Study on mandibular movement trajectory and virtual occlusal pre-adjustment under light and heavy bite force / 中华口腔医学杂志

Objective: To investigate the influence of light and heavy bite force on the mandibular movement trajectories, and the influence of bite force on virtual occlusal pre-adjustment of digital full crown. Methods: From October 2021 to March 2022, 10 postgraduate volunteers (3 males and 7 females, aged 22-26 years) were recruited from Peking University School and Hospital of Stomatology. Maxillary and mandibular digital models of the participants were obtained by intraoral scanning. Jaw relations were digitally transferred under heavy bite force and mandibular movement trajectories under light and heavy bite force were recorded by jaw motion analyser. Three mandibular markers were chosen, namely the mesial proximal contact point of the central incisor (incisal point) and the mesial buccal cusp tips of the bilateral first molars. The three-dimensional displacements of the markers under two kinds of bite force in the intercuspal position (ICP), the sagittal projection of the three-dimensional displacements in the protrusive edge-to-edge position, and the coronal projection of the three-dimensional displacements in the lateral edge-to-edge position of upper and lower posterior teeth were measured. Single-sample t-test was used to compare the three-dimensional displacements and the corresponding sagittal projection and coronal projection with 0, respectively. The left maxillary central incisor and left mandibular first molar were virtually prepared by the reverse engineering software. Then dental design software was used to design digital full crown using the copy method. The mandibular movement trajectories under light and heavy bite force were separately used to guide virtual occlusal pre-adjustment. The three-dimensional deviations (mean deviations and root mean square) between the lingual surface of the left maxillary central incisor or the occlusal surface of the left mandibular first molar and that of the natural tooth before preparation were calculated (light bite force group and heavy bite force group), and the differences between the two groups were compared by the paired t-test. Results: Under the two kinds of bite force, the three-dimensional displacements of the markers in the ICP were (0.217±0.135), (0.210±0.133) and (0.237±0.101) mm, respectively; the sagittal projection of the three-dimensional displacements of the markers in the protrusive edge-to-edge position were (0.204±0.133), (0.288±0.148) and (0.292±0.136) mm, respectively; the coronal projection of the three-dimensional displacements of the mesial buccal cusp tips of the bilateral first molars in the lateral edge-to-edge position were (0.254±0.140) and (0.295±0.190) mm, respectively. The differences between the above displacements and 0 were statistically significant (P<0.05). The results of occlusal pre-adjustment showed that the mean deviations of the lingual surface of the left maxillary central incisor in the light and heavy bite force groups were (0.215±0.036) and (0.195±0.041) mm (t=3.95, P=0.004), respectively. The mean deviations of the occlusal surface of the left mandibular first molar were (0.144±0.084) and (0.100±0.096) mm (t=0.84, P=0.036), respectively. Conclusions: Both the light and heavy bite force have an influence on the mandibular movement trajectories. Virtual occlusal pre-adjustment of prostheses with mandibular movement trajectories under heavy bite force can obtain morphology of lingual or occlusal surfaces closer to the natural teeth before preparation.

A comparative study based on the mandibular movement track and the movement parameters of the virtual articulator in simulating occlusal adjustment / 华西口腔医学杂志

OBJECTIVES@#This study aimed to compare the effects of virtual adjustment on occlusal interferences in mandibular posterior single crown and three-unit bridge restorations by using the mandibular movement track and the movement parameters of a virtual articulator.@*METHODS@#Twenty-two participants were recruited. Digital casts of the maxillary and mandibular arches were obtained using an intraoral scanner, and the jaw registration system was used to record the data of the mandibular movement track and the movement parameters of the articulator. Four kinds of restorations with 0.3 mm occlusal interferences were designed with dental design software. In particular, single crowns were designed for teeth 44 and 46, whereas three-unit bridges were designed for teeth 44-46 and 45-47, and the corresponding natural teeth were virtually extracted. Virtual adjustment of the restorations was performed using two dynamic occlusal recordings, namely, the mandibular movement track and the movement parameters of the virtual articulator. A reverse-engineering software was used to measure the root-mean-square of the three-dimensional deviation of the occlusal surfaces between natural teeth and the adjusted restorations. The differences between the two methods of virtual-occlusion adjustment were compared and analyzed.@*RESULTS@#For the same group of restorations, the three-dimensional deviation of the mandibular movement track group were lower than those of the virtual articulator group, and the differences were statistically significant (P<0.05). For the four groups of restorations adjusted by the same method, the three-dimensional deviation of the 46-tooth single crown was the largest and the smallest three-dimensional deviation was that of the 44-tooth single crown. Statistical differences existed between the 44-tooth single crown and the other groups (P<0.05).@*CONCLUSIONS@#For the occlusal design of posterior single crown and three-unit bridge, the mandibular movement track could be a more effective approach to virtual occlusal adjustment than the movement parameters of the virtual articulator.

Does the Use of Surface Electromyography Could Improve Quality of Life among Patients Rehabilitated by Mandibular Overdentures on Different Attachments?

Abstract Objective: To analyze and compare changes of quality of life parameter among dental patients rehabilitated by the implant-supported overdentures with different attachment systems. Material and Methods: Forty-eight patients were recruited as a study cohort. The implant placement procedure was based on the results obtained by CBCT scanning and individualized surgical templates manufactured for correct implant placement. Each individual received two k3Pro Implants (Sure Type with 4.0 or 4.5 mm in diameter) at the intraforaminal area due to standard protocol of implantation provided by the manufacturer under local anesthesia. All patients were distributed between two groups based on the fact of using either Locator- or ball-attachments. Rank correlation was measured using Spearman correlation coefficient, while linear correlation was evaluated by Pearson correlation coefficient. Results: No statistically meaningful differences were noted regarding patients' distribution among groups considering age (p>0.05) and gender (p>0.05). Provided patient-level analysis demonstrated that increase of conventional full denture service time was positively correlated with escalation of OHIP-EDENT scores. The most prominent inter-correspondences were noted specifically between longevity of denture service and elevation of scores within "Functional limitation" (r=0.61; p<0.05), "Physical pain" (r=0.51; p<0.05) and "Physical disability" (r=0.57; p<0.05) subdomains. No statistically argumented regressions were noted between increase tendency of OHIP-EDENT scores and gender (p>0.05) or age (p>0.05) parameters. Conclusion: Significant improvements of quality of life measured with OHIP-EDENT were noted for both types of attachments compared to the pre-treatment situation independently of additionally provided surface electromyography-based alignment.

Influência da técnica de preparo sobre o contorno cervical dos laminados cerâmicos: relato de caso / Influence of the preparation technique on the cervical contour of ceramic laminates: a case report / Influencia de la técnica de preparación en el contorno cervical de los laminados cerámicos: reporte del caso

Introdução: Devido à crescente demanda estética, a odontologia restauradora se renova na intenção de alcançar melhores resultados na harmonia do sorriso. Entretanto, a atenção deve voltar-se também aos tecidos periodontais, visto que há uma integração entre material restaurador e os tecidos. Objetivo:Descrever e discutir as etapas clínicas para a confecção de laminados cerâmicos, atentando-se a preparos minimamente invasivos, contorno cervical e fatores que podem intervir na longevidade do procedimento.Relato de caso:Paciente do sexo masculino, 28 anos de idade, compareceu a Associação Brasileira de Odontologia, seção de Alagoas, relatando insatisfação em relação ao tamanho dos seus dentes. Os arcos superior e inferior foram moldados para a obtenção dos modelos de estudo e enceramento diagnóstico. Ao início do tratamento foi orientado ao paciente clareamento dental pela técnica combinada. O preparo dos dentes foi guiado por uma matriz de silicone, sendo estes uniformes e conservadores, seguido de moldagem, fase laboratorial e cimentação final. Finalizado o caso foi realizado o ajuste oclusal solicitando ao paciente que realizasse movimentos de lateralidade e protrusão. Conclusões:A técnica do preparo influência na longevidade dos laminados cerâmicos, por relacioanar-se à adesão e a saúde periodontal. O preparo deve ser mínino e limitado ao esmalte dental sempre que possível, determinando assim um maior e melhor prognóstico (AU).

Introduction:Due to the growing aesthetic demand, restorative dentistry is renewed to achieve better results in smile harmony. However, attention should also be turned to periodontal tissues since there is an integration between restorative material and tissues. Objective:To describe and discuss the clinical steps for the manufacture of laminate veneers, paying attention to minimally invasive preparations, cervical contour, and factors that can intervene in the procedure's longevity. Case report:A 28-year-old male patient attended the Brazilian Dental Association, the Alagoas section, reporting dissatisfaction with his teeth' size. The upper and lower arches were molded to obtain the study and diagnostic waxing models. At the beginning of treatment, the patient was instructed by the combined technique. After the case, the occlusal adjustment was performed, asking the patient to perform laterality and protrusion movements. Conclusions:The preparation technique influences the longevity of laminate veneers due to adherence and periodontal health. The preparation should be minimal and limited to dental enamel whenever possible, thus determining a higher and better prognosis (AU).

Introducción: Debido a la creciente demanda estética, la odontología restauradora se renueva para lograr mejores resultados en la armonía de la sonrisa. Sin embargo, también se debe prestar atención a los tejidos periodontales ya que existe una integraciónentre el material restaurador y los tejidos.Objetivo: Describir y discutir los pasos clínicos para la confección de carillas laminares, prestando atención a las preparaciones mínimamente invasivas, al contorno cervical y a los factores que pueden intervenir en la longevidad del procedimiento.Reporte del caso: Un paciente masculino de 28 años asistió a la Asociación Dental Brasileña, sección de Alagoas, reportando insatisfacción con el tamaño de sus dientes. Los arcos superior e inferior fueron moldeados para obtener los modelos de depilación de estudio y diagnóstico. Al comienzo del tratamiento, el paciente fue instruido por la técnica combinada. La preparación de los dientes fue guiada por una matriz de silicona, siendo estas uniformes y conservadoras, seguidas de moldeo, fase de laboratorio y cementación final. Después del caso, se realizó el ajuste oclusal, pidiendo al paciente que realizara movimientos de lateralidad y protuberancia. Conclusiones: La técnica de preparación influye en la longevidad de los laminados cerámicos, debido a la adherencia y la salud periodontal. La preparación debe ser mínima y limitada al esmalte dental siempre que sea posible, determinando así un pronóstico más alto y mejor (AU).

Intervención temprana de la mordida cruzada por la pista directa de Planas: relato de siete años de seguimiento / Early Intervention of Crossbite by Planas Direct Tracks: Follow up Report After Seven Years / Intervenção precoce da mordida cruzada pela Pistas Diretas de Planas: relato de sete anos de seguimento

Resumen Introducción: entre las maloclusiones, la mordida cruzada es la de mayor prevalencia entre los niños en edad preescolar y se considera la principal depreciadora del sistema estomatognático, con un alto riesgo de desarrollar secuelas musculoesqueléticas irreparables en la edad adulta. Por lo tanto, es fundamental elegir un tratamiento eficaz que no requiera la cooperación directa del paciente y que utilice técnicas simples de ortodoncia. El objetivo de este artículo es informar la eficacia del tratamiento de rehabilitación neuroclusal (RNO) con la técnica de las pistas directas de Planas en la corrección temprana de la mordida cruzada posterior y el seguimiento de su estabilidad oclusal durante siete años. Presentación del caso: niña de 4 años de edad, que usó biberón, diagnosticada con mordida cruzada posterior funcional unilateral izquierda y desviación de la línea media. Para el tratamiento de la RNO, se realizaron los ajustes oclusales en los dientes 63, 64 y 65, y después de la desprogramación neuromuscular, se confeccionaron las pistas directas de Planas en los dientes cruzados. Después de 29 días, se corrigió la mordida y se hicieron ajustes oclusales para proporcionar una mayor armonía oclusal. Hubo monitoreamiento cada seis meses durante siete años para verificar el equilibrio y la estabilidad del tratamiento. Conclusiones: la RNO con el uso de pista directa de Planas fue eficaz para corregir la mordida cruzada posterior con una técnica simple y de bajo costo que puede ejecutar el clínico general.

Abstract Introduction: Among malocclusions, that of cross-bite is the most prevalent among preschool children and is considered to be the main depreciator of the stomatognathic system and is further linked to a high risk of developing irreversible musculoskeletal sequelae in adulthood. Thus, it is important to choose an effective treatment early on that does not require the direct cooperation of the patient and that utilizes simple orthodontic techniques in its execution. The objective of this study was to report the efficacy of the Neuroclusal Rehabilitation (RNO) treatment, with the Planas Direct Tracks technique in a case of early treatment of posterior crossbite, and the follow up of its occlusal stability for seven years. Case presentation: a 4-year-old female patient, who was bottle-fed, was diagnosed with a left unilateral functional posterior crossbite and midline deviation. For treatment of RNO, occlusal adjustments were made on the teeth 63, 64 and 65 and after neuromuscular deprogramming, the Direct Planks were made in the crossed teeth. After 29 days, the bite was corrected, and occlusal adjustments were made in order to provide greater occlusal harmony. Monitoring and evaluation took place every six months for seven years in order to verify the balance and stability of the treatment. Conclusion: the RNO treatment with the use of Planas Direct Tracks is an effective solution for the correction of posterior crossbite using a simple, low-cost technique that can be performed by general practitioners.

Resumo Introdução: entre as más oclusões, a mordida cruzada é a de maior prevalência entre as crianças em idade pré-escolar, e se considera a principal depreciadora do sistema estomatognático, com um alto risco de desenvolver sequelas musculoesqueléticas irreparáveis na idade adulta. Portanto, é fundamental escolher um tratamento eficaz que não requeira a cooperação direta do paciente e que utilize técnicas simples de ortodontia em sua execução. O objetivo deste estudo foi informar a eficácia do tratamento de Reabilitação Neuroclusal (RNO), com a técnica das Pistas Diretas de Planas na correto precoce da mordida cruzada posterior e o seguimento de sua estabilidade oclusal durante 7 anos. Apresentação do caso: paciente de sexo feminino de 4 anos de idade, que usou mamadeira, diagnosticada com mordida cruzada posterior funcional unilateral esquerda e desvio da linha média. Para o tratamento da RNO, se realizaram os ajustes oclusais nos dentes 63, 64 e 65, depois da desprogramação neuromuscular, se confeccionaram as Pistas Diretas de Planas nos dentes cruzados. Depois de 29 dias, se corrigiu a mordida e se fizeram ajustes oclusais para proporcionar uma maior harmonia oclusal. O monitoramento se realizou cada seis meses por 7 anos para verificar o equilíbrio e a estabilidade do tratamento. Conclusões: a RNO com o uso de Pista Direta Planas foi eficaz para a correção da mordida cruzada posterior com uma técnica simples, de baixo custo que pode ser realizada pelo clínico geral.

Effect of occlusal adjustment on postoperative pain after root canal treatment: a randomized clinical trial

Abstract The aim of this prospective, randomized, clinical study was to analyze the influence of occlusal adjustment on the prevalence of postoperative pain after endodontic treatment. Seventy-eight patients, diagnosed with symptomatic irreversible pulpitis with indication for endodontic treatment, were selected to participate in the study. The participants were randomized and divided into two groups: in the occlusal adjustment group (OAG), endodontic treatment was performed with subsequent occlusal adjustment. In the control group (CG), endodontic treatment was performed without occlusal adjustment. Treatments were performed by the same operator. Pain occurrence and intensity were recorded on two scales: the verbal rating scale (VRS) and numerical rating scale (NRS). Pain assessment was carried out by a second examiner, blinded to the experiment, 6, 24 and 72 h after endodontic treatment. Data were analyzed using Mann-Whitney, chi-squared, and Fisher's exact tests. In the occlusal adjustment group, 71.1% reported postoperative pain and 67.5% reported pain in the control group. At the 6-hour assessment, 21 individuals reported pain in the occlusal adjustment group and 24 in the control group (p=0.672). At the 24-hour assessment, 18 and 19 individuals reported pain (p=0.991) and at the 72-hour assessment, 8 and 4 reported pain (p=0.219), respectively. Occlusal adjustment did not influence the prevalence of postoperative pain of endodontically treated teeth with symptomatic irreversible pulpitis.

Resumo O objetivo deste estudo prospectivo, randomizado e clínico foi analisar a influência do ajuste oclusal na prevalência de dor pós-operatória após o tratamento endodôntico. Setenta e oito pacientes, diagnosticados com pulpite irreversível sintomática com indicação de tratamento endodôntico, foram selecionados para participar do estudo. Os participantes foram randomizados e divididos em dois grupos: no grupo de ajuste oclusal (GAO), foi realizado tratamento endodôntico com posterior ajuste oclusal. No grupo controle (GC), o tratamento endodôntico foi realizado sem ajuste oclusal. Os tratamentos foram realizados pelo mesmo operador. A ocorrência e a intensidade da dor foram registradas em duas escalas: a escala de classificação verbal (VRS) e a escala de classificação numérica (NRS). A avaliação da dor foi realizada por um segundo examinador, cego para o experimento, 6, 24 e 72 horas após o tratamento endodôntico. Os dados foram analisados utilizando testes de Mann-Whitney, qui-quadrado e exato de Fisher. No grupo de ajuste oclusal, 71,1% relataram dor pós-operatória e 67,5% relataram dor no grupo controle. Na avaliação de 6 horas, 21 indivíduos relataram dor no grupo de ajuste oclusal e 24 no grupo controle (p=0,672). Na avaliação de 24 horas, 18 e 19 indivíduos relataram dor (p=0,991) e, na avaliação de 72 horas, 8 e 4 relataram dor (p=0,219), respectivamente. O ajuste oclusal não influenciou a prevalência de dor pós-operatória após o tratamento endodôntico em dentes com pulpite irreversível sintomática.

Accuracy of Cone Beam Computed Tomography in the Assessment of Mandibular Molar Furcation Defects

Abstract Objective: To evaluate the accuracy of cone-beam computed tomography (CBCT) in the assessment of mandibular molar furcation defects. Material and Methods: Thirty patients with furcation defects were selected, oral hygiene instructions, scaling, and root planing with ultrasonic devices and hand instruments and occlusal adjustments were performed. Pre-surgical clinical measurements were carried out at the buccal aspect of the selected mandibular molars. The horizontal furcation measurements were measured with a Nabers Probe starting at the furcation entrance to the greatest horizontal depth. The degree of furcation involvement was graded from 0 to III. Bone loss in the horizontal and vertical direction and the width of the furcation entrance were measured on CBCT and after reflecting the full-thickness flap and debridement of the defects. The data were analyzed using t-test and Pearson's correlation coefficient. Results: The width of furcation entrance in clinical method was 3.27 ± 0.77, while in CBCT method was 3.35 ± 0.71, clinically the vertical bone loss was 3.61±1.09, while in CBCT was 3.57 ± 1.15, horizontal bone loss in clinical method was 5.08 ± 2.21, while in CBCT was 5.11 ± 2.23. No significant difference between the two methods was noted, and a high correlation between the two methods was observed. With regards to the agreement between the two methods of assessment, the width of furcation entrance revealed a difference between the two methods by 0.08 ± 0.21, while vertical bone loss showed difference between the two methods by -0.04 ± 0.19, the horizontal bone loss showed a mean difference between the two methods by 0.03 ± 0.21. Conclusion: CBCT provided high accuracy for the furcation involvement detection and anatomy of surrounding periodontal tissues.

Tratamiento de ortodoncia en un paciente con resorción radicular externa: reporte de un caso clínico / Orthodontic treatment in a patient with external root resorption: report of a clinical case

La resorción radicular externa generalizada representa un problema a la hora de realizar un tratamiento de ortodoncia, requiere la toma de decisiones que siempre debe estar fundamentada en el diagnóstico llevado a cabo mediante un equipo interdisciplinario. Objetivo: Describir el tratamiento a una paciente con resorción radicular generalizada ante un proceso completo de diagnóstico que debe ser seguido, buscando preservar la estructura dentaria y la inserción conectiva. Caso clínico: Mujer de 14 años de edad, con motivo de consulta: «tengo un diente fuera de lugar¼, con un biótopo dolicofacial, y maloclusión clase II esquelética, clase I molar, clase I canina, discrepancia osteodentaria negativa, perfil convexo, incompetencia labial, incisivo lateral superior cruzado, resorción radicular generalizada, que predomina en incisivos anteriores superiores. El tratamiento fue ortodoncia (con aparatología fija Roth slot 22), extracciones de segundos premolares superiores e inferiores, cierre de espacios acelerado y ajuste oclusal. Resultado: Al finalizar el tratamiento, se logró mejorar la estética, preservación de la inserción conectiva, estructura dental y una oclusión funcional. Conclusiones: Los pacientes con resorción radicular generalizada necesitan ser diagnosticados correctamente, es importante saber que los resultados se limitan a utilizar fuerzas ligeras y controladas, y es de gran utilidad el aprovechamiento del fenómeno de aceleración regional que está dado por las extracciones dentales, cerrando los espacios desde estadios iniciales del tratamiento (AU)

Generalized external root resorption represents a problem when performing orthodontic treatment, it requires making decisions that should always be based on the diagnosis carried out by an interdisciplinary team. Objective: To describe the treatment of a patient with generalized radicular resorption with a complete diagnostic process that must be followed in order to preserve the tooth structure and the connective insertion. Case report: 14-year-old female patient, with reason for consultation: «I have a tooth out of place¼', with a dolichofacial biotype, class II skeletal malocclusion, class I molar, class I dog, negative osseous discrepancy, convex profile, lip incompetence, superior lateral incisor crossed, generalized radicular resorption, which predominates in upper anterior incisors. The treatment was orthodontics (with Roth slot 22 fixed appliances), extractions of upper and lower second premolars, accelerated space closure and occlusal adjustment. Result: At the end of the treatment, aesthetics, preservation of the insertion and dental structure and a functional occlusion were achieved. Conclusions: Patients with generalized root resorption need to be diagnosed correctly, it is important to know that the results are limited to use light and controlled forces and it is very useful to take advantage of the phenomenon of regional acceleration that is given by the dental extractions, closing the spaces from initial stages of treatment (AU)

Reabilitação neuroclusal em paciente odontopediátrico com mordida cruzada posterior unilateral: relato de caso clínico / Neuro-occlusal rehabilitation in pediatric dental patient with unilateral posterior crossbite: clinical case report

Objetivo: relatar a sequência clínica de tratamento para descruzar uma mordida cruzada posterior unilateral na dentição decídua por meio da reabilitação neuroclusal. Relato de caso: o caso clínico foi realizado em um paciente do sexo masculino, com 5 anos de idade, diagnosticado com mordida cruzada posterior unilateral funcional do lado direito. Após a verificação de interferências dentais nos caninos e molares em oclusão cêntrica, realizaram-se os ajustes oclusais. Seguiu-se então o protocolo para confecção de pistas diretas de Planas, utilizando resina composta em planos inclinados na metade vestibular da face oclusal dos dentes 84 e 85 e na face vestibular dos dentes 53, 54 e 55. Logo após a confecção das pistas, observou-se a correção da mordida cruzada e a estabilidade na mudança postural da mandíbula. Considerações finais: a reabilitação neuroclusal por meio de pistas diretas de Planas apresenta grande eficácia na correção da mordida cruzada posterior, proporcionando estabilidade mandibular e estímulo para o crescimento e desenvolvimento crânio-maxilo-facial. (AU)

Objective: To report the clinical treatment sequence to uncross a unilateral posterior crossbite in deciduous dentition using neuro-occlusal rehabilitation. Case report: The clinical case was performed in a 5-year-old male patient diagnosed with a functional unilateral posterior crossbite on the right side. After verifying dental interferences with canines and molars in centric occlusion, the occlusal adjustments were performed. The protocol for producing Planas direct tracks was followed using composite resin in inclined planes in the buccal half of the occlusal surface of teeth 84 and 85 and in the buccal surface of teeth 53, 54, and 55. After the preparation of tracks, the crossbite correction and the stability in postural mandibular change were observed. Final considerations: Neuro-occlusal rehabilitation using Planas direct tracks is highly effective in correcting posterior crossbite, providing mandibular stability and stimulus for the growth and development of the maxillofacial skull. (AU)

Lesões cervicais não cariosas: uma abordagem no controle da dor e tratamento

Objetivo: o objetivo deste trabalho é relatar um caso clínico de hipersensibilidade severa associada a múltiplas lesões cervicais não cariosas, entender o mecanismo de ação e a eficácia dos agentes dessensibilizantes. Relato de caso: paciente do gênero masculino, 38 anos de idade, compareceu à clínica da Faculdade Morgana Potrich com um quadro de hipersensibilidade em vários elementos, bem como, a presença de lesão cervical não cariosa em alguns desses elementos. Durante a anamnese o paciente relatou o hábito de escovar os dentes várias vezes ao dia logo após se alimentar, exercendo muita força durante o ato, relatou também fazer consumo diário de cerveja que possui um pH ácido. Ao realizar análise da oclusão notou-se um desequilíbrio oclusal e contato prematuro nos dentes 24 e 34. O tratamento de escolha para esse caso foi o ajuste oclusal seguido do uso de dessensibilizantes e restaurações em resina composta nos dentes que havia a presença de lesões cervicais não cariosas com perda de estrutura dentária. Considerações finais: após esse tratamento, realizado em várias sessões, foi possível devolver ao paciente a função e eliminar a dor provocada pela hipersensibilidade, proporcionando uma melhor qualidade de vida para esse paciente.

Objective: This study aims to report a clinical case of severe hypersensitivity associated with multiple non-carious cervical lesions and to understand the mechanism of action and the efficacy of desensitizing agents. Case report: A 38-year-old male patient attended the clinic at Faculdade Morgana Potrich with the hypersensitivity of several elements and the presence of non-carious cervical lesion in some of these elements. During anamnesis, the patient reported the habit of toothbrushing several times a day soon after eating, exerting a lot of force in such activity; he also reported the daily consumption of beer, which has an acidic pH. The occlusal analysis showed occlusal disorder and premature contact in teeth 24 and 34. The treatment of choice for this case was the occlusal adjustment followed by the use of desensitizers and composite resin restorations on the teeth with non-carious cervical lesions with loss of dental structure. Final considerations: After this treatment, which was performed in several sessions, it was possible to return function to the patient and eliminate the pain caused by hypersensitivity, providing a better quality of life for this patient.(au)

Eficácia de dois sistemas de polimento na devolução da lisura superficial de restaurações cerâmicas vítreas em dentes posteriores: estudo clínico, randomizado, prospectivo e cego / Efficacy of two polishing systems on the return of surface smoothness of glass-ceramic restorations in posterior teeth: clinical, randomized, prospective and blinded study

O objetivo do estudo foi verificar o repolimento do dissilicato de lítio em boca variando o uso de dois sistemas de polimento em restaurações posteriores. Adicionalmente, o comportamento das restaurações cerâmicas foi avaliado longitudinalmente segundo os critérios USPHS modificados. Participaram do estudo 12 pacientes que necessitavam de pelo menos 2 dentes posteriores bilaterais a serem restaurados com cerâmica em dissilicato de lítio monolítica, totalizando 62 restaurações analisadas. As restaurações foram alocadas em dois grupos, sendo: G1 - 31 restaurações cerâmicas utilizando o sistema de polimento Exa-Cerapol, feltro e pasta diamantada, e G2: idêntico ao G1, utilizando o sistema de polimento Shofu, feltro e pasta diamantada. A escolha das restaurações em cada grupo foi randomizada, segundo o conceito split-mouth design. O atendimento foi realizado por profissionais graduados, calibrados na técnica, porém não cientes das razões do estudo. As restaurações foram replicadas com resina epóxi em 3 momentos: após a cimentação (T0); após o ajuste oclusal (T1); e após o polimento (T2), para análise quantitativa em rugosímetro. Amostras representativas de cada grupo nos mesmos tempos foram levadas para análise em microscópio confocal a laser (LSCM). O comportamento das restaurações cerâmicas foi avaliado longitudinalmente nos tempos (T): T0 ­ após a realização do polimento, T1 -30 dias após, T2 -180 dias após. Não houve diferença estatisticamente significante entre os grupos para os tempos testados (p>0,05). Diferenças estatisticamente significantes foram observadas intra grupos, entre os tempos T0 e T1 e entre T1 e T2 (p<0,05), tanto em G1 quanto em G2. A taxa de sobrevida das restaurações sem fraturas foi de 100%; a sobrevida por ocorrência de complicações biológicas com troca de restaurações (n=1) foi de 98,4%; índice de solturas sem substituição de restauração (n=6) foi de 96,9%. Conclui-se que os dois sistemas foram eficazes no repolimento intrabucal das restaurações em dissilicato de lítio monolítico. O protocolo clínico realizado pelos profissionais graduados se mostrou eficaz com ausência de trincas/fraturas no período de 6 meses de acompanhamento(AU)

The aim of the study was to verify the lithium disilicate repolishing in the mouth by varying the use of two polishing systems in posterior restorations. Additionally, the behavior of ceramic restorations was longitudinally evaluated according to the modified USPHS criteria. The study included 12 patients who needed at least 2 bilateral posterior teeth to be restored with ceramic in monolithic lithium disilicate, totaling 62 restorations analyzed. The restorations were allocated into two groups: G1 - 31 ceramic restorations using the Exa-Cerapol polishing system, felt and diamond paste, and G2: identical to G1 using the Shofu polishing system, felt and diamond paste. The choice of restorations in each group was randomized according to the split-mouth design concept. The service was performed by graduated professionals, calibrated in the technique, but not aware of the reasons for the study. The restorations were replicated with epoxy resin in 3 moments: after cementation (T0); after occlusal adjustment (T1); and after polishing (T2), for quantitative roughness analysis. Representative samples from each group at the same times were taken for analysis by confocal laser microscope (LSCM). The behavior of ceramic restorations was evaluated longitudinally at the times (T): T0 - after polishing, T1 -30 days after, T2 -180 days after. There was no statistically significant difference between the groups for the tested times (p> 0.05). Statistically significant differences were observed between groups T0 and T1 and between T1 and T2 (p <0.05) in both G1 and G2. The survival rate of restorations without fractures was 100%; survival due to the occurrence of biological complications with restoration replacement (n = 1) was 98.4%; Release rate without restoration replacement (n = 6) was 96.9%. It was concluded that both systems were effective in intraabucal repolishing of monolithic lithium disilicate restorations. The clinical protocol performed by the graduated professionals proved to be effective with no cracks / fractures within 6 months of follow-up(AU)

The effects of surface grinding and polishing on the phase transformation and flexural strength of zirconia

PURPOSE: The purpose of this in vitro study was to evaluate the effect of surface grinding and polishing procedures using high speed zirconia diamond burs with different grit sizes on the phase transformation and flexural strength of zirconia.

Simulated occlusal adjustments and their effects on zirconia and antagonist artificial enamel

PURPOSE: The aim of this study was to evaluate the effect of occlusal adjustments on the surface roughness of yttria-tetragonal zirconia polycrystal (Y-TZP) and wear of opposing artificial enamel.

A CAD/CAM-based strategy for concurrent endodontic and restorative treatment

This case report describes a technique in which endodontic treatment and permanent indirect restoration were completed in the same clinical appointment with the aid of a computer-aided design/computer-aided manufacturing (CAD/CAM) system. Two patients were diagnosed with irreversible pulpitis of the mandibular first molar. After access preparation, root canals were located, irrigation was performed until bleeding ceased, and the coronal tooth structure was prepared for indirect restoration. Then, utilizing an interim 3-mm build-up of the endodontic access cavity, a hemi-arch digital scan was performed with an intraoral scanner. Subsequent to digital scanning, restoration design was performed simultaneously with the endodontic procedure. The root canals were shaped using the Race system under irrigation with 2.5% sodium hypochlorite followed by root canal filling. The pulp chamber was subsequently filled with a 3-mm-thick composite resin restoration mimicking the interim build-up previously utilized to facilitate block milling in the CAD/CAM system. Clinical try-in of the permanent onlay restoration was followed by acid etching, application of a 5th generation adhesive, and cementation of the indirect restoration. Once the restoration was cemented, rubber dam isolation was removed, followed by occlusal adjustment and polishing. After 2 years of follow-up, the restorations were esthetically and functionally satisfactory, without complications.

Craneosinostosis sindrómica: Características craneodentofaciales, tratamiento ortodón-tico-quirúrgico y factores asociados a tipos de síndrome / Craniossinostose sindrômica: Características craniodentofaciais, tratamento ortodônti-co-cirúrgico e fatores associados aos tipos de síndrome / Syndromic Craniosynostosis: Craniodentofacial features, orthodontic-surgical treatment and factors associated to types of syndrome

Objetivos: Describir las características craneodentofaciales, tratamientos ortodónticos-quirúrgicos y establecer una aso-ciación entre los tipos de síndrome presentes en pacientes con craneosinostosis sindrómica (CS). Material y métodos: Estudio retrospectivo de registros médicos y de ortodoncia de pacientes con CS. Los datos se recogieron en una forma específica y se sometieron a un análisis estadístico descriptivo para observar la distribución de frecuencias y se utilizó la prueba de Chi cuadrado con un nivel de significación del 5% para asociar el síndrome y los tipos de variables. Resultados: El síndrome de Crouzon fue el tipo predominante (59.2%) y la braquicefalia fue el tipo más frecuente de craneosinostosis (63.6%). Hubo una asociación significativa entre las variables braquicefalia (p = 0,014), presencia de paladar hendido (p = 0,043), mordida cruzada posterior (p = 0,013), distracción osteogénica realizada por elásticos intermaxilares (p = 0,030), barra de Erich (p = 0.007) y la extracción (p = 0.041) y los síndromes estudiados. Conclusión: Los pacientes con CS a menudo tienen cambios craneodentofaciais y algunas variables tienen asociaciones significativas en relación con los tipos de síndromes.

Objectives: Describe the craniodentofacial characteristics, orthodontic-surgical treatments and establish an association between the syndrome types present in patients with syndromic craniosynostosis (SC). Material and methods: Retros-pective study of medical and orthodontic records of patients with SC. Data was collected on a specific form and subjected to descriptive statistical analysis to observe the distribution of frequencies and chi-square test with level of significance of 5% was used to associate syndrome and the types of variables. Results: Crouzon syndrome was the predominant type (59.2%) and brachycephalia was the most prevalent type of craniosynostosis (63.6%). There was a significant association between the variables brachycephaly (p=0.014), presence of cleft palate (p=0.043), posterior cross bite (p=0.013), distrac-tion osteogenesis performed by intermaxillary elastics (p= 0.030), Erich bar (p= 0.007) and extraction (p=0.041) and the syndromes studied. Conclusion: Patients with SC often have craniodentofaciais changes and some variables had signifi-cant associations in relation to the types of syndromes.

Descrever as características craniodentofaciais, tratamentos ortodôntico-cirúrgicos e estabelecer uma associação entre os tipos de síndrome presentes em pacientes com craniossinostose sindrômica (CS). Material e métodos: Estudo retrospectivo de prontuários médicos e ortodônticos de pacientes com CS. Os dados foram coletados em formulário específico e submetidos à análise estatística descritiva para observar a distribuição das frequências e o teste qui-quadrado com nível de significância de 5% foi utilizado para associar a síndrome e os tipos de variáveis. Resultados: A síndrome de Crouzon foi o tipo predominante (59,2%) e a braquicefalia foi o tipo mais prevalente de craniossinostose (63,6%). Houve associação significativa entre as variáveis braquicefalia (p = 0,014), presença de fissura de palato (p = 0,043), mordida cruzada posterior (p = 0,013), distração osteogênica realizada pelos elásticos intermaxilares (p = 0,030), barra de Erich (p= 0,007) e extração (p = 0,041) e as síndromes estudadas. Conclusão: Pacientes com CS frequentemente apresentam alterações craniodentofaciais e algumas variáveis apresentaram associações significativas em relação aos tipos de síndromes.

Complete denture artificial teeth arrangement deformation in wax denture after festooning: deformation over time

PURPOSE: The purpose of this study was to evaluate the deformation of the complete denture artificial teeth arrangement after festooning over time. MATERIALS AND METHODS: 10 wax dentures of equal teeth arrangement and equal gingival contour were used in this study. Festooning of the wax dentures were conducted and 3D model scans were conducted every 10 minutes for 120 minutes. Interdental transverse distances were measured with the scanned images. Statistical analyses were performed with SPSS Ver. 22. 0. RESULTS: Interdental transverse distance between teeth varied from 0.0999 mm to 0.1787 mm. Mean rate of deformation showed statistically significant change between the 40 – 50 minute interval and 50 – 60 minute interval and between the 50 – 60 minute interval and 60 – 70 minute interval. No statistically significant change of the mean rate of deformation was observed later on. CONCLUSION: Monitoring of the interdental transverse distance for 120 minute after festooning have shown the deformation and displacment of the artificial teeth arrangement. From after the 60 – 70 minute interval after festooning, the mean deformation showed no statistically significant change of the mean rate of deformation was observed. Within the limitations of this in vitro study results suggest that the final occlusal adjustment in wax denture before complete denture curing should be proceeded at least 60 minutes later after festooning.

Stability of periodontally compromised teeth after splint and non-surgical therapy: two cases followed-up for 1 to 3 years

This article describes cases of applying non-surgical treatment including scaling and root planing, occlusal adjustment and tooth splinting of periodontally compromised lower anterior incisors Clinical and radiographic evaluations were performed over a 1–3-year period. All clinical parameters and radiographic bone levels improved in both cases. Dramatic regeneration of alveolar bone and lamina dura were observed on radiographic images, and no specific complications occurred during the follow-up period. Within the limitations of this study, these cases demonstrated the possibility of tooth rescue through non-surgical treatment and splinting of periodontally compromised teeth typically considered for extraction.

Temporomandibular Joint Disorder and Occlusal Changes: Case Reports

Occlusion may change spontaneously but dental treatment or trauma in the patients with temporomandibular disorders (TMDs) may also alter occlusion. This report presents three cases displaying occlusal changes. Review of literature emphasizes the significance of TMD treatment. Conservative treatment modalities such as counseling, medication, physical therapy and splint therapy may be selected as initial treatment options. Irreversible or invasive treatment, such as orthodontic, prosthodontic, and occlusal adjustment should not be attempted early. In case there is no response to conservative treatment, joint injection, muscle injection, arthrocentesis or arthroscopic surgery might be performed.

The influence of horizontal cephalic rotation on the deviation of mandibular position

PURPOSE: When performing an occlusal procedure, it is recommended that the patient should be sitting straight with the head in a natural position. An inappropriate mandibular position caused by an incorrect occlusal record registration or occlusal adjustment can result in damaged teeth and cause functional disorders in muscles and temporomandibular joints. The purpose of this study was to clarify the influence of horizontal cephalic rotation on mandibular position by investigating the three-dimensional positions of condylar and incisal points. MATERIALS AND METHODS: A three-dimensional jaw movement measurement device with six degrees of freedom (the WinJaw System) was used to measure condylar and incisal points. The subjects were asked to sit straight with the head in a natural position. The subjects were then instructed to rotate their head horizontally 0°, 10°, 20°, 30°, 40°, 50°and 60° in the right or left direction. RESULTS: The results indicated that horizontal cephalic rotation made the condyle on the rotating side shift forward, downward, and toward the inside, and the condyle on the counter rotating side shift backward, upward, and toward the outside. Significant differences in deviations were found for angles of rotation higher than 20°. The incisal point shifted in the forward and counterrotating directions, and significant differences were found for angles of rotation higher than 20°. CONCLUSION: The mandibular position was altered by horizontal cephalic rotations of more than 20°. It is essential to consider the possibility of deviation of the mandibular position during occlusal procedures.

Polish of interface areas between zirconia, silicate-ceramic, and composite with diamond-containing systems

PURPOSE: Fractures, occlusal adjustments, or marginal corrections after removing excess composite cements result in rough surfaces of all-ceramic FPDs. These have to be polished to prevent damage of the surrounding tissues. The aim of this study was to evaluate the roughness of zirconia, silicate-ceramic, and composite after polish with different systems for intraoral use. MATERIALS AND METHODS: Each set of 50 plates was made of zirconia, silicate-ceramic, and composite. All plates were ground automatically and were divided into 15 groups according to the treatment. Groups Zgrit, Sgrit, and Cgrit received no further treatment. Groups Zlab and Slab received glaze-baking, and group Clab was polished with a polishing device. In the experimental groups Zv, Sv, Cv, Zk, Sk, Ck, Zb, Sb, and Cb, the specimens were polished with ceramic-polishing systems “v”, “k”, and “b” for intraoral use. Roughness was measured using profilometry. Statistical analysis was performed with ANOVA and Scheffé-procedure with the level of significance set at P=.05. RESULTS: All systems reduced the roughness of zirconia, but the differences from the controls Zgrit and Zlab were not statistically significant (P>.907). Roughness of silicate ceramic was reduced only in group Sv, but it did not differ significantly from both controls (P>.580). Groups Cv, Ck, and Cb had a significantly rougher surface than that of group Clab (P < .003). CONCLUSION: Ceramic materials can be polished with the tested systems. Polishing of interface areas between ceramic and composite material should be performed with polishing systems for zirconia first, followed by systems for veneering materials and for composite materials.