OBJECTIVES: The objective of the study was to test the effect of different pretreatments on tensile bond strength (TBS) of adhesively bonded CAD/CAM-generated polymethyl methacrylate (PMMA) crowns to dentin. MATERIALS AND METHODS: Two hundred human molars were prepared and divided into 20 groups (n = 10/group). PMMA crowns were pretreated thusly: Monobond Plus/Heliobond (MH), Visio.link (VL), Ambarino P60 (AM), VP connect (VP), and nontreated as control groups (CG). Two resin cements were used for cementation of crowns: Clearfil SA Cement (CSA) and Variolink II (VAR). TBS was measured initially (24 h water storage, 37 °C) and after aging (5,000 thermal cycles, 5/55 °C). TBS was analyzed using one-way ANOVA with Scheffé post hoc, unpaired Student t, Mann-Whitney U, Kruskal-Wallis H, and chi-squared tests. RESULTS: Within CSA, pretreatment with MH and VL showed higher initial TBS compared with AM-treated groups. All other groups showed no statistical differences. For MH, VL, AM, and VP in combination with CSA, a negative impact of aging was observed (p < 0.001), whereas in all VAR groups, no impact was measured. Pretreatment with MH (p = 0.001) and VP (p = 0.008) presented higher initial TBS for CSA than for VAR. After aging, MH (p = 0.025) and VL (p = 0.034) cemented with VAR showed higher results than CSA. CONCLUSIONS: All tested groups showed very low TBS values. Pretreatments with MH, VL, and VP have minimally improved the tensile strength after aging. CLINICAL RELEVANCE: Although the tensile strength results were low, crowns adhesively cemented with pretreatments with MH, VL, and VP showed, after aging, a higher tensile strength than nontreated groups.
OBJECTIVES: The objective of the study was to test the effect of different pretreatments on tensile bond strength (TBS) of adhesively bonded CAD/CAM-generated polymethyl methacrylate (PMMA) crowns to dentin. MATERIALS AND METHODS: Two hundred human molars were prepared and divided into 20 groups (n = 10/group). PMMA crowns were pretreated thusly: Monobond Plus/Heliobond (MH), Visio.link (VL), Ambarino P60 (AM), VP connect (VP), and nontreated as control groups (CG). Two resin cements were used for cementation of crowns: Clearfil SA Cement (CSA) and Variolink II (VAR). TBS was measured initially (24 h water storage, 37 °C) and after aging (5,000 thermal cycles, 5/55 °C). TBS was analyzed using one-way ANOVA with Scheffé post hoc, unpaired Student t, Mann-Whitney U, Kruskal-Wallis H, and chi-squared tests. RESULTS: Within CSA, pretreatment with MH and VL showed higher initial TBS compared with AM-treated groups. All other groups showed no statistical differences. For MH, VL, AM, and VP in combination with CSA, a negative impact of aging was observed (p < 0.001), whereas in all VAR groups, no impact was measured. Pretreatment with MH (p = 0.001) and VP (p = 0.008) presented higher initial TBS for CSA than for VAR. After aging, MH (p = 0.025) and VL (p = 0.034) cemented with VAR showed higher results than CSA. CONCLUSIONS: All tested groups showed very low TBS values. Pretreatments with MH, VL, and VP have minimally improved the tensile strength after aging. CLINICAL RELEVANCE: Although the tensile strength results were low, crowns adhesively cemented with pretreatments with MH, VL, and VP showed, after aging, a higher tensile strength than nontreated groups.
Authors: Bogna Stawarczyk; Beatrice Sener; Albert Trottmann; Malgorzata Roos; Mutlu Ozcan; Christoph H F Hämmerle Journal: Dent Mater J Date: 2012-05-14 Impact factor: 2.102