Title: 0469 - Testing Control and Experimental μTBS Specimens Prepared From Single Tooth


Mario Sinhoreti, Piracicaba Dental School, UNICAMP
Saulo Geraldeli, University of Florida
Gizele de Padua, University of florida
Fernanda Pires-de-Souza, University of São Paulo
Chiayi Shen (Presenter)
University of Florida


Objectives: The hypothesis was that using dentin quarters from single tooth as control and experimental substrates for μTBS tests could attain same statistical significance as protocol of undivided teeth (one treatment per tooth) but require reduced number of teeth.

Methods: Sixty extracted sound third molars were allocated to DQ (dentin quarter; N=20) and UT (undivided tooth; N=40). Upon exposing the mid dentin using a diamond saw, each tooth in the DQ was cut M-D and B-L to four proportional quarters. To each quarter of individual tooth in DQ and ten-teeth subgroup of UT, an adhesive system was applied per manufacturer’s recommendations. Adhesives were Clearfil SE Bond, Scotchbond Multi-Purpose, Scotchbond Universal (etch-and-rinse) and Scotchbond Universal (self-etch). After composite build-up was made with Filtek Z250, the specimens were sectioned on y and x directions using the same saw. All beams were stored in water for 24h before debonding using the Geraldeli’s device with crosshead speed of 0.75mm/min. To determine number of teeth needed to achieve statistical significance, data were divided into subsets of reduced number of teeth. They were five eight-teeth subsets (two teeth per adhesive; UT1) and two 20-teeth subsets (five teeth per adhesive; UT2) from UT, and four five-teeth subsets (DQ1) and two 10-teeth subsets (DQ2) from DQ.

Results: Two-way ANOVA by GLM (SAS 9.4) shows there is no difference in μTBS between UT and DQ but significant difference (p<0.0001) among adhesives. ANOVA’s of the subsets show that there is a statistically significant difference among subsets of UT1 and no significant difference among subsets within UT2, DQ1 and DQ2. The ranking of adhesives in each subset was consistent with respective UT and DQ.

Conclusions: Five teeth in DQ provided sufficient dentin substrates for comparing four adhesives, while ST protocol required more than two teeth per adhesive to be statistically similar.

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: None