Journal of Dental Research, Vol 67, 71-74, Copyright © 1988 by International & American Associations for Dental Research Online Journals
Wear of composite resin restorations in primary versus permanent molar teeth
J. J. Wendell and W. F. Vann Jr
Department of Pediatric Dentistry, School of Dentistry, University of North Carolina at Chapel Hill 27514, USA.
The purpose of this investigation was to compare the wear rates of
posterior composite resin restorations in primary versus permanent teeth.
Based on theories of composite wear in primary molars, as well as on
empirical observations, we hypothesized that wear would be greater in
permanent tooth restorations. In Part I of the study, quantitative wear
data from four different clinical trials (three permanent tooth studies and
one primary tooth study) were compared. The same posterior composite
restorative material was investigated in each of the four studies. In Part
II of the study, quantitative wear data were drawn from a single clinical
trial wherein the same experimental posterior composite material was placed
in primary and permanent molars in the same children. In Part II, the
baseline sample size included posterior composite restorations placed in 92
primary and 95 permanent molars in all children (ages 7-10). Quantitative
wear data were obtained by the cast assessment method at baseline, six, 12,
and 24 months. The 24-month sample size was based on 48 available primary
molar restorations and 89 permanent molar restorations. The loss of primary
restorations was due almost exclusively to natural exfoliations. Findings
in Part I revealed no significant difference in the wear of primary versus
permanent molar restorations. In Part II, wear findings for primary molar
versus permanent teeth, respectively, were as follows (in micrometers): 47
versus 49 at six months; 86 versus 80 at 12 months; and 133 versus 131 at
24 months. With a Wilcoxon two-sample test and an alpha level of 0.05,
there were no significant differences at any recall for the wear rate of
primary versus permanent restorations. These results differ sharply from
findings reported by others.
