LIGHT AND SCANNING ELECTRON-MICROSCOPIC REPORT OF 4 FRACTURED IMPLANTS

Although they are fortunately rare, implant fractures can cause signif icant problems for both clinicians and patients. The authors present a light and scanning electron microscopic study of four fractured impla nts in two patients. Both patients had parafunctional habits (bruxism) , hypertrophic masticatory muscles, and wear of occlusal surfaces. The scanning electron microscopic study of the fractured surfaces of all four implants showed the presence of fatigue striations. Bending overl oad was probably created by a combination of parafunctional forces, bo ne resorption, posterior location of the implants, and implant diamete r.