Marginal and internal adaptation of composite restorations using a resin liner on deproteinized substrate.
OBJECTIVE
The purpose of this study was to evaluate the use of resin liner on deproteinized substrate on marginal and internal adaptation of composite restorations.


METHODS
Twenty-four recently extracted 3rd molars were selected. The crowns were sectioned in a mesio-distal direction, and the specimens were ground to expose a flat enamel area of at least 6 mm in diameter. Cavities were prepared on the central area of flattened surfaces. The specimens were randomly assigned into four groups (n = 12): SB - 1. Acid etch, 2. Single bond application (SB); NaOCl/SB - 1. acid etch, 2. 10% sodium hypochlorite solution application for 60 s (NaOCl), 3. SB; SB/PL - 1. acid etch, 2. SB, 3. protect liner F (PL); NaOCl/SB/PL - 1. acid etch, 2. NaOCl, 3. SB, 4. PL. All cavities were restored with Filtek Z250 and polished. The outer and internal margins were stained using Caries Detector (Kuraray), observed under the stereomicroscope, and transferred to a computer measurement program. The length of the gap was expressed as a percentage of the total length of the margins observed. Data (internal adaptation) were submitted to ANOVA and Tukey's test.


RESULTS
There were no gaps at enamel outer margins in any specimen of any group. There was no statistically significant difference in internal adaptation between SB (18%) and NaOCl/SB (18%). NaOCl/SB/PL showed the worst internal adaptation (21%), with the higher percentage of internal gaps, statistically differing from SB/PL, which showed the best internal adaptation (12%).


CONCLUSIONS
Resin liner can effectively enhance internal adaptation on demineralized dentin. However, on demineralized and deproteinized dentin it affects the internal adaptation of composite restorations negatively.
Correr
Gisele Maria
GM
Department of Restorative Dentistry, Dental Materials Area, Piracicaba Dental School-UNICAMP, Piracicaba, São Paulo, Brazil. giselefop@yahoo.com
Bruschi Alonso
Roberta Caroline
RC
Puppin-Rontani
Regina Maria
RM
Correr-Sobrinho
Lourenço
L
Coelho Sinhoreti
Mario Alexandre
MA
D000134:Acid Etching, Dental / Q000379:methods*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry*; D003736:Dental Cavity Lining / Q000379:methods*; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods*; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D016877:Oxidants / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012973:Sodium Hypochlorite / Q000737:chemistry; D013499:Surface Properties
D004396:Coloring Agents; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C444701:Filtek Z250; D016877:Oxidants; C409388:Protect Liner F; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate; D012973:Sodium Hypochlorite