Risk Factors in Relation to Dental Implant Failure

Introduction

Dental Implants these days have an increased demand from patients. Many patients think the solution for their dental problems are implants and they believe that the implants never fail.

Publicity and advertising of dental implants can sometimes suggest to the patients that dental implants can be the ultimate solution for their dental problems, these advertisements can raise their expectations as well as giving the impression that dental implants are risk free and last forever. Now with easy finance that’s on offer, more patients have access to dental implants treatments.

There are many other treatments that are available instead of dental implants, such as, periodontal, endodontic, dentures and bridges, each of these treatments or a mixture of all of them could be as good or even better than dental implants, this is why it is important to do the best assessment possible and give the patients as many options that are available. Once the assessment is carried out the clinician and the patient choose the best treatment for them.

When assessing the risk factors for each individual patient you need to consider may aspects, intraoral, general condition of health, expectations of the patients, economic aspects, habits even mental health too.

RISK FACTORS IN RELATION OF AN IMPLANT FAILURE

When a patient comes to us requesting implants we need to do a proper assessment, analysing many aspects. The following are just some of the most common risk factors:

INTERNAL ASPECTS: (age, smoking).

MEDICAL HEATH: (diabetes, overweight, Medications, Bone disease’s, HIV, Radiotherapy, Sjogren’s syndrome, miscellaneous)

INTRA ORAL EXAMINATION: Dental History (oral hygiene, gum disease, reason for tooth loss)

Bone density

Space for implant and restoration

Soft tissue(thickness, keratinised soft tissue

EXTRA ORAL EXAMINATION: Para function ,Type of smile , Aesthetics

MENTAL HISTORY

EXPECTATION OF THE PATIENT

COMMITMENT OF MAINTENANCE OF THE IMPLANTS

INTERNAL ASPECTS

Aspects such as age and smoking:

Age

Early age or the elderly, there are many literatures recommending to do implants after the age of 18 years .Dental Implants are reliable options for patients during the growth phase. However the efficiency of such treatment is uncertain because there are few clinical studies that have evaluated the functional and aesthetic outcomes with long term follow-up ^1, And elderly patients have many medications, probably poor oral hygiene and miscellaneous factors could affect the success of treatment.

Smoking

Early age or the elderly, there are many literatures recommending to do implants after the age of 18 years .Dental Implants are reliable options for patients during the growth phase. However the efficiency of such treatment is uncertain because there are few clinical studies that have evaluated the functional and aesthetic outcomes with long term follow-up ^1, And elderly patients have many medications, probably poor oral hygiene and miscellaneous factors could affect the success of treatment.

MEDICAL HEALTH.

It is essential to do a complete medical history and also if possible consult with the GP of the patient, have laboratory tests carried out and a medical evaluation. Diabetes is one of the possible diseases that could affect a good outcome of the implant treatment and how controlled the glycaemic levels are.

On the basis of the evidence, the results of meta-analytics fail to show a difference in the failure rates for dental implants between patients with well controlled diabetes and patients with diabetes that was not well controlled. However considering the limitations associated with this meta-analysis, the authors determine that the future studies that are well designed and provide adequate controls for confounding factors are required. ^3,  on the other hand. With regular to marginal bone loss there was a statistically significant difference favouring non-diabetic subjects. A greater number of studies are required in the future so that these conclusions can be confirmed. ^4,

Over weight and obesity

The findings of this systematic review indicate that the first hypothesis should be accepted, since no statistically significant difference in implant survival rate between individuals with overweight or obesity and those who are within the ideal weight range. ^5, But it is important to mention the patient snacking could affect oral hygiene.

Medications.

The findings of this systematic review indicate that the first hypothesis should be accepted, since no statistically significant difference in implant survival rate between individuals with overweight or obesity and those who are within the ideal weight range. ^5, But it is important to mention the patient snacking could affect oral hygiene.

Serotonin replacement inhibitors: These days it is very common to have a patient with anti-depressants, citalopram, floraxitine, setraline and is a good point to evaluate if this indication that could affect in implant therapy. Tt is suggested that the intake of SSRI did not significantly affect the implant survival rate.  ^7,  But it is important to consider depression could affect oral hygiene.

Bone disease’s

Osteoporosis

It is an important consideration that the bone quality be assessed before implant treatment. Osteoporosis could affect the bone density. The main outcome of this the meta-analysis indicate that there was no difference in implant survival rate between patient with and without Osteoporosis. ^8,  However still consider as a risk and we need to inform the patient.

Sjogren’s syndrome

It is well known Sjogren’s syndrome causes many complications in oral health increasing gum diseases, failure of restorations and increasing the risk of decay. In conclusion, implant should be considered by dentist as the failure rate is fairly low. SS patients may, however, present a higher MBL around implants than patients from general population. ^9,

AIDS/HIV

If the patient is under control with antiretroviral therapy, they could be acceptable for dental implant treatment. Thus, dental implants are suitable for rehabilitation of HIV positive patients with controlled risk factors and normal CD4+ cell counts.^10, Radiation Therapy

Patient under radiotherapy for head and neck cancer could be affected for xerostomia and affect the cells of the area. Osseo integrated dental implants can be used successfully in the oral rehabilitation of patients with head and neck cancer with a history of radiation therapy. Risk factors such as sex and the mode of radiation therapy can affect implant survival.^11,

Miscellaneous

There are many more conditions and diseases that could affect the success in implant therapy, we need to investigate each of these condition on its own merits.

Combination factors

Some factors if they are isolated don’t represent any risk of implant failure but the combination of this factor may increase the risk of failure.

INTRA ORAL EXAMINATION

Dental History: We need to evaluate oral hygiene of the patient with existent or past gum disease and could this be the reason for the tooth loss.

Oral Hygiene: In order to have any dental treatment to have a good outcome it is essential for the patient to have and maintain good oral health standards. This is even more important in dental implants because the is the basic key to success. If the patient can’t reach acceptable hygiene levels we need to delay/cancel the treatment and find alternative options for treatment.

Gum Disease

It is well known periodontitis, peri-implantitis and peri-implant diseases are intimately connected. If the patient has got an active periodontitis the patient is not a candidate for implants, in this case they need to go under periodontal treatment and get motivated enough to successfully control plaque levels until periodontal disease gets under control, but the patient still needs to make periodic visits to the hygienist.

The existence of peri-implantitis, the tooth location are significantly associated with the periodontal measurements of the remaining teeth. ^12,

Reason for the tooth loss

We need to identify why the patient has lost the tooth or teeth, this is going to assist greatly in treatment planning and success of the implant.

Bone density

The quality and the quantity of bone available is essential  for successful treatment of implants. Poor bone quality must be considered as a local risk factor. In scientific literature, bone quality is often referred as bone density. It is defined in terms of metabolism, cell turn over, mineralisation, maturation and vascularity; each of these factor play a role in the osseointegration success of dental implants. ^13,

The use of volumetric imaging is emerging as a valued aid in planning, placement and restoration of dental implants. Any CBCT scan intended for this purposes must include a scan prosthesis or integrate an optical scan of a diagnostically waxed cast.^14,

Space for implant and restoration

Is important in the treatment plan have enough space for the future restoration.

Soft tissue

Gingival biotype is an influence of the outcomes related with dental implants and is a common risk factor. The delicate biotype is more likely to have complication than a thick biotype. The evidence related to the effect of keratinized mucosa on the changes of attachment or bone levels is limited, and conclusions could not be drawn at present. Further, this review found that a band of keratinized mucosa was not absolutely necessary for the maintenance of peri-implant tissue, whereas lack of adequate keratinized mucosa around the implant might impede proper oral hygiene performance and compromise the aesthetic results.^15,

EXTRA ORAL EXAMINATION

Para function

We need to consider grinding and clenching to succeed in fixation of the implant and the longevity of the restoration.

Type of smile

The smile line relates to the level of upper and lower lip in relation to the corresponding gingival margins. The smile line is of a particular importance in cases which gingival defects and long teeth are included in the smile. A high lip line may be demanding aesthetically. ^16,

 Aesthetics

The increasing demand of dental implants in the aesthetic zone (interior maxilla) is a challenge for the clinician who is seeking not only implant success but also aesthetic predict-ability. With this in mind, the appearance and stability of soft tissues are important factors to consider. ^17,

MENTAL HISTORY

The planning of treatment for patient with mental history should be assessed really carefully before any treatment is carried out. It is possible to have a failure of a treatment even though you have considered all of the aspects.

EXPECTATION OF THE PATIENT

The patients need to be informed of the limitations of dental implants, if their expectations are beyond the clinical possibilities we need to examine alternative treatments.

COMMITMENT OF MAINTENANCE OF THE IMPLANTS

It is also important to commit the patient with regular checkups, x-rays to evaluate the condition of the implant and also regular periodontal treatment and any maintenance the dental implant needs.

Conclusions

One of the complications for dental implants is peri mucositis, peri-implantitis and peri-implant diseases which could lead to the loss of the implant. More studies are needed in this field because we have some of the reasons for this phenomenon at the moment but there are still some unknown.

Another complication could be cosmetic results. Because of this we need to know the patients expectations and be honest and clear with the patient prior to carrying out any treatment, and if the patients expectation are not realistic reject the patient.

Pain could be another complication. although the clinician may see it as a successful treatment , if the patient is in pain this is a failure.

Absence of Osteointegration is the worst case scenario for the patient and the clinician but before the patient starts with any treatment it is important to explain to the patients this risk factor.

A proper assessment must be done, and when assessing the patient we need look at oral health, habits, systemic risk factors, anatomical factors, genetics and combined risk factors. The possible complications in each one of the cases needs to be discussed with the patient, and even a perfectly healthy appearing patient there are risk factor that need to be discussed.

It is also important to commit the patient with regular checkups, x-rays to evaluate the condition of the implant and also regular periodontal treatment and any maintenance the dental implant needs.

References

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