Bond strength of denture teeth determined by 3-point bending test

Objectives: Bond strength between different denture teeth and a heat-cured denture base resin was determined by three point bending test conform to DIN 13914.

Methods: 192 test specimens (5 mm x 5mm x 45 mm) of heat-cured denture base resin SR Ivocap Plus (Ivoclar-Vivadent) combined with 4 different acrylic denture teeth (Vitapan, VITA, G; Genios P, Dentsply, G; SR Orthotyp DCL and SR Orthotyp PE, Ivoclar-Vivadent, FL) were divided into six groups with different surface pre-treatments of teeth (A = teeth without pre-treatment, B = using Al₂O₃ 250 µm, C = using monomer, D = using Al₂O₃ 250 µm + monomer, Probase Cold, E = using Al₂O₃ 250 µm + Palabond, Kulzer, F = using Rocatec, 3M ESPE). After 14 days of storage in water (37°C), all specimens were loaded to fracture by a three point bending test according to DIN 13914 using a universal testing machine (Zwick 1446, v=2mm/min). Medians and 25%/75% percentiles were calculated. Statistics: Mann-Whitney-U-Test (a=0.05).

Results:

Bond strength [N] Median (25%/75%)	A	B	C	D	E	F
Vitapan	187 (153/220)	207 (199/212)	172 (172/181)	182 (170/200)	169 (155/183)	197 (194/208)
SR Orthotyp DCL	126 (118/158)	124 (111/173)	161 (130/174)	139 (121/162)	152 (115/181)	123 (105/149)
SR Orthotyp PE	223 (211/228)	239 (221/255)	250 (226/254)	252 (239/254)	254 (250/267)	217 (204/234)
Genios P	228 (182/237)	211 (201/226)	209 (192/222)	221 (207/226)	244 (238/251)	225 (185/231)

Conclusion: This three point bending test indicated no definite positive effect regarding pre-treatment on bond strength between denture teeth and denture base resin. Significant highest bond strength was found using SR Orthotyp PE and Genios P teeth.