Mechanical Preparation And Wax Elimination on Denture Tooth Bond Strength

OBJECTIVES: Denture tooth surface texture and wax elimination method may influence tooth-resin bond strength. This study evaluated mechanical preparation (MP) of ridge-lap area of denture teeth and wax elimination (WE) method on tooth-resin bond strength. 

METHODS: 300 cross-linked maxillary right central incisors (Bioblend 12E), free of carding wax, were divided into 15 groups (n=20).  Five MP's were included: 1) intact (INTACT); 2) ground-with-carbide-bur (GWCB); 3) air-abrasion (AA); 4) diatoric-chamber (DC); 5) vertical-groove (VG).  Each MP group underwent three WE methods: 1) no wax contact (NONE); 2) boiling water (BW); 3) boiling water and wax solvent (BW-WS).  All teeth were processed to Lucitone-199 heat-cured denture-base resin and bond strength was evaluated with a Zwick universal-testing machine.  Statistical analysis was performed using ANOVA and post-hoc Tukey test (p<0.05). 

RESULTS:  The data revealed significant interaction between type of MP and WE method on bond strength (p=0.0110).  For BW-WS, the GWCB teeth had significantly higher bond strength than teeth that were air-abraded or intact.  For intact tooth surfaces, the teeth with no wax contact had significantly higher bond strength than the other two WE methods.  No significant results were found under other conditions.  Mean bond strength (Newton) and standard deviation for each group are summarized in the table below.  

CONCLUSIONS:  Based on the results of this study, MP of the ridge-lap surface of denture teeth did not affect the bond strength regardless of the WE methods except for the GWCB teeth when combined with BW-WS.  WE with or without wax solvent did not affect the bond strength regardless of the type of MP.  Supported by 2002-2003 ACP/Proctor&Gamble Fellowship in Complete Denture Prosthodontics. Denture teeth supplied by Dentsply International, York, PA.