Magnetic resonance imaging evaluation of articular disk position after orthognathic surgery with or without concomitant disk repositioning: a retrospective study.

OBJECTIVE: The aim of this study was to compare the outcomes of 2 surgical treatment options: one for correction of class II malocclusion skeletal deformity and one for pre-existing temporomandibular joint (TMJ) disorders requiring orthognathic surgery (OS) for correction of dentofacial deformity. STUDY DESIGN: This retrospective study evaluated patients who underwent OS with maxillomandibular advancement (MMA) with or without concomitant TMJ surgery for articular disk repositioning (ADR). Patients were divided into 2 groups: group I (MMA) was treated with OS only (18 patients); and group II (MMA-ADR) was treated with OS and concomitant ADR (19 patients). The sample consisted of 74 TMJs (mean patient age 29.86 years). RESULTS: In group I, 38.5% of the disks that were originally in normal position became displaced after OS, and 33.3% of displaced disks with reduction became nonreducing after OS. In group II, 78.9% of disks exhibited normal position in the final evaluation, and 97.3% of patients showed improved disk position after surgery. There was significant symptom improvement in all patients in group II, but no significant improvement in group I. CONCLUSIONS: OS with ADR appears to produce stable and beneficial results in improving symptoms in patients with displaced disk and TMJ pain.

Influence of scanner, powder application, and adjustments on CAD-CAM crown misfit.

STATEMENT OF PROBLEM: The manufacturers of computer-aided design and computer-aided manufacturing (CAD-CAM) systems emphasize that new technologies can improve the marginal fit of dental crowns. However, data supporting this claim are limited. PURPOSE: The purpose of this in vitro study was to investigate the differences among the following fabrication methods on the marginal discrepancy of dental crowns: intraoral optical scanners, powder application, and adjustments of intaglio surface. MATERIAL AND METHODS: A single human premolar was fixed on a typodont and prepared to receive crowns prepared by the CEREC CAD-CAM system. Three fabrication techniques were used: digital scans using the CEREC Bluecam scanner with titanium dioxide powder (TDP), digital scans using the CEREC Omnicam scanner without TDP, and digital scans using the Omnicam scanner with TDP. Five experimental groups (n=10) were designated: Bluecam (group B), Bluecam with adjustments (group BA), Omnicam (group O), Omnicam with adjustments (group OA), and Omnicam with TDP (group OP). The specimens were scanned using microcomputed tomography to measure the vertical, horizontal, and internal fit and volumetric 3-dimensional (3D) internal fit values of each luting space. The paired t test was used to evaluate mean marginal fit change after adjustments within the same group. One-way analysis of variance and post hoc tests were used to compare groups B, O, and OP (α=.05). RESULTS: Mean vertical fit values ±standard deviations of group B=29.5 ±13.2 µm; BA=26.9 ±7.7 µm; O=149.4 ±64.4 µm; OA=49.4 ±12.7 µm; and OP=33.0 ±8.3 µm. Adjustments in the intaglio surface and TDP application statistically influenced the vertical fit of group O (P<.001). The percentage of vertical fit values <75 µm in group B=89.3%, BA=92.7%, O=31.0%, OA=73.5%, and OP=92.0%. Mean horizontal fit values for group B=56.2 ±21.5 µm; 85.8 ±44.4 µm for group BA; 77.5 ±11.8 µm for group O; 102.5 ±16.2 µm for group OA; and 91.4 ±19.4 µm for group OP. Results from group B were significantly different from those of the other test groups (P<.05). The percentages of horizontal misfit were 61.2% in group B; 73.5% in group BA; 88.1% in group O; 92.4% in group OA; and 85.0% in group OP. Volumetric 3D internal fit values in group B were 9.4 ±1.3 mm3; 10.7 ±1.0 mm3 in group BA; 11.8 ±2.1 mm3 in group O; 11.0 ±1.3 mm3 in group OA; and 9.6 ±0.9 mm3 in group OP. The overall results from groups B and OP were better than those of group O, with regard to vertical misfit and volumetric 3D internal fit. CONCLUSIONS: Different intraoral optical scanners, powder application, and internal adjustments influenced the marginal discrepancy of crowns. Crowns fabricated using the Omnicam system had significantly higher vertical discrepancy and volumetric 3D internal fit than those fabricated using the Bluecam scanner with TDP. Adjustments of the intaglio surface improved the vertical fit of crowns made using the Omnicam scanner; however, TDP application before Omnicam scanning improved the vertical fit as well as the volumetric 3D internal fit value of the luting space of crowns.

Effects of new implant-retained overdentures on masticatory function, satisfaction and quality of life.

The aim of this study is to evaluate the effects of replacing poorly fitting dentures on patient's masticatory function, satisfaction and oral health-related quality of life. Fourteen patients with conventional maxillary complete dentures and mandibular overdentures retained by two implants bar clip system had their dentures replaced. The laboratory tests for the analysis of masticatory performance were conducted using an "Optocal" food simulator test. Questionnaires were used to evaluate patient satisfaction with dentures and impact of oral health on quality of life. Tests were conducted and questionnaires were administered before and 1, 3 and 6 months after the patient had adapted to the new dentures. Masticatory performance data and satisfaction with dentures (Visual Analogic Scale) were statistically analyzed by ANOVA and Tukey b test, satisfaction with dentures (SATs P) and impact of oral health on quality of life were evaluated using the Wilcoxon and Friedman tests (a=.05). There was no statistically significant improvement in masticatory function after denture replacement, although better outcomes were observed. Satisfaction with dentures and total score obtained using the OHIPedent showed significant improvement. It can be suggested that the potential for grinding food, patient satisfaction and aspects of quality of life improved immediately after denture replacement.

Avaliar os efeitos da substituição de próteses mal adaptadas na função mastigatória, satisfação e qualidade de vida relacionada à saúde bucal do paciente. Quatorze pacientes com próteses totais convencionais maxilarese overdentures retidas por dois implantes mandibularessistem abarra clip etiveram suas prótes essubstituídas .Os testes laboratoriais para análise da performance mastigatória foram realizados utilizando um simulador de alimento "Optocal". Foram utili za dos questionários para avaliar a satisfação com a prótese eo impacto da saúde bucal na qualidade de vida. Os testes foram realizados e os questionários foram aplicados antes, 1, 3 e 6 mes esapós o paciente ter adaptado às novas próteses. Os dados da performance mastigatória e satisfação com a prótese (EscalaAnalógica Visual) foram analisados estatistica mente por análise de variância e teste de Tukey b, a satisfação com próteses (SATs P) e o impacto da saúde bucal na qualidade de vida foram avaliados pormeio dos testes de Wilcoxon e Friedman (a = 0,05). Não houvem elhora estatisticamente significativa na função mastigatória após a troca daspróteses, em boram elhores resultados foram observados após a substituição. Satisfação com a prótese e a somatória total obtida utilizando o OHIPEdent mostraram melhora signi ficativa. Podese sugerir que o potencial de trituração dos alimentos, a satisfação do paciente com as nova spróteses e aspectos da qualidade de vida melhorar amimediatamente após a substituição da prótese.

Effects of new implant-retained overdentures on masticatory function, satisfaction and quality of life

The aim of this study is to evaluate the effects of replacing poorly fitting dentures on patient’s masticatory function, satisfaction and oral healthrelated quality of life. Fourteen patients with conventional maxillary complete dentures and mandibular overdentures retained by two implants bar clip system had their dentures replaced. The laboratory tests for the analysis of masticatory performance were conducted using an “Optocal” food simulator test. Questionnaires were used to evaluate patient satisfaction with dentures and impact of oral health on quality of life. Tests were conducted and questionnaires were administered before and 1, 3 and 6 months after the patient had adapted to the new dentures. Masticatory performance data and satisfaction with dentures (Visual Analogic Scale) were statistically analyzed by ANOVA and Tukey b test, satisfaction with dentures (SATs P) and impact of oral health on quality of life were evaluated using the Wilcoxon and Friedman tests (a=.05). There was no statistically significant improvement in masticatory function after denture replacement, although better outcomes were observed. Satisfaction with dentures and total score obtained using the OHIPedent showed significant improvement. It can be suggested that the potential for grinding food, patient satisfaction and aspects of quality of life improved immediately after denture replacement.

Avaliar os efeitos da substituição de próteses mal adaptadas na função mastigatória, satisfação e qualidade de vida relacionada à saúde bucal do paciente. Quatorze pacientes com próteses totais convencionais maxilares e overdentures retidas por dois implantes mandibulares sistema barra clip e tiveram suas próteses substituídas .Os testes laboratoriais para análise da performance mastigatória foram realizados utilizando um simulador de alimento “Optocal”. Foram utili za dos questionários para avaliar a satisfação com a prótese eo impacto da saúde bucal na qualidade de vida. Os testes foram realizados e os questionários foram aplicados antes, 1, 3 e 6 meses após o paciente ter adaptado às novas próteses. Os dados da performance mastigatória e satisfação com a prótese (EscalaAnalógica Visual) foram analisados estatistica mente por análise de variância e teste de Tukey b, a satisfação com próteses (SATs P) e o impacto da saúde bucal na qualidade de vida foram avaliados pormeio dos testes de Wilcoxon e Friedman (a = 0,05). Não houve melhora estatisticamente significativa na função mastigatória após a troca das próteses, embora melhores resultados foram observados após a substituição. Satisfação com a prótese e a somatória total obtida utilizando o OHIPEdent mostraram melhora significativa. Pode se sugerir que o potencial de trituração dos alimentos, a satisfação do paciente com as novas próteses e aspectos da qualidade de vida melhoraram imediatamente após a substituição da prótese.

Micro-computed tomography evaluation of marginal fit of lithium disilicate crowns fabricated by using chairside CAD/CAM systems or the heat-pressing technique.

STATEMENT OF PROBLEM: No consensus exists concerning the acceptable ranges of marginal fit for lithium disilicate crowns fabricated with either heat-pressing techniques or computer-aided design and computer-aided manufacturing (CAD/CAM) systems. PURPOSE: The purpose of the study was to evaluate with micro-computed tomography the marginal fit of lithium disilicate crowns fabricated with different chairside CAD/CAM systems (Cerec or E4D) or the heat-pressing technique. MATERIAL AND METHODS: Lithium disilicate crowns were fabricated to fit an in vitro cast of a single human premolar. Three fabrication techniques were used: digital impressions with Cerec 3D Bluecam scanner with titanium dioxide powder, followed by milling from IPS e.max CAD for Cerec; digital impressions with E4D Laser scanner without powder, followed by milling from IPS e.max CAD for E4D; and fabrication from IPS e.max Press by using the lost-wax and heat-pressing techniques. Each crown was fixed to the cast and scanned with micro-computed tomography to obtain 52 images for measuring the vertical and horizontal fit. Data were statistically analyzed by 1-way ANOVA, followed by the Tukey honestly significant difference test (α=.05). RESULTS: The mean values of vertical misfit were 36.8 ±13.9 µm for the heat-pressing group and 39.2 ±8.7 µm for the Cerec group, which were significantly smaller values than for the E4D group at 66.9 ±31.9 µm (P=.046). The percentage of crowns with a vertical misfit <75 µm was 83.8% for Cerec and heat-pressing, whereas this value was 65% for E4D. Both types of horizontal misfit (underextended and overextended) were 49.2% for heat-pressing, 50.8% for Cerec, and 58.8% for E4D. CONCLUSIONS: Lithium disilicate crowns fabricated by using the Cerec 3D Bluecam scanner CAD/CAM system or the heat-pressing technique exhibited a significantly smaller vertical misfit than crowns fabricated by using an E4D Laser scanner CAD/CAM system.

Effects of abutment taper on the uniaxial retention force of cement retained implant restorations / Effects of abutment taper on the uniaxial retention force of cement retained implant restorations / Efeito da conicidade do pilar na resistência de união de coroas cimentadas sobre implantes

Aim: The purpose of this study was to evaluate the bond strength of metallic crowns cemented to straight and angled customizable abutments with zinc phosphate. Material and Method: Thirty-nine external hex nalogs and abutments were divided in group S: customizable straight abutment (n = 10), group A17 with 17° angled abutment (n = 10) and group A30 with 30° angled abutment (n = 10) all cemented with zinc phosphate. The metal copings were cemented onto their corresponding metal dies according manufacture guidelines. Data from the all groups were compared with a 1-way ANOVA (?=.05) and Tukey's test. SEM evaluation were performed (n = 3) aiming to investigate microscopic features of the abutment-cement-crown interfaces. Results: The mean force (SD) required to dislodge the crowns in the S, A17 and A30 groups was 357.26 (62.21) N; 251.50 (20.13) N and 276.70 (17.96) N respectively. The Tukey test (p <0.05) revealed a significant statistically differences between the groups (p =.002) and the 17° angled abutment and 30° angled abutment group were statistically similar to each other and different from the group of straight abutments. Zinc phosphate showed an inhomogeneous cement line in SEM analysis. Conclusions: Within the limitations of this study, it can be conclude that the available surface area and convergence of the abutments axial walls of the straight abutments positively influenced bond strength in metallic crowns cemented with zinc phosphate.

Retrieval technique for the Branemark Novum protocol: replacement of a lost implant.

In the past, the Branemark Novum protocol for the immediate functional loading of a mandibular fixed implant supported prosthesis provided an effective alternative for select patients. However, the manufacturer has discontinued this design, and only a few selected prosthetic-related replacement components are currently available. This clinical report presents the loss of an implant associated with a discontinued system. To take advantage of all of the preexisting components, it proposes a rescue procedure that allows continuous use of the original fixed restoration during the restoration of the tripod support at the implant level.

Avaliação da eficiência mastigatória por dois métodos: colorimetria e tamises / Mastigatory function avaluation by two methods: colorimetry and sifters

Objetivo: Correlacionar dois métodos para verificação da performance mastigatória. Método: Foram selecionados 13 pacientes que portavam Prótese total superior e prótese parcial fixa classe I de Kennedy inferior para realizar dois testes que medem a performance mastigatória. O primeiro teste, chamado de método das tamises, utiliza-se do Optocal como alimento-teste, dividido em 3 porções com 17 g que o paciente deve mastigar realizando 20 ou 40 ciclos mastigatórios. Após isso, é feita a análise do DGM. Em seguida, o paciente realizava a mastigação de uma cápsula, contendo grânulos de fuccina, seguindo os mesmos ciclos mastigatórios descritos no outro método. Após isso, as cápsulas foram enviadas a laboratório específico para análise da coloração. Resultado: Não houve correlação entre os métodos testados, após análise estatística utilizando o método de correlação de Pearson, com ?=0.05. Conclusão: O método da colorimetria, embora mais simples e de fácil execução do que o método das tamises, não se mostrou correlato a este. Deve-se, portanto, realizar ajustes na cápsula, a fim de torná-la mais macia, ou no método de análise do corante.

Purpose: Correlating two methods of verification of masticatory performance. Method: Thirteen patients were selected with was reabilitated with maxillar total denture and mandibular removible partial Kennedy Class I denture to perform two tests witch measure masticatory performance. The first test, called the method of sieves, uses the Optocal as test-food, divided into three portions with 17 g that the patient should chew doing 20 or 40 masticatory cycles. After that, we perform the DGM? analysis. Then the patient should chew a capsule containing fuchsin beads, following the same chewing cycles described in the other method. Thereafter, the capsules were sent to a specific laboratory for analysis. Results: There was no correlation between the tested methods, after statistical analysis using the Pearson correlation method, with ? = 0.05. Conclusions: Even colorimetric method, was a simple and easy to perform method, it was not correlated to the sifters method. Adjustments are necessary, in the capsule in order to make it softer or in the analisys? method.