Preload is applied to screws manually or using a torque wrench in dental implant systems, and the preload applied must be appropriate for the purpose. The aim of this study was to assess screw loosening and bending/torsional moments applied by clinicians of various specialties following application of manual tightening torque to combinations of implants and abutments. Ten-millimeter implants of 3.7 and 4.1 mm diameters and standard or solid abutments were used. Each group contained five implant-abutment combinations. The control and experimental groups comprised 20 and 160 specimens, respectively. Implants in the experimental group were tightened by dentists of different specialties. Torsional and bending moments during tightening were measured using a strain gauge. Control group and implants with preload values close to the ideal preload were subjected to a dynamic loading test at 150 N, 15 Hz, and 85,000 cycles. The implants that deformed in this test were examined using an optical microscope to assess deformities. Manual tightening did not yield the manufacturer-recommended preload values. Dynamic loading testing suggested early screw loosening/fracture in samples with insufficient preload.

Florid cemento-osseous dysplasia (FCOD) is a benign jaw lesion originating from periodontal ligament tissues usually asymptomatic and diagnosed accidentally at routine dental radiographic examination. The purpose of this paper is to report three cases diagnosed as FCOD with their clinical, radiographic and histological findings. Radiologic and clinical symptoms of three cases diagnosed as FCOD are presented. Serum alkaline phosphatase test and biopsy taken from two of the patients are discussed to eliminate the Paget's disease. Three patients diagnosed as FCOD and called for routine follow-up. Because of no sign of infection or osteomyelitis, conservative treatment was applied. Radiographic examination is significant for the diagnosis of florid cemento-osseous dysplasia, especially in the asymptomatic cases. The roles of the dentist are to ensure the follow-up of the diagnosed patients and to take the necessary measures for preventing from the infections.

Kose TE, et al. J Adv Prosthodont. 2015 Oct;7(5):380-385. http://dx.doi.org/10.4047/jap.2015.7.5.380