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.

Stress distribution in peri-implant bone, implants, and prostheses: 3D-FEA of marginal bone loss and prosthetic design / Distribuição de estresse no osso peri-implantar, implantes e próteses: análise 3D-FEA de perda óssea marginal e design protético

Objective: In response to the demand for dental implants, extensive research has been conducted on methods for transferring load to the surrounding bone. This study aimed to evaluate the stresses on the peripheral bone, implants, and prostheses under scenarios involving of the following variables: prosthesis designs, vertical bone heights, load angles, and restorative materials. Material and Methods: Three implants were inserted in the premolar and molar regions (5-6-7) of the two mandibular models. Model 1 represented 0 mm marginal bone loss and Model 2 simulated 3 mm bone loss. CAD/CAM-supported materials, hybrid ceramic (HC), resin-nano ceramic (RNC), lithium disilicate (LiSi), zirconia (Zr), and two prosthesis designs (splinted and non-splinted) were used for the implant-supported crowns. Forces were applied vertically (90°) to the central fossa and buccal cusps and obliquely (30°) to the buccal cusps only. The stresses were evaluated using a three-dimensional Finite Element Analysis. Results: Oblique loading resulted in the highest stress values. Of the four materials, RNC showed the low stress in the restoration, particularly in the marginal area. The use of different restorative materials did not affect stress distribution in the surrounding bone. The splinted prostheses generated lower stress magnitude on the bone, and while more stress on the implants were observed. Conclusion: In terms of the stress distribution on the peri-implant bone and implants, the use of different restorative materials is not important. Oblique loading resulted in higher stress values, and the splinted prosthesis design resulted in lower stress (AU)

Objetivo: Em resposta à demanda por implantes dentários, extensa pesquisa foi realizada sobre métodos para transferir carga ao osso circundante. Este estudo buscou avaliar os estresses no osso periférico, implantes e próteses em cenários que envolvem as seguintes variáveis: designs de próteses, alturas ósseas verticais, ângulos de carga e materiais restauradores. Material e Métodos: Três implantes foram inseridos nas regiões dos pré-molares e molares (5-6-7) de dois modelos de mandíbula. O Modelo 1 representou perda óssea marginal de 0 mm e o Modelo 2 simulou perda óssea de 3 mm. Materiais suportados por CAD/CAM, cerâmica híbrida (HC), cerâmica nano-resina (RNC), dissilicato de lítio (LiSi), zircônia (Zr) e dois designs de próteses (sintetizadas e não-sintetizadas) foram utilizados para as coroas suportadas por implantes. Forças foram aplicadas verticalmente (90°) à fossa central e cúspides bucais e obliquamente (30°) apenas às cúspides bucais. Os estresses foram avaliados usando Análise de Elementos Finitos tridimensional. Resultados: Cargas oblíquas resultaram nos valores mais altos de estresse. Entre os quatro materiais, RNC mostrou baixo estresse na restauração, especialmente na área marginal. O uso de diferentes materiais restauradores não afetou a distribuição de estresse no osso circundante. Próteses sintetizadas geraram menor magnitude de estresse no osso, enquanto mais estresse nos implantes foi observado. Conclusão: Em termos de distribuição de estresse no osso peri-implantar e implantes, o uso de diferentes materiais restauradores não é crucial. Cargas oblíquas resultaram em valores mais altos de estresse, e o design de prótese sintetizada resultou em menor estresse. (AU)

Aesthetic Dentistry - What You Decided and What I Want: Shade Selection

ABSTRACT Objective: To assess the relationship between patients' and dentists' perceptions of shade selection and its impact on satisfaction with the prosthesis. Material and Methods: A single group pre-post study was conducted at the Prosthodontics department of a teaching hospital in India. One hundred ten participants were selected through a systematic random sampling technique with inclusion and exclusion criteria. Patients' attitudes regarding the aesthetics of their maxillary anterior teeth were recorded using a validated questionnaire. Shades for the intended prosthetic crown selected by the dentist and chosen by the patient were recorded separately, and patient satisfaction with the appearance of the final prosthesis was recorded. We used descriptive statistics followed by Pearson's Chi-square test and a binomial logistic regression model for inferential statistics. Results: 109 participant's data were available for final analysis. Patients choose lighter shades than the dentist's selection, which is statistically significant (p=0.000). 73.4% were satisfied with the final prosthesis, and the binomial logistic regression model identified using patient-selected shade for the final prosthesis was significantly associated with patients' satisfaction with the final prosthesis (OR=3.3, p=0.001). Conclusion: The patient's preference should be considered with the dentist's option when selecting a shade to create good esthetics.

Rehabilitación implanto protésica en paciente con injerto mandibular de larga data / Implant-prosthetic rehabilitation in a patient with a longstanding mandibular graft / Reabilitação protética com implantes em pacientes com enxerto mandibular de longa data

En la actualidad es cada vez más frecuente la consulta de pacientes que siendo sometidos en edades tempranas a cirugías de extirpación tumoral y posterior reconstrucción con injertos presentan problemas tanto funcionales como estéticos, el uso de prótesis implantosoportadas mejora la calidad de vida, pero al mismo tiempo representan un desafío por la baja disponibilidad ósea. Se presenta un caso clínico de rehabilitación protésica implantosoportada en una paciente con gran déficit óseo mandibular como consecuencia de le extirpación de una neoplasia y posterior injerto de costilla. Se colocaron 2 implantes osteointegrados en hueso remanente y rehabilitación con prótesis removible sostenida a una barra colada. Por ser un tratamiento poco invasivo y conservador fue aceptado fácilmente por la paciente y la mejora tanto en la estética como en la función fue notoria.

Nowadays, it is becoming more and more frequent to see patients who underwent surgery for tumor removal and subsequent reconstruction with grafts at an early age, presenting both functional and esthetic problems. The use of implant-supported prostheses improves the quality of life, but at the same time represents a challenge due to the low availability of bone. A clinical case of implant-supported prosthetic rehabilitation is presented in a patient with a great mandibular bone deficit as a consequence of the removal of a neoplasm and subsequent rib graft. Two osseointegrated implants were placed in the remaining bone and rehabilitation with a removable prosthesis supported by a cast bar. Being a minimally invasive and conservative treatment, it was easily accepted by the patient and the improvement in both esthetics and function was notorious.

Atualmente, são cada vez mais frequentes os pacientes submetidos à cirurgia de remoção de tumores e posterior reconstrução com enxertos em idade precoce que apresentam problemas funcionais e estéticos. O uso de próteses implanto-suportadas melhora a qualidade de vida, mas, ao mesmo tempo, representa um desafio devido à baixa disponibilidade de osso. Apresentamos um caso clínico de reabilitação protética implanto-suportada em um paciente com grande déficit ósseo mandibular em consequência da remoção de uma neoplasia e posterior enxerto de costela. Dois implantes osseointegrados foram colocados no osso remanescente e a reabilitação foi feita com uma prótese removível suportada por uma barra de gesso. Por se tratar de um tratamento minimamente invasivo e conservador, foi facilmente aceito pelo paciente e a melhora na estética e na função foi perceptível.

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.

The possible association between the types of soft palate and gag reflex: a preliminary study / A possível associação entre os tipos de palato mole e o reflexo de vômito: um estudo preliminar

Objective: whether gag reflex, a common problem encountered during dental procedures, is associated with the different types of the soft palate has not been addressed so far. This preliminary study sought to assess the potential association between the different types of soft palate and gag reflex. Material and Methods: one hundred dental patients were recruited. The type of soft palate was determined. Subjective (self-reported) gag reflex was recorded based on many questions and past experience and on a 0-6 VAS. Objective assessment of gag reflex was done using different maneuvers where the posterior part of the tongue and the soft palate were touched by dental mirror, and by taking impression for the upper arch. The association between the types of soft palate and the subjective and objective recorded gag reflex were statistically tested. Results: there were 53 (53%), 33 (33%) and 14 (14%) of the participants with class I, class II and class III soft palate, respectively. A significant association was found between the type of the soft palate and gag reflex in response to one of the subjective items (P= 0.039), more prominent among females (P= 0.009). Concerning the objective assessment, no significant associations were found among males. Meanwhile more females with class II and class III suffered gag reflex and/or actual gagging upon taking the impression (P = 0.001). Conclusion: this study illustrated an association between the type of soft palate and gag reflex, and its severity in females (more specifically soft palate types II and III) more than in males (AU)

Objetivo: o reflexo de vômito, um problema comum encontrado durante procedimentos odontológicos, está ou não associado aos diferentes tipos de palato mole, não foi ainda abordado até o momento. Este estudo preliminar procurou avaliar a possível associação entre os diferentes tipos de palato mole e o reflexo de vômito. Material e Métodos:cem pacientes odontológicos foram recrutados. O tipo de palato mole foi determinado. O reflexo de vômito subjetivo (auto-relatado) foi registrado com base em muitas perguntas e experiências anteriores e em um VAS de 0-6. A avaliação objetiva do reflexo de vômito foi feita por meio de diferentes manobras onde a parte posterior da língua e o palato mole foram tocados por espelho dental e por meio de moldagem da arcada superior. A associação entre os tipos de palato mole e o reflexo de vômito subjetivo e objetivo registrado foi testada estatisticamente. Resultados: houve 53 (53%), 33 (33%) e 14 (14%) participantes com palato mole classe I, classe II e classe III, respectivamente. Foi encontrada associação significativa entre o tipo de palato mole e o reflexo de vômito em resposta a um dos itens subjetivos (P= 0,039), mais proeminente no sexo feminino (P= 0,009). Em relação à avaliação objetiva, não foram encontradas associações significativas entre os homens. Enquanto isso, mais mulheres com classe II e classe III sofreram reflexo de vômito e/ou engasgo real ao receber a impressão (P = 0,001). Conclusão: este estudo ilustrou uma associação entre o tipo de palato mole e reflexo de vômito e sua gravidade em mulheres (mais especificamente palato mole tipos II e III) mais do que em homens. (AU)

Mechanical behavior of different machinable ceramic crowns using vertical and horizontal preparations: an in-vitro study / Comportamento mecânico de diferentes coroas cerâmicas usináveis usando preparos verticais e horizontais: um estudo in vitro

Objective: the aim of this study was to compare the mechanical behavior of different ceramics when used in thin vertical preparations versus traditional horizontal preparation. Material and Methods: two stainless-steel dies were milled to simulate a minimally invasive vertical preparation (VP) and a traditional horizontal preparation (HP) for an all-ceramic crown of a maxillary first premolar. The stainless-steel dies were duplicated using epoxy resin. Eighty monolithic crowns were milled and divided into 2 groups according to preparation design. Each design group was subdivided into 4 sub-groups according to material (n=10): IPS e.max CAD (lithium disilicate), Bruxzir shaded zirconia (full contour zirconia), CeraSmart (resin nanoceramic) and CEREC Tessera (advanced lithium disilicate). The crowns were cemented on their relevant epoxy resin dies using self-adhesive resin cement. All specimens were subjected to 15,000 thermocycles and then loaded to fracture in a universal testing machine. Data were analyzed using two-way ANOVA and Tukey pair wise comparison test. Results: the fracture resistance mean values of the VP (1344 + 118 N) was significantly lower than the HP design (1646 + 191 N). Ceramic crowns made of full contour zirconia had higher fracture resistance mean values (2842 + 380 N) than advanced lithium disilicate (1272 + 125 N) followed by lithium disilicate crowns (983 + 52 N) and resin nanoceramic (882 + 61 N). Conclusion: both vertical and horizontal preparations, regardless the different ceramic materials, showed clinically acceptable fracture resistance values. (AU)

Objetivo: o objetivo deste estudo foi comparar o comportamento mecânico de diferentes cerâmicas quando utilizadas em preparos verticais finos ou preparos horizontais tradicionais. Material e Métodos: dois modelos de aço inoxidável foram fresados para simular um preparo vertical minimamente invasivo (PV) e um preparo horizontal tradicional (PH) para uma coroa totalmente em cerâmica de um primeiro pré-molar superior. As matrizes de aço inoxidável foram duplicadas usando resina epóxi. Oitenta coroas monolíticas foram fresadas e divididas em 2 grupos de acordo com o desenho do preparo. Cada grupo foi subdividido em 4 subgrupos de acordo com o material (n=10): IPS e.max CAD (dissilicato de lítio), zircônia Bruxzir (zircônia de contorno total), CeraSmart (resina nanocerâmica) e CEREC Tessera (dissilicato de lítio avançado). As coroas foram cimentadas em suas respectivas matrizes de resina epóxi usando cimento resinoso autoadesivo. Todos os espécimes foram submetidos a 15.000 ciclos térmicos e então carregados até a fratura em uma máquina de teste universal. Os dados foram analisados usando ANOVA com dois fatores e teste de comparação por pares de Tukey. Resultados: os valores médios de resistência à fratura do PV (1344 + 118 N) foram significativamente menores do que PH (1646 + 191 N). As coroas de cerâmica feitas de zircônia de contorno total apresentaram maiores valores médios de resistência à fratura (2842 + 380 N) do que dissilicato de lítio avançado (1272 + 125 N), seguido por coroas de dissilicato de lítio (983 + 52 N) e resina nanocerâmica (882 + 61 N). Conclusão: preparos verticais e horizontais, independentemente dos diferentes materiais cerâmicos, apresentaram valores de resistência à fratura clinicamente aceitáveis. (AU)

Evaluation of an integrated teaching model of oral preclinical practice based on endodontic-restorative sequential treatment / 口腔疾病防治

Objective@#Evaluate the effect of an integrated teaching model of oral preclinical practice based on endodontic-restorative sequential treatment to provide a reference for the exploration of the teaching mode of the stomatology specialty. @* Methods @#This retrospective study was reviewed and approved by the Ethics Committee. The study was divided into 2 groups. There were 450 2018-grade and 2019-grade students in the discipline integration teaching method (DIT) group, and a preclinical practice course (root canal therapy and fixed prosthetic treatments were integrated into an endodontic-restorative sequential treatment) using the DIT method was applied. There were 443 2016-grade and 2017-grade students in the traditional teaching method (TT) group, and a TT preclinical practice course (root canal therapy and fixed prosthetic treatments training courses were taught separately) was applied. Both groups were taught by the same two teachers. The scores of clinical skills examination and treatment planning were compared between the two groups. In addition, students in the two groups were asked to complete the questionnaires about the teaching methods, and students in Group DIT and their teachers were asked to complete the questionnaires on their degree of satisfaction with the DIT method in the preclinical course. @*Results @# Students in the DIT group had an average score of 90.2 ± 4.16 in the practical skill evaluation, which was higher than that of the TT group (86.3±3.57) (P = 0.001). In the case analysis, 91.8% (413/450) of the students in the DIT group successfully planned the treatment, compared to a significantly lower rate in the TT group of 74.7% (331/443) (P = 0.001). The questionnaire results showed that recognition degrees of cultivated clinical thinking, improved indication analysis ability, improved operational skills, stimulated enthusiasm for learning, and improved autonomous learning were higher in the DIT group than in the TT group, and both teachers (2/2) and 98.4% (443/450) of students recognized the DIT method. @*Conclusions@#The DIT method significantly improved students’ learning quality and ability, proved effective in the endodontic-restorative sequential treatment practice course and was more acceptable to teachers and students. The DIT method is more effective than the TT method in improving students’ clinical thinking and operation ability.

Bibliometric Analysis of Removable Partial Denture-related Research in Dentistry

@#The objective of this study was to characterise articles published in removable partial denture (RPD) research from 1948 to 2022 to identify the most influential journals, publications, authors, and core research areas using bibliometric analysis. The Scopus database was used to retrieve publications with titles containing the truncated search term (“removable partial denture*” OR “removable prostho*”). Data analysis and visualisation were done using Microsoft Excel, Biblioshiny software and VOSviewer. A total of 2,484 articles were analyses from 1948 till 2022, representing an annual growth rate of 4.9%. The Journal of Prosthodontic Research demonstrated the highest average normal citation rate, with productive authors with highest citations being from Japan. From 1948 to 1999, most in-vitro and clinical research focused on the basic concept of RPD using cobalt-chromium as a framework before shifting to titanium in 2000. RPD research after 2012 focuses on new technology and non-metalbased frameworks as an alternative to metal-based frameworks. Wakabayashi and Fueki were the most prominent researchers, according to a three-field plot analysis, with the Journal of Prosthetic Dentistry, Journal of Oral Rehabilitation, and Journal of Prosthodontic Research among the authors’ preferred journals. “CAD/CAM” and “3D printing” were identified as emerging themes in year 2020 to 2022, while “selective laser melting” was the trending keyword in 2017 to 2019. Research on “oral health and quality of life” has been identified as core research area in RPD-related research. RPD research on digital dentistry and new framework materials is anticipated to increase in the future with the incorporation of research on quality of life.

A Bibliometric Analysis of Resin-Bonded Bridge: Performance Analysis and Science Mapping

@#The objective of this study was to identify and characterise various resin-bonded bridge (RBB) articles published in dental journals using bibliometric analysis. The search was performed using the Scopus database to generate publications related to RBB. Data analysis and visualisation were done using Microsoft Excel, Biblioshiny software or VOSviewer. The trend of publication shows an annual growth rate of 7.19 percent within the years 1973–2022. Sixteen articles were cited more than 100 times, with seven highly cited articles focusing on the survival and/or complications of RBB. Matthias,Kern is the most prolific author in RBB research with Journal of Prosthetic Dentistry being the most influential journal. “survival”, “dental bonding” and “zirconia” were identified as core research areas for RBB for the past 10 years. Future research on the incorporation of new technology in prosthesis fabrication to assess the survival and longevity of RBB is expected to increase, with an emphasis on bonding to new materials. This paper presents an overview of scientific production, prominent researchers and countries, emerging keywords and core research areas in RBB research.

Correlation between vertical dimension of occlusion and different facial measurements among a sample of sudanese adults / Correlación entre la dimensión vertical de la oclusión y diferentes medidas faciales en una muestra de adultos sudaneses

Aim: This study aimed to evaluate the correlation between vertical dimension of occlusion (VDO) and various facial measurements in a sample of Sudanese adults. Material and Methods: A total of 113 dental students (33 males and 80 females) with a mean age of 21.7±1.26 years were enrolled in this study. Different facial measurements including (Eye-Mouth, Eye-Eye, Eye-Ear, and Ear Height) were compared with two different measurements of VDO: N-Gn (from the tip of the nose to the tip of the chin), and Sn-Me (from the base of the nose to the bottom of the chin). Pearson's correlation coefficient test was utilized for the correlation between the measured parameters. A p-value of less than 0.05 was considered significant for all analyses. Results: A significant positive correlation was shown between all measured facial distances and both measured VDO distances. Though, the strongest correlation was seen for the eye-mouth distance (r= 0.725, p<0.001), while the weakest was for ear height (r= 0.254, p= 0.007). A paired t-test revealed a significant longer N-Gn distance than Sn-Me distance. Also, it has been shown that there were no significant differences between right and left sides of the face. Conclusion: The distance measured from the outer canthus of the eye to the angle of the mouth can be used to predict Subnasale-Menton (Sn-Me) distance.

Objetivo: Este estudio tuvo como objetivo evaluar la correlación entre dimensión vertical oclusal (DVO) y varias medidas faciales en una muestra de adultos sudaneses. Material y Métodos: Un total de 113 estudiantes de odontología (33 hombres y 80 mujeres) con una edad media de 21,7 ± 1,26 años se inscribieron en este estudio. Se compararon diferentes medidas faciales que incluyen (ojo- boca, ojo-ojo, ojo-oído y altura de la oreja) con dos medidas diferentes de DVO: N-Gn (desde la punta de la nariz hasta la punta del mentón) y Sn -Yo (desde la base de la nariz hasta la parte inferior del mentón). Se utilizó la prueba del coeficiente de correlación de Pearson para la correlación entre los parámetros medidos. Un valor de p inferior a 0,05 se consideró significativo para todos los análisis. Resultados: Se mostró una correlación positiva significativa entre todas las distancias faciales medidas y ambas distancias DVO medidas. Sin embargo, la correlación más fuerte se observó para la distancia ojo-boca (r=0,725, p<0,001), mientras que la más débil fue para la altura de las orejas (r=0,254, p=0,007). Una prueba de t pareada reveló una distancia N-Gn significativamente más larga que la distancia subnasal-mentón. Además, se ha demostrado que no hubo diferencias significativas entre los lados derecho e izquierdo de la cara. Conclusión: La distancia medida desde el canto externo del ojo hasta el ángulo de la boca puede utilizarse para predecir la distancia subnasal-mentón.

Técnica endocrown como alternativa restauradora para dentes tratados endodonticamente: relato de caso clínico / Endocrown technique as a restorative alternative for endodontically treated teeth: a case report

Este trabalho teve como objetivo apresentar um relato de caso clínico de uma restauração do tipo coroa endocrown cerâmica em um dente molar tratado endodonticamente. Paciente com 45 anos de idade, sexo feminino, procurou a clínica do Centro Universitário da Serra Gaúcha (FSG) relatando a necessidade de reabilitação protética no primeiro molar inferior do lado esquerdo. Com base no exame radiográfico e exame clínico foi constatado um primeiro molar inferior do lado esquerdo com tratamento endodôntico satisfatório, mas uma extensa destruição coronária. Após a aprovação da paciente e indicações para a utilização da técnica, optou-se pela confecção de uma coroa endocrown em cerâmica reforçada por dissilicato de lítio. Foi realizado o preparo do remanescente dentário, envolvendo a câmara pulpar, com ângulos arredondados e expulsivos e, após a moldagem do mesmo com silicone de adição, utilizando a técnica simultânea e duplo fio. O provisório foi realizado com resina quimicamente ativada na cor 62 e, na sessão seguinte a coroa endocrown foi ajustada e polida. Após receber o protocolo de condicionamento adequado da peça, a mesma foi cimentada com cimento autopolimerizável Multilink N. Pode-se concluir que a alternativa restauradora Endocrown é um tratamento conservador e favorável para dentes com extensa destruição coronária, permitindo adequada estética e função(AU)

This study aimed to present a clinical case report of an endocrown ceramic crown restoration in na endodontically treated molar tooth. A 45-year-old female patient sought the clinic at the Centro Universitário da Serra Gaúcha (FSG), reporting the need for prosthetic rehabilitation on the lower left first molar. Based on the radiographic and clinical examination, the first molar presented satisfactory endodontic treatment, but extensive coronary destruction. After the approval of the patient and indications for the use of the technique, it was decided to make an endocrown with reinforced ceramic by lithium disilicate. The remaining tooth was prepared, involving the pulp chamber, with rounded and expulsive angles and, after the impression with silicone using the simultaneous and double wire technique was taken. The provisional was made with chemically activated resin in color 62 and, in the following session, the endocrown crown was adjusted and polished. After receiving the proper conditioning protocol, it was lutted with Multilink N self-curing cement. It can be concluded that the Endocrown restorative alternative is a conservative and favorable treatment for teeth with extensive coronary destruction, allowing adequate aesthetics and function(AU)

Artificial intelligence in prosthodontics: a scoping review on current applications and future possibilities

Artificial intelligence (AI) is the data-driven disruptive technology of modern times. AI is reforming every field from space science to dentistry. Bio-medical provides various advantages over conventional diagnosis, treatment planning, patient documentation and management. Every field is implementing AI for the ease of both doctors and patients. In this present work, the review was done for the implementation of AI in prosthodontics. Prosthetic dentistry or prosthodontics is one of the branches of dentistry, mainly deals with replacement and rehabilitation of missing teeth with the help of fixed and removable prosthesis or with biocompatible substitutes like implants. In addition, it also helps to restore proper soft and hard tissues of the mouth, thereby improving the overall health status of the oral cavity. The following review highlightedthe present-day technology of AIin dental prosthetics and its efficacy in diagnosing and constructing more patient-specific prosthesis. In conclusion, it is seen that AI is twin fold technology having both applications and limitations in dentistry.

Acurácia dimensional e adaptação de endocrowns obtidas por diferentes ferramentas de manufatura assistida por computador / Trueness and adaptation of endocrowns obtained by different computeraided manufacturing devices

A partir dos avanços da tecnologia CAD/CAM na Odontologia, observa-se a crescente utilização da manufatura aditiva na confecção de peças protéticas. Este trabalho propões a avaliação da acurácia interna e linha de cimentação de endocrowns produzidas através de manufatura aditiva e subtrativa. Para isso foi produzido um modelo mestre preparado para coroa endocrown, o qual foi posteriormente escaneado para desenho e fabricação das restaurações, segundo sua manufatura: aditiva (n=14) e subtrativa (n=14). As endocrowns tiveram sua parte interna escaneadas e através de software de inspeção foram comparadas as diferenças entre o projeto (CAD) e a restauração manufaturada, com a distribuição no interior de cada espécime de 90 pontos de aferição equidistantes. Seus respectivos valores de desvio foram utilizados para o cálculo de um valor eficaz (root mean square - RMS). Além disso, foi mensurada a desadaptação entre as endocrowns e modelo mestre, mediante a técnica da réplica de silicone digital, com aferição da linha de cimentação em pontos padronizados e distribuídos de forma equidistantes na região marginal, axial e pulpar, bem como a mensuração da linha de cimentação absoluta. Os dados da veracidade/acurácia interna passaram por teste de normalidade e comparação estatística pelo teste t student não pareado (α=0,05). Os resultados para veracidade interna RMS (Impresso 49.6032 µm ± 3.8917 e fresado 48.5554µm ± 2.2992) não demonstraram diferença estatística significante entre os grupos (p valor >0.05), entretanto sob avaliação qualitativa em gráfico de cores, houve distorções entre as peças produzidas e o projeto em software CAD, com padrões de distorção distintos segundo o tipo de manufatura. Quanto aos resultados da linha de cimentação, os valores de cada região passaram por teste de normalidade e comparação pelo teste t student não pareado (α=.05). Sem diferença estatística (p valor >0.05) na região marginal (impresso 52.9121 µm ± 10.8946 e fresado 61.8303 µm ± 13.4616) e linha de cimentação absoluta (impresso 84.642µm ± 8.0161 e fresado 89.1016µm ± 10.7006.). Contudo nos resultados da linha de cimentação em região axial (impresso 78.2094µm ± 10.5483 e fresado 95.3686µm ± 9.550), bem como região pulpar (impresso 160.9635µm ± 18.3995 e fresado 131.11µm ± 23.7442), houve diferença estatística significante entre os grupos (p < 0,05). Conclui-se, portanto, com relação aos valores gerais, tais como a linha de cimentação absoluta e veracidade interna, que não houve diferença estatística significante entre as duas manufaturas. Todavia, quanto a avaliações locais da linha de cimentação, o grupo impresso apresentou os melhores resultados em região axial, o grupo fresado em região pulpar e ambos os grupos com resultados semelhantes estatisticamente para região marginal. (AU)

Following the advances in CAD/CAM technology in dentistry and the increasing use of additive manufacturing in prosthetic dentistry, this study proposes the evaluation of the trueness and cementation line adaptation of endocrowns produced through additive and subtractive manufacturing. A master model prepared for endocrown and scanned for design and fabrication of restorations, according to their manufacture type: additive (n=14) and subtractive (n=14). The endocrowns had their internal area scanned and, through an inspection software, the differences between the design (CAD) and the manufactured restoration were compared, based by the distribution in each specimen of 90 equidistant measurement points. And their respective deviation values were used for the calculation of Root Mean Square (RMS). In addition, the misfit between the endocrowns and the master model was measured using the digital silicone replica technique, and the cementation line measured at standardized and equidistant points in marginal, axial, and pulp regions. As well as the measurement of the absolute cementation line. The trueness data underwent a normality test and statistical comparison by the unpaired student t test (α=.05). The results for RMS internal trueness (Printed 49.6032 µm ± 3.8917 and milled 48.5554 µm ± 2.2992) did not show a statistically significant difference between the groups (p value >0.05), however under qualitative evaluation in a color map, there are distortions between the crowns produced and the design in CAD software, following different patterns according to the manufacture type. As for the results of the cementation line, the data of each region underwent a normality test and comparison by the unpaired t student test (α=.05). No statistical difference (p value >0.05) in the marginal region (printed 52.9121 µm ± 10.8946 and milled 61.8303 µm ± 13.4616) and absolute cementation line (printed 84.642µm ± 8.0161 and milled 89.1016 µm ± 10.7006.) were observed. However, in the results of the cementation line at the axial region (printed 78.2094µm ± 10.5483 and milled 95.3686µm ± 9.550), as well the pulp region (printed 160.9635µm ± 18.3995 and milled 131.11µm ± 23.7442), there was a statistically significant difference between the groups (p < 0.05). This study concludes that in relation to the global values, such as the absolute cementation line and internal trueness, that there was no statistically significant difference between the two manufacturing types. However, regarding the local assessments of the cementation line, the printed group presented the best results in the axial region, the milled group in the pulp region, and both groups with statistically similar results for the marginal region. (AU)

Fixed-prosthodontics in Nigerian private practice settings

Context: Private practice dentistry is predominant in Nigeria. Audits of fixed-prosthodontic practice in these settings are rare and will highlight capacity and guide training. This study aimed to assess the scope and quality of fixed-prosthodontic practice in such settings in Nigeria. Objectives: The study sought to assess: Participants' sociodemographic and their diagnostic and preoperative practices. The quality of impression making and operative technique, reviews and maintenance, temporization practices and communication with the laboratory.The range of treatments given and provision of advanced treatments. Materials and Methods: An adapted questionnaire was administered electronically on Nigerian dentists practicing fixed-prosthodontics in private practice settings. Retrieved data underwent descriptive statistics and associations were tested with the Fischer's Exact and Chi-Square tests using IBM SPSS Statistics version 21. Statistical significance was set at p≤0.05. Results: A total of 100 valid responses with a male:female ratio of 2.1:1 from 16 states wereretrieved. Fifty-nine participants had only first degrees and mean experience was 14.3±9.5 years. There were 27 adequate responses with regards to range of treatments offered. Sixty-three participants practiced direct temporization. Twenty-one and 14 participants regularly practiced implantology and CAD/CAM dentistry respectively. Direct temporization was significantly associated with increasing education (X2=6.03, p=0,05) and experience (X2=13.2, p=0.03). Conclusion: Only a few Nigerian dentists in private practice gave an adequate range of treatment. Most of them prefer direct temporization. Implantology and CAD/CAM dentistry practice are improving, but are still not very common.

Patients' Management Patterns for Restorative Treatment Procedures: A 4-Year Overview at the Restorative Clinic of a Tertiary Hospital in Nigeria

Abstract Objective: To determine the patients' management pattern for restorative treatment procedures at the Restorative Dentistry Clinic at the Lagos State University Teaching Hospital (LASUTH). Material and Methods: A descriptive and retrospective study design was employed to determine patients' management patterns for the restorative treatment procedures at the Restorative Dentistry Clinic at LASUTH. Treatment records of patients who attended the Restorative Clinic at the Lagos State University Hospital, Ikeja, Lagos, Nigeria, from 2011 to 2014 were reviewed; the effective treatments during the period under review were recorded as treatment procedures and were recorded as operative, endodontic, fixed prosthodontics, and removable procedures. Results: A total of 14,437 (75%) operative; 1,353 (7.0%) endodontic; and 559 (2.9%) fixed prosthodontics and 2,852 (14.9%) removable prosthodontic procedures were carried out during the period under review. This study showed that operative procedures were the most performed restorative procedures, whereas removable prosthodontics and endodontic procedures ranked second and third, respectively, to operative procedures. Fixed prosthodontics procedures were the least performed restorative procedures. Conclusion: This study showed that more efforts were being expended by dentists on operative services compared to endodontic, removable, and fixed prosthodontics services combined. Comprehensive studies, embracing all disciplines of dentistry, should be carried out to determine the level of demand and clinical relevance of procedures in clinical dental practice and hence to set specific and general objectives of dental education for the populace. Access to dental health Insurance services should also be increased in the country.

Prosthetic complications and quality of life among wearers of mandibular overdenture with the Facility-Equator system

Abstract This longitudinal study aimed to assess the performance of the Facility-Equator system as mandibular overdenture (MO) retainers from a prosthetic perspective during 2 years of loading and to investigate the oral health-related quality of life (OHRQoL) and whether prosthetic events can affect the OHRQoL. Twenty-four patients (68.1 ± 7.51 years) reported their OHRQoL through the Geriatric Oral Health Assessment Index (GOHAI) and Oral Health Impact Profile (OHIP-EDENT) questionnaires before MO loading and after 1 and 2 years of usage. Prosthetic occurrences were recorded during this period. Data were analyzed using the Wilcoxon test, Mann-Whitney test, and Spearman correlation coefficients. Of the 127 prosthetic events that occurred in the first year, the most frequent events were prosthesis adjustments (16.5%), dislodgement of the Equator attachment (14.17%), and O-ring replacement (11.8%). Eighty-seven prosthetic events were recorded in the second year, the most frequent events being prosthesis adjustments (27.6%), O-ring replacement (20.7%), and recapturing the female matrix (11.5%). All domains of the GOHAI and OHIP-EDENT questionnaires exhibited a significant difference (p < 0.05) between the baseline and 1- and 2-year evaluations, except in the Social Disability and Psychological Discomfort domains (p > 0.05) of OHIP-EDENT after 1 year. Complications related to prosthetic maintenance, such as fracturing of the prosthesis, Equator dislodgement, prosthesis rebasing, and new overdenture confection, affect the OHRQoL (p < 0.05), primarily the Physical Pain and Discomfort domains, especially in the first year of MO loading.

Biomechanical Research Progress on Oral Masticatory Mucosa / 医用生物力学

According to its location and function, the oral mucosa can be divided into masticatory mucosa, coated mucosa and special mucosa. Oral masticatory mucosa, including hard palate and gingival mucosa, bears the chewing pressure and friction, and plays an important role in denture restoration. The study on biomechanics of oral masticatory mucosa is helpful to better understand and solve clinical problems related to oral masticatory mucosa. In this review, the progress of biomechanical researches on oral masticatory mucosa was summaried from three aspects: anatomical and physiological analysis, biomechanical characteristics (stress-strain curve, Poisson’s ratio, friction coefficient) and clinical significance, in order to provide further theoretical basis for the researches in oral prosthodontics-related areas.

Application of a metal occlusal surface and split framework in the treatment of a patient with mandibular distal extension absence and insufficient occlusogingival distance / 口腔疾病防治

Objective@# To investigate the effect of a metal occlusal surface and stress interruption design on minimally invasive prosthodontics for patients with distal extension absence and insufficient occlusal gingival distance.@*Methods @# We retrospectively studied the case of minimally invasive prosthodontic (Vitallium 2000) combined with a metal occlusal surface for distal extension absence in a patient with insufficient occlusal gingival distance; the stress breaking design and pressure impression technology are examined, and relevant articles are reviewd. @*Results@#The design effectively solves the problems of insufficient occlusal gingival distance, large occlusal force and easy denture fracture. Reviewing the relevant literature, stress interruption design can effectively protect abutment teeth, but the behavior of stress interruption design and stress conduction phenomena in the mouths of patients has not been reported. The T-scan test results of this study showed that before and after wearing the denture, the occlusal force distribution ratio of the patient changed from 77.5% on the left and 22.5% on the right to 61.3% on the left and 38.7% on the right. The occlusal force distribution ratio of the right dentition to the total occlusal force increased by 16.2%, and the occlusal force became better distributed. Further analysis showed that the occlusal forces on the left and right sides were nearly the same in the initial occlusion stage. As the occlusal force was further increased, the proportion of the occlusal force on the right side decreased in the middle of the occlusion stage and further decreased in the final occlusion stage until it reached a dynamic balance. The above T-scan test and literature review results suggest that this dynamic balance phenomenon of bite force is related to the stress interruption design and the stress conduction effect of the split framework.@* Conclusion @#The composite of stress interruption design and metal occlusal surface allows for minimally invasive prosthodontics for the treatment of distal extension absence in patients with insufficient occlusal gingival distance.

Screwdriver aspiration during implant surgery: case report and literature review / 口腔疾病防治

Objective @#To discuss and summarize the preventive measures and treatment methods for aspiration/ingestion during dental procedures.@*Methods @# One case of aspiration during an implant operation was reported, and the literature on aspiration/ingestion during oral procedures was reviewed.@*Results@#An implant screwdriver accidentally slipped into the mouth of the patient during implant surgery. The patient experienced no obvious discomfort except a few coughs. The surgeon and assistant paused the procedure immediately to search for the screwdriver, but it was not found. The patient declared that there was no special abnormality, such as breathing disorder or chest distress, so we considered that the foreign body was ingestion. After the implant surgery was completed, no foreign body was found in the stomach via gastroscopy. Chest X-ray and CT showed a dense metal shadow in the lower lobe of the left lung. Under local anesthesia, bronchoscopy and biopsy forceps were used by respiratory physicians to clip out the foreign body. After removal of the foreign body, the patient had no obvious discomfort but a slight cough. Cephalexin and metronidazole were given for three days to prevent infection. Three days later, the patient had no complaints of respiratory discomfort. After reviewing the literature, we found that the operation should be paused immediately after aspiration/ingestion occurs during dental procedures and that the dental chair should be laid down to prevent the foreign body from descending deeper, which may increase the difficulty of removal and cause gastrointestinal and respiratory tract injury. The position of the foreign body should be determined by imaging examination, and the corresponding means to remove the foreign body should be performed.@*Conclusion @# Patients may have no obvious symptoms after aspiration/ingestion during dental procedures, and the foreign body can be removed after imaging examination.