Adhesive bond strength of provisional screw‐retained CAD‐CAM crowns to titanium bases: An in vitro evaluation

Purpose To assess the adhesive bond strength of two provisional screw‐retained computer‐aided design and computer‐aided manufacturing (CAD‐CAM) crowns bonded to titanium bases (TiB) following artificial aging, tensile testing, and failure mode analysis. Materials and Methods Ninety CAD‐CAM hybrid abutment crowns (HAC) were evaluated: poly(methyl)‐methacrylate ([PMMA], n = 40), polymer‐infiltrated ceramic network ([PICN], n = 40), and lithium disilicate ceramic ([LS 2 ], n = 10, control). HACs were cemented to TiB (internal hex, 4.3 mm diameter, 4 mm height, n = 90) using two permanent resin‐based cements. Artificial aging was performed via thermocycling (5000 cycles, 5°C–55°C). Tensile bond strength (TBS) was assessed, and failure mode distribution was analyzed using loupes magnification and scanning electron microscopy. Non‐parametric tests were used due to non‐normal data. Mann–Whitney and Kruskal–Wallis tests compared cement and crown type impact on TBS. Chi‐square tests analyzed differences in failure mode and dominant cement location. Results All specimens withstood artificial aging. One LS 2 sample was excluded after exceeding the testing limit (>1118 N). PICN demonstrated the highest median TBS (749.8 N), significantly outperforming PMMA ( p < 0.001) and LS 2 ( p = 0.029, unadjusted pairwise Mann–Whitney U ). Cement type was not a statistically significant factor within material groups. Mixed failure modes (79.8%) were predominant, and adhesive failures accounted for 20.2%. Cement remnants were primarily localized on the TiB surface (49.4%). Conclusion PICN exhibited superior bonding performance, indicating its suitability for immediate loading in implant‐supported restorations. In contrast, PMMA may require modified cementation protocols to achieve optimal retention. These findings provide critical insights for material selection in prosthetic rehabilitation.