Reversibility of experimental peri-implant mucositis compared with experimental gingivitis in humans

Adjunctive efficacy of probiotics in the treatment of experimental peri-implant mucositis with mechanical and photodynamic therapy: a randomized, cross-over clinical trial

AIM

To evaluate the adjunctive clinical efficacy of probiotics in the treatment of peri-implant mucositis (p-iM) with professionally administered plaque removal (PAPR) and photodynamic therapy (PDT).

MATERIALS AND METHODS

Following p-iM induction, patients underwent PAPR + PDT and were randomly assigned to receive the professional and home-based administration of probiotics (Lactobacillus plantarum and Lactobacillus brevis) (test treatment) or placebo preparation (control treatment) according to a cross-over design. Clinical parameters were assessed at six sites for each implant before as well as at 2 and 6 weeks after professional treatment administration.

RESULTS

Twenty patients contributing one dental implant each were included. Immediately before treatment and at 6 weeks, the median number of sites with bleeding on probing (BoP+) sites per implant unit was 4 (3-6) and 2 (0-2) (p < 0.001), respectively, for test treatment, and 3.5 (2-4) and 2 (0-3) (p = 0.03), respectively, for control treatment. No significant difference in clinical outcomes was observed between treatment groups.

CONCLUSION

The combination of PAPR and PDT either alone or associated with probiotics determined a significant reduction in the number of BoP+ sites at 2 and 6 weeks around implants with p-iM. The adjunctive use of probiotics did not significantly enhance the clinical outcomes of PAPR + PDT.

Bleeding on probing around dental implants: a retrospective study of associated factors

AIM

To (i) identify factors associated with the probability of a peri-implant site to be positive to bleeding on probing (BoP+) and (ii) compare BoP+ probability around dental implants and contra-lateral teeth.

METHODS

In 112 patients, data related to 1725 peri-implant sites and 1020 contra-lateral dental sites were retrospectively obtained. To analyse the association between patient-, implant- and site-related factors and BoP+ probability, a logistic, three-level model was built with BoP as the binary outcome variable (+/-).

RESULTS

BoP+ probability for a peri-implant site with probing depth (PD) of 4 mm was 27%, and the odds ratio increased by 1.6 for each 1-mm increment in PD (p < 0.001). Also, BoP+ probability was higher in females compared to males (OR = 1.61; p = 0.048), and lower at posterior compared to anterior dental implants (OR = 0.55; p < 0.01). No significant difference in BoP+ probability was observed between peri-implant and contra-lateral dental sites when controlling for the difference in PD.

CONCLUSIONS

The probability of a peri-implant site to bleed upon probing is (i) associated with PD, implant position and gender, and (ii) similar to that observed at contra-lateral dental sites when controlling for the effect of PD.

Pro-inflammatory cytokines at zirconia implants and teeth. A cross-sectional assessment

OBJECTIVES

The aim of this study was to compare the expression of host-derived markers in peri-implant/gingival crevicular fluid (PCF/GCF) and clinical conditions at ceramic implants and contralateral natural teeth. As a secondary objective, we compared zirconia implants with titanium implants.

METHODS

One zirconia implant (ZERAMEX® Implant System) and one contralateral natural tooth were examined in 36 systemically healthy subjects (21 males, 15 females, mean age 58). The levels of Il-1β, Il-1RA, Il-6, Il-8, Il-17, b-FGF, G-CSF, GM-CSF, IFNɣ, MIP-1β, TNF-α, and VEGF were assessed in PCF/GCF using the Bio-Plex 200 Suspension Array System. The plaque index (PI), gingival index (GI), probing depth (PD), and bleeding on probing (BOP) were assessed at six sites around each implant or tooth. Titanium implants were also assessed when present (n = 9).

RESULTS

The zirconia implants were examined after a loading period of at least 1.2 years (average 2.2 years). The mean PI was significantly lower at zirconia implants compared to teeth (p = 0.003), while the mean GI, PD, and BOP were significantly higher (p < 0.001). A correlation was found in the expression of Il-1RA, Il-8, G-CSF, MIP-1β, and TNF-α at zirconia implants and teeth. The levels of IL-1β and TNF-α were significantly higher at zirconia implants than at teeth. No significant differences were found between zirconia and titanium implants. A correlation was found between the levels of IL-1RA, IL-8, GM-CSF, and MIP-1β at zirconia and titanium implants.

CONCLUSIONS

The correlation in the expression of five biomarkers at zirconia implants and teeth, and of four biomarkers at zirconia and titanium implants, is compatible with the existence of a patient-specific inflammatory response pattern. Higher mean GI, PD, and BOP around implants suggests that the peri-implant mucosa may be mechanically more fragile than the gingiva.

CLINICAL RELEVANCE

Similar expression of selected biomarkers at zirconia implants and teeth and at zirconia and titanium implants reflects existence of patient-specific inflammatory response patterns.

Occlusal trauma and mucositis or peri-implantitis?

BACKGROUND AND OVERVIEW

The aim of this study was to describe the effects of bruxism in peri-implant bone loss 6 years after the placement of a successful implant-supported prosthesis, to describe its treatment, and to propose a differential diagnosis of the lesion.

CASE DESCRIPTION

A 62-year-old, nonsmoking, systemically healthy partially edentulous woman received 2 osseointegrated implants in the mandibular left region, which supported a 3-element fixed prosthesis. Six years later, the patient reported the development of bruxism. Clinical examination results indicated bleeding on probing, deepening of the peri-implant sulcus, and marginal soft-tissue overgrowth. Radiographic images suggested peri-implant bone loss. The authors diagnosed the lesion as trauma from occlusion and mucositis. Treatment involved anti-infective therapy and the use of a bite platform, resulting in bone recovery after 10 months. These results were maintained for 4 years.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Considering the existing contradictions in the literature, this case highlights the role of trauma from occlusion in the onset, progression, and treatment of lesions produced by occlusal overload around osseointegrated implants. In addition, it provides clinical background on the outcomes of anti-infective therapy associated with the use of a bite platform in the treatment of combined lesions of mucositis and trauma from occlusion in osseointegrated implants.

Clinical, Immune, and Microbiome Traits of Gingivitis and Peri-implant Mucositis

Tissues surrounding dental implants and teeth develop clinical inflammation in response to microbial stimuli. However, the literature suggests that differences exist in the microbial insult and inflammatory responses leading to gingivitis and peri-implant mucositis. In this pilot study, the authors use for the first time a systems biology approach to comprehensively evaluate clinical parameters, selected inflammatory markers, and the microbiome of subject-matched tooth and implant sites during native inflammation and in response to experimental plaque accumulation. Fifteen subjects with 2 posterior implants and corresponding contralateral teeth were examined at enrollment; at day 0, after reinstitution of gingival/mucosal health; at days 7, 14, and 21, during stent-mediated oral hygiene (OH) abstention; and at day 42, after resumption of OH. The subgingival microbiome was evaluated via 16S rRNA gene sequencing and 8 selected inflammatory markers measured in crevicular fluid. Comparison of teeth and implants via general linear models based on orthogonal polynomials showed similar responses in clinical parameters, inflammatory mediators, and proportions of individual microbial taxa during OH abstention. Implants, however, accumulated less plaque and underwent more heterogeneous shifts in microbiome structure. A multilevel, within-group, sparse partial least squares analysis of covariation of microbial, inflammatory, and clinical parameters throughout all study visits found inflammation around teeth and implants positively correlated with IL-1 alpha and IL-1 beta and with the proportions of Selenomonas, Prevotella, and 5 species-level phylotypes. Gingivitis, however, showed a stronger positive correlation with lactoferrin and IL-1ra and a stronger negative correlation with Rothia. Peri-implant mucositis, on the contrary, correlated positively with certain microbial taxa not associated with gingivitis by a previous study or the current one. In summary, differences existed between implants and tooth sites in microbiome evolution during OH abstention and in the correlation of specific inflammatory mediators and microbial taxa with clinical inflammation. Common biological features, however, were also identified for gingivitis and mucositis.

Microbial Profiles and Detection Techniques in Peri-Implant Diseases: a Systematic Review

Objectives

To describe the microbial profiles of peri-implant diseases and the main detection methods.

Material and Methods

A literature search was performed in MEDLINE via PubMed database to identify studies on microbial composition of peri-implant surfaces in humans published in the last 5 years. Studies had to have clear implant status definition for health, peri-implant mucositis and/or peri-implantitis and specifically study microbial composition of the peri-implant sulcus.

Results

A total of 194 studies were screened and 47 included. Peri-implant sites are reported to be different microbial ecosystems compared to periodontal sites. However, differences between periodontal and peri-implant health and disease are not consistent across all studies, possibly due to the bias introduced by the microbial detection technique. New methods non species-oriented are being used to find ‘unexpected’ microbiota not previously described in these scenarios.

Conclusions

Microbial profile of peri-implant diseases usually includes classic periodontopathogens. However, correlation between studies is difficult, particularly because of the use of different detection methods. New metagenomic techniques should be promoted for future studies to avoid detection bias.

The Efficacy of Supportive Peri-Implant Therapies in Preventing Peri-Implantitis and Implant Loss: a Systematic Review of the Literature

Objectives

To study the efficacy of supportive peri-implant therapies in preventing clinical and radiological signs of peri-implantitis and implant loss.

Material and Methods

Longitudinal human studies, published between January 1, 2006, and February 1, 2016, were included based on an electronic search using MEDLINE and EMBASE databases and complemented by a manual search. Articles were included only if 1) they comprised a group of patients involved in/adhering to regular supportive peri-implant therapies (SPTs) and a control group without such therapies or with poor adherence to them, 2) the protocol of the SPTs was clearly described and 3) the outcome was indicated by means of clinical/radiological changes or implant loss.

Results

After initially identifying a total of 710 titles and abstracts, 12 full text articles were selected for eligibility assessment. Seven studies, three prospective and four retrospective, fulfilled the inclusion criteria for this review.

The frequency of recall visits varied between the studies from a minimum of one visit every three months to an individually tailored regimen. In all the studies a lack of SPTs or poor adherence to them resulted in significantly higher frequencies of sites with mucosal bleeding, deepened peri-implant pockets or alveolar bone loss. In line with the above, a lack of/poor adherence to SPTs was associated with higher implant loss.

Conclusions

To prevent peri-implantitis, an individually tailored supportive programme based on patient motivation and re-instruction in oral hygiene measures combined with professional implant cleaning seem to be crucial.

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.

Effectiveness of enamel matrix derivative on the clinical and microbiological outcomes following surgical regenerative treatment of peri-implantitis. A randomized controlled trial

OBJECTIVE

This randomized clinical trial aimed at comparing radiological, clinical and microbial effects of surgical treatment of peri-implantitis alone or in combination with enamel matrix derivative (EMD).

METHODS

Twenty-six subjects were treated with open flap debridement and decontamination of the implant surfaces with gauze and saline preceding adjunctive EMD or no EMD. Bone level (BL) change was primary outcome and secondary outcomes were changes in pocket depth (PD), plaque, pus, bleeding and the microbiota of the peri-implant biofilm analyzed by the Human Oral Microbe Identification Microarray over a time period of 12 months.

RESULTS

In multivariate modelling, increased marginal BL at implant site was significantly associated with EMD, the number of osseous walls in the peri-implant bone defect and a Gram+/aerobic microbial flora, whereas reduced BL was associated with a Gram-/anaerobic microbial flora and presence of bleeding and pus, with a cross-validated predictive capacity (Q(2) ) of 36.4%. Similar, but statistically non-significant, trends were seen for BL, PD, plaque, pus and bleeding in univariate analysis.

CONCLUSION

Adjunctive EMD to surgical treatment of peri-implantitis was associated with prevalence of Gram+/aerobic bacteria during the follow-up period and increased marginal BL 12 months after treatment.

Experimental mucositis and experimental gingivitis in persons aged 70 or over. Clinical and biological responses

Objectives

To compare in persons aged 70 years or older the clinical and inflammatory changes occurring around implants and natural teeth during and after a phase of undisturbed plaque accumulation.

Material and methods

Twenty partially edentulous participants with titanium implants refrained from oral hygiene practices while being clinically monitored in weekly intervals for 21 days. Teeth and implants were then cleaned, oral hygiene resumed, and the participants were further monitored for 3 weeks. Twelve biomarkers were assessed in gingival and peri‐implant crevicular fluid (GCF, PCF).

Results

During 3 weeks of oral hygiene abstention, the gingival index (GI) continuously increased. On day 21, there were significantly more sites with GI >1 at implants than at teeth. After restarting oral hygiene, the GI decreased markedly in both groups. Throughout the experiment, the plaque index was significantly higher on teeth than on implants.

The different biomarkers reacted variably. IL‐1β increased significantly with plaque accumulation. IL‐1β, GM‐CSF, TNF‐α, and IFN‐γ were significantly higher in GCF compared to PCF at day 21. IL‐8 decreased significantly in GCF up to day 14. MIP‐1β decreased significantly in GCF, but not in PCF. At the 3‐week follow‐up, the levels of all biomarkers assessed in GCF and PCF had returned to baseline values.

Conclusions

In an elderly cohort, plaque accumulation induced an inflammatory reaction around both teeth and implants. Although there was less plaque accumulation on implants, the peri‐implant mucosa showed a stronger clinical response than gingiva.

Implant surface roughness alterations induced by different prophylactic procedures: an in vitro study

AIM

To evaluate surface roughness alterations at the smooth neck of dental implants after the use of eight different prophylactic procedures.

MATERIALS AND METHODS

50 tissue level implants (Institut Straumann AG, Basel, Switzerland) were used for the present investigation. The smooth collar of each implant was divided into two segments, each treated with one of eight cleaning procedures: use of a rubber cup (RCZ) or a brush (BZ) combined with an abrasive paste containing zirconium or a paste derived from perlite (RCP, BP); use of 2 composite resin burs reinforced by zirconium glass fibers (F1, F2); and use of an air-polishing system with glycine powder and two power settings (AP1, AP2). The qualitative alterations were recorded by means of a laser profilometer and the mean roughness (R_a ) and mean roughness profile depth (R_z ) were reported. Twenty untreated surfaces were used as controls.

RESULTS

The implant collars treated with RCZ (R_a  = 0.33 μm, R_z  = 2.43 μm) or BZ (R_a  = 0.30 μm, R_z  = 3.70 μm) yielded the highest roughness values, followed by the surfaces treated with RCP (R_a  = 0.28 μm, R_z  = 2.02 μm), with BP (R_a  = 0.25 μm, R_z  = 2.16 μm) and by the use of F1 (R_a  = 0.27 μm, R_z  = 2.22 μm) and F2 (R_a  = 0.27 μm, R_z  = 2.04 μm). The lowest roughness values were observed in the AP1 (R_a  = 0.23 μm, R_z  = 1.60 μm) and AP2 (R_a  = 0.16 μm, R_z  = 1.06 μm) group, respectively. Implant collars treated with AP2 yielded statistically significantly lower (P = 0.01) R_z values compared with untreated surfaces.

CONCLUSION

All tested procedures did not increase implant surface roughness significantly. Treatment with an air-powder abrasive system at high-pressure setting resulted in a smoothening of the implant collar surface.

Peri-Implant Sulcus Fluid (PISF) Matrix Metalloproteinase (MMP) -8 Levels in Peri-Implantitis

INTRODUCTION

Matrix Metalloproteinase (MMP) -8 plays crucial role in pathogenesis of periodontitis and is also a possible biomarker candidate in peri-implantitis.

AIM

The aim of the study was to analyse MMP-8 levels in peri-Implant Sulcus Fluid (PISF) from peri-implantitis affected implants in smoking and non-smoking patients with different periodontal health status of natural teeth before and after peri-implantitis treatment.

SETTINGS AND DESIGN

Altogether 29 patients with peri-implantitis were recruited and divided into two study groups (11 with healthy periodontium or gingivitis, i.e. no marginal bone loss, and 18 with chronic periodontitis).

MATERIALS AND METHODS

PISF sample from one implant with peri-implantitis from each patient was collected at the baseline and six months after conservative and surgical peri-implantitis treatment, and clinical parameters were registered. Samples were analysed for MMP-8 with dento ELISA method applying a monoclonal antibody. Mucosal cell samples were also analysed for IL-1 gene polymorphism. PISF MMP-8 levels' differences between periodontal diagnosis groups and between smokers' and non-smokers' were analysed. Also, IL-1 polymorphism profiles were compared between study groups.

RESULTS

PISF MMP-8 levels were higher at the baseline compared to and after the treatment when all sampled implant sites were analysed together (p = 0.001). MMP-8 levels' distribution was broader in periodontitis patients' PISF samples, and only in periodontitis patients' group levels decreased statistically significantly after the treatment (p = 0.005). Smokers'and non-smokers' PISF MMP-8 was at similar level both at the baseline and after the treatment. No difference between distributions of IL-1 genotypes was found between study groups.

CONCLUSION

MMP-8 levels increase in peri-implantitis affected implants both in non-periodontitis and periodontitis patients, but levels still after treatment of the condition reflect intensified host response around implants and indicate challenges of controlling peri-Implantitis with any treatment modality.

Attributable fractions, modifiable risk factors and risk stratification using a risk score for peri-implant pathology

PURPOSE

This study aimed to estimate the impact of risk factors for peri-implant pathology, to identify potentially modifiable factors, and to evaluate the accuracy of the risk algorithm, risk scores and risk stratification.

METHODS

This retrospective case-control study with 1275 patients (255 cases; 1020 controls) retrieved a model according to the predictors: history of Periodontitis, bacterial plaque, bleeding, bone level, lack of passive fit or non-optimal screw joint, metal-ceramic restoration, proximity to other implants/teeth, and smoking habits. Outcome measures were the attributable fraction; the positive and negative likelihood ratios at different disease cut-off points illustrated by the area under the curve statistic.

RESULTS

Six predictors may be modified or controlled directly by either the patient or the clinician, accounting for a reduction in up to 95% of the peri-implant pathology cases. The positive and negative likelihood ratios were 9.69 and 0.13, respectively; the area under the curve was 0.96; a risk score was developed, making the complex statistical model useful to clinicians.

CONCLUSIONS

Based on the results, six predictors for the incidence of peri-implant pathology can be modified to significantly improve the outcome. It was possible to stratify patients per risk category according to the risk score, providing a tool for clinicians to support their decision-making process.

Influence of different instrumentation modalities on the surface characteristics and biofilm formation on dental implant neck, in vitro

OBJECTIVES

To evaluate surface characteristics of implants after using different instruments and biofilm formation following instrumentation.

MATERIAL AND METHODS

Thirty-five commercially available dental implants were embedded into seven plastic models, attached to a phantom head and randomly assigned to seven instrumentation groups: (1) stainless steel (SSC) or (2) titanium curettes (TC); air-polisher using glycine-based (3) perio (PP) or (4) soft (SP) powders or (5) erythritol powder (EP); and an ultrasonic device using (6) stainless steel (PS) or (7) plastic-coated instruments (PI). Half of each implant neck in each group (n = 5) was treated once (30 s), while the other half was left uninstrumented (control). An eighth (8) treatment group used a bur/polisher to smooth two implants (SM). Following instrumentation implants were rinsed (5 ml Ringer's solution), analysed under a scanning electron microscope (SEM) and subjected twice (separately) to bacterial colonization with Streptococcus gordonii (2 h) and a mixed culture (S. gordonii, Actinomyces naeslundii, Fusobacterium nucleatum, Porphyromonas gingivalis and Tannerella forsythia; 24 h).

RESULTS

Visual assessment of SEM pictures revealed surface modifications (smoothening to roughening) following instrumentation. These alterations differed between the instrument groups and from the control. Quantitative scoring of the photographs revealed that SSC caused a significantly rougher surface compared to other instruments (P < 0.05), except for SP (P = 0.057) and PP (P = 0.108). After bacterial colonization no significant differences (P > 0.05) were evident between instrumented or control surfaces in either culture.

CONCLUSIONS

Overall, no significant differences were observed in the surface characteristics (except for SSC) or bacterial colonization based on one-time instrumentation.

Impact of Maintenance Therapy for the Prevention of Peri-implant Diseases: A Systematic Review and Meta-analysis

At the present time, peri-implantitis has become a global burden that occurs with a frequency from 1% to 47% at implant level. Therefore, we aimed herein at assessing the impact of peri-implant maintenance therapy (PIMT) on the prevention of peri-implant diseases. Electronic and manual literature searches were conducted by 3 independent reviewers using several databases, including MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register, for articles up to June 2015 without language restriction. Articles were included if they were clinical trials aimed at demonstrating the incidence of peri-implant diseases under a strict regime or not of PIMT. Implant survival and failure rate were studied as secondary outcomes. A meta-analysis was conducted to evaluate the influence of PIMT and other reported variables upon peri-implant diseases. Thirteen and 10 clinical trials were included in the qualitative and quantitative analysis, respectively. Mucositis was affected by history of periodontitis and mean PIMT at implant and patient levels, respectively. Similarly, significant effects of history of periodontal disease were obtained for peri-implantitis for both implant and patient levels. Furthermore, mean PIMT interval was demonstrated to influence the incidence of peri-implantitis at implant but not patient level. PIMT interval showed significance at both levels. For implant survival, implants under PIMT have 0.958 the incident event than those with no PIMT. Within the limitations of the present systematic review, it can be concluded that implant therapy must not be limited to the placement and restoration of dental implants but to the implementation of PIMT to potentially prevent biologic complications and hence to heighten the long-term success rate. Although it must be tailored to a patient's risk profiling, our findings suggest reason to claim a minimum recall PIMT interval of 5 to 6 mo. Additionally, it must be stressed that even in the establishment of PIMT, biologic complications might occur. Thus, patient-, clinical-, and implant-related factors must be thoroughly explored.

Efficacy of alternative or adjunctive measures to conventional treatment of peri-implant mucositis and peri-implantitis: a systematic review and meta-analysis

In patients with peri-implant mucositis and peri-implantitis, what is the efficacy of nonsurgical (i.e. referring to peri-implant mucositis and peri-implantitis) and surgical (i.e. referring to peri-implantitis) treatments with alternative or adjunctive measures on changing signs of inflammation compared with conventional nonsurgical (i.e. mechanical/ultrasonic debridement) and surgical (i.e. open flap debridement) treatments alone? After electronic database and hand search, a total of 40 publications (reporting on 32 studies) were finally considered for the qualitative and quantitative assessment. The weighted mean changes (WM)/ and WM differences (WMD) were estimated for bleeding on probing scores (BOP) and probing pocket depths (PD) (random effect model). Peri-implant mucositis: WMD in BOP and PD reductions amounted to -8.16 % [SE = 4.61] and -0.15 mm [SE = 0.13], not favouring adjunctive antiseptics/antibiotics (local and systemic) over control measures (p > 0.05). Peri-implantitis (nonsurgical): WMD in BOP scores amounted to -23.12 % [SE = 4.81] and -16.53 % [SE = 4.41], favouring alternative measures (glycine powder air polishing, Er:YAG laser) for plaque removal and adjunctive local antibiotics over control measures (p < 0.001), respectively. Peri-implantitis (surgical): WMD in BOP and PD reductions did not favour alternative over control measures for surface decontamination. WM reductions following open flap surgery (±resective therapy) and adjunctive augmentative therapy amounted to 34.81 and 50.73 % for BOP and 1.75 and 2.20 mm for PD, respectively. While mechanical debridement alone was found to be effective for the management of peri-implant mucositis, alternative/adjunctive measures may improve the efficacy over/of conventional nonsurgical treatments at peri-implantitis sites. Adjunctive resective and/or augmentative measures are promising; however, their beneficial effect on the clinical outcome of surgical treatments needs to be further investigated.

Small-diameter titanium grade IV and titanium-zirconium implants in edentulous mandibles: five-year results from a double-blind, randomized controlled trial

BACKGROUND

The aim of this study was to compare the 5-year survival and success rates of 3.3 mm dental implants either made from titanium-zirconium (TiZr) alloy or from Grade IV titanium (Ti Grade IV) in mandibular implant-based removable overdentures.

METHODS

The core study had a follow-up period of 36 months and was designed as a randomized, controlled, double-blind, split-mouth multicenter clinical trial. Patients with edentulous mandibles received two Straumann Bone Level implants (diameter 3.3 mm, SLActive®), one of TiZr (test) and one of Ti Grade IV (control), in the interforaminal region. This follow-up study recruited patients from the core study and evaluated the plaque and sulcus bleeding indices, radiographic crestal bone level, as well as implant survival and success 60 months after implant placement.

RESULTS

Of the 91 patients who initially received implants, 75 completed the 36 month follow-up and 49 were available for the 60 month examination. Two patients were excluded so that a total of 47 patients with an average age of 72 ± 8 years were analysed. The characteristics and 36-month performance of the present study cohort did not differ from the non-included initial participants (p > 0.05). In the period since the 36-month follow-up examination, no implant was lost. The cumulative implant survival rate was 98.9 % for the TiZr group and 97.8 % for the Ti Grade IV group. Crestal bone level changes at 60 months were not different in the test and control group (TiZr -0.60 ± 0.69 mm and Ti Grade IV -0.61 ± 0.83 mm; p = 0.96). The cumulative implant success rate after 60 months was 95.8 and 92.6 % for TiZr and Ti Grade IV, respectively.

CONCLUSIONS

After 60 months, the positive outcomes of the 36 month results for TiZr and Ti Grade IV implants were confirmed, with no significant differences with regard to crestal bone level change, clinical parameters and survival or success rates. TiZr implants performed equally well compared to conventional Ti Grade IV 3.3 mm diameter-reduced implants for mandibular removable overdentures.

TRIAL REGISTRATION

Registered on www.clinicaltrials.gov: NCT01878331.

Protein biomarkers and microbial profiles in peri-implantitis

OBJECTIVES

The aim of the present investigation was to determine the profile of peri-implant crevicular fluid (PICF) biomarkers combined with microbial profiles from implants with healthy peri-implant tissues and peri-implantitis to assess real-time disease activity.

MATERIAL AND METHODS

Sixty-eight patients were included in this cross-sectional study. They were divided into two groups: 34 patients with at least one healthy implant (control) and 34 with at least one peri-implantitis affected implant (test). Total DNA content and qPCR analysis for periodontal bacteria obtained from subgingival plaque samples (Aggregatibacter actinomycetemcomitans, Prevotella intermedia, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola) and a PICF analysis for IL-1β, VEGF, MMP-8, TIMP-2, and OPG were performed. The individual and combined diagnostic ability of each biomarker for peri-implantitis and target bacterial species were analyzed.

RESULTS

The mean concentration of IL-1β (44.6 vs. 135.8 pg/ml; P < 0.001), TIMP-2 (5488.3 vs. 9771.8 pg/ml; P = 0.001), VEGF (59.1 vs. 129.0 pg/ml; P = 0.012), and OPG (66.5 vs. 111.7 pg/ml; P = 0.050) was increased in the peri-implantitis patients. The mean expression of MMP-8 (6029.2 vs. 5943.1 pg/ml; P = 0.454) and did not reveal a meaningful difference among groups. Total bacterial DNA of selected microorganisms was associated with a threefold or greater increase in peri-implantitis although no statistical significant difference. The ability to diagnose diseased sites was enhanced by T. denticola combined with IL-1β, VEGF, and TIMP-2 PICF levels.

CONCLUSION

The present data suggest that the increased levels of the selected PICF-derived biomarkers of periodontal tissue inflammation, matrix degradation/regulation, and alveolar bone turnover/resorption combined with site-specific microbial profiles may be associated with peri-implantitis and could have potential as predictors of peri-implant diseases.

Subgingival microbiome in patients with healthy and ailing dental implants

Dental implants are commonly used to replace missing teeth. However, the dysbiotic polymicrobial communities of peri-implant sites are responsible for peri-implant diseases, such as peri-implant mucositis and peri-implantitis. In this study, we analyzed the microbial characteristics of oral plaque from peri-implant pockets or sulci of healthy implants (n = 10), peri-implant mucositis (n = 8) and peri-implantitis (n = 6) sites using pyrosequencing of the 16S rRNA gene. An increase in microbial diversity was observed in subgingival sites of ailing implants, compared with healthy implants. Microbial co-occurrence analysis revealed that periodontal pathogens, such as Porphyromonas gingivalis, Tannerella forsythia, and Prevotella intermedia, were clustered into modules in the peri-implant mucositis network. Putative pathogens associated with peri-implantitis were present at a moderate relative abundance in peri-implant mucositis, suggesting that peri-implant mucositis an important early transitional phase during the development of peri-implantitis. Furthermore, the relative abundance of Eubacterium was increased at peri-implantitis locations, and co-occurrence analysis revealed that Eubacterium minutum was correlated with Prevotella intermedia in peri-implantitis sites, which suggests the association of Eubacterium with peri-implantitis. This study indicates that periodontal pathogens may play important roles in the shifting of healthy implant status to peri-implant disease.

Probiotic supplements and debridement of peri-implant mucositis: a randomized controlled trial

OBJECTIVE

The aim of this double-blind randomized placebo-controlled trial was to evaluate the effects of probiotic supplements in adjunct to conventional management of peri-implant mucositis.

MATERIALS AND METHODS

Forty-nine adult patients with peri-implant mucositis were consecutively recruited after informed consent. After initial mechanical debridement and oral hygiene instructions, the patients received a topical oil application (active or placebo) followed by twice-daily intake of lozenges (active or placebo) for 3 months. The active products contained a mix of two strains of Lactobacillus reuteri. Patients were clinically monitored and sampled at baseline and after 1, 2, 4, 12 and 26 weeks. The clinical end-points were pocket-probing depth (PPD), plaque index (PI) and bleeding on probing (BOP). In addition, the subgingival microbiota was processed with checkerboard DNA-DNA hybridization and samples of gingival crevicular fluid (GCF) were analyzed for selected cytokines with the aid of multiplex immunoassays.

RESULTS

After 4 and 12 weeks, all clinical parameters were improved in both the test and the placebo group. PPD and BOP were significantly reduced compared with baseline (p < 0.05), but no significant differences were displayed between the groups. The clinical improvements persisted 3 months after the intervention. No major alterations of the subgingival microflora were disclosed and the levels of inflammatory mediators in GCF did not differ between the groups.

CONCLUSIONS

Mechanical debridement and oral hygiene reinforcement resulted in clinical improvement of peri-implant mucositis and a reduction in cytokine levels. Probiotic supplements did not provide added benefit to placebo.

Efficacy of patient-administered mechanical and/or chemical plaque control protocols in the management of peri-implant mucositis. A systematic review

AIM

To systematically assess the efficacy of patient-administered mechanical and/or chemical plaque control protocols in the management of peri-implant mucositis (PM).

MATERIAL AND METHODS

Randomized (RCTs) and Controlled Clinical Trials (CCTs) were identified through an electronic search of three databases complemented by manual search. Identification, screening, eligibility and inclusion of studies was performed independently by two reviewers. Studies without professional intervention or with only mechanical debridement professionally administered were included. Quality assessment was performed by means of the Cochrane Collaboration's tool for assessing risk of bias.

RESULTS

Eleven RCTs with a follow-up from 3 to 24 months were included. Definition of PM was lacking or heterogeneously reported. Complete resolution of PM was not achieved in any study. One study reported 38% of patients with complete resolution of PM. Surrogate end-point outcomes of PM therapy were often reported. The choice of control interventions showed great variability. The efficacy of powered toothbrushes, a triclosan-containing toothpaste and adjunctive antiseptics remains to be established. High quality of methods and reporting was found in four studies.

CONCLUSIONS

Professionally- and patient-administered mechanical plaque control alone should be considered the standard of care in the management of PM. Therapy of PM is a prerequisite for the prevention of peri-implantitis.

Biofilm removal from implants supported restoration using different instruments: a 6-month comparative multicenter clinical study

OBJECTIVES

The aim of this study was to compare the efficacy of different instruments on biofilm removal from implant supported restorations.

MATERIALS AND METHODS

The study was designed as comparative multicenter clinical study including patients proceeding from the Milan, Naples, and Buenos Aires, with a peri-implant mucositis. Implants enrolled for the study were allocated in 4 groups and treated with ultrasonic scalers with plastic tips, with titanium curettes, with airflow with glycine powder, and with rubber cup and polishing paste, respectively. mPI was assessed at baseline, immediately after therapy, at 1, 3, and 6 months. mBI, PD, and REC were assessed at baseline, 1, 3, and 6 months. All parameters were recorded on six sites per implant. Kruskal-Wallis and Mann-Whitney tests were used to compare groups and centers. A generalized linear model for repeated measures was chosen for inter-group comparison. An intra-group comparison was performed with repeated measure ANOVA test to assess differences between baseline and recalls.

RESULTS

A total of 89 patients (39 males, 50 females) were enrolled in the study, and 141 implants were available for the analysis. 55 implants were enrolled in University of Buenos Aires, 32 in University of Milan, and 54 in University of Naples. There were no significant differences between the four groups in inflammatory status reduction of peri-implant mucosa.

CONCLUSIONS

Non-surgical therapy is effective in reducing peri-implant mucositis. Sonic scaler with plastic tip and rubber cup with polishing paste showed higher efficacy when compared with titanium curettes or airflow with glycine powder.

Peri-implant diseases: a review of treatment interventions

The ideal management of peri-implant diseases focuses on infection control, detoxification of implant surfaces, regeneration of lost tissues, and plaque-control regimens via mechanical debridement (with or without raising a surgical flap). However, a variety of other therapeutic modalities also have been proposed for the management of peri-implantitis. These treatment strategies encompass use of antiseptics and/or antibiotics, laser therapy, guided bone regeneration, and photodynamic therapy. The aim of this article was to review indexed literature with reference to the various therapeutic interventions proposed for the management of peri-implant diseases.

Antimicrobial mouthrinse use as an adjunct method in peri-implant biofilm control

Great possibilities for oral rehabilitation emerged as a result of scientific consolidation, as well as a large number of dental implant applications. Along with implants appeared diseases such as mucositis and peri-implantitis, requiring management through several strategies applied at different stages. Biofilm accumulation is associated with clinical signs manifest by both tooth and implant inflammation. With this in mind, regular and complete biofilm elimination becomes essential for disease prevention and host protection. Chemical control of biofilms, as an adjuvant to mechanical oral hygiene, is fully justified by its simplicity and efficacy proven by studies based on clinical evidence. The purpose of this review was to present a consensus regarding the importance of antimicrobial mouthrinse use as an auxiliary method in chemical peri-implant biofilm control. The active ingredients of the several available mouthrinses include bis-biguanide, essential oils, phenols, quaternary ammonium compounds, oxygenating compounds, chlorine derivatives, plant extracts, fluorides, antibiotics and antimicrobial agent combinations. It was concluded that there is strong clinical evidence that at least two mouthrinses have scientifically proven efficacy against different oral biofilms, i.e., chlorhexidine digluconate and essential oils; however, 0.12% chlorhexidine digluconate presents a number of unwanted side effects and should be prescribed with caution. Chemical agents seem beneficial in controlling peri-implant inflammation, although they require further investigation. We recommend a scientifically proven antiseptic, with significant short and long term efficacy and with no unwanted side effects, for the prevention and/or treatment of peri-implant disease.

Interleukin-1β level in peri-implant crevicular fluid and its correlation with the clinical and radiographic parameters

Background and Objectives:

Assessing only the clinical and radiographic parameters for evaluation of dental implants may not be enough as they often reflect extensive inflammatory changes in the periodontal tissues. As peri-implant crevicular fluid (PICF) can give us a more prompt and objective measure of the disease activity, the purpose of this case series is to assess the peri-implant health status of single tooth dental implants not only clinically and radiographically but also biochemically.

Materials and Methods:

Thirteen patients were subjected to dental implants at single edentulous sites using a conventional surgical approach. At baseline, 6 months, and 12 months after implant placement, the clinical and radiographic parameters were recorded. Additionally, IL-1β in PICF was estimated using the ELISA kit at 6^th and 12^th month.

Results:

The clinical and radiographic parameters differed significantly around the implants at different time intervals with IL-1β levels showing highly significant differences between 6 months (31.79 ± 12.26 pg/μl) and 12 months (113.09 ± 51.11 pg/μl). However, Spearman's correlation coefficient showed no correlation with the clinical and radiographic parameters.

Interpretation and Conclusion:

Assessment of the various parameters confirmed that all the implants had a healthy peri-implant status. Although the levels of IL-1β in PICF were elevated at the 12^th month, they were well within the healthy range as observed by previous studies. This indicates that IL-1β, a biochemical marker, can be used as an adjunct to clinical and radiographic parameters in the assessment of EARLY inflammatory changes around implants.

Periodontal health--challenges in restorative dentistry

As the population ages and life expectancy increases, clinicians today find themselves in the wake of an ever-growing demand for high-quality aesthetic dental treatment, by increasingly informed patients. The long-term success of both cosmetic and restorative dentistry is dependent on well designed restorations and the health of the periodontal tissues. Overhanging restorations, full crown restorations with poor marginal fit, and implant-supported prosthetics with inadequate hygiene access all increase the risk for periodontal sequelae and interproximal caries. When planning restorative treatment, consideration should be given to the restorative design, the need for hygiene access and the location of intended implants. In addition, the patient's manual dexterity and ability to manipulate oral hygiene aids is a crucial consideration, as is adequate access for the hygienist to manually debride and maintain the restorations.

Experimental peri-implant mucositis at different implant surfaces

OBJECTIVES

To histologically and immunologically assess experimental peri-implant mucositis at surface enhanced modified (mod) hydrophilic titanium implants.

MATERIALS AND METHODS

In a split-mouth design (n = 6 foxhounds), four different implants were inserted on each side of the maxilla: three titanium-zirconium alloy implants (TiZr) with either modSLA (sand-blasted, acid etched and chemically mod), modMA (machined, acid etched and chemically mod), or M (machined) surfaces in the transmucosal portion, and one titanium implant with a machined transmucosal portion (TiM). Experimental mucositis was induced at one randomly assigned side (NPC), whereas the contra-lateral maxillary side received mechanical plaque removal three times per week (PC). At 16 weeks, tissue biopsies were processed for histological (primary outcome: apical extension of the inflammatory cell infiltrate measured from the mucosal margin - PM-aICT) and immunohistochemical (CD68 antigen reactivity) analyses. Peri-implant sulcus fluid was analysed for interleukin (IL)-1β, IL-8, matrix metalloproteinase (MMP)-8 and myeloperoxidase (MPO).

RESULTS

Mean PM-aICT values varied between 1.86 (TiZrmodSLA) and 3.40 mm (TiM) in the UPC group, and between 0.88 (TiZrmodSLA) and 2.08 mm (TiZrM) in the PC group. Mean CD68, IL-1β, IL-8, MMP-8 and MPO values were equally distributed between mod- and control implants in both NPC and PC groups.

CONCLUSIONS

The progression of experimental mucositis was comparable at all implant surfaces investigated.

Comparison of pro-inflammatory cytokines and bone metabolism mediators around titanium and zirconia dental implant abutments following a minimum of 6 months of clinical function

OBJECTIVES

Dental implant abutments are fundamental prosthetic components within dentistry that require optimal biocompatibility. The primary aim of this cross-sectional study was to preliminarily assess differences in the pro-inflammatory cytokine and bone metabolism mediator protein expression in the peri-implant crevicular fluid (PICF) adjacent to transmucosal abutments.

MATERIAL AND METHODS

Abutments were fabricated from either titanium or zirconia in patients previously receiving single-tooth implant therapy. All subjects sampled in this study had an identical implant system and implant-abutment connection. Participants (n = 46) had an average time of clinical function for 22 months (6.2-72.8 months, ±SD 17 months) and received a clinical and radiographic examination of the implant site at the time of PICF sampling using a paper strip-based sampling technique. Cytokine, chemokine, and bone metabolism mediator quantities (picograms/30 s) were determined using a commercial 22-multiplexed fluorescent bead-based immunoassay instrument. A total of 19 pro-inflammatory cytokines and seven bone metabolism mediators were evaluated.

RESULTS

Multivariable analyses provided no evidence of a group (titanium or zirconia), gender, or age effect with regard to the expression of pro-inflammatory mediators evaluated. Significant (P = 0.022) differences were observed for the bone mediator leptin, with titanium abutments demonstrating significantly elevated levels in comparison with zirconia. Osteopontin demonstrated a significant (P = 0.0044) correlation with age of the subjects.

CONCLUSIONS

No significant differences in pro-inflammatory cytokine or bone metabolism mediator profiles were observed biochemically, with the exception of leptin, for the abutment biomaterials of titanium or zirconia The molecular PICF findings support the observed clinical biocompatibility of both titanium and zirconia abutments.

Cellular populations of periimplant tissues: cytological analysis with sulcular microbrushing

PURPOSE

Cellular populations of gingival crevicular fluid cytological analysis of integrated implants sites have been investigated by using sulcular cytological brushing, as a means of providing an objective and reproducible technique for monitoring periimplant tissue health.

MATERIALS AND METHODS

A total of 60 patients with osteointegrated implants bearing at least for 2 years were divided in 2 groups, A and B. Group A consisted of 30 subjects who presented scarce oral hygiene. In Group B, 30 subjects with a good oral hygiene were included.

RESULTS

Comparative analysis of the data obtained by sulcular microbrushing of the 2 groups put into evidence significative differences in the expression of the microbiological and the cytological parameters.

CONCLUSION

Clinical monitoring of parodontal and periimplant tissues makes use of several diagnostic tests ranging from clinical and radiological tests to biological assays. However, none of these techniques allows to evaluate periimplant tissue cytological status. This preliminary study suggested sulcular microbrushing might be a useful tool in the early diagnosis and in the micrological monitoring of peri-implantitis.

Patient-specific analysis of periodontal and peri-implant microbiomes

Periodontally involved teeth have been implicated as 'microbial reservoirs' in the etiology of peri-implant diseases. Therefore, the purpose of this investigation was to use a deep-sequencing approach to identify the degree of congruence between adjacent peri-implant and periodontal microbiomes in states of health and disease. Subgingival and peri-implant biofilm samples were collected from 81 partially edentulous individuals with periodontal and peri-implant health and disease. Bacterial DNA was isolated, and the 16S rRNA gene was amplified and sequenced by pyrotag sequencing. Chimera-depleted sequences were compared against a locally hosted curated database for bacterial identification. Statistical significance was determined by paired Student's t tests between tooth-implant pairs. The 1.9 million sequences identified represented 523 species. Sixty percent of individuals shared less than 50% of all species between their periodontal and peri-implant biofilms, and 85% of individuals shared less than 8% of abundant species between tooth and implant. Additionally, the periodontal microbiome demonstrated significantly higher diversity than the implant, and distinct bacterial lineages were associated with health and disease in each ecosystem. Analysis of our data suggests that simple geographic proximity is not a sufficient determinant of colonization of topographically distinct niches, and that the peri-implant and periodontal microbiomes represent microbiologically distinct ecosystems.

Guided Bone Regeneration Using Glass-Reinforced Hydroxyapatite and Collagen Membrane in the Treatment of Peri-Implantitis

Implant therapy has provided the clinician a wide variety of treatment options with respect to the replacement of missing natural teeth. With more number of dentists practicing implant dentistry, one is likely to be presented with peri-implantitis and implant related failures in day to day practice. Peri-impant mucositis can be reversed by elimination of the biofilm but peri-implantitis which results in bone loss and subsequent exfoliation of the implant if left unattended have to be treated using a regenerative approach in addition to conventional non surgical therapy. The present case demonstrates the guided bone regeneration procedure using a glass-reinforced HA and collagen membrane in the treatment of an intrabony defect around the implant. Nine months post operative radiograph revealed complete resolution of the defect. This novel composite alloplast shows promise in treating such lesions.Keywords: Peri-implantitis, Guided bone regeneration, Alloplast, Dental implant, Bone graft, Collagen membrane, Implant decontamination.

Peri-implant versus periodontal wound healing

AIM

Peri-implant gingival healing following one-stage implant placement was investigated and compared to periodontal healing.

METHODS

Healing at surgical sites [implant (I) and adjacent teeth (T+)] was compared to non-operated tooth (T-) in non-smokers receiving one-stage implant. Periodontal Indices (PI, GI) were recorded at surgery and up to 12 weeks post-operatively. Peri-implant (PICF) and gingival crevicular fluids (GCF) were analysed for cytokines, collagenases and inhibitors. Data were analysed by linear mixed model regression analysis and repeated measures anova.

RESULTS

Forty patients (22 females; 21-74 years old) completed the study. Surgical site GI, increased at week 1, decreased significantly during early healing (weeks 1-3; p = 0.0003) and continually decreased during late healing (weeks 6-12) for I (p < 0.01). PICF volume decreased threefold by week 12 (p = 0.0003). IL-6, IL-8, MIP-1β and TIMP-1 levels significantly increased at surgical sites at week one, significantly decreasing thereafter (p < 0.016). Week one IL-6, IL-8 and MIP-1β levels were ~threefold higher and TIMP-1 levels 63% higher, at I compared to T+ (p = 0.001).

CONCLUSION

Peri-implant gingival healing, as determined by crevicular fluid molecular composition, differs from periodontal healing. The observed differences suggest that peri-implant tissues, compared to periodontal tissues, represent a higher pro-inflammatory state.

Necessity of keratinized tissues for dental implants: a clinical, immunological, and radiographic study

BACKGROUND

Necessity of keratinized tissues (KTs) for maintaining health around dental implants (DIs) remains as a controversial issue.

PURPOSE

The aim of this study was to investigate the effects of KT width (KTW) on peri-implant tissues by evaluating peri-implant clinical and inflammatory parameters.

MATERIALS AND METHODS

Sixty DIs were included in this 6-month longitudinal study. After classifying DI based on the presence of KTs at the buccal aspect as with adequate/inadequate KTW, DIs were randomly assigned into three study groups. In the first group, while free gingival graft (FGG) was performed, DIs in maintenance (M) group were followed up by standardized maintenance procedures at baseline, first, third, and sixth months as with DI with adequate KTW (Control). Clinical parameters, peri-implant sulcular fluid (PISF) volume, PISF Interleukin 1β concentration, and bone loss were analyzed.

RESULTS

Significant improvements in clinical and immunological parameters were noted only for FGG for the whole study period. Statistical differences detected between the treatment groups (FGG vs M) were for gingival index at all time points and for PISF volume at sixth month. For the other parameters evaluated, while lower values were observed for FGG, statistically no differences were noted between the groups.

CONCLUSIONS

Based on the results of this study, it can be suggested that FGG performed around DIs lacking KT is a reliable method, leading to significant improvements in clinical and inflammatory parameters. Further long-term studies including more DIs are needed to clarify the role of KT on maintenance of DIs.