Hierarchical decisions on teeth vs. implants in the periodontitis-susceptible patient: the modern dilemma.

It is estimated that advanced periodontitis typically affects about 10% of most adult populations studied. These individuals can be considered highly susceptible to periodontitis and often present difficulties for clinicians in therapeutic decision making, especially when dental implants are involved. Poor plaque control and smoking are well established risk factors for periodontitis, as well as for peri-implant disease. Long-term follow-up studies have clearly demonstrated that treatment of periodontal disease, even if advanced, can be successful in arresting disease progression and preventing (or at least significantly delaying) tooth loss. With the increasing development of implant dentistry, traditional well documented and evidence-based therapies to treat periodontal diseases may sometimes not be used to their full potential. Instead, there appears to be an increasing tendency to extract periodontally compromised teeth and replace them with implants, as if implants can solve the problem. However, peri-implant diseases are prevalent, affecting between 28% and 56% of people with implants, and (at the implant level) 12-43% of implants. A history of periodontal disease, smoking and poor oral hygiene are all risk factors for developing peri-implantitis. Unlike periodontitis, there are currently no predictable means for treating peri-implantitis, although resective surgery seems to be the most effective technique. Consequently, if implant treatment is considered in patients who are susceptible to periodontitis, it should be preceded by appropriate and adequate periodontal treatment or re-treatment to control the condition, and should be followed by a stringent supportive maintenance program to prevent the development of peri-implant disease. The decision whether implant treatment should be performed should be based on an assessment of the patient's risk profile at the subject level, as well as at the site level.

Marginal bone level changes at dental implants after 5 years in function: a meta-analysis.

BACKGROUND: It is important that peri-implant bone breakdown caused by, for example, undue load and/or peri-implantitis, is prevented or minimized. Some continuous loss of marginal bone is generally accepted, but the question remains as to what extent it must occur. PURPOSE: The purpose of this study was to compile and compare data on peri-implant marginal bone level changes from prospective studies that have registered the peri-implant marginal bone level radiographically at the time of prosthetic loading, and after 5 years of follow-up for implant systems currently available on the market. MATERIALS AND METHODS: A literature search was carried out to identify prospective studies on peri-implant marginal bone level changes around dental implants. To be included in a meta-analysis, the implant systems should have been subjected to at least two independent studies. Copycats without documentation were not accepted. RESULTS: Forty prospective studies that presented with a 5-year data were identified. Three implant systems met the inclusion criteria of having at least two independent studies; Astra Tech Dental Implant System® (Astra Tech AB, Mölndal, Sweden), Brånemark System (Nobel Biocare AB, Göteborg, Sweden), and Straumann Dental Implant System (Institute Straumann AG, Basel, Switzerland). The pooled mean marginal bone level change amounted to -0.24 mm (95% CI -0.345, -0.135) for the Astra Tech Dental Implant System, 0.75 mm (95% CI -0.802, -0.693) for the Brånemark System, and 0.48 mm (95% CI -0.598, -0.360) for the Straumann Dental Implant System over 5 years, with a statistically significant difference (p < .01) between the systems. CONCLUSIONS: The identified implant systems showed an annual bone loss below or much below what hitherto has been set up as a limit for success. A careful documentation of marginal bone level changes should be mandatory for all implant systems before being marketed. It is also time for revision of existing success criteria to refine the basis for clinical quality judgment of implant treatment.

Immediate implant placement with transmucosal healing in areas of aesthetic priority. A multicentre randomized-controlled clinical trial I. Surgical outcomes.

OBJECTIVES: To compare the clinical outcomes of standard, cylindrical, screw-shaped to novel tapered, transmucosal (Straumann Dental implants immediately placed into extraction sockets. MATERIAL AND METHODS: In this randomized-controlled clinical trial, outcomes were evaluated over a 3-year observation period. This report deals with the need for bone augmentation, healing events, implant stability and patient-centred outcomes up to 3 months only. Nine centres contributed a total of 208 immediate implant placements. All surgical and post-surgical procedures and the evaluation parameters were discussed with representatives of all centres during a calibration meeting. Following careful luxation of the designated tooth, allocation of the devices was randomly performed by a central study registrar. The allocated SLA titanium implant was installed at the bottom or in the palatal wall of the extraction socket until primary stability was reached. If the extraction socket was >or=1 mm larger than the implant, guided bone regeneration was performed simultaneously (Bio Oss and BioGide. The flaps were then sutured. During non-submerged transmucosal healing, everything was done to prevent infection. At surgery, the need for augmentation and the degree of wound closure was verified. Implant stability was assessed clinically and by means of resonance frequency analysis (RFA) at surgery and after 3 months. Wound healing was evaluated after 1, 2, 6 and 12 weeks post-operatively. RESULTS: The demographic data did not show any differences between the patients receiving either standard cylindrical or tapered implants. All implants yielded uneventful healing with 15% wound dehiscences after 1 week. After 2 weeks, 93%, after 6 weeks 96%, and after 12 weeks 100% of the flaps were closed. Ninety percent of both implant designs required bone augmentation. Immediately after implantation, RFA values were 55.8 and 56.7 and at 3 months 59.4 and 61.1 for cylindrical and tapered implants, respectively. Patient-centred outcomes did not differ between the two implant designs. However, a clear preference of the surgeon's perception for the appropriateness of the novel-tapered implant was evident. CONCLUSIONS: This RCT has demonstrated that tapered or standard cylindrical implants yielded clinically equivalent short-term outcomes after immediate implant placement into the extraction socket.

The structure of periodontal tissues formed following guided tissue regeneration therapy of intra-bony defects in the monkey.

OBJECTIVE: To describe the periodontal tissues formed following guided tissue regeneration (GTR) therapy of intra-bony defects (IBD). METHODS: Eight adult Macaca fascicularis monkeys were used. Proximal IBD were created at the mandibular second pre-molars and second molars. After 3 months, GTR surgery was performed. The animals were euthanized at 6 months and 2 years after surgery. Block biopsies were harvested, and prepared for histological analysis. RESULTS: At 6 months the defect had healed with new cementum (NC), periodontal ligament (PDL) and bone. The NC seemed to be firmly anchored to the dentin. Supra-crestally, the NC consisted of a 10 microm thick layer of acellular extrinsic fibre cementum (AEFC). Sub-crestally, the NC was considerably thicker and consisted of an inner layer of AEFC and an outer thicker layer of cellular mixed fibre cementum (CMFC). The extrinsic fibre density amounted to about 10 fibres per 100 microm. The PDL was wider than the pristine PDL and widened in coronal direction. After 2 years of healing, the thickness of the NC in the sub-crestal compartment had increased by about 20 microm and the fibre density had increased by about 50%. CONCLUSION: After 2 years of healing the structure of the regenerated tissues resembled that of pristine periodontal tissues.

Adjunctive benefits of systemic amoxicillin and metronidazole in non-surgical treatment of generalized aggressive periodontitis: a randomized placebo-controlled clinical trial.

BACKGROUND: The objective of this study was to assess the adjunctive clinical effect of the administration of systemic amoxicillin and metronidazole in the non-surgical treatment of generalized aggressive periodontitis (GAP). METHODS: Forty-one systemically healthy subjects with GAP were included in this 6-month double-blind, placebo-controlled, randomized clinical trial. Patients received a course of full-mouth non-surgical periodontal treatment delivered over a 24 h period using machine-driven and hand instruments. Test subjects received an adjunctive course of systemic antibiotic consisting of 500 mg amoxicillin and 500 mg metronidazole three times a day for 7 days. Clinical parameters were collected at baseline, and at 2 and 6 months post-treatment. RESULTS: In both the test and the placebo groups, all clinical parameters improved at 2 and 6 months. In deep pockets (> or =7 mm), the test treatment resulted in an additional 1.4 mm (95% confidence interval 0.8, 2.0 mm) in full-mouth probing pocket depth (PPD) reduction and 1 mm (0.7, 1.3 mm) of life cumulative attachment loss (LCAL) gain at 6 months. In moderate pockets (4-6 mm), the adjunctive benefit was smaller in magnitude: PPD reduction was 0.4 mm (0.1, 0.7 mm) and LCAL gain was 0.5 mm (0.2, 0.8 mm). In addition, the 6-month data showed LCAL gains > or =2 mm at 25% of sites in test patients compared with 16% in placebo (p=0.028). Similarly, PPD reductions of 2 mm or more were observed in 30% of sites in test and 21% of sites in placebo patients. Seventy-four percent of pockets with PPD > or =5 mm at baseline were 4 mm or shallower at 6 months in the test group. This compared with 54% in the placebo group (p=0.008). Disease progression at 6 months was observed at 1.5% of test and 3.3% of sites in test and placebo, respectively (p=0.072). CONCLUSIONS: These data indicate that a 7-day adjunctive course of systemic metronidazole and amoxicillin significantly improved the short-term clinical outcomes of full-mouth non-surgical periodontal debridement in subjects with GAP.

Periodontal wound healing following GTR therapy of dehiscence-type defects in the monkey: short-, medium- and long-term healing.

OBJECTIVE: To describe periodontal wound healing in dehiscence-type defects following guided tissue re-generation (GTR) therapy. METHODS: Ten adult Macaca fascicularis monkeys were used. Buccal dehiscence-type defects were created at the maxillary second pre-molars and second molars. After 3 months, GTR surgery was performed. The animals were euthanized at 6 weeks, 6 months and 2 years after surgery. Block biopsies were harvested, and prepared for histological analysis. RESULTS: A new attachment apparatus was structured already after 6 weeks of healing. A 10-20 microm thin layer of acellular extrinsic fibre cementum (AEFC) had formed along the instrumented root surface. At 6 months, the thickness of the supracrestal cementum was comparable with that at 6 weeks, while the thickness of the subcrestal cementum had increased to 40-60 microm. In this zone, the cementum consisted of an inner layer of AEFC attached to the circum-pulpal dentin and an outer layer of cellular mixed fibre cementum (CMFC). The numerical extrinsic fibre density was twice that at 6 weeks. At 2 years, the periodontal tissues resembled the pristine periodontium. CONCLUSION: Periodontal healing following GTR therapy of recession-type defects will result in a restitutio ad integrum, i.e. healing by re-generation. A continuous maturation process occurs over at least 2 years.

Baseline radiographic defect angle of the intrabony defect as a prognostic indicator in regenerative periodontal surgery with enamel matrix derivative.

INTRODUCTION: The baseline radiographic defect angle has previously been correlated with the clinical outcomes of intrabony defects treated with access flap or guided tissue regeneration. The aim of this study was to investigate whether an association exists between baseline radiographic defect angle and treatment outcome when enamel matrix derivative (EMD) is used in periodontal regenerative surgery. MATERIALS AND METHODS: Baseline radiographs were collected from the test group of a previously published clinical trial using a population of 166 patients treated for chronic periodontitis. All intrabony defects were > or =3 mm for inclusion in the original study. Either modified or simplified papilla preservation technique was used to access the defect. The roots were conditioned with an EDTA gel and the primary outcome measure was clinical attachment level (CAL) change, 1 year after surgery. RESULTS: Sixty-seven radiographs were measurable. The probability of obtaining CAL gain >3 mm was 2.46 times higher (95% confidence interval: 1.017-5.970) when the radiographic defect angle was < or =22 degrees than when it was > or =36 degrees. CONCLUSIONS: This study showed that there was a significant association between baseline radiographic defect angle and CAL gain at 1 year. The observed increased odds ratio of obtaining CAL gain of > or =4 mm after regenerative surgery with EMD is used in narrow (< or =22 degrees ) intrabony defects, suggests that the baseline radiographic defect angle might be used as a prognostic indicator of treatment outcome.

Longitudinal study on the distribution of proximal sites showing significant bone loss.

BACKGROUND, AIMS: In 1973, a random sample of 574 dentate individuals aged 15, 20, 30, 40, 50, and 60 years in the city of Jönköping, Sweden, were examined clinically and radiographically to assess oral health and overall treatment needs. Periodontal examination included registration of plaque, gingivitis, probing depths at four aspects of each tooth, and interproximal bone height measurements on full-mouth intraoral radiographs. In 1990, 17 years later, the same individuals were invited to participate in a new investigation. Of these, 433 (75%) agreed to participate in the investigation and were re-examined (Hugoson & Laurell 2000). The proximal alveolar bone height at all interproximal sites was measured and expressed as per cent of tooth length. Only teeth that were present in both 1973 and 1990 were included in the assessment of changes in bone score. From the age of 30 years, about 80% of the population had one or more sites with a bone loss of 2-3 mm or more. Seventeen per cent of the individuals had more than six such sites, indicating destructive periodontal disease. Bone loss occurred at sites both with and without previous bone loss. The present study was undertaken to test the hypothesis that sites with a bone loss of 10% or more of the tooth length (2-3 mm) during the 17 years were randomly distributed in the dentition. MATERIAL AND METHODS: Of the 13,197 sites examined in individuals 20-60 years at baseline, 1201 sites (9.0%) in 998 teeth with a bone loss corresponding to 10% or more of the tooth length were found and included in the analysis. A probability test for binomial distribution was used to test the null hypothesis that all teeth had the same risk of losing bone regardless of its position in the dentition. The valid risk for each tooth was 3.571% and the null hypothesis was rejected at the 95% confidence interval. RESULTS: Although all tooth types were affected by tooth loss, some teeth, namely 17, 16, 42, 41, and 31, showed a higher incidence of sites losing bone, whereas 46, 45, 44, and 36 had a lower incidence. Loser sites in smokers appeared more at random. CONCLUSION: Sites that will develop periodontal break-down over time may appear at random, although with higher risk at maxillary molars and lower incisors. For the early detection of destructive periodontitis, periodontal examination that includes all teeth should be made routine in every dental check-up.

Acellular dermal matrix allografts to achieve increased attached gingiva. Part 2. A histological comparative study.

BACKGROUND: In part 1 of this study, we compared the clinical efficacy of freeze-dried acellular dermal matrix (ADM) allograft in 6 patients with autogenous free gingival graft (FGG) in 6 patients for increasing the width of attached gingiva in the mandibular anterior area. The purpose of the present study was to histologically compare the microstructure of ADM and FGG treated sites from the same group. METHODS: Biopsies were harvested from all 12 patients at 6 months postsurgery. The biopsies included the grafted sites with adjacent alveolar mucosa and gingiva propria and also donor palatal mucosa saved at the time of surgery. The 5 microm thick, neutral buffered formalin fixed, paraffin-embedded tissue sections were stained with hematoxylin and eosin (H&E), Masson's trichrome, and Verhoeff-van Gieson stains in order to investigate the density of collagen and elastic fibers. Additional sections were stained with periodic acid-Schiff (PAS) and Papanicolaou's stain to identify the presence of glycogen granules in the epithelial layer and to highlight the keratin layer respectively. RESULTS: The unique appearance of ADM-derived tissue did not parallel any known oral mucosa. The connective tissue portion contained dense to extremely dense collagen fibers along with scattered elastic fibers. The demarcations between the ADM graft and the coronal gingiva as well as the apical alveolar mucosa were usually not very defined. A moderate to thin epithelial layer, with heterogeneous expression of keratinization and flat epithelium-connective tissue interface, covered the lamina propria. Both the thickness of the epithelium and the degree of keratinization decreased in apical direction, being mostly para- or orthokeratinized in the area close to gingiva and non-keratinized adjacent to the alveolar mucosa. In the FGG-treated sites, the density of collagen fibers was less than in ADM-derived tissue, palatal mucosa, and gingiva. Elastic fibers were very sparse, comparable to gingiva, but much less than in ADM-derived tissue. The epithelium was moderate, somewhat thinner but the shape of the rete ridges resembled that of palatal mucosa. Similar to gingiva epithelium, the epithelium of the FGG-treated area was relatively uniform in both thickness and keratinization, mostly para-keratinized with a well defined border to the non-keratinized alveolar mucosa. Underneath the FGG-alveolar mucosa junction, a scar band composed of extremely dense collagen fibers consistently existed. CONCLUSIONS: The results of this 6-month histological evaluation suggest that: 1) the resultant tissue types of ADM grafts were similar to "scar" tissue; 2) the non-vital dermal matrix of ADM allograft lacked the capability of directing cyto-differentiation of the covering epithelium; 3) autogenous FGG-derived tissue was neither identical to donor palatal mucosa nor to adjacent gingiva propria; 4) the connective tissue of donor palatal mucosa only partially contributed to the differentiation of the epithelium covering the FGG-treated area; and 5) the epithelium/connective tissue microenvironment surrounding the recipient site influenced the epithelial differentiation of the graft; this may play a more critical role in ADM grafting than in the grafting of autogenous FGG.