RESUMEN
The resistance to abrasion of presently available composite restorative materials is unsatisfactory; the utilization of such materials in conventionally prepared occlusal and occluso-proximal stress-bearing restorations has been therefore contraindicated. In a private practice study carried-out between 1972-77, porous triangular-shaped ceramic inserts were polymerized into the centric-stop areas of 528 Class-II composite restorations. Clinical and electron microscopic evaluation have shown a greatly increased resistance to abrasion in the ceramic insert areas as well as no significant attrition of the antagonist cusp. 95% of the restoration were judged functionally and esthetically very satisfactory. Only 1,1% of the inserts demonstrated fracture and partial loss of ceramic material during the test period. The five-year study has shown the procedure to be relatively simple to learn and suitable for private practice application.