Investigation of Influencing Factors Concerning the Long-Term Result of Root Amputation. A Retrospective Analysis of 261 Root Amputations.

Introduction: Root amputation (RA) is a well established method for tooth preservation. Aim of this retrospective study was the identification und investigation of parameters which are influencing the long-term result after root amputation. Methods: 216 patients (♂ 111, ♀ 106) on which in total 261 root amputations were performed could be included. Inclusion criteria were: (1) postoperative success of RA minimum 12 months, (2) availability of postoperative x-ray, (3) availability of minimum 1 radiological control. In addition to the long-term result, tooth type, age, use of synthetic bone replacement material, parodontal status and gender was investigated concerning the long-term prognosis after RA. Results: The results show 5 year success-rate (5-y-SR) of 78.2% and a 10 year success rate (10-y-SR) of 63.1%. The comparison of the tooth types (molars, premolars, frontal teeth) showed for the upper frontal teeth a 5-y-SR of 81.5% and a 10-y-SR of 62.7%. The upper premolars had a 5-y-SR of 68.8% and a 10-y-SR of 55.0%. The upper molars had a 5-y-SR of 88.1% and a 10-y-SR of 77.2%. The 5-y-SR of the lower frontal teeth was 83.1%, the 10-y-SR 71.2%. The lower premolars showed a 5-y-SR and a 10-y-SR of 72.6%. The lower molars had a 5-y-SR of78.8% and a 10-y-SR of 59.6%. There was no statistical difference in-between all these tooth types. The evaluation of the 5-y-SR and 10-y-SR of the age-groups (20 years, 20-40 years, 40-60 years, ≥60 years) showed, that the teeth of the patients between 20 up to 40 years had the best prognosis after RA (5-y-SR = 86.3% and 10-y-SR = 71.8%). In contrast the age-group of ≥60 years had the lowest success rate with a 5-y-SR of 63.7% and a 10-y-SR of 48.5%. There was a statistical significant difference between the age-group 20-40 years and the age-group 40-60 years (p ≤ 0.019). In-between the age-groups 20-40 years and the age-group ≥60 years the deviation was highly significant (p ≤ 0.001). Between the age-group 40-60 and ≥60 years was no statistical difference. No benefit for the use of synthetic bone replacement material could be seen in comparison to a normal blood clot in the bony amputation defect. Concerning the parodontal status no statistical difference could be evaluated. However, there was a clear tendency that teeth with a healthy parodontal status have a better prognosis after RA. There was no dependency concerning the gender and the success rates after RA. Discussion: The results of this study show, that RA can be performed with long-term success on all tooth types. However, with increasing age the prognosis is decreasing significantly. Dental implantology is a safe alternative therapy option nowadays. With success-rates above 90%, even in elder patients, implantology guaranties a longer success in log-term. Conclusion: RA is still a treatment option for long-term tooth preservation. In younger patients with a clear indication RA should be considered as treatment of choice. Tooth extraction and dental implantation should be recommended in the case doubtful indication, particularly in elder patients and after a primary unsuccessful root amputation. Keywords: root amputaion, oral surgery, dental implantation, endodontics