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Long‐term retention of lithium disilicate crowns with a current bioactive cement
Author(s) -
Streiff Kerry R.,
Lepe Xavier,
Johnson Glen H.
Publication year - 2021
Publication title -
journal of esthetic and restorative dentistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.919
H-Index - 60
eISSN - 1708-8240
pISSN - 1496-4155
DOI - 10.1111/jerd.12718
Subject(s) - materials science , crown (dentistry) , molar , cementation (geology) , cement , lithium disilicate , dentistry , composite material , medicine , ceramic
Objective To determine if a recent bioactive cement provides acceptable lithium disilicate crown retention after long‐term aging with monthly thermocycling. Materials and Methods Extracted molars prepared with flat occlusal, 20° taper, ~4 mm axial. Prepared teeth assigned to two groups for equal mean surface areas per group. Lithium disilicate crowns fabricated with occlusal bar to facilitate removal. Crowns etched with 9.5%HF and cleaned. Cements were Ceramir Crown & Bridge QuikCap (CM) and Ketac Cem Maxicap (KC). Before cementation, specimens stored in 37°C water. Crowns cemented with 196 N force, placed in 37 ° C, 100% humidity oven for setting. Specimens thermocycled (5–55°C) 5000 cycles monthly for 6 months; otherwise stored in phosphate buffered saline solution. Crowns removed axially at 0.5 mm/min. Removal forces recorded and stresses calculated using areas. Independent t‐ test ( α = 0.05). Results Levene test not significant ( P = 0.649). CM removal stresses and forces ( P < 0.001) were higher (1.93 MPa, 261.4 N) compared to KC (1.06 MPa, 139.4 N). CM cement found principally on crown intaglio, KC found with most cement on prepared tooth. Chi‐square significant ( P < 0.001). Conclusions Following long‐term aging with monthly thermocycling, lithium disilicate crowns were best retained by CM cement, however both cements are capable of retaining lithium disilicate crowns with preparations of ideal taper and length. Clinical Significance Results serve as a basis for bioactive cement selection for retaining lithium disilicate crowns. Without optimal axial length, taper of preparation or retentive features, Ceramir Crown and Bridge QuikCap offers a bioactive cement with improved long‐term retention when compared to Ketac Cem Maxicap for lithium disilicate crowns.