[Guidelines for surgical treatment of chronic periodontitis in Belgium]

Periodontal surgery is the most effective procedure to reduce pocket depth and to gain clinical attachment at deep sites. This is not surprising as surgery provides the best access and enables the clinician to extensively alter hard and soft tissues if necessary. Still, nonsurgical debridement is usually adopted as an initial measure of treatment for all sites. This reflects the conventional scheme of periodontal therapy; that is, overall non-surgical debridement followed by re-evaluation and surgery if and wherever necessary. The underlying reasons for organizing periodontal care as such are discussed in this manuscript. The importance of patient's compliance in terms of oral hygiene in the planning of surgical treatment is also highlighted and explained.

[Guidelines for maintenance care of chronic periodontitis in Belgium]

The importance of maintenance care for controlling periodontitis and preventing disease recurrence is well-documented. Supportive periodontal therapy is essentially based on periodontal risk assessment, oral hygiene reinforcement and professional cleaning. As most of the referred periodontal patients return to the general practitioner at some point, supportive periodontal therapy should be continued in general practice. This manuscript offers the clinician, in particular the general practitioner, a number of guidelines to organize maintenance care.

[Therapeutic choices and prognosis related to teeth or implants]

Preservation of natural teeth is the ultimate goal of dentistry today. Regular screening for periodontal disease, followed by infection control whenever necessary, positively affects tooth preservation, the more when the patients complies with therapy and regular maintenance. The dentist is, however, often confronted with treatment dilemmas and has to decide whether to extract or preserve teeth, to extirpate or extract, to keep or to implant, to make removable or fixed prostheses. Decision making is depending on the prognosis of teeth and becomes more difficult when teeth are supporting prosthetic restorations because the question arises: "How long will the teeth and the restoration survive?". Systematic reviews have revealed that teeth and implants have a similar prognosis. They are prone to biological and technical complications, the latter determining long term prognosis. Implant survival rates are around 93% after 10 years but the survival of the construction ranges between 80% and 90% depending on the type and extension. Complications are reported in the order of 35%. Prosthetic restoration on natural teeth have a 10-year survival of 80-90% with 34% of complications. The present paper gives a brief overview of the prognosis of dental treatments and discusses arguments that may be of help to make treatment decision choices.

[Guidelines for the use of antimicrobial agents in the treatment of chronic periodontitis in Belgium]

Mechanical debridement, with of without flap elevation, is a difficult and technique-sensitive procedure resulting in suboptimal treatment outcome from time to time. Therefore, it is not surprising that antibiotics and antiseptics, used alone or in combination with scaling and root planing, have always been fairly successful in clinical practice. For a number of reasons discussed in this paper, routine use of these agents cannot be justified. Especially in general practice these agents should not be prescribed; at least not for treating periodontitis.

[Guidelines for periodontal diagnosis in Belgium]

Proper examination of patients is essential in assessing treatment needs. This includes at least a thorough anamnesis and clinical examination. As periodontal diseases are highly-prevalent in Belgium, every patient should be examined as such on a routine basis in general practice. After all, early detection of pathology avoids extensive periodontal therapy and favours tooth retention in the end, which is the ultimate goal. This manuscript offers the clinician, in particular the general practitioner, a number of guidelines in reference to periodontal diagnosis.

[Need for clinical guidelines for chronic periodontitis in general and specialized Belgian practice]

As the prevalence of periodontitis is more than 40 % in the adult Belgian population, periodontists are clearly understaffed to treat this disease in all patients. Therefore, it seems logic that mild forms of chronic periodontitis are treated by the general practitioner especially because Belgium lacks dental hygienists. Important prerequisites for organizing periodontal care as such relate to the general practitioner who should use the same techniques, have comparable communicative skills to motivate patients and create a similar amount of time for periodontal treatment as the specialist. After all, the patient has the right to qualitative treatment regardless of the level of education of the care provider. In order to guarantee this in general practice as much as possible, there is a need for clinical guidelines developed by specialists. These guidelines should not only support the general practitioner in treating disease; above all, they should assist the dentist in periodontal diagnosis. Hitherto, periodontal screening by general dentists seems to be infrequently performed even though reimbursement of the Dutch Periodontal Screening Index is implemented in the Belgian healthcare security system. In this manuscript possible explanations for this phenomenon are discussed. Apart from the need for guidelines in general practice, guidelines for surgical treatment seem compulsory to uniform treatment protocols in specialized practice. Extreme variation in the recommendation of surgery among Belgian specialists calls for consensus statements.

[The development of clinical guidelines for the diagnosis and treatment of chronic periodontitis in Belgium]

In many disciplines of medicine guidelines are developed for the diagnosis and treatment of disease. These are essentially intended to standardize care and to optimize communication between the general practitioner and the specialist. Guidelines have already been described in the literature for chronic periodontitis. However, given the unique conditions in Belgium, these may not be appropriate for the average dental practice. In this manuscript the development of Belgian clinical guidelines for the diagnosis and treatment of chronic periodontitis is described. Basically, ten clinical questions were used as a basis for a thorough literature search. Evidence-based clinical guidelines were developed and adapted during three peer review sessions. In the final session Belgian specialists, who had all been invited, participated. This made sure that the scientific input was sufficiently transformed into clinical guidelines which are actually feasible today in Belgium.

[Peri-implantitis]

Millions of partially or fully edentulous patients worldwide have been treated by means of dental implants ever since the description of the osseointegration process by PI Brånemark. Despite high success rates, different biological and mechanical complications do occur. Peri-implantitis is a chronical infection around dental implants with irreversible crestal bone loss. Like periodontitis, peri-implantitis is a multifactorial disease caused by pathogenic species in a sensitive host. Today treatment of peri-implantitis is highly unpredictable, hence regular follow-up and prevention seems warranted. As the number of patients rehabilitated with dental implants is growing, the incidence will certainly increase. Guidelines about diagnostics, prevention and treatment of peri-implantitis are mentioned in this article based on current scientific evidence.

[The choice between 'conservation of a tooth using endodontic treatment and crown restoration' or 'extraction of the tooth and its replacement by an implant'. Recommendations for a single tooth]

Recent studies provide evidence that root canal treatment results in excellent clinical outcomes for our patients, which is in favour of the preservation of teeth. Therefore, endodontic treatment remains a highly predictable method to retain teeth with irreversible pulpal disease. Retention rates of root filled teeth of more than 90 percent have been shown. At present there are many alternative treatments available to preserve or replace diseased teeth and considerable progress has been made in this field. With the increasing popularity of implants and for some too complicated the root canal anatomy, more teeth than before are extracted to be replaced with implants. Unfortunately, there has not been that much of research identifying the best strategies for selecting one treatment approach over another. Consequently there is a need for recommendations regarding endodontic versus implant therapy.

[Guidelines for non-surgical treatment of chronic periodontitis in Belgium]

Non-surgical root debridement is usually the first step in the treatment of chronic periodontitis. This can be performed in one day or in multiple sessions over several weeks using manual instruments and/or power-driven instruments. Besides scaling and root planing, the removal of plaque-retaining factors and mechanical oral hygiene measures are essential for a favourable treatment outcome.

A model study on flapless implant placement by clinicians with a different experience level in implant surgery

INTRODUCTION

Some implant companies advocate that flapless surgery is easy to perform and beneficial for aesthetics and patients morbidity. However, studies objectively analyzing the position in the bone of implants installed with this approach are lacking. This in vitro model study was performed to analyse deviations in position and inclination of implants placed with flapless surgery compared with the ideally planned position and to examine whether the outcome is affected by experience level.

METHODS

Identical radio-opaque resin models were developed with a silicon lining mimicking the soft tissues and six edentulous single tooth spaces. Eighteen clinicians (six periodontists, six general dentists and six students) drilled four implant sites each (Straumann AG, Basel, Switzerland) with a flapless approach. Corresponding CT-scan images of the models were available. A virtual implant program (Simplant, Materialise NV, Leuven, Belgium) was used to plan the ideal position and to compare this with the implant angulation and position of the test implants.

RESULTS

There were no significant differences between the experience groups for all parameters except for global deviations between dentist and students, angle deviations between dentists and students and horizontal deviations between specialists and students. In incisor sites, specialists and students deviated significantly more in global deviation and depth than dentists. In premolar and molar sites, there were no significant differences except for horizontal deviations between specialists and dentists in molar sites. As a consequence of the malpositioning, perforations were seen in 59.7% (43/72) of the implant occasions when the artificial mucosa was removed from the model.

CONCLUSION

The three-dimensional location of implants installed with flapless approach differs significantly from the ideal, although neighbouring teeth were present and maximal radiographical information was available. Within the limitations of this in vitro model study it seems necessary to point out that these deviations would in a clinical situation lead to complications such as loss of implant stability, aesthetical and phonetical consequences. The outcome is not influenced by the level of experience with implant surgery. This points out that more precise measurements of soft tissue in situ or additional use of guiding systems are recommendable.

A Literature Review on Biomaterials in Sinus Augmentation Procedures

BACKGROUND

Sinus augmentation is a common procedure to increase bone volume and allow for proper implant placement in the atrophic posterior maxilla. Although the patient's own bone is considered the best grafting material, various synthetic or bovine-derived alternatives are used to simplify the grafting procedure.

PURPOSE

The overall objective of this review was to assess the efficacy of different graft materials used in sinus augmentation procedures as demonstrated in animal studies.

MATERIALS AND METHODS

A specific and sensitive database was initially created via PUBMED, focusing on studies published in English peer-reviewed journals between 1995 and 2004 and kept updated until 2006.

RESULTS

Twenty-six articles were available for comparison and discussion; none concerned the use of alloplastic materials; 24 were comparative histomorphometric; and two were biomechanical studies. Because of a great variability in study designs, different implant types, great range in follow-up, and lack of specific integration or loading period, a comparison of the studies and the biomaterials used was difficult.

CONCLUSIONS

In general, autogenous bone is the most predictable material of choice for augmentation procedures, despite a 40% resorption, because it is highly osteoconductive and less dependent on sinus floor endosteal bone migration. The addition of bovine bone mineral to autogenous bone can be beneficial for graft success because it acts as a slowly resorbing space maintainer. Porous hydroxyapatite is suitable when mixed with autogenous bone because it enhances bone formation and bone-to-implant contact in augmented sinuses. Histological evaluation showed that demineralized freeze-dried bone is inferior to other materials. Within the limitation of the animal studies examined in this review and only based on histological examination, the initial osseointegration of implants seems independent of the biomaterial used in grafting procedures.

Immediate loading in the completely edentulous mandible: technical procedure and clinical results up to 3 years of functional loading

OBJECTIVES

This prospective mono-center study describes a clinical technique to provide dental implants with a temporary cross-arch cantilever bridge functionally loaded on the day of fixture insertion and discusses the 3-year follow-up of four to six machined surface Brånemark implants installed in the interforamina area.

MATERIAL AND METHODS

Ninety Brånemark implants were installed in 18 edentulous mandibles. Five patients were heavy smokers and one had Down syndrome. The day of surgery, a 10 unit provisional glassfiber-reinforced cantilever bridge was installed. The final 12 unit bridge was in place after an average of 144 days (range 10-332). Bone-to-implant level was assessed radiologically from the day of surgery up to 3 years.

RESULTS

Two out of five fixtures were lost within 3 months in the Down syndrome patient but the provisional bridge continued to function on the three remaining implants until the patient was successfully reoperated. Another implant was lost after 11 months due to a non-detected fracture in the metal framework, resulting in overloading of the cantilever part. As no additional losses occurred during the follow-up time (range 57-26 months), the total failure rate is 3/91 (3.3%). Seventeen of the 18 patients are loading their implants more than 3 years and nine have moved beyond the 4-year period. Average bone remodelling as measured on the apical radiographs from 12 patients at 0, 12 and 36 months revealed a statistically significant bone loss from the initial 0.1 mm [standard deviation (SD) 0.2; range 0-0.7] toward 1.8 mm (SD 0.2; range 1.6-2.2) during the first year of function. (Wilcoxon's signed rank test; P<0.002). After 3 years, no further significant bone loss occurred.

CONCLUSION

This 3-year study shows that machined surface Brånemark implants can be immediately loaded with cross-arch cantilever bridges with an average bone-remodelling pattern indicative of a steady state after 1 year of loading.

Clinical Consequences of IL-1 Genotype on Early Implant Failures in Patients under Periodontal Maintenance

BACKGROUND

Implant failure and biologic complications such as periimplantitis are not completely avoidable. Are there any genetic and microbiologic parameters that could be used to identify patients at risk for implant failure, preferably prior to treatment? This would result in improvement of the diagnostics, treatment decision, and risk assessment.

PURPOSE

The aims of this retrospective study were to describe (1) the absolute failure rate of Brånemark System implants (Nobel Biocare AB, Göteborg, Sweden) consecutively installed over a 10-year period in partially edentulous patients treated for periodontal disease prior to implant treatment and under regular professional maintenance, (2) the rate of interleukin-1 (IL-1) polymorphism in those patients who experienced at least one implant failure during the first year of function, and (3) the prevalence of periodontal pathogens in dental and periimplant sites with and without signs of inflammation.

MATERIAL AND METHODS

Of 766 patients, 81 encountered at least one implant failure; 22 patients were clinically examined and were tested genetically for IL-1 genotypes. The presence of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella nigrescens was analyzed.

RESULTS

The absolute implant survival rate for the whole population was 95.32%; 10.57% of the patients encountered an implant loss. Implant loss in the examined group (n = 22) was 32 of 106 (30.1%); 10 (45%) of the 22 patients were smokers, and 6 (27%) of the 22 patients were IL-1 genotype positive. Patients positive for IL-1 genotype were not more prone to implant loss; however, a significant synergistic effect with smoking was demonstrated. Between patients who were IL-1 genotype positive and those who were IL-1 genotype negative, the differences in regard to bleeding on probing or periodontal pathogens did not reach statistical significance.

CONCLUSION

The overall implant failure rate in a population treated and maintained for periodontal disease is similar to that of healthy subjects. A synergistic effect found between smoking and a positive IL-1 genotype resulted in a significantly higher implant loss. This indicates that further research with a larger patient group should focus on multifactorial analysis for adequate risk assessment.

The value of the centre of rotation in initial and longitudinal tooth and bone displacement

Force application on teeth and bone structures results in orthodontic and orthopaedic movements. The effect of force application during different time intervals (initial and longitudinal displacements) can be evaluated by describing the displacement vectors or by constructing the centres of rotation of the displacements. The aim of this investigation was to review different experimental studies to compare the position of the centre of rotation (CR) with the displacement vectors of the object (tooth or bone) after force application. The results indicate that the measuring procedure and the use of the CR to describe the displacement are very sensitive: a large discrepancy in the position of the CR does not necessarily lead to a major change in the displacement vector of the object. Displacement vectors seem to be more appropriate in describing both initial and longitudinal tooth or bone displacements.

Early loading of machined-surface Brånemark implants in completely edentulous mandibles: healed bone versus fresh extraction sites

BACKGROUND

Restoration of edentulous mandibles with dental implants installed with a two-stage or one-stage surgical approach, yet with delayed loading, is a predictable and successful treatment.

PURPOSE

The present prospective study evaluated the success up to 3 years of function of nonroughened machined-surface Brånemark System implants (Nobel Biocare AB, Gothenburg, Sweden) loaded early or immediately with a fixed 12-unit bridge.

MATERIALS AND METHODS

In total, 184 implants were installed in 36 patients: 30 with healed bone and 6 with some remaining teeth, which were extracted simultaneously with implant installation. The provisional or final prostheses were installed 0 to 52 (mean 18.2) days later.

RESULTS

Thirteen of 184 (7.1%) implants failed within 3 months of loading in 5 of 36 (13.9%) patients: 1 of 153 implants (0.7%) failed in healed bone, and 12 of 31 (39%) failed in fresh extraction sites. This consequently meant a loss of 3 of 36 (8.3%) prostheses, all in the extraction group. No implants were lost during 3 years of functional loading (16 patients, 75 implants). The average marginal bone level measured initially and after 1, 2, and 3 years was 0.8 mm (SD = 0.5), 1.0 mm (SD = 0.4), 1.1 mm (SD = 0.3), and 1.4 mm (SD = 0.5), respectively.

CONCLUSIONS

Four to six Brånemark implants with nonroughened machined titanium surfaces can be loaded early or immediately with cross-arch restorations in healed mandibulary bone, but this cannot be recommended for fresh extraction sites.

Early loading of four or five Astra Tech fixtures with a fixed cross-arch restoration in the mandible

BACKGROUND

A change in implant placement has emerged recently from two-stage to one-stage surgery and to earlier and even immediate loading of the fixtures.

PURPOSE

The aim of this study was to verify whether four or five fixtures installed in the edentulous mandible were suitable for early loading with a cross-arch fixed restoration.

MATERIALS AND METHODS

In 25 consecutively treated patients (28-88 yr), four or five Astra Tech fixtures (Mölndal, Sweden) were installed in edentulous mandibles. During the same surgical procedure, the abutments were connected. An impression was taken immediately after surgery. All patients received a fixed prosthetic rehabilitation of 10 to 12 teeth made of a cast metal framework and acrylic teeth/gingiva within a month. The fixtures were followed up clinically and radiographically for 7 to 24 months. Bone level was measured from the most coronal point of the vertical part of the fixture to the most apical bone level mesially or distally.

RESULTS

No fixtures were lost during follow-up. No postoperative complications occurred. Radiographic analysis showed a mean bone level of 0.6 mm after 7 to 12 months. Fixtures followed up from 13 to 18 and 19 to 24 months showed a mean bone level of 0.7 mm. Around two fixtures, the bone level was found at the first implant thread. All other fixtures showed the bone level somewhere along the vertical unthreaded part of the fixture.

CONCLUSIONS

Early loading within 1 month of four or five Astra Tech fixtures in the edentulous mandible is a predictable procedure for a follow-up period of 6 to 24 months.

Patient satisfaction and quality of single-tooth restorations

This retrospective study focuses on patient opinion and professionally assessed quality of single-tooth restorations of Brånemark fixtures. Patients were treated by periodontists for fixture installation and/or abutment connection and by referring general practitioners for prosthetic rehabilitation. Seventy-eight consecutively treated patients were sent a questionnaire regarding aesthetics, phonetics and overall satisfaction. Forty-eight patients (52 fixtures) returned the questionnaire. Forty were able to attend a clinical examination by an independent examiner. The quality of 43 single implant crowns was evaluated according to the modified guidelines for assessment of quality and professional performance used for evaluation of design, fit, occlusion/articulation and aesthetics. Bone to implant level was assessed radiographically. Patients were very positive about aesthetics, phonetics, eating comfort and overall satisfaction. Nevertheless, 6/40 patients would not undergo the same treatment again, yet all of them would recommend it to others. The professionally rated quality of the crowns was perfect in 17 and acceptable in 25 cases. One crown needed modification to prevent future complications. Two crowns had already been replaced as a result of porcelain fracture; one restoration showed abrasion and one was damaged. With a mean loading time of 33 months (range: 3-89 months), none of the patients returning the questionnaire had encountered fixture loss. All except five fixtures showed bone remodelling at or above the first implant thread. It is concluded that single Brånemark fixtures installed by periodontists and restored by general practitioners are of an acceptable clinical quality to satisfy the patient.