["Cochrane Oral Health Group's Trials Register, CENTRAL, Medline via PubMed and EMBASE; no restrictions on language, published before February 1st 2013.", 'Observational studies reporting outcomes from irradiated and non-irradiated patients were eligible for inclusion as were randomised controlled trials (RCTs) and controlled clinical trials (CCTs) assessing irradiated patients submitted to different implant-based treatment protocols.', "Screening of titles, abstracts and full texts was by two reviewers, with disagreements resolved through discussion, consensus, or failing this by consultation with a third reviewer. Data extraction was in duplicate and attempts were made to contact authors for missing data. Risk of bias was assessed using adapted versions of the Cochrane Collaboration's tool (for RCTs and CCTs) and the Newcastle-Ottawa scale for observational studies.", 'Fifteen trials with 10,150 implants were included with 1,689 (14.3%) placed in irradiated mouths. There were 13 case series and two RCTs. three of the studies were on hyperbaric oxygen (HBO) therapy. Neither of the RCTs was rated as low risk of bias. Mean survival rates ranged from 46.3% to 98% with pooled estimates showing that implant failure was statistically significantly higher in irradiated patients compared to patients who had not undergone radiotherapy (an increase of 174%) with a risk ratio of 2.74 (95% confidence interval {CI}: 1.86, 4.05; p<0.00001). In maxillary sites, the risk ratio was 5.96 (95% CI:2.71, 13.12;p<0.00001) with the risk of loss increasing to 496%. Hyperbaric oxygen therapy did not reduce the risk of implant failure showing a risk ratio of 1.28 (95% CI:0.19, 8.82).'] Do radiotherapy associated with higher rates of dental implant loss?