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Effect of Polishing Direction on the Marginal Adaptation of Composite Resin Restorations
Author(s) -
StPierre Laurie,
Bergeron Cathia,
Qian Fang,
Hernández Maria Marcela,
Kolker Justine L.,
Cobb Deborah S.,
Vargas Marcos A.
Publication year - 2013
Publication title -
journal of esthetic and restorative dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.919
H-Index - 60
eISSN - 1708-8240
pISSN - 1496-4155
DOI - 10.1111/jerd.12020
Subject(s) - polishing , composite number , materials science , molar , composite material , enamel paint , bevel , resin composite , dentistry , medicine , structural engineering , engineering
Problem Polishing composite resin restorations may lead to marginal defects and gap formation. Purpose To assess the effect of polishing direction on the marginal adaptation of composite resin restorations using two composite resins and two polishing systems. Materials and Methods Forty extracted human molars were sectioned along their mesio‐distal axis. Buccal and lingual enamel was flattened and a triangular preparation, 0.87‐mm deep and 3‐mm wide, representing two 60° bevels, was performed. Specimens were randomly assigned to eight groups ( N = 20) and restored with two composite resins: a nanofilled ( F iltek S upreme U ltra, 3M ESPE , S t. P aul, MN , USA ) or a microhybrid (Point 4, K err, O range, CA , USA ) and finished with two polishing techniques: polishing discs ( S of‐ L ex XT , 3M ESPE ) or rubber polishers ( H i L uster P lus, K err, B ioggio, S witzerland). On each specimen, both margins were polished with the same technique, one margin from composite resin to tooth and the other from tooth to composite resin. Replicas were made for field emission scanning electron microscope observation (200×) and quantitative margin analysis was performed based on four criteria. Data were analyzed with a paired‐sample t ‐test, a two‐sample t ‐test, and one‐way analysis of variance or their nonparametric analog. Results Significant differences were found in most groups between polishing directions with better marginal adaptation from composite resin to tooth than from tooth to composite resin. Differences between composite resins and polishing techniques seemed to be dependent on certain combinations of composite resin, polishing technique, and polishing direction. Conclusion Polishing from composite resin to tooth leads to better marginal adaptation than polishing from tooth to composite resin. Clinical Significance The results obtained from this in vitro study suggest that polishing direction influences the marginal adaptation of composite resins and that polishing from composite resin to tooth structure should be clinically performed whenever possible on accessible margins to preserve marginal integrity and esthetics.