Survival rate and load to failure of premolars restored with inlays: An evaluation of different inlay fabrication methods.

STATEMENT OF PROBLEM: Studies that evaluate the survival rate and load to fracture of premolars restored with inlays produced using different methods are lacking. PURPOSE: The purpose of this in vitro study was to compare the survival rate and fracture load of premolars restored with inlays fabricated using different methods. MATERIAL AND METHODS: Thirty maxillary premolars were selected, embedded, and prepared to receive inlays fabricated using different methods (n=10): LaCom-digital scanning with Lava C.O.S. scanner (3M ESPE), followed by milling of composite resin block (Lava Ultimate; 3M ESPE) in a milling unit; CeCom-digital scanning with Cerec 3D Bluecam scanner (Dentsply Sirona), followed by milling of a Lava Ultimate block in Cerec (Dentsply Sirona); PresDis-impression with polyvinyl siloxane, inlay made using the lost wax technique, and IPS e.max Press (Ivoclar Vivadent AG) pressed ceramic (lithium disilicate). A dual-polymerizing resin cement system was used to lute the inlays. Inlays were mechanically cycled (2 Hz, 106 mechanical pulses, 80 N) after 24 hours, and the specimens were stored in distilled water at 37°C for 11 months. Then, a fatigue test was conducted using a 10-Hz frequency and 400-N load on the inner inclines of the cusps. The test was complete when the specimen fractured or when the specimen reached 1.5×106 cycles. The specimens that survived fatigue testing were submitted to a single-load fracture test in a universal testing machine and analyzed using a stereoscope for failure classification. Survival rates were estimated using the Kaplan-Meier method and log-rank test (Mantel-Cox). Fracture load data were analyzed using 1-way ANOVA (α=.05). RESULTS: No significant differences were detected among the groups for the survival rate (P=.87) or for the load to fracture (P=.78). Most failures were longitudinal, catastrophic fractures. CONCLUSIONS: Premolars restored with inlays fabricated using the tested methods had similar survival rates and loads to fracture.

Influence of Endodontic Treatment and Retreatment on the Fatigue Failure Load, Numbers of Cycles for Failure, and Survival Rates of Human Canine Teeth.

INTRODUCTION: This study evaluated the effects of endodontic treatment and retreatment on the fatigue failure load, numbers of cycles for failure, and survival rates of canine teeth. METHODS: Sixty extracted canine teeth, each with a single root canal, were selected and randomly divided into 4 groups (n = 15): untreated, teeth without endodontic intervention; prepared, teeth subjected only to rotary instrumentation; filled, teeth receiving complete endodontic treatment; and retreated, teeth retreated endodontically. After the different endodontic interventions, the specimens were subjected to fatigue testing by the stepwise method: 200 N (× 5000 load pulses), 300 N, 400 N, 500 N, 600 N, 800 N, and 900 N at a maximum of 30,000 load pulses each or the occurrence of fracture. Data from load to failure and numbers of cycles for fracture were recorded and subjected to Kaplan-Meier and Log Rank tests (P < .05), in addition to Weibull analysis. The fractures of the specimens were classified as repairable or catastrophic. RESULTS: The retreated, filled, and untreated groups presented statistically significantly higher fatigue failure loads and numbers of cycles for failure than did the prepared group. Weibull analysis showed no statistically significant difference among the treatments for characteristic load to failure and characteristic number of cycles for failure, although, for number of cycles, a higher Weibull modulus was observed in filled and retreated conditions. The predominant mode of failure was catastrophic. CONCLUSION: Teeth subjected to complete endodontic treatment and retreatment behaved similarly in terms of fatigue failure load and number of cycles to failure when compared with untreated teeth.

Influence of generalized joint hypermobility on temporomandibular joint and dental occlusion: a cross-sectional study. / Influência da hipermobilidade articular generalizada sobre a articulação temporomandibular e a oclusão dentária: estudo transversal.

PURPOSE: To evaluate the dental occlusion and temporomandibular joint in women with and without generalized joint hypermobility. METHODS: Generalized joint hypermobility was assessed by the Beighton score. Individuals were divided into two groups: with and without hypermobility. The Research Diagnostic Criteria for Temporomandibular Disorders was used to evaluate the temporomandibular joint. Dental occlusion was assessed according to Angle classification, overjet and overbite measures, presence of open bite or crossbite, pattern of disocclusion, and occlusal interference. RESULTS: Forty-three women participated voluntarily in the study: 17 in the group with hypermobility and 26 in the group without hypermobility. The frequencies of joint noise and deviation during mouth opening were greater in the hypermobility group (52.9% vs. 38.5% and 76.5% vs. 50%, respectively), but without statistical significance. None of the volunteers presented ideal occlusion and no significant difference was found in Angle Class between the groups. The hypermobility group presented a higher percentage of changes in occlusion (29.4% of overbite, 47.1% of overjet, and 17.6% of crossbite), with crossbite showing statistical difference between the groups. CONCLUSION: Hypermobility does not influence occlusion and range of mandibular motion in the women assessed. Nevertheless, the higher percentage of articular noise and uncorrected deviation during mouth opening shown by the group with hypermobility, even without statistical difference, may constitute evidence of correlation between hypermobility and temporomandibular disorder.

Influência da hipermobilidade articular generalizada sobre a articulação temporomandibular e a oclusão dentária: estudo transversal / Influence of generalized joint hypermobility on temporomandibular joint and dental occlusion: a cross-sectional study

RESUMO Objetivo Avaliar a oclusão dentária e a articulação temporomandibular de mulheres com e sem hipermobilidade articular generalizada. Método A hipermobilidade foi avaliada pelo Escore de Beighton, e as voluntárias foram distribuídas, conforme o escore obtido, em dois grupos: com e sem hipermobilidade. A articulação temporomandibular foi avaliada por meio do instrumento Critérios de Diagnóstico para Pesquisa de Desordens Temporomandibulares, e a avaliação oclusal compreendeu a classificação de Angle, presença de sobremordida, sobressaliência e mordida cruzada, padrão de desoclusão e interferências oclusais. Resultados 43 mulheres participaram voluntariamente da pesquisa, 17 no grupo com hipermobilidade e 26 no grupo sem hipermobilidade. A frequência de ruídos articulares e de desvio na abertura da boca foi maior no grupo com hipermobilidade (52,9% versus 38,5% e 76,5% versus 50%, respectivamente), sem diferença significante. Quanto à oclusão, nenhuma voluntária apresentou uma oclusão ideal e não se verificou diferença significativa na Classe de Angle entre os grupos. As alterações na oclusão obtiveram percentual maior no grupo com hipermobilidade (29,4% de sobremordida, 47,1% de sobressaliência e 17,6% de mordida cruzada), sendo que a mordida cruzada apresentou diferença estatística entre os grupos. Conclusão A hipermobilidade não influenciou a oclusão e as amplitudes de movimentos mandibulares nas mulheres avaliadas. Contudo, o maior percentual de ruídos articulares e de desvio não corrigido apresentado pelo grupo com hipermobilidade, mesmo sem diferença entre os grupos, pode constituir um indício de relação entre hipermobilidade e disfunção temporomandibular.

ABSTRACT Purpose To evaluate the dental occlusion and temporomandibular joint in women with and without generalized joint hypermobility. Methods Generalized joint hypermobility was assessed by the Beighton score. Individuals were divided into two groups: with and without hypermobility. The Research Diagnostic Criteria for Temporomandibular Disorders was used to evaluate the temporomandibular joint. Dental occlusion was assessed according to Angle classification, overjet and overbite measures, presence of open bite or crossbite, pattern of disocclusion, and occlusal interference. Results Forty-three women participated voluntarily in the study: 17 in the group with hypermobility and 26 in the group without hypermobility. The frequencies of joint noise and deviation during mouth opening were greater in the hypermobility group (52.9% vs. 38.5% and 76.5% vs. 50%, respectively), but without statistical significance. None of the volunteers presented ideal occlusion and no significant difference was found in Angle Class between the groups. The hypermobility group presented a higher percentage of changes in occlusion (29.4% of overbite, 47.1% of overjet, and 17.6% of crossbite), with crossbite showing statistical difference between the groups. Conclusion Hypermobility does not influence occlusion and range of mandibular motion in the women assessed. Nevertheless, the higher percentage of articular noise and uncorrected deviation during mouth opening shown by the group with hypermobility, even without statistical difference, may constitute evidence of correlation between hypermobility and temporomandibular disorder.

Influência da hipermobilidade articular generalizada sobre a articulação teoromandibular, mastigação e deglutição: estudo transversal / Influence of generalized joint hypermobility on temporomandibular joint, mastication and deglutition: a cross-sectional study

OBJETIVO: avaliar a articulação temporomandibular, as funções de mastigação e deglutição em mulheres assintomáticas com e sem hipermobilidade articular generalizada e a associação entre estas variáveis. MÉTODOS: foram avaliadas 43 voluntárias no Serviço de Atendimento Fonoaudiológico da Universidade Federal de Santa Maria. Ahipermobilidadefoi avaliada pelo Escore de Beighton e, a partir dos escores obtidos, as voluntárias foram distribuídas em dois grupos: com (n=17) e sem hipermobilidade (n=26). A articulação temporomandibular foi examinada pelo instrumento Critérios de Diagnóstico para Pesquisa de Desordens Temporomandibularese as funções de mastigação e deglutição foram avaliadas por meio do exame miofuncional orofacial. RESULTADOS: a avaliação clínica da articulação temporomandibular demonstrou predomínio de ruídos articulares durante movimentos mandibulares (52,9%) e de desvio na abertura da boca (76,5%) nas voluntárias do grupo com hipermobilidade, sem diferença significante entre os grupos. No exame da função mastigatória, apesar da maioria das voluntárias apresentar padrão de mastigação bilateral alternado, a frequência desse foisignificantemente menor no grupo com hipermobilidade (p=0,05). Foi verificada uma associação significante(p=0,02) entre o padrão de mastigação e de abertura da boca, apenas no grupo sem hipermobilidade, e não houve diferença na deglutição entre os grupos. CONCLUSÃO: as mulheres assintomáticas apresentaram indícios de que a hipermobilidade predispõe à ocorrência de desvio na abertura da boca e ruídos articulares. Não houve diferença na função de deglutição, porém verificou-se uma frequência menor de mastigação bilateral alternada no grupo com hipermobilidade em relação ao sem hipermobilidade. .

PURPOSE: to evaluate temporomandibular joint, mastication and deglutition in asymptomatic women with and without generalized joint hypermobility and the association between these variables. METHODS: forty-three volunteers were evaluated at the Speech-Language-Hearing Service of Federal University of Santa Maria. Hypermobility was evaluated according to the Beighton score and, based on the obtained scores, the volunteers were distributed into two groups: with (n=17) and without hypermobility (n=26). The temporomandibular joint was examined by Research Diagnostic Criteria for Temporomandibular Disorders instrument, and mastication and deglutition functions were assessed through a myofunctional orofacial assessment. RESULTS: the clinical evaluation of the temporomandibular joint showed predominance of joint sounds during jaw movement (52.9%) and mouth opening deviation (76.5%) in the hypermobility group, without statistical significant difference. In the examination of the masticatory function, although most of the volunteers showed a bilateral chewing pattern, the frequency of this pattern was significantly lower in the hypermobility group (p=0.05). A significant association (p=0.02) between chewing and mouth opening pattern was found only in the group without hypermobility, and there was no difference between groups regarding the deglutition function. CONCLUSION: asymptomatic women showed evidence that hypermobility predisposes the occurrence of mouth opening deviation and joint sounds. There was no difference in the deglutition function, but lower frequency of alternating bilateral chewing was found in the group with hypermobility compared to the group without hypermobility. .

Associação entre funções estomatognáticas, oclusão dentária e sinais de disfunção temporomandibular em mulheres assintomáticas / Association among stomatognathic functions, dental occlusion and temporomandibular disorder signs in asymptomatic women

OBJETIVO: verificar a associação entre funções estomatognáticas de mastigação e deglutição, oclusão dentária e sinais de disfunção temporomandibular em mulheres assintomáticas. MÉTODOS: as funções estomatognáticas foram avaliadas pelo exame miofuncional orofacial; o exame da oclusão dentária compreendeu: classificação de Angle; medidas de sobrepasse horizontal e vertical; presença de mordida aberta e cruzada; e a avaliação da articulação temporomandibular foi realizada pelo instrumento Critérios de Diagnóstico para Pesquisa de Desordens Temporomandibulares. RESULTADOS: foram avaliadas 43 mulheres com idade média de 23,7 anos. O exame miofuncional orofacial demonstrou alterações no padrão de mastigação (30,2%) e contrações atípicas na mastigação (18,6%) e deglutição (58,1%). Quanto à oclusão dentária, houve predomínio de classe I de Angle (74,4%), porém nenhuma voluntária apresentou uma oclusão ideal. A avaliação da articulação temporomandibular apresentou amplitude de movimento dentro da normalidade, presença de desvio na abertura da boca (60,5%) e diagnóstico de disfunção temporomandibular (16,3%). Houve associação significante entre presença de ruídos articulares e diagnóstico de disfunção temporomandibular e contrações atípicas na deglutição; padrão de abertura e contrações atípicas na mastigação; e não houve associação entre a Classe Oclusal de Angle, padrão de mastigação e disfunção temporomandibular. CONCLUSÃO: voluntárias assintomáticas apresentaram alterações das funções estomatognáticas, como contrações atípicas durante a deglutição e mastigação, as quais foram associadas com a presença de ruídos articulares e padrão de abertura da boca. Tais achados podem ser atribuídos a desequilíbrios e incoordenação dos músculos envolvidos nessas funções. Nenhuma voluntária apresentou oclusão ideal e não foram encontradas associações com esta condição. .

PURPOSE: to determine the association between chewing and swallowing stomatognathic functions, dental occlusion and temporomandibular dysfunction signs in asymptomatic women. METHODS: the stomatognathic functions were evaluated through orofacial myofunctional examination; the dental occlusion examination included: Angle classification; overjet and overbite measures; openbite and crossbite presence; and the temporomandibular joint evaluation was performed by the Diagnostic Criteria for Temporomandibular Disorders Research Instrument. RESULTS: 43 women with an average age of 23.7 years old were evaluated. The orofacial myofunctional examination showed changes in mastication pattern (30.2%), chewing (18.6%) and swallowing (58.1%) atypical contractions. Regarding the dental occlusion Angle Class I was predominant (74.4%), however no volunteer had an ideal occlusion. The temporomandibular joint evaluation showed the range of movement within normal, presence of mouth opening deviation (60.5%) and temporomandibular dysfunction diagnosis (16.3%). There was a significant association between presence of joint noises and temporomandibular dysfunction diagnosis and atypical swallowing contractions; opening pattern and atypical chewing contractions; there was no association between Angle Occlusal Class, chewing pattern and temporomandibular disorders. CONCLUSION: asymptomatic volunteers showed alterations of stomatognathic functions such as atypical contractions during swallowing and chewing, which were associated to joint noises and mouth opening pattern. These results can be attributed to imbalances and lack of coordination of the muscles involved in these functions. No volunteer showed an ideal occlusion and no associations with this condition were found. .