Influence of adhesive system and bevel preparation on fracture strength of teeth restored with composite resin.
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.
Department of Conservative Dentistry, Federal University of Rio Grande do Sul, Porto Alegre, RS, Brazil.
Fábio Herrmann
FH
Coelho-de-Souza
Analice da Cunha
Ada C
Rocha
Alessandro
A
Rubini
Celso Afonso
CA
Klein-Júnior
Flávio Fernando
FF
Demarco
D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins / Q000627:therapeutic use; D019245:Compressive Strength; D001840:Dental Bonding / Q000379:methods; D003737:Dental Cavity Preparation / Q000295:instrumentation / Q000379:methods*; D003738:Dental Cements / Q000627:therapeutic use*; D003762:Dental Instruments; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000009:adverse effects* / Q000379:methods; D003799:Dental Stress Analysis; D006801:Humans; D019279:Resin Cements / Q000627:therapeutic use; D018709:Statistics, Nonparametric; D014082:Tooth Fractures / Q000209:etiology*
C554641:Adper single bond 2; C438313:Clearfil SE Bond; D003188:Composite Resins; D003738:Dental Cements; C444701:Filtek Z250; D019279:Resin Cements