANOVA unidireccional para las comparaciones, según correspondiera. Se consideró significativo un valor de p<0,05. Resultados: El ángulo medio formado por OP y ATL fue de 8,5±3,69º para el nivel superior, 4,68±3,13º para la línea media y 2,89±2,57º para la línea inferior. Se encontró una diferencia significativa entre las medias de los tres ángulos (p< 0,001), mientras que no se encontró diferencia significativa (p>0,05) entre ambos sexos con respecto a los ángulos medidos. Conclusión: La línea que une el borde inferior del ala de la nariz con el borde inferior del trago de la oreja fue la línea más confiable en términos de paralelismo para determinar la orientación del plano oclusal.

Cambios en parámetros masticatorios con prótesis parcial removible para dientes posteriores perdidos / Changes in masticatory parameters with removable partial dentures for missing posterior teeth

Introducción: el reemplazo de dientes perdidos aspira a mejorar la función masticatoria. Aunque hay diferentes opciones para ello, la conveniencia de la prótesis parcial removible (PPR) es su bajo costo. Objetivo: comparar el desempeño masticatorio (DM) después de 20 ciclos masticatorios y al umbral de la deglución (UD) en adultos de 50 a 70 años con dientes posteriores perdidos (DPP), con/sin PPR; y los ciclos hasta la deglución. Material y métodos: estudio transversal en 35 adultos con dientes anteriores y PPR bien ajustadas y utilizadas para comer. El lado de prueba fue el lado con más DPP. El DM se evaluó después de 20 ciclos y al UD utilizando un alimento prueba artificial (Optosil Comfort®) con/sin la PPR en orden aleatorizado. Las partículas se tamizaron para determinar el tamaño medio de partícula (TMP) como medida del DM. Los ciclos se contaron visualmente. Estadística descriptiva y comparaciones con SPSS-v23. Resultados: hubo diferencias significativas (p ≤ 0.05) al masticar con/sin PPR. El TMP fue más pequeño (mejor DM) con la PPR después de 20 ciclos y al UD (3.9 vs 4.4 mm y 3.2 vs 4.2 mm). Los ciclos para llegar al UD disminuyeron con la PPR (40 vs 47). Conclusión: a pesar de una mejora limitada de la función masticatoria, las PPR ayudan a preparar los alimentos en partículas más pequeñas antes de deglutirlas. La mejoría en DM con PPR es de 24% al UD, realizando menos ciclos antes de deglutir sus alimentos (AU)

Introduction: replacement of missing teeth should improve masticatory function. Although there are different options removable partial dentures (RPD) are used due to their lower cost. Objective: to compare masticatory performance (MP) after 20 chewing-cycles and swallowing-threshold (ST) in 50-70 year-old adults with missing posterior teeth (MPT) with and without their cast-metal RPD; chewing cycles until swallowing were also compared. Material and methods: 35 adults participated in this cross-sectional study. Subjects with anterior teeth and welladjusted RPDs, used for eating were included. The side with more MPT was selected as the test side. MP was evaluated after 20 cycles and ST using an artificial test-food (Optosil Comfort®) with/without the RPD (subject-own-control) (randomized order). Chewed particles were sieved to determine medium-particle-size (MPS) as a measure of MP. Chewing cycles were visually counted. Descriptive statistics and comparisons were run with SPSS v23. Results: there were significant differences (p ≤ 0.05) for all parameters when chewing with/without the RPD. MPS was smaller (better MP) with the RPD (3.9 vs 4.4 mm and 3.2 vs 4.2 mm) after 20 cycles and ST respectively. Cycles required to reach ST were less when chewing with the denture (40 vs 47). Conclusion: despite a limited improvement of masticatory function RPDs help patients prepare their food into smaller particles before swallowing. Improvement in MP with RPDs for patients with MPT is 24% at ST and they perform fewer chewing cycles before swallowing food (AU)

Research progress on neutrophil extracellular traps in oral infectious diseases / 口腔疾病防治

@#Eutrophils are the first innate immune cells to reach the site of inflammation. Neutrophils produce neutrophil extracellular traps (NETs) that can quickly capture and limit the spread of pathogens, facilitating the removal of pathogens and their debris. Neutrophils in the oral cavity are specifically transformed from circulating neutrophils in the blood, and the number of NETs released by oral neutrophils is much higher than that of circulating neutrophils, thus better maintaining the balance of the oral microenvironment. As a bimorphic fungus, only the mycelium phase of Candida albicans can induce NETs, which is related to the neutrophils' ability to sense the size of pathogenic microorganisms through neutrophil elastase. However, spherical Staphylococcus aureus are much smaller than Candida albicans, and they can still induce NETs. Porphyromonas gingivalis, as one of the microorganisms in the periodontitis complex, induces fewer NETs than Streptococcus oralis and Actinomycetes, which are two common oral microorganisms, and there may be a mechanism allowing them to escape neutrophilic immunity in the early stage of periodontitis. Although the two main pathways of NET production have been studied in detail, the mechanisms involved in the induction of NETs by different microorganisms, especially from oral neutrophils, are not well understood. This review describes the mechanism of the immune effects of pathogenic microorganisms on neutrophil NETs in the oral cavity, providing a reference for the search for therapeutic targets and the development of key drugs for treating oral infectious diseases.

Crioterapia en pacientes geriátricos con estomatitis subprótesis

Introducción: En la actualidad se emplean nuevas alternativas no invasivas para la remoción de diversos procesos inflamatorios del epitelio mucoso bucal, siendo la crioterapia una técnica fisioterapéutica basada en la aplicación del frío intenso con nitrógeno líquido para producir en la piel o mucosas del organismo una congelación y destrucción local de células y tejidos afectados de forma controlada. Objetivo: Evaluar los efectos terapéuticos de la criocirugía en pacientes geriátricos portadores de estomatitis subprótesis. Métodos: Se efectuó un estudio descriptivo y transversal de 50 pacientes adultos mayores, de ambos sexos, diagnosticados con estomatitis subprótesis y asistidos en la consulta estomatológica del Policlínico de Especialidades referente al Hospital Clinicoquirúrgico Universitario Saturnino Lora Torres de la provincia Santiago de Cuba, en el periodo comprendido desde marzo de 2022 hasta igual mes de 2023. Resultados: Se evidenció que las congelaciones entre 20 y 30 segundos y los deshielos entre 91 y 120 segundos fueron los más eficaces en la destrucción de la mucosa palatina dañada, logrando la regeneración tisular en un tiempo mínimo con la indicación de uno a tres ciclos de enfriamientos rápidos y deshielos lentos en una sesión terapéutica. La ausencia de síntomas fue lo más relevante en la evolución postquirúrgica. Conclusiones: La crioterapia demostró ser un método eficaz e inocuo para regenerar los tejidos lesionados al realizar congelaciones rápidas con deshielos lentos. Este método crioquirúrgico, fácil de aplicar y atraumático, logró una óptima reparación y reepitelización de los tejidos bucales dañados con excelentes respuestas terapéuticas, evitando complicaciones postquirúrgicas como la infección y el sangramiento local.

Introduction: At present, new non-invasive alternatives are used for the removal of various inflammatory processes of the oral mucous epithelium; being cryotherapy a physiotherapeutic technique based on the application of intense cold with liquid nitrogen to produce freezing on the skin or mucous membranes of the organism and local destruction of affected cells and tissues in controlled manner. Objective: To evaluate the therapeutic effects of cryotherapy in geriatric patients with sub-prosthesis stomatitis. Methods: A descriptive and cross-sectional study of 50 older adult patients, of both sexes, clinically diagnosed with subprosthesis stomatitis and assisted in the dentistry consultation of the Specialties Polyclinic referring to the Saturnino Lora Torres University Clinical Surgical Hospital in the city of Santiago de Cuba, in the period from March 2022 to the same month of 2023. Results: It was evidenced that freezing between 20 and 30 seconds and thawing between 91 and 120 seconds were the most effective in the destruction of the damaged palatal mucosa, achieving tissue regeneration in a minimum time with the performance of 1 to 3 cycles of rapid cooling and slow thawing in a therapeutic session. The absence of symptoms was the most relevant in the post-surgical evolution. Conclusions: Cryotherapy proved to be an effective and innocuous method to regenerate injured tissues when fast freezing with slow thawing. This cryosurgical method, easy to apply and atraumatic, achieved optimal repair and re-epithelization of damaged oral tissues with excellent therapeutic responses, avoiding post-surgical complications such as infection and local bleeding.

Prosthetic maintenance assessment for implant fixed complete dentures and implant overdentures: a randomized clinical trial / Avaliação da manutenção protética para próteses totais fixas suportadas por implantes e Overdentures: um ensaio clínico randomizado

Objective: The rehabilitation choice for the edentulous patients usually lies between the fixed and removable prosthetic options. The treatment decisions are affected by many factors where complications and maintenance needs are both considered crucial factors, in addition to the cost effectiveness of the chosen treatment. Material and Methods: This study was applied on 44 edentulous patients, where 22 patient for each group were enrolled in the outpatient clinic of prosthodontics, Cairo University as per a set of eligibility criteria. Four inter-foraminal implants were installed for all eligible participants. Three months later, healing abutments were used for soft tissue preparation prior to the fabrication of the final prosthesis. A prosthetic treatment option was then randomly allocated to obtain two equal groups via computer generated randomization program; Group. A received telescopic implant overdentures, and Group. B received screw retained dentures. All Complications (Screw loosening or fracture, tooth or denture base fracture and mucositis) were reported after overdenture insertion along the follow up period (1, 6, 9 and 12 months respectively). Results: The frequency of the screw loosening for hybrid overdentures where (59.1%) compared to (27.3%) of telescopic prosthesis at 12 months follow up period (p=0.035), mucositis reporting at 6m interval had shown the highest frequency in both groups (Group A (54.5%), Group B (81.8%), (p=0.045), all other reported complications that lack statistical significance either within the same group or between both groups at different time intervals. Conclusion: Both treatment modalities; telescopic implant overdenture and hybrid fixed screw-retained are reliable for restoring the completely edentulous arches, the decision whether to make a fixed or removable implant denture shall be guided with the patient preference together with the dentist assessment in relation (AU)

Objetivo: A escolha da reabilitação para pacientes edêntulos geralmente recai entre próteses fixas e removíveis. As decisões de tratamento são afetadas por muitos fatores onde as complicações e as necessidades de manutenção são consideradas critérios cruciais, além do custo-efetividade do tratamento escolhido. Material e Métodos: Este estudo foi aplicado em 44 pacientes edêntulos, onde 22 pacientes para cada grupo foram matriculados no ambulatório de prótese dentária da Universidade do Cairo de acordo com um conjunto de critérios de elegibilidade. Quatro implantes interforaminais foram instalados para todos os participantes elegíveis. Três meses depois, pilares de cicatrização foram utilizados para preparação dos tecidos moles antes da fabricação da prótese final. Uma opção de tratamento protético foi então alocada aleatoriamente para obter dois grupos iguais por meio de andomização gerada através programa de computador. O Grupo A recebeu overdentures de implantes telescópicos e o Grupo B recebeu dentaduras fixas parafusadas sobre os implantes. Todas as complicações (afrouxamento ou fratura do parafuso, fratura da base do dente ou da prótese e mucosite) foram relatadas após a inserção da overdentures ao longo do período de acompanhamento (1, 6, 9 e 12 meses, respectivamente). Resultados: A frequência do afrouxamento do parafuso para Overdentures híbridas (59,1%) em comparação com (27,3%) da prótese telescópica no período de acompanhamento de 12 meses (p=0,035), o relato de mucosite no intervalo de 6 meses mostrou a maior frequência em ambos os grupos (Grupo A (54,5%), Grupo B (81,8%), p=0,045, todas as outras complicações relatadas foram sem significância estatística dentro do mesmo grupo ou entre os dois grupos em intervalos de tempo diferentes. Conclusão: Ambas as modalidades de tratamento; overdentures sobre implantes telescópicos e próteses híbridas fixas parafusadas são confiáveis para reabilitar as arcadas completamente edêntulas. A decisão de fazer uma prótese fixa ou removível sobre implantes deve ser guiada pela preferência do paciente juntamente com a avaliação do dentista em relação ao estado geral do paciente e sua saúde bucal. (AU)

A simplified technique for fabricating complete dentures for patients with Parkinson's disease: a case report / Técnica simplificada como alternativa para confecção de próteses totais para paciente com Doença de Parkinson: relato de caso

BACKGROUND AND OBJECTIVE: Parkinson's disease is a neurological disorder that affects 1% of individuals aged 60 years and older. The associated symptoms can impose limitations on the available dental treatment options. CASE DESCRIPTION: This case report follows the CARE guidelines and presents an adapted and simplified technique to fabricate complete dentures for a 74-year-old male edentulous patient with Parkinson's disease. This modified technique enabled the fabrication of complete dentures in 4 clinical sessions of approximately 40 minutes. The first session involved manufacturing a preliminary impression with fast-setting alginate. The base plates and occlusal rims were then adjusted for artificial teeth arrangement during the second session. The final prosthesis was completed in the third session, which involved a teeth try-in and fabrication of a functional impression with low-melting thermoplastic material and polyether. Finally, denture installation was performed in the fourth session and follow-up consisted of 3 weekly sessions. DISCUSSION: Considering that the treatment provided satisfactory aesthetics and function, mastication and socialization benefits, and improved the self-esteem and well-being of the older patient with Parkinson's disease, the authors suggest this adapted and simplified technique for fabricating complete dentures. (AU)

JUSTIFICATIVA E OBJETIVO: A doença de Parkinson é uma desordem neurológica que afeta 1% dos indivíduos com 60 anos ou mais. Os sintomas associados podem impor limitações nas opções de tratamento odontológico disponíveis. DESCRIÇÃO DO CASO: Este relato de caso segue o protocolo CARE e apresenta uma adaptação da técnica simplificada para confecção de novas próteses totais, para um paciente edêntulo, do sexo masculino, de 74 anos com doença de Parkinson. Essa técnica modificada possibilita a confecção de próteses totais em quatro sessões clínicas de aproximadamente 40 minutos. A primeira sessão envolveu uma moldagem preliminar com alginato de presa rápida. As placas articulares com rodetes de cera foram ajustadas para montagem dos dentes artificiais durante a segunda sessão. A prótese definitiva foi concluída na terceira sessão, que envolveu a prova dos dentes e moldagem funcional com material termoplástico de baixa fusão e poliéter. Por fim, a instalação da prótese foi realizada na quarta sessão e o acompanhamento consistiu em três sessões semanais. DISCUSSÃO: Considerando que o tratamento proporcionou estética e função satisfatórias, benefícios mastigatórios e de socialização, melhora da autoestima e bem-estar do idoso com doença de Parkinson, os autores sugerem o uso da adaptação da técnica simplificada para confecção de prótese total. (AU)

Effect of Ozonated Water on the Color Stability of Denture Teeth and Heat Polymerized Acrylic Base Resin

Abstract Objective: To determine the effect of ozonated water on the color stability of denture tooth and denture bases. Material and Methods: Thirty denture base discs consisting of 15 Acropars and 15 ProBase Hot specimens with the dimensions of 40 × 5 mm were prepared. Fifteen denture teeth in shade A1 (Ivoclar Vivadent, Schaan, Liechtenstein) were mounted in a specific acrylic jig. All specimens were immersed in three solutions (1% sodium hypochlorite, ozonated water, and distilled water) for four months (one year of clinical use). Color measurements were done with a spectrophotometer and assessed using the CIE L*a*b* colorimetric system (0, 4, 8, 12, and 16 weeks). Data were analyzed using the three-way ANOVA and Tukey test (α=0.05). Results: Tukey's post hoc test revealed a significant change in color in the Acropars denture base for the distilled water group compared to the ozonated water and 1% hypochlorite (p<0.05). Regarding the ProBase Hot denture base, significantly less color change was observed in the 1% hypochlorite group compared to the ozonated water and distilled water (p≤0.001). For the denture teeth, significantly less color change was seen in the distilled water group than in the ozonated water (p=0.015) and 1% hypochlorite (p<0.05) groups. Conclusion: The color change of denture bases and denture tooth in ozonated water are acceptable. Ozonated water can be considered a good disinfectant for cleaning dentures.

The effect of different framework's material on strain induced in distal abutment in mandibular Kennedy's class II: an in-vitro study / O efeito de diferentes materiais de estrutura na deformação induzida na distal do pilar da classe II de Kennedy mandibular: um estudo in vitro

Objective: This study aims to compare the strain induced in the supporting structures of unilateral mandibular removable partial denture frameworks retained by extra-coronal attachments fabricated with three different materials. Material and Methods: Three mandibular class II digitally designed and printed acrylic models with detachable abutments were used to fabricate three removable partial denture framework with extra coronal attachments from three different materials. A total of 33 models were prepared for strain testing (n=11). Models were divided into three groups according to framework's material: porcelain fused to cobalt chromium (PFM), polyetherketoneketone (PEKK) and polyetheretherketone (PEEK) group. Unilateral load of 60 N was applied in the three groups and strains were measured around the main abutment and saddle area using strain gauge. Results: Statistical analysis was performed using Shapiro-Wilk's test and by checking data distribution. Data were found to be non-parametric and were analysed using Kruskal-Wallis test followed by Dunn's post hoc test with Bonferroni correction. PFM group showed significantly the highest strain values around abutment, slot 1 (1mm distal to the socket of the last abutment) and slot 2 (1 cm away from slot 1) respectively (843.00±23.08, 91.00±6.52 and 1274.00±65.71) than the other tested groups (p<0.05) at same tested sites respectively followed by PEKK group (384.00±37.48, 81.00±2.24 and 135.00±0.00) and PEEK group (29.00±4.18, 63.00±4.47 and 52.00±5.70). Conclusions: PEEK and PEKK for partial denture framework with extra coronal attachments are adequate alternative to PFM due to their good mechanical response applying less strain on supportive structures in free-end cases. PEEK induces lower strain magnitude on the supporting structures when compared to PEKK. (AU)

Objetivo: Este estudo tem como objetivo comparar a tensão induzida nas estruturas de suporte de estruturas de próteses parciais removíveis mandibulares unilateraisretidas por encaixes extracoronários fabricados com três materiais diferentes. Material e Métodos: Três modelos mandibulares de classe II digitalmente projetados e impressos em acrílico com pilares destacáveis foram usados para fabricar três estruturas de próteses parciais removíveis com encaixes extracoronários de três materiais diferentes. Um total de 33 modelos foram preparados para testes de deformação (n=11). Os modelos foram divididos em três grupos de acordo com o material da estrutura: porcelana fundida com cobalto-cromo (PFM), poliétercetonacetona (PEKK) e polieteretercetona (PEEK). Carga unilateral de 60 N foi aplicada nos três grupos e as deformações foram medidas em torno do pilar principal e área de sela usando medido de tensão. Resultados: A análise estatística foi realizada por meio do teste de Shapiro-Wilk e com a verificação da distribuição dos dados. Os dados mostraram-se não paramétricos e foram analisados pelo teste de Kruskal-Wallis seguido pelo de Dunn com correção de Bonferroni. O grupo PFM mostrou significativamente os maiores valores de tensão ao redor do pilar, slot 1 (1mm distal do último pilar) e slot 2 (1 cm de distância do slot 1) respectivamente (843,00±23,08, 91,00±6,52 e 1274,00±65,71) do que os outros grupos testados (p<0,05) nos mesmos locais testados, respectivamente, seguido pelo grupo PEKK (384,00±37,48, 81,00±2,24 e 135,00±0,00) e grupo PEEK (29,00±4,18, 63,00±4,47 e 52,00±5,70). Conclusão: PEEK e PEKK para estrutura de prótese parcial com encaixes extracoronários são alternativas adequadas ao PFM devido à sua boa resposta mecânica aplicando menos tensão nas estruturas de suporte em casos de extremidade livre. O PEEK induz menor magnitude de deformação nas estruturas de suporte quando comparado ao PEKK (AU)