Objectives: To evaluate an innovative rapid laboratory technique for fabricating provisional single crowns for immediately restored implants in the anterior maxilla. Methods: Twenty-eight participants for single implant crowns were randomly allocated to a conventional two-stage loading control group and an immediate restoration test group. Tapered, roughened-surface implants were placed and implant-level impressions taken at surgery for all participants. Fourteen provisional crowns for the control group were placed at second stage surgery after a 26-week healing period, and another 14 for the test group within four hours of implant placement. All were made using an innovative rapid laboratory technique. Denture tooth facings were secured in position onto temporary titanium abutments with light-cured composite and silane bonding. The provisional crowns were worn by the participants (out of occlusion) for 8 weeks, prior to definitive ceramo-metal crown placement. Simultaneous in-vitro tests were done on composite /polymethylmethacrylate samples using shear bond strength tests and four-point bend tests to evaluate ultimate bond strengths and crack propagation were also conducted to compliment the clinical results.
Results: There were no clinical fractures or complications of the 28 provisional crowns placed using the innovative method, in either the control group or test group. The in vivo tests revealed that the nature of the crack propagation at the denture tooth facing /composite interface supported the clinical application of the provisional crowns.
Conclusion:. Single provisional implant crowns can be provided successfully within four hours with this innovative technique, without the chance of clinical fracture for a period of eight weeks, prior to permanent crowns. Supported by Southern Implants, South Africa.