1. Smoking

Bain and Moy1 have shown a higher failure rate of implants in individuals that smoke.  This particular study reviewed the outcomes of 2,194 implants placed in 540 patients over a six year period.   The overall failure rate of 5.92% was consistent with other studies; however, when patients were subdivided into smokers and non-smokers, it was found that a significantly greater percentage of failures occurred in smokers (11.28%) than in non-smokers (4.76%).  Many recent studies confirmed the same findings.  Sanchez-Perez et al2 found that the dose of tobacco affects the risk of implant failure with the risk increasing from 10% to 30% from light smokers (less that 10 cigarettes per day) to heavy smokers (greater than 20 cigarettes per day).  Therefore, it is recommended that you stop smoking prior to implant placement to reduce the risk of implant failure.

1) Bain and Moy: The association between the failure of dental implants and cigarette smoking, International Journal of Oral and Maxillofacial Implants 1993; 8:609-615

2) Sanchez-Perez A, Moya-Villaescusa MJ, Caffesse RG.  Tobacco as a risk factor for survival of dental implants.  J Periodontol 2007; 78:351-359


2. Bisphosphonates

Bisphophonates are a class of medications given to those that suffer from osteoporosis as well as other disorders.  There is evidence that prolonged use of bisphosphonates, particularly if given intravenouly, is a contraindication to all elective oral surgical procedures including implant placement.  It may lead to a condition called osteonecrosis which is exposed painful necrotic bone in the jaw as it suppresses bone turn over.  Ideally, surgical treatment should be performed well before commencing the therapy.  

Scully C. et al:  Dental Endosseous Implants in patients on bisphosphonate therapy. Implant Dentistry 2006; 15 (3):212-218


3. Haemophilia and other blood disorders