Expansion of the alveolar bone crest with ultrasonic surgery device: clinical study in mandible.

The purpose of this paper was to document the application to the split-crest mandibular procedure in two stage in order to avoid cortical resorption due to periosteal detachment in buccal cortical bone of the alveolar crest. Twenty-two healthy patients with non-contributory past medical history (14 women and 8 men, all non-smokers, mean age 59 years, range 54-65 years) were included in this study. After buccal mucoperiosteal flap was followed by a sagittal corticotomy in the coronal area of the alveolar crest and a second sagittal corticotomy, but in a lower (basal) position and two vertical corticotomies in the buccal wall, using a ultrasonic surgery device (Surgysonic, Esacrom, Imola Italy). Adequate crest expansion was achieved without compromising cortical vascularisation by utilising a combination of scalpel, thin chisels and threaded osteotomes (Bone System, Milano, Italy). Postoperative results were assessed by panoramic and periapical radiographs. Ossification of the osteotomy lines was evident and could be observed as sites with increasing radiopacity on panoramic and periapical radiographs 3 months after implants insertion. No dehiscence of the mucosa was observed. No patient suffered from hypoaesthesia. The mean horizontal bone increase in coronal area was 5±3 mm. Mandibular ridge expansion using a split-crest technique that included grafting the implant sites with a ultrasonic surgery device is a viable therapeutic alternative for implant placement in this patient population.

Analysis and structural examination of screw loosening in oral implants.

Biological and technical failures of implants have already been reported. Mechanical factors are certainly of importance in implant failures, even if their exact nature has not yet been established. The abutment screw fracture or loosening represents a rare, but quite unpleasant failure. The aim of the present research is an analysis and structural examination of screw thread or abutment. In this study broken screws were excluded. A total of 58 screw thread loosening were observed, 5 Branemark, (Nobel Biocare, Gothenburg, Sweden) 4 Implant Innovation (Riverside Drive Palm Beach Gardens, FL, USA) and 7 Restore (Lifecore Biomedical, Chaska, Minnesota, USA) and 42 T.B.R. implant (Benax, Ancona, Italy). The loosened abutment screws were retrieved and analyzed under SEM. Many alterations and deformations were present in concavities and convexities of screw threads.