Two- and ten-year follow-up of patients responding and non-responding to the surgical treatment of peri-implantitis: A retrospective evaluation.

OBJECTIVES: To report a follow-up of patients following the surgical anti-infective treatment of peri-implantitis and to identify possible risk indicators for the progression of disease during supportive peri-implant therapy. MATERIAL AND METHODS: Following peri-implant surgery, 41 patients (213 implants) were enrolled in a supportive peri-implant therapy. At the 2-year follow-up, two groups of patients were identified, with or without residual peri-implant pockets (responding and non-responding group). Eighteen patients (85 implants) of the non-responding group were followed for further 8 years. RESULTS: At the 2-year examination, 73 of the 117 treated implants (62.4%) presented healthy peri-implant condition, while 44 (37.6%) presented persisting peri-implantitis associated with substantial bone loss before treatment. The 10-year examination of the non-responding group revealed that 1) 84% of the implants that regained health following surgery remained healthy during the entire observation period; 2) 66% of the implants with residual pockets following surgery maintained stable peri-implant condition; and 3) 29% of all treated implants showed disease progression, and 11 of those were extracted. Presence of pockets at 3-4 sites of the implants was identified as risk indicator for progression of peri-implantitis. CONCLUSION: The peri-implant health achieved following therapy was maintained for most of the implants during the follow-up. Residual pockets were a frequent finding at implants with substantial bone loss before treatment. Presence of pockets around the entire circumference of the implants resulted as a risk indicator for further disease progression. The probability of progression of peri-implant disease increased with increased observation time.

Periimplant Disease and Prosthetic Risk Indicators: A Literature Review.

PURPOSE: The purpose of this review was to search in international published peer-review articles, data regarding prosthetic risk indicators affecting the incidence, prevalence, or treatment outcome of periimplant diseases. MATERIALS AND METHODS: A literature search was performed in MEDLINE via PubMed database of the US National Library of Medicine of articles published until February 2018; a manual search was also added. Randomized controlled trials, controlled trials, prospective and retrospective cohort studies with a minimum of 20 subjects, having cases with/without exposure to the risk indicator were included. Articles written in another language than English were not included. RESULTS: The 17 articles reviewed indicated the cement residuals at abutments were identified as risk factors for both mucositis and periimplantitis. Among the screw-retained prosthetic reconstructions, prostheses screwed directly to the implants have higher risk to develop periimplant disease. The accessibility and the possibility to perform adequate plaque control around the prosthetic suprastructure decreases the risk for periimplant disease; convex emergence profiles seem to increase it. The crown margins located submucosa may impair the periimplant treatment outcome. CONCLUSION: Prosthetic reconstruction on implants should be designed in a way to allow accessibility to proper plaque control. Screw-retained suprastructure and crown margins located supra-mucosa should be preferred when possible. When using cement-retained suprastructure, attention should be given to remove cement residuals.

Intra-surgical vs. radiographic bone level assessments in measuring peri-implant bone loss.

OBJECTIVE: To evaluate the accuracy between the intra-surgical and the peri-apical radiographic measurements of bone loss at implant with peri-implantitis. MATERIALS AND METHODS: A total of 46 Brånemark implants in 24 patients with diagnosis of peri-implantitis were included in the study. The amount of peri-implant bone loss occurred at those implants was measured during peri-implant surgery and compared to the radiographic bone loss measured by three independent examiners. RESULTS: The mean bone loss measured on radiographs underestimated the intra-surgical bone loss at the correspondent sites (0.7 mm at the mesial and 0.6 mm at the distal sites); this underestimation was found to be a consistent finding in all the three examiners. Only 21% of the radiographic measurements corresponded to the clinical bone loss assessments, while an over- and underestimation within a range of ± 1-2 mm was recorded in 57% of the cases. There was a moderate positive linear correlation between the radiographic measurements and the clinical bone loss for mesial and distal sites (r = range 0.58-0.65). The variability between the three examiners in the radiographic measurements was frequently on the range of ± 1-2 mm. CONCLUSION: The radiographic measurements of bone loss at implant affected by peri-implantitis often underestimated the clinical bone loss occurred at the implants. A difference of about ± 1-2 mm in the estimation of radiographic bone loss could be merely assigned as inter-examiner different assessments.

Clinical and microbiological findings in patients with peri-implantitis: a cross-sectional study.

OBJECTIVE: The aim of this study was to analyze clinical and microbiological characters in subjects and implants affected and not affected by peri-implantitis. Additionally, same features were analyzed also intra-individually, comparing healthy and diseased implants within the same subject. MATERIALS AND METHODS: A total of 534 patients who received at least 1 implant and coming to routine check-up or spontaneous visits at the University of Valencia were recruited. Clinical parameters including Bleeding on probing (BoP), Probing pocket depth (PPD), and Pi were screened. Samples for microbiological analysis were obtained from three locations: peri-implant sulci (PIS), inner parts of the implant connections (I), and gingival sulci of neighboring teeth (GS). Quantitative real-time PCR was performed for total counts of 10 microorganisms. RESULTS: A total of 534 patients with 1507 dental implants were analyzed. The prevalence of peri-implantitis was found 10.3% for patients and 7.3% for implants. Higher percentage of healthy periodontal subjects were found in the non-peri-implantitis group. The analysis within the 53 patients affected by peri-implantitis revealed that the implants affected by peri-implantitis presented a higher percentage of plaque, BoP, and number of implants presenting <2 mm attached gingiva. Additionally, more cemented crowns and implants inserted in bone-augmented sites were found among the diseased implants. The microbiologic analysis presented no relevant differences between the analysis at the peri-implant sulcus (PIS) and the connections inside the abutments surfaces (PI). The microbial composition at the neighboring teeth (GS) resembled the composition found at the PIS with a high frequency of Pg, Tf, Pi, PM, and Ec. CONCLUSIONS: The results of this study seem to indicate that inadequate oral hygiene and the presence of bleeding from the gingiva/mucosa in patients with dental implant were associated with an higher prevalence of peri-implantitis; moreover, in the patients affected by peri-implantitis, the lack of sufficient height keratinized mucosa (<2 mm) and bone regenerative procedures at implant level were also associated to higher prevalence of peri-implantitis as well.

Primary prevention of peri-implantitis: managing peri-implant mucositis.

AIMS: Over the past decades, the placement of dental implants has become a routine procedure in the oral rehabilitation of fully and partially edentulous patients. However, the number of patients/implants affected by peri-implant diseases is increasing. As there are--in contrast to periodontitis--at present no established and predictable concepts for the treatment of peri-implantitis, primary prevention is of key importance. The management of peri-implant mucositis is considered as a preventive measure for the onset of peri-implantitis. Therefore, the remit of this working group was to assess the prevalence of peri-implant diseases, as well as risks for peri-implant mucositis and to evaluate measures for the management of peri-implant mucositis. METHODS: Discussions were informed by four systematic reviews on the current epidemiology of peri-implant diseases, on potential risks contributing to the development of peri-implant mucositis, and on the effect of patient and of professionally administered measures to manage peri-implant mucositis. This consensus report is based on the outcomes of these systematic reviews and on the expert opinion of the participants. RESULTS: Key findings included: (i) meta-analysis estimated a weighted mean prevalence for peri-implant mucositis of 43% (CI: 32-54%) and for peri-implantitis of 22% (CI: 14-30%); (ii) bleeding on probing is considered as key clinical measure to distinguish between peri-implant health and disease; (iii) lack of regular supportive therapy in patients with peri-implant mucositis was associated with increased risk for onset of peri-implantitis; (iv) whereas plaque accumulation has been established as aetiological factor, smoking was identified as modifiable patient-related and excess cement as local risk indicator for the development of peri-implant mucositis; (v) patient-administered mechanical plaque control (with manual or powered toothbrushes) has been shown to be an effective preventive measure; (vi) professional intervention comprising oral hygiene instructions and mechanical debridement revealed a reduction in clinical signs of inflammation; (vii) adjunctive measures (antiseptics, local and systemic antibiotics, air-abrasive devices) were not found to improve the efficacy of professionally administered plaque removal in reducing clinical signs of inflammation. CONCLUSIONS: Consensus was reached on recommendations for patients with dental implants and oral health care professionals with regard to the efficacy of measures to manage peri-implant mucositis. It was particularly emphasized that implant placement and prosthetic reconstructions need to allow proper personal cleaning, diagnosis by probing and professional plaque removal.

Maintenance therapy in patients following the surgical treatment of peri-implantitis: a 5-year follow-up study.

AIM: To evaluate the outcomes of conventional periodontal maintenance therapy on patients surgically treated for peri-implantitis. MATERIAL AND METHODS: 27 patients with 149 dental implants were monitored during 5 years every 6 months. At each recall visit, the prostheses were removed to have proper access for implant examination and supra- and sub-gingival instrumentation. Sub-gingival instrumentation was performed using an ultrasonic instrument with under 0.12% chlorhexidine irrigation. RESULTS: At baseline (6 months following peri-implant surgery), 149 implants (78 not treated and 71 treated) were available for analysis. Of the 71 treated implants, 43 presented healthy peri-implant condition, while 28 had residual peri-implant pockets either of 4-5 mm or ≥ 6 mm associated with bleeding on probing/suppuration. The longitudinal evaluation revealed that the plaque and the bleeding index scores were low during the entire follow-up period, and healthy peri-implant conditions were maintained for both the 78 non-treated and the 43 treated "healthy" implants. Of the 28 implants with residual pockets, nine showed clinical attachment loss during the 5-year follow-up. Thus, of 71 treated implants, probing attachment loss occurred in only in 9 (13%) of the implants in four patients during the 5-year period. The presence of residual pockets at three or four sites of the implants (circumferential type of pockets) was frequently associated with increased probing pocket depth (PPD) and attachment loss, while this was not the case for implants with the presence of pockets at one or two sites only (site specific). CONCLUSION: In patients with a high standard of oral hygiene and enrolled in a recall system every 6 months, the peri-implant conditions obtained following peri-implant surgery were maintained stable for the majority of subjects and implants during a 5-year period. Presence of residual pockets around the circumference of the implants seemed to be a high predictor for disease progression.

Probing at implants with peri-implantitis and its relation to clinical peri-implant bone loss.

OBJECTIVES: To evaluate the probing depth at implants with signs of peri-implantitis before and following the removal of the prosthetic reconstructions and its relation with the peri-implant bone level as revealed by open access flap surgery. MATERIAL AND METHODS: Twenty-nine patients with 89 implants with diagnosis of peri-implantitis were included in the study. The probing pocket depth at implants before (PPD-1) and following (PPD-2) the removal of the prosthetic reconstructions was measured at four sites of the implants. These measurements were also analysed in relation to the amount of peri-implant bone loss measured during peri-implant surgery. RESULTS: The results showed that in only 119 (37%) of the sites, the measurements were similar between PPD-1 and PPD-2; in 124 sites (39%), the difference was ±1 mm, in 47 sites (15%) it was ±2 mm and in the rest of the sites it was ±3 mm. A high linear and statistically significant (P = <0.001) correlation between PPD-2 and the bone loss measured at implants for all and single surfaces was observed (r = 0.67, range 0.64-0.69), while PPD-1 yielded a weak and no statistically significant correlation (r = 0.35, range 0.27-0.42). The analysis of the bone loss at implants showed that 59 implants (66%) had an amount of bone loss that was similar at all the four surfaces, while in 30 implants, the bone loss differed for the various sites. A higher extent of bone loss was often detected at the buccal compared with the other sites. CONCLUSION: The results of this study yielded differences in the pocket probing measurements at implants with or without the prosthetic reconstruction in place and that the probing pocket depth following the removal of the prosthesis had a high correlation with the amount of bone loss at implants assessed during surgery.

Radiographic bone level and soft tissue dimensional changes following explantation of implants affected by peri-implantitis: A retrospective exploratory evaluation.

BACKGROUND: While the dimensional alteration of alveolar bone following tooth extraction have been extensively descripted in the literature, no information is available regarding potential hard and soft tissues changes following implant explantation. AIM: To evaluate the radiographic bone healing and the horizontal and vertical soft tissue dimensional alterations at implant extraction alveoli, 6 months following implant explantation. MATERIAL AND METHODS: Data from 31 patients scheduled for extraction of one implant with persisting peri-implantitis despite treatment were analysed. Bone crest level changes and the extent of bone healing at the apical aspect of the implant socket were assessed on the radiographs prior and 6 months following explantation. Regression analyses assessed the impact of various predictors (e.g., bone crest level, presence/absence of buccal bone) on bone level changes. Fisher's exact probability test was applied to assess the difference in probability to have mucosa recession of ≥2 mm in the presence or absence of alveolar buccal bone. RESULTS: A vertical bone loss of 0.8 mm (standard deviation [SD] = 1.3) of the peri-implant bone crest and a gain of 0.8 mm (SD = 1.1) from the bottom of the peri-implant defect were recorded. Complete healing was noted in the intact implant extraction socket (i.e., the part of the implant not affected by peri-implantitis). A reduction of 0.4 mm (SD = 0.7) of the alveolar mucosa height was recorded in concomitant with a decrease of 0.7 mm (SD = 0.8) of the mucosa width. These alterations were more pronounced in the absence of the alveolar buccal bone. CONCLUSION: The results of the present explorative study indicated a decrease in the height and width of the alveolar soft and hard tissues following explantation of peri-implantitis affected implants, and these changes were more pronounced in the absence of the buccal bone wall. Nevertheless, the apical portion of the implant alveolus (the intact implant socket) tend to heal with no further bone loss.

The effect of a toothpaste containing aloe vera on established gingivitis.

The aim of the study was to evaluate the effect of a toothpaste containing high concentrations of Aloe vera on the reduction of plaque and gingivitis in patients attending regular dental care by a dental hygienist. Fifteen subjects participated in this randomized, double-blind, intra-individual and controlled clinical study. Participants were non-smokers, with signs of gingivitis (bleeding index 30%) and no signs of periodontitis. Subjects were followed for three 6-month periods during which they used either their own toothpaste, or an Aloe vera or a control toothpaste. Plaque and gingival indices were recorded atthe start and end of each period. There was a statistically and clinically significant reduction of about 20% of the plaque and gingivitis indices at the end of the clinical trial compared to baseline values, but no differences between the Aloe vera and the control toothpaste. It may be concluded that in patients motivated to improve their oral hygiene habits, the use of a toothpaste containing Aloe Vera showed no additional effect on plaque and gingivitis compared to a control toothpaste.

Longitudinal study on the effect of keratinized mucosal augmentation surrounding dental implants in preventing peri-implant bone loss.

Background: Dental implant therapy is a well-established method of prosthetic rehabilitation of missing teeth. To maintain the health of the surrounding tissue, management of risk factors/indicators and daily maintenance are important. It still remains controversial whether a certain amount of keratinized mucosal width is essential for maintaining the health of peri-implant tissue. The purpose of this multicenter retrospective study was to assess the correlation between bone loss around dental implant and the amount of keratinized tissue width. Methods: A total of 1,644 implants were evaluated. Data was collected about participants' general and dental history, as well as implant details. Bone resorption around implant was calculated from intra-oral radiographs taken after 1 year and more than 3 years of function. Implants were classified into three groups; received free gingival graft or apically repositioned flap surgery for increasing the keratinized mucosa ≥2 mm width (group A), keratinized mucosa width ≥2 mm (group B), and keratinized mucosa width <2 mm (group C). These data were analyzed by propensity score analysis and a generalized linear regression analysis was performed to compare the bone resorption among groups. Results: Mean functional time was 55.8 months (SD = 20.5) in group A, 67.6 months (SD = 28.1) in group B, and 74.5 months (SD = 32.9) in group C. Mean bone resorption of groups A, B, and C were 0.08 mm (SD = 0.40), 0.18 mm (SD = 0.66), and 0.44 mm (SD = 0.40). Groups A and B had significantly lower bone resorption than group C. Conclusion: The results in this study show the importance of keratinized mucosa in maintaining the peri-implant bone. Our findings also suggest that mucosal transplantation is useful, as opposed to narrowing of the keratinized mucosa.

Outcome of surgical treatment of peri-implantitis: results from a 2-year prospective clinical study in humans.

AIM: The aim of the present study was to evaluate the outcome of a surgical procedure based on pocket elimination and bone re-contouring for the treatment of peri-implantitis. MATERIAL AND METHODS: The 31 subjects involved in this study presented clinical signs of peri-implantitis at one or more dental implants (i.e. ≥6 mm pockets, bleeding on probing and/or suppuration and radiographic evidence of ≥2 mm bone loss). The patients were treated with a surgical procedure based on pocket elimination and bone re-contouring and plaque control before and following the surgery. At the time of surgery, the amount of bone loss at implants was recorded. RESULTS: Two years following treatment, 15 (48%) subjects had no signs of peri-implant disease; 24 patients (77%) had no implants with a probing pocket depth of ≥6 mm associated with bleeding and/or suppuration following probing. A total of 36 implants (42%) out of the 86 with initial diagnosis of peri-implantitis presented peri-implant disease despite treatment. The proportion of implants that became healthy following treatment was higher for those with minor initial bone loss (2-4 mm bone loss as assessed during surgery) compared with the implants with a bone loss of ≥5 mm (74% vs. 40%). Among the 18 implants with bone loss of ≥7 mm, seven were extracted. Between the 6-month and the 2-year examination, healthy implants following treatment tended to remain stable, while deepening of pockets was observed for those implants with residual pockets. CONCLUSION: The results of this study indicated that a surgical procedure based on pocket elimination and bone re-contouring and plaque control before and following surgery was an effective therapy for treatment of peri-implantitis for the majority of subjects and implants. However, complete disease resolution at the site level seems to depend on the initial bone loss at implants. Implants with no signs of peri-implantitis following treatment tended to remain healthy during the 2-year period, while a tendency for disease progression was observed for the implants that still showed signs of peri-implant disease following treatment.

The secretion of cytokines by peripheral blood mononuclear cells of patients with periodontitis and healthy controls when exposed to H2S.

Background: Hydrogen sulfide(H2S) is a bacterial metabolite produced as a result of bacterial growth in subgingival pockets, suggested to partake in the pathogenesis of periodontitis. H2S has previously been shown to induce the secretion of the pro-inflammatory cytokines IL-1ß and IL-18 via the NLRP3 inflammasome in monocytes. Objective: To investigate the non-NLRP3 inflammasome-dependent immunological response of human peripheral blood mononuclear cells (PBMCs) of periodontitis patients and healthy controls exposed to H2S in vitro. Methods: PBMCs of periodontitis patients(N = 31) and healthy controls(N = 32) were exposed to 1 mM sodium hydrosulfide (NaHS) at 37°C for 24 h and the secretion of cytokines was compared to resting cells. TNF-α, IFN-γ, IL-6, IL-8, IL-12p40, IL-12p70, IL-17, MCP-1, and IL-1Ra secretions were measured with Bio-Plex Pro™ Human Cytokine Assay. Results: H2S triggered the secretion of the pro-inflammatory IFN-γ, IL-6, IL-17, TNF-α, IL-12p40, and IL-12p70, while the reverse was seen for IL-1Ra. In addition, a higher basal secretion of IFN-γ, IL-6, IL-12p70, IL-17 and MCP-1 was seen from PBMCs of periodontitis patients compared to healthy controls. Conclusion: The bacterial metabolite H2S triggers the secretion of pro-inflammatory cytokines from PBMCs and may thus have a prominent role in the host-bacteria interplay in periodontitis.

Peri-implantitis in partially edentulous patients: association with inadequate plaque control.

OBJECTIVE: The aim of the present study was to describe some clinical periodontal features of partially edentulous patients referred for the treatment of peri-implantitis. MATERIAL AND METHODS: The 23 subjects involved in this study were selected from consecutive patients referred to the department of Periodontology Södra Alvsborgs Hospital, Borås, Sweden, for treatment of peri-implantitis during 2006. The patients had clinical signs of peri-implantitis around one or more dental implants (i.e.>or=6 mm pockets, bleeding on pockets and/or pus and radiographic images of bone loss to>or=3 threads of the implants) and remaining teeth in the same and/or opposite jaw. The following clinical variables were recorded: Plaque Index (PI), Gingival Bleeding Index (GBI) Probing Pocket Depth (PPD), Access/capability to oral hygiene at implant site (yes/no), Function Time. The patients were categorized in the following sub-groups: Periodontitis/No periodontitis, Bone loss/No bone loss at teeth, Smoker/Non-smokers. RESULTS: Out of the 23 patients, the majority (13) had minimal bone loss at teeth and no current periodontitis; 5 had bone loss at teeth exceeding 1/3 of the length of the root but not current periodontitis and only 5 had current periodontitis. Six patients were smokers (i.e. smoking more than 10 cig/day). The site level analysis showed that only 17 (6%) of the 281 teeth present had >or=1 pocket of >or=6mm, compared to 58 (53%) of the total 109 implants (28 ITI and 81 Brånemark); 74% of the implants had no accessibility to proper oral hygiene. High proportion of implants with diagnosis of peri-implantitis were associated with no accessibility/capability for appropriate oral hygiene measures, while accessibility/capability was rarely associated with peri-implantitis. Indeed 48% of the implants presenting peri-implantitis were those with no accessibility/capability for proper oral hygiene (65% positive predict value) with respect to 4% of the implants with accessibility/capability (82% negative predict value). CONCLUSION: The results of the study indicate that local factors such as accessibility for oral hygiene at the implant sites seems to be related to the presence or absence of peri-implantitis. Peri-implantitis was a frequent finding in subjects having signs of minimal loss of supporting bone around the remaining natural dentition and no signs of presence of periodontitis (i.e. presence of periodontal pockets of >or=6 mm at natural teeth). Only 6 of the examinated subjects were smokers. In view of these results we should like to stress the importance of giving proper oral hygiene instructions to the patients who are rehabilitated with dental implant and of proper prosthetic constructions that allow accessibility for oral hygiene around implants.

H2S mediates increased interleukin (IL)-1ß and IL-18 production in leukocytes from patients with periodontitis.

Background: The mechanisms involved in the interplay between the bacteria and the host cells in periodontitis are not fully understood. Aim: To investigate the effect of the bacterial metabolite H2S on the pro-inflammatory cytokines interleukin (IL)-1ß and IL-18 from periodontitis patients and healthy controls, and to evaluate the composition of the subgingival microbiota with its capacity to produce H2S. Methods: Subgingival bacterial samples from patients with periodontitis (N=32) and healthy controls (N=32) were investigated for H2S production and bacterial composition. Peripheral blood mononuclear cells (PBMCs) were cultured in the presence/absence of 1mM H2S for 24h and cytokine concentrations were measured. Results: Subgingival plaque from periodontitis patients had more H2S producing bacteria and produced more H2S, than healthy controls. PBMCs exposed to H2S secreted significantly more IL-1ß and IL-18 (p<0.0001) than untreated control PBMCs from both groups. PBMCs from the periodontitis patients secreted higher levels of the cytokines, both spontaneously (IL-1ß p=0.0001; IL-18 p=0.09) and after exposure to H2S (IL-1ß p=0.03; IL-18 p=0.04), which is a new finding not previously reported. Conclusions: H2S, from the subgingival microbiota, can contribute to a host inflammatory response through secretion of the pro-inflammatory cytokines IL-1ß and IL-18. Since this response differs between individuals, it may also reflect the susceptibility of the host to develop periodontitis.

Local risk indicators - Consensus report of working group 2.

In implant dentistry, plaque control and oral hygiene practices are essential to limit the risk of complication and failure in the long term. All conditions around an implant in function that influence the load and pathogenicity of the microbiota are considered local risk indicators. They concern the prosthetic suprastructure design and the possibility for the patient to easily access each implant for plaque removal. Use of cemented prostheses should be limited to avoid excess cement acting as a foreign body and leading to peri-implant disease. The crown margins should be supramucosal, and the connection should be precise to avoid a gap between the implant and the suprastructure. Every implant system is characterised by a specific design, surface texture and connection type. These features may influence peri-implantitis development and progression, and the clinician should consider the risk of infection when selecting an implant. The soft-tissue conditions around the implant, the width of keratinised mucosa, and the phenotype and thickness of the mucosa are also considered major risk indicators, as the presence of any mucosal defect around an implant can increase plaque accumulation and result in tissue inflammation. The pathogenicity of the microbiota around an implant is primarily dependent on pocket depth. Deep pockets around implants should be avoided and, if present, closely monitored and/or reduced. Proximity to natural teeth presenting endodontic and/or periodontal lesions may result in implant contamination, but the influence of the type of edentulism on perio-pathogen presence is still unclear. These local conditions around an implant have a clear influence on peri-implant diseases development and progression, but there is still only limited evidence regarding their role as true risk indicators.

Non-surgical mechanical treatment of peri-implant mucositis: the effect of sub-mucosal mechanical instrumentation following supra-mucosal plaque removal. A 7-month prospective single cohort study.

PURPOSE: To evaluate the effect of sub-mucosal mechanical instrumentation following supra-mucosal plaque removal in the treatment of peri-implant mucositis. MATERIALS AND METHODS: A total of 44 patients, 27 from a specialist clinic in Sweden, and 17 from a Japanese one, were included. The 44 patients had a total of 175 implants of which 84 (48%) had clinical signs of mucositis (bleeding on probing [BoP]) and no radiographic bone loss. At baseline, the 44 patients received professional supra-mucosal plaque removal and oral hygiene instruction and motivation. Following the 1-month examination, sub-mucosal instrumentation was initiated using ultrasonic and hand instruments. Patients were then examined at 4 and 7 months. Presence of plaque, marginal bleeding, BoP and probing pocket depth (PPD) changes were recorded at each examination in an unblinded manner. RESULTS: One month following supra-mucosal plaque removal, the number of treated implants with BoP was reduced from 84 to 44 (48% reduction) with a concomitant decrease of the mean PPD of 0.6 mm (95% CI: -0.5 to -0.7), from 4.4 ± 1.0 mm (mean ± SD) to 3.8 ± 1.0 mm, P < 0.0001. Following sub-mucosal instrumentation, a further reduction of 9% (from 44% to 36%) of BoP was recorded, with a concomitant reduction of the mean PPD of 0.3 mm (95% CI: -0.1 to -0.4) at the 7-month examination. CONCLUSIONS: The improvement of the clinical condition (absence of marginal bleeding, BoP and PPD reduction at treated implants) following non-surgical treatment of mucositis appeared to be in great part because of supra-mucosal plaque removal, while the sub-mucosal instrumentation seemed to have only a minor additional effect. Deep implant position compared to neighbouring teeth/implant was associated with persisting mucositis following treatment. The presence of deep pockets following treatment was associated with BoP, screw-retained prostheses without abutment and sub-mucosal crown margins.

Extent and location of bone loss at dental implants in patients with peri-implantitis.

Peri-implantitis is an infectious disease, which leads to loss of supporting bone around dental implants. To evaluate the extent and location of bone loss, 43 patients with peri-implantitis were examined. The bone loss was clinically measured at the time of dental surgery. Data revealed that 25% of subjects had bone loss associated with all their implants although the majority of the subjects had fewer than 50% of their implants affected by bone loss. A total number of 264 implants were examined and 131 of those had peri-implantitis associated bone loss. The pattern of bone loss at implants varied between and within subjects and location in the jaws. The highest proportion of implants with peri-implantitis was found in the upper jaw and within this group, at implants located in the incisor area of the upper jaw; the lowest was the canine area of the lower jaw. The highest proportion of implants that lost ≥ 2/3 of their bone support was found in the incisor area of the maxilla. We concluded that in the presence of peri-implant inflammation, bone quantity and characteristics may influence the progression of peri-implantitis bone loss at dental implants. We hypothesize that the ability of the bone to withstand occlusal forces will be altered as consequence of the loss of bone at the neck of the implants. To achieve an understanding of the local degradation of bone due to peri-implantitis, we need to analyze the microstructure of the bone as well the cellular biology of the peri-implant inflammation.

Polylactide and polyglycolide sponge used in human extraction sockets: bone formation following 3 months after its application.

OBJECTIVES: The aim of this study was to evaluate (i) the degree of bone mineralization in the alveolar sockets 3 months following the use of a bio-absorbable graft material and (ii) the degree of resorption of the grafted material. MATERIALS: Twenty patients, undergoing periodontal therapy, participated in this study. All patients were scheduled for extraction of one or more compromised monoradicular teeth and scheduled for replacement of the extracted teeth with dental implants. METHODS: Following elevation of full-thickness flaps and extraction of teeth, the alveolar sockets were filled with a bioabsorbable polylactide-polyglycolide acid sponge (Fisiograft) (Test group - T) or natural healing by clot formation was allowed (Control group - C). The flaps were sutured with no attempt to achieve primary closure of the surgical wound. Re-entry for implant surgery was performed 3 months following the extractions. RESULTS: Fifteen biopsies (seven T and nine C) were harvested from the sites where the implants were placed. The biopsies harvested from the T sites revealed that the alveolar sockets healed with newly trabecular bone, highly mineralized and well structured. Particles of the grafted material could not be identified in any of the T biopsies. The bone formed in the C sites was also well structured, with a slightly minor percentage of mineralized bone. In both T and C biopsies, the apical portion presented a higher degree of mineralization compared with the coronal portion. CONCLUSIONS: The results of this study indicated that the use of a bio-absorbable synthetic sponge of polylactide-polyglycolide acid did not interfere with the formation of new bone in the alveolar sockets and that the characteristics of the 3-month newly formed bone seemed to be optimal for dental implants' insertion. The biocompatibility, safety and characteristics of Fisiograft suggest that the material is suitable for filling alveolar sockets following extractions, to prevent volume reduction and collapse of the overlying soft tissue flaps.

Ridge preservation following tooth extraction using a polylactide and polyglycolide sponge as space filler: a clinical and histological study in humans.

BACKGROUND: The placement of different graft materials and/or the use of occlusive membranes to cover the extraction socket entrance are techniques aimed at preserving/reducing alveolar ridge resorption. The use of grafting materials in fresh extraction sockets has, however, been questioned because particles of the grafted material have been found in alveolar sockets 6-9 months following their insertion. AIM: The aims of the study were to (i). evaluate whether alveolar ridge resorption following tooth extraction could be prevented or reduced by the application of a bioabsorbable polylactide-polyglycolide sponge used as a space filler, compared to natural healing by clot formation, and (ii). evaluate histologically the amount and quality of bone tissue formed in the sockets, 6 months after the use of the bioabsorbable material. MATERIAL AND METHODS: Thirty-six patients, undergoing periodontal therapy, participated in this study. All patients were scheduled for extraction of one or more compromised teeth. Following elevation of full-thickness flaps and extraction of teeth, measurements were taken to evaluate the distance between three landmarks (mesio-buccal, mid-buccal, disto-buccal) on individually prefabricated stents, and the alveolar crest. Twenty-six alveolar sockets (test) were filled with a bioabsorbable polylactide-polyglycolide acid sponge (Fisiograft), while 13 sockets (controls) were allowed to heal without any filling material. The flaps were sutured with no attempt to achieve primary closure of the surgical wound. Re-entry for implant surgery was performed 6 months following the extractions. Thirteen biopsies (10 test and three control sites) were harvested from the sites scheduled for implant placement. RESULTS: The clinical measurements at 6 months revealed, in the mesial-buccal site, a loss of bone height of 0.2 mm (1.4 SD) in the test and 0.6 mm (1.1 SD) in the controls; in the mid-buccal portion a gain of 1.3 mm (1.9 SD) in the test and a loss of 0.8 mm (1.6 SD) in the controls; and in the distal portion a loss of 0.1 mm (1.1 SD) in the test and of 0.8 (1.5 SD) mm in the controls. The biopsies harvested from the test sites revealed that the new bone formed at 6 months was mineralized, mature and well structured. Particles of the grafted material could not be identified in any of the 10 test biopsies. The bone formed in the control sites was also mature and well structured. CONCLUSION: The results of this study indicate that alveolar bone resorption following tooth extraction may be prevented or reduced by the use of a bioabsorbable synthetic sponge of polylactide-polyglycolide acid. The quality of bone formed seemed to be optimal for dental implant insertion.