Meta-analysis Of Dental Implants Survival Factors After Jaw Radiotherapy

Objective: Using Meta-analysis method to investigate and evaluate the correlationbetween the dental implant survival rate in irradiated jaw and the influence factorsincluding time interval after radiotherapy, jaw location, irradiation dosage andhyperbaric oxygen treatment, and to provide available evidence for clinical practice.Methods: A systematic search of Cochrane Library, MEDLINE, EMBASE, CNKI, VIP,CBM databases restricted to Chinese and English language from1980to June,2013,was performed to collect the literatures about success/failure rate of dental implantsplaced in irradiated jaw. The failure rate of dental implants was used as an index toanalysis the following factors including time interval after radiotherapy, jaw location,irradiation dosage and hyperbaric oxygen treatment according to the methodology forCochrane systematic review. Meta-analysis was processed using Review Manager5.2program, selecting fixed or random model based on the heterogeneity test. Sensitivityanalysis was taken to evaluate the stability and reliability of the results. Funnel plotswas done to access the publication bias.Results：12literatures were selected according to the including and excluding standers.The evidences levels of the including studies were Ib and IIb. Four literatures wereconsidered to have high risk of bias and eight were moderate. The factors which showstatistically significant differences are jaw location and irradiation dosage. Therespectively pooled estimates are as following:（ORlocation=12.69，95%CI：4.74-7.56， P<0.00001， I2=61%）（ORdosage=0.39、95%CI：0.25-0.62、 P<0.0001，I2=0%）. The results of this meta-analysis show no statistically significant differencebetween time intervals after radiotherapy/HBO and implant survival rate in irradiatedjaw. The pooled estimates are:（ORtime=1.27,95%CI:0.95-1.70，P=0.10，I2=22%）、（ORHBO=1.6295%CI：0.29-9.05,P=0.58，I2=89%）. By changing the effect models,sensitivity analysis of different factors shows that the "time interval" and "jaw location"have similar results with their original studies indicating these two results are stable andreliable, but the results of group“hyperbaric oxygen treatment” have totally differentresult showing the result is unstable. Conclusion:1、Implants placed in irradiated mandible and radiation dosage minor of50Gydoses show higher survival rates.2、There’s no statistically significant difference in placing implants in irradiatedjaw in6-12months than12months after radiotherapy.3、There’s not enough evidence to confirm that hyperbaric oxygen treatment canimprove the implant survival rate4、Since analysis are affected by the raw data, more high-quality large sampleRCTs should be designed for clinical.