Surgical treatment of peri-implantitis with or without a deproteinized bovine bone mineral and a native bilayer collagen membrane: A randomized clinical trial.

AIM: To assess whether the use of deproteinized bovine bone mineral (DBBM) and native bilayer collagen membrane (NBCM) improved healing of peri-implantitis-related bone defects at 12 months. MATERIALS AND METHODS: In a multi-centre, randomized clinical trial, 32 individuals received surgical debridement (control group [CG]), and 34 received adjunct use of DBBM and NBCM (test group [TG]). Radiographic defect fill (RDF), probing pocket depth (PPD), bleeding on probing (BOP), suppuration (SUP), recession (REC), cytokines (IL-1ß, IL-1RA, IL-6, IL-8, IL-12, IP10, PDGF-BB, TNF-α, VEGF), and patient-reported outcomes (PROs) were evaluated at 3, 6, 9, and 12 months. RESULTS: RDF at the deepest site amounted 2.7 ± 1.3 mm in TG and 1.4 ± 1.2 mm in CG (p <.0001). PPD was reduced by 1.9 mm in TG and 2.3 mm in CG (p = .5783). There were no significant differences between groups regarding reductions of BOP, SUP, REC, cytokines levels, or oral health impact profile (OHIP)-14 scores at 12 months. Successful treatment (RDF ≥ 1.0 mm, PPD ≤5 mm, ≤1/4 site with BOP grade 1, no SUP) was identified in 32% in TG and 21% in CG. CONCLUSIONS: DBBM and NBCM resulted in significantly more RDF than debridement alone. No difference was found in any clinical parameters or PROs between the groups. ClinicalTrials.gov Identifier: NCT02375750.

Surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane: a 5-year follow-up.

AIM: To compare two regenerative surgical treatments for peri-implantitis over 5 years. MATERIAL & METHODS: Twenty-five individuals with peri-implantitis remained at study endpoint. They were treated with a bone substitute and a resorbable membrane (13 individuals with 23 implants) [Group 1], or with bone substitute alone (12 individuals with 22 implants) [Group 2]. All study individuals were kept on a strict maintenance programme every third month. RESULTS: Five-year follow-up demonstrated clinical and radiographic improvements in both groups. No implants were lost due to progression of peri-implantitis. Probing depths were reduced by 3.0 ± 2.4 mm in Group 1, and 3.3 ± 2.09 mm in Group 2 (NS). In both groups, radiographic evidence of bone gain was significant (p < 0.001). At year 5, the average defect fill was 1.3 mm (SD ± 1.4 mm) in Group 1 and 1.1 mm (SD ± 1.2 mm) in Group 2 (mean diff; 0.4 95% CI -0.3, 1.2, p = 0.24). Bleeding on probing decreased in both groups. Baseline and year 5 plaque scores did not differ between groups and was reduced from 50% to 15%. CONCLUSION: Both procedures resulted in stable conditions. Additional use of a membrane does not improve the outcome.

Long-term stability of surgical bone regenerative procedures of peri-implantitis lesions in a prospective case-control study over 3 years.

OBJECTIVES: To evaluate the extent of bone fill over 3 years following the surgical treatment of peri-implantitis with bone grafting with or without a membrane. MATERIAL AND METHODS: In a non-submerged wound-healing mode, 15 subjects with 27 implants were treated with a bone substitute (Algipore(®)) alone and 17 subjects with 29 implants were treated with the bone substitute and a resorbable membrane (Osseoquest(®)). Implants with radiographic bone loss ≥1.8 mm following the first year in function and with bleeding and/or pus on probing were included. Following surgery, subjects were given systemic antibiotics (10 days) and rinsed with chlorhexidine. After initial healing, the subjects were enrolled in a strict maintenance programme. RESULTS: Statistical analysis failed to demonstrate changes in bone fill between 1 and 3 years both between and within procedure groups. The mean defect fill at 3 years was 1.3 ± (SD) 1.3 mm if treated with the bone substitute alone and 1.6 ± (SD) 1.2 mm if treated with an adjunct resorbable membrane, (p=0.40). The plaque index decreased from approximately 40-10%, remaining stable during the following 2 years. CONCLUSION: Defect fill using a bone substitute with or without a membrane technique in the treatment of peri-implantitis can be maintained over 3 years.

Microbiologic results after non-surgical erbium-doped:yttrium, aluminum, and garnet laser or air-abrasive treatment of peri-implantitis: a randomized clinical trial.

BACKGROUND: The purpose of this study is to assess clinical and microbiologic effects of the non-surgical treatment of peri-implantitis lesions using either an erbium-doped:yttrium, aluminum, and garnet (Er:YAG) laser or an air-abrasive subgingival polishing method. METHODS: In a 6-month clinical trial, 42 patients with peri-implantitis were treated at one time with an Er:YAG laser or an air-abrasive device. Routine clinical methods were used to monitor clinical conditions. Baseline and 6-month intraoral radiographs were assessed with a software program. The checkerboard DNA-DNA hybridization method was used to assess 74 bacterial species from the site with the deepest probing depth (PD) at the implant. Non-parametric tests were applied to microbiology data. RESULTS: PD reductions (mean ± SD) were 0.9 ± 0.8 mm and 0.8 ± 0.5 mm in the laser and air-abrasive groups, respectively (not significant). No baseline differences in bacterial counts between groups were found. In the air-abrasive group, Pseudomonas aeruginosa, Staphylococcus aureus, and Staphylococcus anaerobius were found at lower counts at 1 month after therapy (P <0.001) and with lower counts in the laser group for Fusobacterium nucleatum naviforme (P = 0.002), and Fusobacterium nucleatum nucleatum (P = 0.002). Both treatments failed to reduce bacterial counts at 6 months. Porphyromonas gingivalis counts were higher in cases with progressive peri-implantitis (P <0.001). CONCLUSIONS: At 1 month, P. aeruginosa, S. aureus, and S. anaerobius were reduced in the air-abrasive group, and Fusobacterium spp. were reduced in the laser group. Six-month data demonstrated that both methods failed to reduce bacterial counts. Clinical improvements were limited.

Short-term effects of an anti-inflammatory treatment on clinical parameters and serum levels of C-reactive protein and proinflammatory cytokines in subjects with periodontitis.

BACKGROUND: Periodontal disease is the most common multifactorial disease, afflicting a very large proportion of the adult population. Periodontal disease secondarily causes increases in the serum levels of C-reactive protein (CRP) and other markers of inflammation. An increased level of CRP reflects an increased risk for cardiovascular disease. The aim of the current randomized clinical trial was to evaluate the short-term effect of a combination of dipyridamole and prednisolone (CRx-102) on the levels of high-sensitivity (hs)-CRP, proinflammatory markers in blood, and clinical signs of periodontal disease. METHODS: Fifty-seven patients with >/=10 pockets with probing depths >/=5 mm were randomized into two groups in this masked single-center placebo-controlled study: CRx-102 (n = 28) and placebo (n = 29). hs-CRP levels, inflammatory markers (interleukin [IL]-6, -1beta, -8, and -12, tumor necrosis factor-alpha, and interferon-gamma [IFN-gamma]), bleeding on probing (BOP), and changes in probing depths were evaluated. The subjects received mechanical non-surgical therapy after 42 days, and the study was completed after 49 days. RESULTS: At day 42, the differences in the hs-CRP, IFN-gamma, and IL-6 levels between the two groups were statistically significant (P <0.05), whereas no difference was found for the other inflammatory markers. There was no change in probing depth or BOP between the two groups. CONCLUSION: The administration of CRx-102 resulted in significant decreases in hs-CRP, IFN-gamma, and IL-6, but it did not significantly change BOP or probing depths.

Non-surgical treatment of peri-implant mucositis and peri-implantitis: a literature review.

OBJECTIVES: To review the literature on non-surgical treatment of peri-implant mucositis and peri-implantitis. MATERIAL AND METHODS: A search of PubMed and The Cochrane Library of the Cochrane Collaboration (CENTRAL) as well as a hand search of articles were conducted. Publications and articles accepted for publication up to November 2007 were included. RESULTS: Out of 437 studies retrieved a total of 24 studies were selected for the review. Thus the available evidence for non-surgical treatment of peri-implant mucositis and peri-implantitis is scarce. CONCLUSIONS: It was observed that mechanical non-surgical therapy could be effective in the treatment of peri-implant mucositis lesions. Furthermore, the adjunctive use of antimicrobial mouth rinses enhanced the outcome of mechanical therapy of such mucositis lesions. In peri-implantitis lesions non-surgical therapy was not found to be effective. Adjunctive chlorhexidine application had only limited effects on clinical and microbiological parameters. However, adjunctive local or systemic antibiotics were shown to reduce bleeding on probing and probing depths. Minor beneficial effects of laser therapy on peri-implantitis have been shown; this approach needs to be further evaluated. There is a need for randomized-controlled studies evaluating treatment models of non-surgical therapy of peri-implant mucositis and peri-implantitis.

Long time follow up of implant therapy and treatment of peri-implantitis.

Dental implants have become an often used alternative to replace missing teeth, resulting in an increasing percentage of the adult population with implant supported prosthesis. Although favourable long-term results of implant therapy have been reported, infections occur. Until recently few reports included data on peri-implant infections, possibly underestimating this complication of implant treatment. It is possible that some infections around implants develop slowly and that with time peri-implantitis will be a common complication to implant therapy as an increasing number of patients have had their implants for a long time (>10 years). Data on treatment of peri-implant lesions are scarce leaving the clinician with limited guidance regarding choice of treatment. The aim of this thesis was to study the frequency of implant loss and presence of peri-implant lesions in a group of patients supplied with Brånemark implants 9-14 years ago, and to relate these events to patient and site specific characteristics. Moreover three surgical treatment modalities for peri-implantitis were evaluated. The thesis is based on six studies; Studies I-III included 218 patients and 1057 implants followed for 9-14 years evaluating prevalence of, and factors related to implant loss (Paper I) and prevalence of peri-implant infections and related factors (Paper I-III). Study IV is a review describing different treatment modalities of peri-implant infections. Study V is a prospective cohort study involving 36 patients and 65 implants, evaluating the use of a bone substitute with or without the use of a resorbable membrane. Study VI is a case series with 12 patients and 16 implants, evaluating a bone substitute in combination with a resorbable membrane and submerged healing. This thesis demonstrated that: After 9-14 years the survival rates of dental implants are high (95.7%). Implant loss seems to cluster within patients and are related to periodontitis evidenced as bone loss on radiographs at remaining teeth before implant placement. (Paper I) Peri-implantitis is a common clinical entity after 9-14 years. (Paper II) Using the implant as the statistical unit the level of keratinized mucosa and pus were explanatory for a bone level at > or =3 threads (1.8 mm). When the patient was used as a statistical unit a history of periodontitis and smoking were explanatory for peri-implantitis. (Paper III) Animal research has demonstrated that re-osseointegration can occur. The majority of human studies were found to be case reports. Using submerged healing and bone transplants, bone fill can occur in peri-implant defects. (Paper IV) Surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane resulted in similar pocket depth reduction, attachment gain and defect fill. (Paper V) Bone substitute in combination with a resorbable membrane and a submerged healing resulted in defect fill > or =2 threads (1.2 mm) in 81% of the implants. (Paper VI) In conclusion: 9-14 years after implant installation peri-implant lesions are a common clinical entity. Smokers and patients with a history of periodontal disease are at higher risk to develop peri-implantitis. Clinical improvements and defect fill can be obtained with various surgical techniques using a bone substitute.

Surgical treatment of peri-implantitis using a bone substitute with or without a resorbable membrane: a prospective cohort study.

OBJECTIVES: The aim of this prospective cohort study was to compare two regenerative surgical treatment modalities for peri-implantitis. MATERIAL AND METHODS: Thirty-six patients having a minimum of one osseointegrated implant, with a progressive loss of bone amounting to > or =3 threads (1.8 mm) following the first year of healing, combined with bleeding and/or pus on probing, were involved in this study. The patients were assigned to two different treatment strategies. After surgical exposure of the defect, granulomatous tissue was removed and the infected implant surface was treated using 3% hydrogen peroxide. The bone defects were filled with a bone substitute (Algipore). In 17 patients (Group 1), a resorbable membrane (Osseoquest) was placed over the grafted defect before suturing. In 19 patients (Group 2), the graft was used alone. RESULTS: One-year follow-up demonstrated clinical and radiographic improvements. Probing depths were reduced by 2.9 mm in Group 1 and by 3.4 mm in Group 2. Defect fill amounted to 1.5 and 1.4 mm, respectively. There was no significant difference between the groups. CONCLUSION: It is possible to treat peri-implant defects with a bone substitute, with or without a resorbable membrane.

Submerged healing following surgical treatment of peri-implantitis: a case series.

OBJECTIVES: The aim was to study a regenerative surgical treatment modality for peri-implantitis employing submerged healing. MATERIAL AND METHODS: Twelve patients, having a minimum of one osseointegrated implant with peri-implantitis, with a progressive loss of >or=3 threads (1.8 mm) following the first year of healing were involved in the study. After surgical exposure of the defect, granulomatous tissue was removed and the implant surface was treated using 3% hydrogen peroxide. The bone defects were filled with a bone substitute (Algipore), a resorbable membrane (Osseoquest) was placed over the grafted defect and a cover screw was connected to the fixture. The implant was then covered by flaps and submerged healing was allowed for 6 months. After 6 months the abutment was re-connected to the supra-structure. RESULTS: A 1-year follow-up demonstrated clinical and radiographic improvements. Probing depth was reduced by 4.2 mm and a mean defect fill of 2.3 mm was obtained. CONCLUSION: Treatment of peri-implant defects using a bone graft substitute combined with a resorbable membrane and submerged healing results in defect fill and clinical healthier situations.

IL-1RN gene polymorphism is associated with peri-implantitis.

OBJECTIVES: Interleukin (IL)-1alpha, IL-1beta and their natural specific inhibitor IL-1 receptor antagonist (IL-1ra) play a key role in the regulation of the inflammatory response in periodontal tissues. Polymorphisms in the IL-1 gene cluster have been associated with severe adult periodontitis. We aimed to investigate the IL-1 gene cluster polymorphisms in patients with peri-implantitis. MATERIAL AND METHODS: The study included 120 North Caucasian individuals. A total of 71 patients (mean age 68 years, 76% smokers) demonstrating peri-implantitis at one or more implants as evidenced by bleeding and/or pus on probing and bone loss amounting to >3 threads on Brånemark implants and 49 controls (mean age 66 years, 45% smokers) with clinical healthy mucosa and no bone loss around the implants were recruited for the study. The titanium implants, ad modum Brånemark, had been in function for at least 2 years. Mouthwash samples were collected and used for genotyping of the bi-allelic polymorphisms IL-1A(-889), IL-1B(+3953), IL-1B(-511) and a variable number of tandem repeat IL-1RN gene polymorphisms using PCR technique. RESULTS: Significant differences were found in the carriage rate of allele 2 in the IL-1RN gene between peri-implantitis patients and controls (56.5% vs. 33.3%, respectively; odds ratios (OR) 2.6; 95% confidence interval (CI) 1.2-5.6; P=0.015). Logistic regression analysis taking smoking, gender and age into account confirmed the association between the IL-1RN allele 2 carriers and peri-implantitis (OR 3; 95% CI 1.2-7.6; P=0.02). CONCLUSIONS: Our results provide evidence that IL-1RN gene polymorphism is associated with peri-implantitis and may represent a risk factor for this disease.

Nine- to fourteen-year follow-up of implant treatment. Part I: implant loss and associations to various factors.

OBJECTIVES: The aim of the present study was to evaluate the long-term result of implant therapy, using implant loss as outcome variable. MATERIAL AND METHOD: Two hundred and ninty-four patients had received implant therapy (Brånemark System) during the years of 1988-1992 in Kristianstad County, Sweden. The patients were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 9-14 years after implant placements, the patients were again called in for a complete clinical and radiographic examination. RESULTS: Two hundred and eighteen patients treated with 1057 implants were examined. Twenty-two patients had lost 46 implants and 12 implants were considered "sleeping implants". The overall survival rate was 95.7%. Implant loss appeared in a cluster in a few patients and early failures were most common. Eight patients lost more than one fixture. A significant relationship was observed between implant loss and periodontal bone loss of the remaining teeth at implant placement. Maxillary, as opposed to mandibulary implants, showed more implant loss if many implants were placed in the jaw. A significant relationship between smoking habits and implant loss was not found. CONCLUSION: A history of periodontitis seems to be related to implant loss.

Nine- to fourteen-year follow-up of implant treatment. Part II: presence of peri-implant lesions.

OBJECTIVES: The aim of this study was to analyse the proportions of peri-implant lesions at implants after 9-14 years of function. MATERIAL AND METHODS: Two hundred and ninety-four patients underwent implant therapy during the years 1988-1992 in Kristianstad County. These individuals were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 218 patients with 999 implants were examined clinically and radiographically. RESULTS: Forty-eight per cent of the implants had probing depth > or =4 mm and bleeding on probing (peri-implant mucositis). In 20.4% of the implants, the bone level was located 3.1 mm apical to the implant shoulder. Progressive bone loss (> or =1.8 mm) during the observation period was found in 7.7% of the implants. Peri-implantitis defined as bone loss > or =1.8 mm compared with 1-year data (the apical border of the bony defect located at or apical to the third thread, i.e. a minimum of 3.1 mm apical to the implant shoulder), combined with bleeding on probing and or pus, were diagnosed among 16% of the patients and 6.6% of the implants. CONCLUSION: After 10 years in use without systematic supportive treatment, peri-implant lesions is a common clinical entity adjacent to titanium implants.

Nine- to fourteen-year follow-up of implant treatment. Part III: factors associated with peri-implant lesions.

OBJECTIVE: The aim of the present paper was to analyse, on patient and implant basis, factors related to peri-implant lesions. MATERIAL AND METHODS: Two hundred and eighteen patients treated with titanium implants were examined for biological complications at existing implants 9-14 years after initial therapy. The effects of several potentially explanatory variables, both on patient and on implant levels, were analysed. RESULTS: On the implant level, the presence of keratinized mucosa (p = 0.02) and plaque (p = 0.005) was associated with mucositis (probing depth > or =4 mm + bleeding on probing). The bone level at implants was associated with the presence of keratinized mucosa (p = 0.03) and the presence of pus (p < 0.001). On the patient level, smoking was associated with mucositis, bone level and peri-implantitis (p = 0.02, <0.001 and 0.002, respectively). Peri-implantitis was related to a previous history of periodontitis (p = 0.05). CONCLUSIONS: Individuals with a history of periodontitis and individuals who smoke are more likely to develop peri-implant lesions.

Treatment of peri-implant infections: a literature review.

OBJECTIVES: The purpose of the present paper is to review available information on the treatment of peri-implant mucositis and peri-implantitis. MATERIALS AND METHODS: The results of animal research and human studies are presented. Proposed strategies for the treatment of peri-implantitis presented in the literature are also included. RESULTS: Most of the information accessible at this time derives from case reports. The reports provide evidence that efforts to reduce the submucosal infection may result in short-term improvements of the peri-implant lesion. They also indicate that regenerative procedures in intrabony peri-implant defects can result in the formation of new bone. CONCLUSIONS: Several uncertainties remain regarding the treatment of peri-implantitis. Properly conducted long-term follow-ups of consecutively treated cases would seem to be a realistic avenue for accumulation of more information. This may assist in establishing the predictability, magnitude and stability of improvements that can be achieved.

Failure to induce supracrestal bone growth between and around partially inserted titanium implants using bone morphogenetic protein (BMP): an experimental study in dogs.

The effect of bone morphogenetic protein on supracrestal bone growth around partially inserted implants in a dog model is described. The lower premolar teeth (P1, P2, P3 and P4) were extracted on both sides of the mandible in six dogs. At a surgical exposure 12 weeks later, two 10-mm turned titanium implants were partially inserted, approximately 15 mm apart, in the areas of the P1 and P3 in each side of the mandible, allowing five threads to protrude from the bone crest. A titanium mesh was fastened to the coronal aspect of the two fixtures and the space beneath the mesh was filled with bone morphogenetic protein (S300 BMP) in combination with an insoluble bone matrix carrier, or with the carrier alone. The mesh was covered with an ePTFE membrane. Thus, a space for potential bone formation was created between the two implants. The surgical flaps were coronally positioned and secured with vertical mattress sutures. After 16 weeks of healing, biopsy specimens were retrieved and examined histologically. Bone was not formed around the protruding implants or in the created space between the implants in any case. The carrier was incompletely resorbed. We conclude that supracrestal bone growth beyond the crestal limit with or without BMP in such a large space as in this experimental design may not be possible.

Dog model for study of supracrestal bone apposition around partially inserted implants.

A dog model for study of supracrestal bone growth around partially inserted implants is described. The mandibular premolar teeth (P1, P2, P3 and P4) were extracted on both sides of the mandible in four dogs. At a surgical exposure 12 weeks later, two 10 mm titanium implants were partially inserted on each side, 15 mm apart, in the areas of the P1 and the P3 so that five threads protruded from the bone crest. A titanium mesh was fastened to the coronal aspect of the two fixtures and covered with an ePTFE membrane. Thus, a space for potential bone formation was created between the two implants. The surgical flaps were coronally positioned and secured with vertical mattress sutures. After 12 weeks of healing, biopsy specimens were retrieved and examined histologically. In three of the four dogs under study, the partially inserted implants had integrated and the intended large wound spaces had been created around the noninserted parts of the implants. However, bone was not formed around the protruding implants. Accordingly, this experimental model may prove useful for future studies on the use of various procedures that hypothetically may enhance bone formation.