ABSTRACT
The aim of this study was to evaluate the fracture strength of teeth with different cavosurface margin cavity preparations and restored with composite resin and different adhesive systems. Eighty premolars were randomly divided in 8 groups, as follow: G1- sound teeth; G2- MOD preparation (no restoration); G3- Adper Single Bond without bevel preparation (butt joint); G4- Adper Single Bond with bevel preparation; G5- Adper Single Bond with chamfer preparation; G6- Clearfil SE Bond without bevel (butt joint); G7- Clearfil SE Bond with bevel preparation; G8- Clearfil SE Bond with chamfer preparation. The adhesive systems were applied according to manufacturers' instructions. Composite resin (Filtek Z250) was incrementally placed in all cavities. After 24 h, the specimens were tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukey's test (fracture strength) and Fisher's exact test (fracture pattern). The confidence level was set at 95% for all tests. Prepared and non-restored teeth showed the worst performance and G4 exhibited the highest fracture strength among all groups (p<0.05). In conclusion, all restorative treatments were able to recover the fracture strength of non-restored teeth to levels similar to those of sound teeth. Using a total-etch adhesive system with bevel preparation significantly improved the resistance to fracture.
Subject(s)
Dental Cavity Preparation/methods , Dental Cements/therapeutic use , Dental Marginal Adaptation , Dental Restoration, Permanent/adverse effects , Tooth Fractures/etiology , Analysis of Variance , Bicuspid , Composite Resins/therapeutic use , Compressive Strength , Dental Bonding/methods , Dental Cavity Preparation/instrumentation , Dental Instruments , Dental Restoration, Permanent/methods , Dental Stress Analysis , Humans , Resin Cements/therapeutic use , Statistics, NonparametricABSTRACT
The aim of this study was to evaluate the fracture strength of teeth with different cavosurface margin cavity preparations and restored with composite resin and different adhesive systems. Eighty premolars were randomly divided in 8 groups, as follow: G1- sound teeth; G2- MOD preparation (no restoration); G3- Adper Single Bond without bevel preparation (butt joint); G4- Adper Single Bond with bevel preparation; G5- Adper Single Bond with chamfer preparation; G6- Clearfil SE Bond without bevel (butt joint); G7- Clearfil SE Bond with bevel preparation; G8- Clearfil SE Bond with chamfer preparation. The adhesive systems were applied according to manufacturers instructions. Composite resin (Filtek Z250) was incrementally placed in all cavities. After 24 h, the specimens were tested in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukeys test (fracture strength) and Fishers exact test (fracture pattern). The confidence level was set at 95 percent for all tests. Prepared and non-restored teeth showed the worst performance and G4 exhibited the highest fracture strength among all groups (p<0.05). In conclusion, all restorative treatments were able to recover the fracture strength of non-restored teeth to levels similar to those of sound teeth. Using a total-etch adhesive system with bevel preparation significantly improved the resistance to fracture.
O objetivo deste estudo foi determinar, in vitro, a resistência à fratura de pré-molares superiores com diferentes preparos do ângulo cavossuperficial e restaurados com resina composta com distintos sistemas adesivos. Foram selecionados 80 dentes, divididos em 8 grupos: G1- hígidos; G2- preparos M.O.D.; G3- Single Bond sem bisel; G4- Single Bond com bisel reto; G5- Single Bond com bisel chanfrado; G6- Clearfil SE Bond sem bisel; G7- Clearfil SE Bond com bisel reto e G8- Clearfil SE Bond com bisel chanfrado. Os grupos 3-8 foram restaurados com resina composta Z250, pela técnica incremental. Os corpos-de-prova foram submetidos ao teste de resistência à fratura em máquina universal de ensaios, a uma velocidade de 0,5 mm/min. Os dados foram analisados estatisticamente pelos testes ANOVA, Tukey e exato de Fisher (α=0,05). O grupo 2 apresentou resistência inferior aos demais e o grupo 4 mostrou-se mais resistente à fratura do que os demais grupos (p<0,05). Concluiu-se que o bisel reto foi o preparo mais efetivo quando associado a adesivos dentinários com condicionamento ácido prévio. Ambos adesivos dentinários usados foram capazes de devolver a resistência perdida com o preparo cavitário.
Subject(s)
Humans , Dental Marginal Adaptation , Dental Cavity Preparation/methods , Dental Cements/therapeutic use , Dental Restoration, Permanent/adverse effects , Tooth Fractures/etiology , Analysis of Variance , Bicuspid , Compressive Strength , Composite Resins/therapeutic use , Dental Instruments , Dental Stress Analysis , Dental Bonding/methods , Dental Cavity Preparation/instrumentation , Dental Restoration, Permanent/methods , Resin Cements/therapeutic use , Statistics, NonparametricABSTRACT
Restaurar um dente que apresente grande perda de estrutura dentinária radicular é possível desde que sejam considerados critérios para reforçar o remanescente. Soluções para este problema têm desafiado os dentistas por séculos. Os autores demonstraram, através de um relato de caso clínico, que o reforço radicular é um procedimento viável e eficaz para preservar elementos dentais que seriam extraídos, impossíveis de serem reabilitados pela fragilidade radicular. O presente caso mostra essa situação radicular no dente 21, onde foi realizada a técnica do reforço. Utilizaram-se materiais como: pino fototransmissor Luminex, adesivo dentinário Single Bond e resina dual Relyx, após foi confeccionado um núcleo metálico fundido e uma prótese fixa unitária metalocerâmica.A resistência dos adesivos dentinários, as propriedades físicas da resina composta semelhantes às da dentina e o uso de pinos fototransmissores podem, juntamente com a técnica preconizada, proporcionar o resultado desejado.