Survival and complications: A 9- to 15-year retrospective follow-up of dental implant therapy

Long-term follow-up of oral implant therapy seldom report all biological and technical complications. The objective of this study was to evaluate the long-term (9-15 years) outcome after dental implant therapy, assess survival and complication rates. In addition, to identify the risk indicators of these complications at patient and implant levels. Patients (n = 376) treated with dental implants (n = 1095) between 1999 and 2005 at a specialist clinic in Stockholm, Sweden, were included. Longitudinal data were collected retrospectively from digital dental records. A subset of the included patient underwent a clinical examination at the 9-15 years follow-up (n = 163). Chi-square tests, Kaplan-Meier analyses and the general estimating equations (GEE) procedure were adopted for multilevel analyses. The cumulative implant survival rate up to 15 years was 82.6% (SE 4.1%). The prevalences of biological and technical complications at patient level were 52% and 32%, respectively. In total, 763 complications occurred, 65% of patients experienced at least one complications. Implant loss occurred significantly more frequently in subjects with a history of treated severe periodontitis Stage III-IV (P = .008) and in cases when complications were registered during implant surgery (P = .010). Smoking was a significant risk indicator for peri-implantitis (P = .006). The long-term implant survival and complication rates at patient level were 83% and 79%, respectively. Implant loss was significantly more frequent for subjects with a history of treated severe periodontitis and if complication was registered during implant surgery. Smoking was a significant risk indicator for peri-implantitis.     

How to evaluate PCR assays for the detection of low‐level DNA

High sensitivity of PCR‐based detection of very low copy number DNA targets is crucial. Much focus has been on design of PCR primers and optimization of the amplification conditions. Very important are also the criteria used for determining the outcome of a PCR assay, e.g. how many replicates are needed and how many of these should be positive or what amount of template should be used? We developed a mathematical model to obtain a simple tool for quick PCR assay evaluation before laboratory optimization and validation procedures . The model was based on the Poisson distribution and the Binomial distribution describing parameters for singleplex real‐time PCR‐based detection of low‐level DNA. The model was tested against experimental data of diluted cell‐free foetal DNA. Also, the model was compared with a simplified formula to enable easy predictions. The model predicted outcomes that were not significantly different from experimental data generated by testing of cell‐free foetal DNA. Also, the simplified formula was applicable for fast and accurate assay evaluation. In conclusion, the model can be applied for evaluation of sensitivity of real‐time PCR‐based detection of low‐level DNA, and may also assist in design of new assays before standard laboratory optimization and validation is initiated.     

Effects of PREPARE,a Multi-component,School-Based HIV and Intimate Partner Violence (IPV) Prevention Programme on Adolescent Sexual Risk Behaviour and IPV: Cluster Randomised Controlled Trial

Young South Africans, especially women, are at high risk of HIV. We evaluated the effects of PREPARE, a multi-component, school-based HIV prevention intervention to delay sexual debut, increase condom use and decrease intimate partner violence (IPV) among young adolescents. We conducted a cluster RCT among Grade eights in 42 high schools. The intervention comprised education sessions, a school health service and a school sexual violence prevention programme. Participants completed questionnaires at baseline, 6 and 12 months. Regression was undertaken to provide ORs or coefficients adjusted for clustering. Of 6244 sampled adolescents, 55.3 % participated. At 12 months there were no differences between intervention and control arms in sexual risk behaviours. Participants in the intervention arm were less likely to report IPV victimisation (35.1 vs. 40.9 %; OR 0.77, 95 % CI 0.61–0.99; t(40) = 2.14) suggesting the intervention shaped intimate partnerships into safer ones, potentially lowering the risk for HIV.