Restoring cervical lesions with flexible composites.
OBJECTIVE
Flexure at the tooth cervix has been suggested to dislodge cervical restorations more rapidly. The objective of this randomized controlled clinical trial was to test the hypothesis that a higher composite flexibility better withstands tooth flexure stress.


METHODS
One hundred and forty-two non-carious cervical lesions were restored with composites with contrasting stiffness. Seventy-one patients randomly received two cervical restorations placed following two out of the three experimental groups: (1) the three-step etch-and-rinse adhesive Permaquick applied with the stiff micro-hybrid composite Amelogen Hybrid (PMQ/A-Hy, Ultradent), (2) Permaquick applied with the more flexible micro-filled composite Amelogen Microfill (PMQ/A-Mi, Ultradent), or (3) the 'golden standard' three-step etch-and-rinse adhesive Optibond FL applied with the micro-hybrid composite Prodigy (O-FL/Pro, Kerr).


RESULTS
The recall rate at 7 years was 80%. No statistically significant difference was found for any of the parameters evaluated neither between both adhesives, nor between both composites (McNemar, p>0.05). Eleven percent of the O-FL/Pro restorations were clinically unacceptable due to loss of retention (5.5%) and severe marginal discoloration (5.5%). In the PMQ-group, 22% of the PMQ/A-Mi restorations (8% loss of retention, 5% severe enamel margin defects, 3% severe dentin margin defects, 6% severe marginal discoloration, 3% extreme sensitivity) and 19% of the PMQ/A-Hy restorations (13% loss of retention, 3% severe enamel margin defects, 3% severe marginal discoloration) needed repair or replacement.


CONCLUSIONS
The clinical performance of the three adhesive/composite combinations was good and reliable during the 7-year clinical trial. It was concluded that the composite stiffness does not affect the clinical longevity of cervical composite restorations.
Peumans
M
M
Department of Conservative Dentistry, School of Dentistry, Oral Pathology and Maxillo-facial Surgery, Catholic University of Leuven, Kapucijnenvoer 7, B-3000 Leuven, Belgium. marleen.peumans@med.kuleuven.ac.be
De Munck
J
J
Van Landuyt
K L
KL
Kanumilli
P
P
Yoshida
Y
Y
Inoue
S
S
Lambrechts
P
P
Van Meerbeek
B
B
D003188:Composite Resins / Q000737:chemistry; D003763:Dental Leakage; D018772:Dental Marginal Adaptation; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D003807:Dentin Sensitivity; D004548:Elasticity; D006801:Humans; D010316:Particle Size; D018583:Pliability; D011446:Prospective Studies; D019279:Resin Cements; D016037:Single-Blind Method; D018709:Statistics, Nonparametric; D019237:Tooth Cervix
D003188:Composite Resins; D019279:Resin Cements; C106662:amelogen