Contraindications for dental implants
With advancements in dental implants design and surgical techniques, there are very few absolute contraindications for dental implants treatment.
The common belief that the lack of bone precludes dental implants placement is no longer true. With advancements in bone grafting materials and techniques, a lack of bone is no longer a contraindication. Neither is advanced age a contraindication . We have successfully placed dental implants in patients older than 80 years old and they have been very successful . Of course careful, meticulous surgical techniques are important and older patients require a slightly longer bone healing period.
The following are categories of patients who require special considerations prior to placement of teeth implants
Patients with uncontrolled diabetes have impaired wound healing and increased risks of wound infection . A patient is a diabetic if the blood sugar is more than 120mg/dl.
Dental implants can be placed in mildly diabetic patients (<150 mg/dl) and moderately diabetic patients (< 200mg/dl ) .For these groups of patients, there should be special emphasis on stress reduction protocol, diet control before and after aseptic surgical techniques and antibiotics cover. Sedation is preferred for advanced dental implant procedures carried out in diabetic patients. Insulin therapy should be adjusted to half dose on the morning of the surgery.
For patients with fasting blood sugar fluctuating widely and often exceeding 250mg/dl (uncontrolled diabetes ), all dental implant procedures should be aborted.
Smokers on the whole suffer a multitude of medical problems including higher rates of diabetes , osteoporosis and heart attacks. Therefore it is not surprising to find that smokers have higher rates of complications with dental implants.
The risks of failures in smokers is the highest in the first year ,with slight decreases in failure rates up to five years post implant installation.
Strietzel FP, Reichart PA, Kale A et al 2007.
Most studies have shown that the failure rate of implant s in smokers is twice that of non smokers.
Strietzel FP, Reichart PA, Kale A et al 2007
Hinode D, Tanabe S, Yokoyama M et al 2006
De Luca S, Habsha E, Zarb GA .2006
Woo VV, Chuang SK, Daher S et al 2004
McDermott NE, Chuang SK, Woo VV et al 2003
Wallace RH 2000
Nogeurol B, Munoz R, Mesa F et al 2006
Susarla SM,Chuang SK,Dodson TB et al 2008
Light and moderate smokers have similar risks of implant failures, with heavy smokers (> 20 cigarettes a day ) having the highest risk .
Sanchez-Perez A,Moya- Villaescusa MJ, Caffesse RG 2007.
Smokers also have a higher incidence of gum inflammation ( peri-implantitis ) and a higher rates of complications in bone grafting for dental implants.
Strietzel FP, Reichart PA, Kale A et al 2007
Patients who are smokers can have dental implant treatment but they have to be aware of the higher risks of dental implant failures. Smokers are advised to stop smoking during the healing period and where possible, prior to dental implant placement.
Ministry of Health Clinical Guidelines for Dental Implants 2012
With improvements in long term survival rates of patient s who have undergone head and neck radiotherapy for cancer treatment , their needs for dental implants to improve their quality of life , is increasingly an important consideration.
Because of the delicate health of these patients, dental implant treatment should be done by experienced dental specialists. It should not be done as part of routine general dental practices.
Esposito M, Grusovin MG, Patel S 2008.
The radiation dosage is an important consideration
Radiation doses between 48-65Gy produce very few failures in dental implants.
At doses above cumulative radiation effect of 120 Gy, high dental implant failure rates are encountered.
Granstrom G, Jacobsson M, Tjellstrom A 1992
Preferably, dental implants should be placed before radiotherapy for better healing .
Studies have shown that teeth implants placed before radiotherapy have a lower rate of failure.
Brogniez Vet al 2002
Oral bisphosphonates are commonly prescribed for treatment of osteoporosis.
Studies have shown that some patients on oral bisphosphonates develop osteonecrosis of the jaws ( delayed healing syndrome ) . This is usually related to some surgical trauma to the jaw bone. However, the incidence is low unlike that for intravenous bisphosphonates . While dental implants are not contraindicated for patients on oral bisphosphonates, the surgical procedure must be done carefully and skillfully.
Madrid C, Sanz M .2009
Marx RE, Sawatari Y, Fortin, M et al 2005
The American Dental Association (ADA), based on extensive studies
by Cartsos VM, Zhu S, Zavras Al 2008, concluded that dental implants for patients on oral bisphosphonates are not contraindicated as the risk of developing osteonecrosis is low .
However, teeth implants are definitely contraindicated in patients on i.v bisphosphonates.