Microfractures in metal-ceramic and all-ceramic implant-supported fixed dental prostheses caused by superstructure fixation

Abstract

The effect of ceramic veneering on the passivity of fit of cast metal and CAD/CAM-fabricated zirconia ceramic implant-supported three-unit cement-retained restorations was investigated, as well as the effect of misfit stress on the marginal integrity of ceramic veneers. Superstructures were fabricated using cast metal or by CAD/CAM milling of presintered or HIP zirconia ceramic (n=10). Before and after veneering, strain gages were used to measure in vitro the strain developed in all the restorations as a result of superstructure fixation. Fluorescent penetrant method was used to detect microcracks developed in ceramic veneers. Cast frameworks showed significantly higher strain values than CAD/CAM frameworks (p=0.000). Veneering significantly increased strain development in all CAD/CAM frameworks (p=0.000). Compared to zirconia ceramic restorations, significantly more microcracks were observed in cast restorations (p=0.000) both before and after superstructure fixation.

Comparison of marginal and internal fit of press-on-metal and conventional ceramic systems for three- and four-unit implant-supported partial fixed dental prostheses: An in vitro study

“…3,6,[10][11][12][13][14] Clinically acceptable misfit levels have been defined for fixed dental prostheses at between 50 and 120 mm. 3,[15][16][17] For computer-based restorations, a marginal gap of under 200 mm has been stated to be clinically acceptable.…”

Influence of Cobalt Chromium Framework Fabrication Techniques on Marginal Accuracy and Fracture Behavior of Implant-Supported Metal Ceramic Bridges

“…The porcelain veneering process itself might have resulted in microcrack formation at the cervical margins of the bridge retainers as mentioned earlier in the literature by many authors who also stated that cementation of implant supported restorations led to a general increase in the number of detectable microcracks. (33) The marginal gap values of samples fabricated by new CAD/CAM technology were clinically acceptable (34) , furthermore, their fracture resistance results were higher than the normal masticatory forces applied on the premolar and molar teeth. (35)(36)(37) Consequently, the new Co -Cr fabrication technique (CAD/CAM soft milling /post sintering) is considered successful in terms of marginal accuracy and fracture resistance.…”

Terminology focused on design and retention methods used for anterior resin-bonded fixed partial dentures in English literature: A scoping review

“…Group 3 gathered terms for the one-retainer design of RBFPD as presented in Table 7 [ [43] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] , [56] , [57] , [58] , [59] , [60] , [61] , [62] , [63] , [64] , [65] , [66] , [67] , [68] , [69] , [70] , [71] , [72] , [73] , [74] , [75] , [76] , [77] , [78] , [79] , [80] , [81] , [82] , [83] , [84] , [85] , [86] , [87] , [88] , [89] , [90] , [91] , [92] , [93] , [94] , [95] , [96] , [97] , [98] , [99] , [100] , [101] , [102] , [103] , [104] , [105] , [106] , [107] , [108] ,…”