Human histologic evaluation of a six-year-old threaded implant retrieved from a subject with osteoporosis.

AIM: The aim of this case report was to present the evaluation of the bone-to-implant contact in an implant retrieved from a subject with osteoporosis after six years of load. BACKGROUND: Systemic conditions associated with osteoporosis have been postulated to contribute to the severity of alveolar bone loss. The increase in human life expectancy, the increased number of elderly subjects who are partially or totally edentulous, and the use of dental implants for oral habilitation in subjects with osteoporosis has raised several questions. REPORT: A 68-year-old woman with postmenopausal osteoporosis received a prosthetic evaluation of an implant-supported restoration. Histologically, the peri-implant bone appeared healthy. The peri-implant bone appeared in close contact with the implant surface, whereas marrow spaces could be detected in other areas along with prominently stained cement lines. The mean of bone-to-implant contact was 62.51+1.96. CONCLUSION: The results of the evaluation of the dental implant reported here suggest the presence of osteoporosis may not be a contra-indication for implant placement at least after osseointegration has already been established.

Ki-67 expression in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising from dental cysts.

This study investigated whether or not an ameloblastoma developing in the wall of a dentigerous cyst is a distinct lesion from the unicystic ameloblastoma. An immunohistochemical evaluation of Ki-67 in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising in dentigerous cysts was done. The values of Ki-67 positivity were 3.14 for the dentigerous cyst, between 5.32 and 16.56 for unicystic ameloblastoma, and 11.77 for ameloblastoma arising in a dentigerous cyst. Statistically significant differences were found between the dentigerous cyst and the unicystic ameloblastoma and between the dentigerous cyst and the ameloblastoma arising from a dentigerous cyst. No statistically significant difference was present between unicystic ameloblastoma and ameloblastoma arising from dentigerous cyst. These immunohistochemical data confirm the hypothesis that an ameloblastoma arising from a dentigerous cyst has a similar biological behavior to the unicystic ameloblastoma and should be considered as merely a histologic variant.

Histologic evaluation of 2 human immediately loaded and 1 titanium implants inserted in the posterior mandible and submerged retrieved after 6 months.

Immediate loading can be successfully used in implant dentistry. Many factors are thought to be of importance in obtaining mineralized tissues at the interface. One such factor is the implant surface characteristics. The authors retrieved, after a 6-month loading period, 2 immediately loaded implants and 1 submerged implant, each of which had been inserted in posterior mandibles. Histology showed that, in both immediately loaded implants, mineralized tissue was present at the interface, and the bone-implant contact percentage was about 65% to 70%. No gaps, fibrous tissue, or inflammatory infiltrates were present at the interfaces. In the submerged (control) implant, the bone-implant contact percentage was much lower (about 35%). Our results showed that immediate loading of dental implants, even in the posterior regions of the jaw bones, hadn't caused untoward effects on the formation of mineralized tissues at the interface, producing, on the contrary, a higher bone-implant contact percentage than in the control implant, and thus, immediate loading can be a possible alternative procedure in implant dentistry.

Single-tooth Morse taper connection implants after 1 year of functional loading: a multicentre study on 302 patients.

PURPOSE: This prospective clinical study evaluated the survival rate and the implant-crown success of 314 Morse taper connection implants, used for single-tooth replacement, after 1 year of functional loading. MATERIALS AND METHODS: Over a 4-year period (January 2003 to January 2007), 314 implants (168 maxilla, 146 mandible) were inserted in 302 patients (128 males, 174 females, aged between 23 to 79 years) in six different clinical centres. The sites included anterior (n = 118) and posterior (n = 196) teeth. To evaluate implant-crown success, the following clinical, prosthetic and radiographic parameters were assessed: modified plaque index (mPI), modified sulcus bleeding index (mBI), probing depth (PD), distance from the implant crown margin to the coronal border of the peri-implant mucosa (DIM), width of keratinised mucosa (KM), prosthesis function, and the distance between the implant shoulder and first crestal bone-implant contact (DIB). Success criteria included: absence of suppuration and mobility, PD<5.0 mm, absence of prosthetic complications, absence of continuous peri-implant radiolucency, and DIB<1.5mm after 1-year of functional loading. Prosthetic restorations were all-ceramic (n=116) and metal-ceramic (n=198) crowns. RESULTS: The implant survival rate was 98.4% (5 implant losses, 1 drop-out). A few prosthetic complications (0.6% implant-abutment loosening) were reported. The mean DIB was 0.887 + or - 0.308mm. Among the survived implants (308), four did not fulfill the success criteria, giving an implant-crown success of 98.7%. CONCLUSION: The use of Morse taper connection implants represents a successful procedure for single-tooth replacement, in the anterior and posterior areas of both arches. The high mechanical stability amy reduce prosthetic complications.