Clinical performance of provisional screw-retained metal-free acrylic restorations in an immediate loading implant protocol: a 242 consecutive patients' report.
OBJECTIVE
To evaluate the clinical performance of provisional screw-retained metal-free acrylic restorations in an immediate loading implant protocol.


METHODS
Two hundred and forty-two consecutive patients were selected retrospectively, who received 1011 implants and 311 immediate provisional screw-retained implant restorations (2-4 h after implant surgery). The patients were monitored for a period of 2-3 months, until they were referred for a final restoration. The primary variables recorded include the survival time and the appearance of fractures in the provisional restoration, and the independent variables included age, sex, dental arch, type of restoration, type of attachment and components used, as well as cantilevers and opposing dentition. A survival analysis (Kaplan-Meier) and a Cox regression analysis were performed.


RESULTS
Twenty-three restorations in 20 patients (8.26%, 95% CI 4.8-11.7) showed at least one fracture (7.39%). More than half of the new fractures (52%, 12 cases) occurred in the first 4 weeks. The cumulative survival probability observed was greater in mandible (P=0.05) and non-cantilever restorations (P=0.001), and in those opposed by full restorations or natural teeth (P=0.001). With an opposing implant-supported prosthesis, the risk of fracture was multiplied by 4.7, and the use of cantilevers as well as the location of the restoration in the maxilla multiply the risk by 3.4-3.5.


CONCLUSIONS
Immediate provisional screw-retained metal-free implant-supported restorations can be considered a reliable restoration (92.6% remain intact) for the healing period of 3 months.
Suarez-Feito
Jose-María
JM
Section of Periodontology, Faculty of Dentistry and Medicine, University of Oviedo, Oviedo, Spain.
Sicilia
Alberto
A
Angulo
Jorge
J
Banerji
Subir
S
Cuesta
Isabel
I
Millar
Brian
B
D000180:Acrylic Resins; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001863:Bone Screws; D015921:Dental Implants; D017268:Dental Prosthesis Retention / Q000295:instrumentation*; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003794:Dental Restoration, Temporary; D003799:Dental Stress Analysis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D003765:Models, Dental; D016016:Proportional Hazards Models; D016896:Treatment Outcome
D000180:Acrylic Resins; D015921:Dental Implants