This thesis focuses on prevention and treatment of biological complications around dental implants.

Background

An increasing number of individuals have restorations that are anchored to the jaws by dental implants. Modern-day implants are a Swedish invention that became available to patients in the 1970s. Implant restorations are common and several patients have had their implants for more than twenty years. The long-time survival rate is good, but as with all treatments, complications do occur. These complications can be technical problems, like fractures of the framework, discolouring and wear of the prosthesis, or fractures of the actual implant. Biological complications appear initially as peri-implant mucositis (PiM) which is a bacterially induced inflammation of the soft tissue around an implant. PiM may progress into peri-implantitis (Pi) that involves the implant supporting bone and can ultimately lead to loss of the implant. The prevalence of complications has been debated. Depending on patient population and definition used, the prevalence has been reported in the range of 19-65% for PiM and 1-47% for Pi. Treatment of peri-implant diseases consists of reinforcement of the patients’ oral hygiene, non-surgical mechanical therapy and incases with bone loss adjacent to the implant surgical interventions may be needed. Irrespective of treatment method complete resolution of the diseases is rare and even though no evidence exists that the use of antibiotics improves the treatment outcome antibiotics are often prescribed. Frequent use of antibiotics is a main contributor to the development of bacterial resistance that has developed into a serious global problem. Probiotics are live bacteria that inadequate doses are beneficial to the host and under certain circumstances have demonstrated abilities to hamper inflammations.

Aims

The aim of the thesis was to clarify whether 1) probiotics administered in lozenges can prevent or lower the inflammatory reaction to plaque accumulation, 2) if the use of probiotics as an adjunct to mechanical treatment of peri-implant mucositis has a beneficiary effect, and 3) if systemically administered antibiotics given as additive enhance the outcome following the treatment of peri-implant mucositis and peri-implantitis.

Methods

Four studies were designed to fulfil the aim:

·        a placebo controlled cross-over study testing whether probiotics can prevent or lower the inflammatory response to a bacterial challenge.

·        a placebo controlled RCT study evaluating whether probiotics given as an additive to mechanical treatment of peri-implant mucositis provides any benefits.

·        a RCT study evaluating whether systemically administered antibiotics given as an additive to mechanical treatment of periimplant mucositis are beneficial.

·        a RCT study evaluating whether systemically administered antibiotics given as an additive to surgical treatment of periimplantitis are beneficial.

Clinical, microbiological, and immunological parameters were used to analyse study outcomes.

Results

·        Daily probiotic lozenges had no significant effect on the inflammatory response in an experimental gingivitis model compared to placebo.

·        Daily probiotic lozenges as additive to oral hygiene instructions and mechanical debridement had no significant effect on the clinical, microbiological, or immunological outcome in the treatment of peri-implant mucositis compared to placebo.

·        Systemically administered antibiotics as additive to oral hygiene instructions and mechanical debridement had no significant effect on the clinical or microbiological outcome in the treatment of peri-implant mucositis.

·        Systemically administered antibiotics as additive to oral hygiene instructions and surgical mechanical debridement had no significant effect on the clinical or microbiological outcome in the treatment of peri-implantitis.

Conclusions

Neither probiotics containing Lactobacillus reuteri or Azithromycin have any major effect on the treatment outcome of periimplant mucositis or peri-implantitis when given as additive to conventional treatment. The use of daily lozenges containing Lactobacillus reuteri yields no benefits when it comes to preventing gingivitis under experimental gingivitis conditions.