Clinical Comparison of Bulk-fill Restorative and Nano-fill Resin Composite

The aim of this study is to evaluate the clinical performance of a nano-fill and a bulk fill resin composite in class II restorations.

In accordance with a split-mouth design, 50 patients will be received at least one pair of restorations, restored with a nanofill resin composite (Filtek Ultimate [FU]) and with a bulk fill resin composite (Tetric EvoCeram Bulk Fill [TB]). Each restorative resin will be used with its respective adhesive system according to the manufacturers' instructions. A total of 104 class II restorations will be placed by two operators. The restorations will be blindly evaluated by two examiners at baseline and at 1-, 2-, 3-, 4-, 5-, 6-, 7- and 8- year using modified US Public Health Service Ryge criteria. The comparison of the two restorative materials for each category will be performed with the chi-square test (a=0.05). The baseline scores will be compared with those at the recall visits using the Cochran Q-test.

Observers will evaluate the restorations will be performed using the modified United State Public Health Service criteria regarding marginal adaptation. Marginal adaptation will evaluated by 2 independent clinicians. Visual inspection with a mirror at 18 inches will be performed . A score means the higher score of clinical acceptability while C and D score means that the restoration has failed and needs to be replaced. Alpha 1: Harmonious outline Alpha 2: Marginal gap (max 100μ) with discoloration (removable) Bravo: Marginal gap (> 100μ) with discoloration (unremovable) Charlie: The restoration is fractured or missed.

Observers will evaluate the restorations will be performed using the modified United State Public Health Service criteria regarding marginal discoloration. Marginal discoloration will be evaluated by 2 independent clinicians. Visual inspection with a mirror at 18 inches will be performed . A score means the higher score of clinical acceptability while C score means that the restoration has failed and needs to be replaced. Alpha: No discoloration anywhere along the margin between the restoration and the adjacent tooth. Bravo: Slight discoloration along the margin between the restoration and the adjacent tooth. Charlie: The discoloration penetrated along the margin of the restorative material in a pulpal direction.

Observers will evaluate the restorations will be performed using the modified United State Public Health Service criteria regarding retention rate. Retention rate will be evaluated by 2 independent clinicians. Visual inspection with a mirror at 18 inches was performed . A score means the higher score of clinical acceptability while C and D score means that the restoration has failed and needs to be replaced. Alpha 1:Clinically excellent Alpha 2: Clinically good with slight deviations from ideal performance, correction possible without damage of tooth or restoration Bravo: Clinically sufficient with few defects, corrections or repair of the restoration possible Charlie: Restoration is partially missed Delta: Restoration is totally missed

Observers will evaluate the restorations will be performed using the modified United State Public Health Service criteria regarding anatomic form. Anatomic form will be evaluated by 2 independent clinicians. Visual inspection with a mirror at 18 inches was performed . A score means the higher score of clinical acceptability while C score means that the restoration has failed and needs to be replaced. Alpha 1: Continuous with existing anatomical form Alpha 2: Slightly discontinuous due to some chipping on the proximal ridge Bravo: Discontinuous with existing anatomical form due to material loss but proximal contact still present Charlie: Proximal contact is lost with ridge fracture.

Observers will evaluate the restorations will be performed using the modified United State Public Health Service criteria regarding color change. Color changes will be evaluated by 2 independent clinicians. Visual inspection with a mirror at 18 inches was performed . A score means the higher score of clinical acceptability while C score means that the restoration has failedand needs to be replaced. Alpha: The restoration matches the adjacent tooth structure in color and translucency. Bravo: Light mismatch in color, shade or translucency between the restoration and the adjacent tooth. Charlie: The mismatch in color and translucency is outside the acceptable range of tooth color and translucency.

Inclusion Criteria: a need for at least two but not more than four posterior tooth-colored restorations the presence of teeth to be restored in occlusion teeth that were symptomless and vital a normal periodontal status a good likelihood of recall availability. Exclusion Criteria: partly erupted teeth absence of adjacent and antagonist teeth poor periodontal status adverse medical history potential behavioral problems