Analysis of load transfer and stress distribution by splinted and unsplinted implant-supported fixed cemented restorations.
Controversy remains over the rehabilitation of implant-supported restorations regarding the need to splint adjacent implant-supported crowns. This study compared the effects of simulated occlusal loading of three implants restored with cemented crowns, splinted versus unsplinted. Three adjacent screw-shaped implants were passively inserted into three holes drilled in a photo-elastic model. Two combinations of cemented restorations were fabricated; three adjacent unsplinted and three adjacent splinted crowns. Strain gauges were connected to the implant necks and to the margins of the overlaying crowns. Fifteen axial static loads of 20-kg loadings were carried out right after each other via a custom-built loading apparatus. Strain gauges located on the implant neck supporting splinted restoration demonstrated significantly (P < 0.001) more strain (sum of strains = 3348.54 microstrain) compared with the single crowns (sum of strains = 988.57 microstrain). In contrast, significantly (P < 0.001) more strain was recorded on the strain gauges located on the restoration margins of the single crowns (sum of strains = 756.32 microstrain) when compared with splinted restorations (sum of strains = 186.12 microstrain). The concept of splinting adjacent implants to decrease loading of the supporting structures may require re-evaluation. The clinical relevance of these findings needs further investigation.
Nissan
J
J
Department of Oral Rehabilitation, The Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel. nissandr@post.tau.ac.il
Ghelfan
O
O
Gross
M
M
Chaushu
G
G
D001732:Bite Force; D002484:Cementation / Q000379:methods; D002858:Chromium Alloys / Q000737:chemistry; D003442:Crowns; D000044:Dental Abutments; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D055119:Elastic Modulus; D006801:Humans; D008422:Materials Testing; D008953:Models, Anatomic; D018583:Pliability; D011312:Pressure; D013314:Stress, Mechanical; D013499:Surface Properties
D002858:Chromium Alloys; D015921:Dental Implants