a follow-up on bone graft stability and implant success

Background Until now, sinus floor elevation represents the gold standard procedure in the atrophic maxilla in order to facilitate dental implant insertion. Although the procedure remains highly predictive, the perforation of the Schneiderian membrane might compromise the stability of the augmented bone and implant success due to chronic sinus infection. The aim of this retrospective cohort study was to show that a membrane tear, if detected and surgically properly addressed, has no influence on the survival of dental implants and bone resorption in the augmented area. Methods Thirty-one patients with 39 perforations could be included in this evaluation, and a control group of 32 patients with 40 sinus lift procedures without complications were compared regarding the radiographically determined development of bone level, peri-implant infection, and implant loss. Results Implant survival was 98.9% in the perforation group over an observation period of 2.7 (± 2.03) years compared to 100% in the control group after 1.8 (± 1.57) years. The residual bone level was significantly lower in the perforation group (p = 0.05) but showed no difference direct postoperatively (p = 0.7851) or in the follow-up assessment (p = 0.2338). Bone resorption remained not different between both groups (p = 0.945). A two-stage procedure was more frequent in the perforation group (p = 0.0003) as well as peri-implantitis (p = 0.0004). Conclusions Within the limits of our study, the perforation of the Schneiderian membrane did not have a negative impact on long-term graft stability or the overall implant survival

Comparison of radiographic and clinical outcomes following immediate provisionalization of single-tooth dental implants placed in healed alveolar ridges and extraction sockets

Purpose The primary goal of this study was to compare implant survival 12 months after immediate loading of single implants placed in healed ridges versus extraction sockets Secondary outcomes were to compare marginal bone adaptation and soft tissue changes over time Materials and Methods A prospective multicenter clinical investigation was initiated to assess clinical performance of immediately loaded implants in the maxilla Implant survival was ascertained at the time of impression making (8 to 10 weeks) and after 1 year by clinical stability Radiographic marginal bone levels, soft tissue levels, and plaque and bleeding scores were compared with baseline values (implant placement and provisionalization) Results One hundred thirty nine patients received 157 implants in the maxilla Single implants with provisional crowns were placed in extraction sockets of 55 patients (58 implants) and in healed ridges of 60 patients (65 implants) In addition, 19 patients (23 implants) required bone grafting prior to implant placement, and 11 implants in 10 patients among all groups were not immediately loaded because of insufficient initial stability after surgery Three implants (5 2%) failed in extraction sites and one implant (1 5%) failed in a healed ridge The mean change in marginal bone level 1 year after implant placement was 1 30 mm (SD 2 52) (gain) in extraction sockets and -0 40 mm (SD 1 43) (loss) in healed ridges The mucosal zenith was stable or moved incisally following definitive crown placement in 83 7% of immediate implants and 87 0% of implants placed in healed ridges Plaque and inflammation scores were low and did not differ between groups Conclusions The responses of local bone and soft tissues at immediately loaded implants placed in extraction sockets or healed ridges were similar Furthermore, these 1 year results suggest that clinical management of esthetically critical soft tissue may be predictably achieved in both indications INT J ORAL MAXILLOFAC IMPLANTS 2010,25 1222-123

Influence of SORL1 gene variants: association with CSF amyloid-β products in probable Alzheimer\u27s disease

SORL1 gene variants were described as risk factors of Alzheimer\u27s disease (AD). We investigated the association of four SORL1 variants with CSF levels of Aβ42 and Aβ40 in 153 AD patients recruited from a multicenter study of the German Competence Net Dementias. Only one SORL1 SNP was associated with altered Aβ42 levels in the single marker analysis (SNP21: p = 0.011), the other SNPs did not show an association with Aβ42 or Aβ40 CSF levels. Haplotype analysis identified a three marker SORL1 haplotype consisting of SNP19 T-allele, SNP21 G-allele and SNP23 A-allele (T/G/A) which was associated with reduced Aβ42 CSF levels in AD patients (p = 0.003). Aβ40 levels were also lower in carriers of this haplotype; however, this did not reach statistical significance (p = 0.15). We found a SORL1 haplotype which was associated with CSF levels of amyloid-β cleavage products, measured as altered levels of Aβ42. Thus our data suggest that SORL1 gene variants might influence AD pathology