OBJECTIVE: To determine the presence and extent of adaptation defects during class II composite resin placement employing three restorative techniques and a number of experienced clinicians. METHODS: Class II preparations were simulated in 3 part test dies (TD). Nine clinicians restored the TD employing three restorative procedures: application of composite resin only (C), adhesive system followed by composite (AC) and flowable resin followed by composite (FC). After the restorative procedures, each TD was opened and adaptation analyzed. The proximal wall (PW) and pulpal floor (PF) were evaluated using stereomicroscope at a magnification of 32x. The relative areas of gaps at proximal margins as well as lacking adaptation to the pulpal floor were measured employing image analysis software (Image Pro-Plus®). The areas were measured in µm² but converted to percentage of total area. Statistics analysis involved ANOVA and Tukey (p<0.05). RESULTS: Every die evaluated exhibited incomplete adaptation. The tables 1 and 2 show the mean (M-%), standard deviation (SD) and number of samples (N).

Table 1: Total surfaces evaluated for all techniques.

Evaluated surfaces	M(%) ± SD (N)	a=0.5
PW	4.46 ± 4.41 (27)	I
PF	5.05 ± 3.30 (27)	I

Table 2: Restorative techniques.

Groups	M(%) ± SD (N)	a=0.5
C	3.94 ± 1.78 (9)	a
AC	4.85 ± 4.65 (9)	a
FC	6.21 ± 4.51 (9)	a

CONCLUSION: Composite resin placement in these test dies indicated that regardless of the restorative technique, clinically significant margin gaps and inadequate pulpal wall adaptation were present. Clinicians must be advised to re-evaluate the composite resin placement techniques. (Supported by CAPES BEX:0088/04-8, CNPq: 201471/03-05 and Department of Biomaterials and Biomimetics - NYUCD)