Occlusal Pressure Analysis of Complete Dentures after Microwave Disinfection: A Clinical Study.

PURPOSE: This clinical study evaluated the effect of microwave disinfection protocols on the occlusal pressure pattern of dentures. MATERIALS AND METHODS: Dentures were constructed for 40 patients and evaluated as follows (n = 20). Group 1: Patients had the maxillary dentures submitted to microwave disinfection, once a week, for 4 weeks. Group 2: Patients had the maxillary dentures submitted to microwave disinfection, three times a week, for 4 weeks. Occlusal contacts were recorded on five occasions: 30 days after denture insertion and before first disinfection (baseline or control group); 1 week after disinfection; 2 weeks after disinfection; 3 weeks after disinfection; 4 weeks after disinfection. Occlusal contacts were analyzed by T-Scan III. Intergroup analysis was performed using the Mann-Whitney test and intragroup analysis using the Friedman test with significance of 5%. RESULTS: The results showed no significant difference between groups during the periods. The data on parameters loss of denture adaptation or complaints showed that patients used their dentures regularly for eating and expressed comfort and satisfaction in all experimental periods. The evaluation of functional occlusion revealed that the distribution of the occlusal contacts remained unaltered after disinfection. CONCLUSION: Microwave disinfection protocols as studied in this report did not influence occlusal contacts of the complete dentures.

Influence of microwave disinfection on the dimensional stability of denture reline polymers.

PURPOSE: The purpose of this study was to evaluate the effect of microwave disinfection (3 minutes at 650 W) on the dimensional stability of hard chairside reline resins (Kooliner, Tokuyama Rebase II, Ufi Gel hard, New Truliner) and one heat-polymerizing denture base resin (Lucitone 550). MATERIALS AND METHODS: A split mold with reference points was used to make specimens (50.0-mm diameter, 0.5-mm thick) from each material, divided into five test groups (n = 8). The distances between the points on the mold were measured (gold standard), and compared with those obtained from the specimens after polymerization (baseline readings) after one, two, three, and four cycles of disinfection by microwave irradiation. RESULTS: ANOVA and Tukey tests (alpha= 0.05) showed that Kooliner was significantly affected by all disinfection cycles (p < 0.05) when compared with baseline measurements. New Truliner resin was significantly affected by three and four cycles of microwave disinfection when compared with baseline measurements (p < 0.05). For Tokuyama Rebase II, Ufi Gel hard, and Lucitone 550, no significant dimensional changes were found. CONCLUSIONS: Microwave disinfection promoted shrinkage of Kooliner and New Truliner. The dimensional stability of Tokuyama Rebase II, Ufi Gel Hard, and Lucitone 550 was not affected by microwave disinfection.

Influence of microwave disinfection on the linear dimensional stability of complete dentures: a clinical study.

This clinical study evaluated the effect of two microwave disinfection protocols at 650 W for 3 minutes (group 1, once a week; group 2, three times a week) on the linear dimensional stability of complete dentures. Measurements were taken across four reference points: before the first microwave disinfection (baseline) and after each week of disinfection. Furthermore, the dentures were monitored clinically. Group 2 showed significantly greater shrinkage than group 1 in all evaluated weeks. During clinical monitoring, no significant findings were observed. Even though dimensional changes occurred, the clinical evaluation did not yield any changes in either group.

Comparison of the occlusal vertical dimension after processing complete dentures made with lingualized balanced occlusion and conventional balanced occlusion.

STATEMENT OF PROBLEM: An increase in occlusal vertical dimension (OVD) may occur after processing complete dentures. Although many factors that generate this change are known, no information is available in the dental literature regarding the effect that the occlusal scheme may have on the change in OVD. PURPOSE: This in vitro study compared the increase in OVD, after processing, between complete dentures with teeth arranged in lingualized balanced occlusion and conventional balanced occlusion. MATERIAL AND METHODS: Thirty sets of complete dentures were evaluated as follows: 15 sets of complete dentures were arranged in conventional balanced occlusion (control) and 15 sets of complete dentures were arranged in lingualized balanced occlusion. All dentures were compression molded with a long polymerization cycle. The occlusal vertical dimension was measured with a micrometer (mm) before and after processing each set of dentures. Data were analyzed using an independent t test (alpha=.05). RESULTS: The mean increase in the OVD, after processing, was 0.87 +/- 0.21 mm for the control group and 0.90 +/- 0.27 mm for the experimental group. There was no significant difference between the groups. CONCLUSION: After processing, dentures set in lingualized balanced occlusion showed an increase in OVD similar to those set in conventional balanced occlusion. CLINICAL IMPLICATIONS: Although the 2 occlusal concepts resulted in similar increases in the OVD after processing, the lingualized balanced occlusion may result in easier occlusal adjustments, as the less complicated occlusal scheme uses a smaller number of centric occlusion contact points.

Carga imediata e carga tardia em overdentures sobre implante / Immediate loading and delayed loading on implant overdentures

A estabilidade primária e o período de cicatrização sem carga dos implantes dentais por aproximadamente 3 a 6 meses têm sido considerados, por anos, importante para permitir a osseointegração dos implantes. Entretanto, estudos recentes têm encorajado o encurtamento do período de cicatrização e o carregamento imediato tem sido proposto para pacientes completamente edêntulos. Altas taxas de sucesso são geralmente relatadas no carregamento imediato. Apesar das evidências, muitas controvérsias ainda existem sobre aconfiabilidade dos dados relatados, freqüentemente devido ao insuficiente acompanhamento, inadequado tamanho da amostra e falta decritérios de sucesso bem definidos. O objetivo dessa investigação foi revisar a literatura para avaliar estudos sobre o carregamento imediato ou precoce de implantes em mandíbulas e maxilas edêntulas e reabilitadas com overdentures implanto-suportadas. As taxas de sucesso encontradas na literatura odontológica sugerem que o carregamento imediato ou precoce de implantes dentais pode ser aplicado sob condições controladas.

The primary stability and the healing period without loading of dental implants for approximately 3 to 6 months have been considered for years important to allow osseointegration of dental implants. However, recent studies have encouraged a shortening of the healing period and immediate loading has been proposed for completely edentulous patients. High survival rates were generally reported in the immediate loading. In spite of evidences, much controversy still exists over the reliability of the reported data, frequently due to insufficient follow-up, inadequate sample size and lack of well defined success criteria. The objective of this investigation was to review the literature to evaluate studies about early and immediate loading of implants placed in the edentulous mandible and maxilla and rehabilitated with implant-supported overdentures. The success rates achieved in dental literature suggest that immediate orearly loading of dental implants can be applied under controlled conditions.

Avaliação clínica da estabilidade dimensional de próteses totais submetidas à desinfecção por microondas / Clinical evaluation of dimensional stabiblity of complete dentures after microwave disinfection

A energia por microondas tem sido recomendada para desinfetar próteses totais. Entretanto, os ciclos de desinfecção podem afetar a estabilidade dimensional das bases de próteses. Assim, o objetivo deste estudo clínico foi avaliar o efeito de dois protocolos de desinfecção por microondas na estabilidade dimensional de próteses totais, analisando a estabilidade dimensional linear, o percentual de força oclusal obtido a partir dos contatos oclusais cêntricos e as ocorrências clínicas. Foram confeccionadas próteses totais para quarenta pacientes totalmente edêntulos. Todas as próteses foram prensadas com a resina Lucitone 550. Após a colocação, aguardou-se 30 dias para submeter as próteses às condições experimentais como a seguir: Grupo 1 (G1)- 20 pacientes tiveram as próteses maxilares submetidas a desinfecção por microondas (650 W / 3 minutos), uma vez por semana, durante 4 semanas. Grupo 2 (G2)- 20 pacientes tiveram as próteses maxilares submetidas a desinfecção por microondas (650 W / 3 minutos), três vezes por semana, durante 4 semanas. Para avaliar a estabilidade dimensional linear, mensurações foram realizadas entre quatro pontos de referência (primeiros pré-molares e segundos molares bilateralmente) antes da primeira desinfecção por microondas (baseline) e após cada semana de desinfecção. Um software foi utilizado para mensurar as distâncias entre os pontos de referência a partir de fotografias padronizadas. As dimensões médiolateral e anteroposterior e a área foram calculadas. Os dados foram analisados pelos testes ANOVA two-way, Tukey e t-Student (_=0,05). O sistema T-Scan III foi utilizado para avaliar o percentual de força oclusal obtido a partir dos contatos oclusais cêntricos. Os contatos oclusais cêntricos foram capturados, antes da primeira desinfecção por microondas (baseline) e após cada semana de desinfecção, por meio...

Microwave energy has been recommended for disinfecting complete dentures. However, the microwave disinfection cycles may affect the dimensional stability of denture bases. Therefore, the purpose of this clinical study was to evaluate the effect of two microwave disinfection protocols on the dimensional stability of complete dentures, analyzing the linear dimensional stability, the percent occlusal force obtained from centric occlusal contacts and the clinical events. Complete dentures were constructed for forty totally edentulous patients. All dentures were conventionally processed with heat-polymerized acrylic resin (Lucitone 550). After insertion of complete dentures, it was expected 30 days to submit the dentures to the experimental conditions as follows: Group 1 (G1)- 20 patients had the maxillary complete dentures submitted to microwave disinfection (650 W/ 3 minutes), once a week, for four weeks. Group 2 (G2)- 20 patients had the maxillary complete dentures submitted to microwave disinfection (650 W/ 3 minutes), three times a week, for four weeks. To evaluate the linear dimensional stability, measurements were taken across four reference points (first premolars and second molars bilaterally) before of first microwave disinfection (baseline) and after each week of disinfection. Software was used to measure distances between reference points from standardized photographs. Mediolateral and anteroposterior dimensions and area between reference points were calculated. The dimensional data obtained were analyzed using two-way ANOVA, Tukey test and t test (_ = .05). To evaluate the percent occlusal force obtained from centric occlusal contacts, the T-Scan III system was used. The centric occlusal contacts were measured, before of first microwave disinfection (baseline) and after each week of disinfection, using pressure-sensitive sheets and studied in T-Scan software. The occlusal data...

Relação central em indivíduos dentados: estudo comparativo das posições condilares no plano sagital determinadas pelos métodos guiado não forçado e inclinação da cabeça para trás / Centric relation in dentate subjects: comparative study of condylar positions in the sagittal plane determined by methods unstrained hinging movement and inclination of head backward

Esta pesquisa comparou posicionamentos condilares no plano sagital de dois métodos de registro da relação central (RC): guiado não forçado (GNF) e inclinação da cabeça para trás (ICT). Os modelos superior e inferior de 30 indivíduos adultos, dentados naturais bimaxilares, foram montados em um articulador Whip Mix. Foi adaptado, na região das caixas condilares, um instrumento de registro semelhante a um Buhnergraph. Mordidas em cera refinadas com Temp-Bond, obtidas pelos métodos em estudo, orientaram a demarcação de pontos representativos dos posicionamentos condilares nos lados direito e esquerdo. As distâncias entre os pontos obtidos foram mensuradas com um projetor de perfil (Nikon, modelo 6C, Japão). Concluiu-se: 1. a distância entre os pontos de registro do lado direito não foi igual à do esquerdo, não sendo essa diferença estatisticamente significativa; 2. a média geral das distâncias entre os pontos de registro foi de 0,54 mm, com desvio padrão de 0,24 mm; 3. o método GNF demonstrou maior tendência em produzir posicionamentos condilares mais posteriores do que o método ICT; 4. em sentido infra-superior, não houve predomínio de um método sobre outro no sentido dos posicionamentos condilares