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Necessity of bevels for box only Class II composite restorations
N J Opdam1, J J Roeters, R Kuijs
1University of Nijmegen, The Netherlands.
Statement Of Problem:
The tooth preparation of a bevel is recommended to improve marginal quality of a composite restoration. However, in small Class II restorations, it is unclear if a bevel also contributed to a better marginal fit.
Purpose:
This study investigated the influence of tooth preparation design on microleakage of minimal posterior Class II composite restorations.
Material And Methods:
Box-shaped Class II tooth preparations for posterior composite restorations in maxillary premolars were restored with a total etch technique. The tooth preparations were beveled or non-beveled and the box prepared at a right angle cervically or additionally excavated. The facial and lingual box margins were also either beveled or unbeveled. The teeth were thermocycled and immersed in a dye solution. After sectioning specimens, dye penetration at the facial and palatal margins was recorded.
Results:
A bevel-reduced microleakage both at the cervical and ascending walls. Enamel cracks were observed along certain unbeveled margins as recorded in this study. The additional excavation did not contribute to reduction of microleakage.
Conclusions:
Tooth preparation of a bevel is recommended for an optimal marginal seal in small box-type Class II composite restorations.