Peri-implant evaluation in type 2 diabetes mellitus patients: a 3-year study

Factors affecting radiographic marginal bone resorption at dental implants in function for at least 5 years: A multicenter retrospective study

OBJECTIVE

To evaluate the influence of patient and implant-related factors on the changes of marginal bone levels (MBL) at implants with a follow-up ≥5 years.

MATERIALS AND METHODS

At baseline (within 6 months from prosthetic insertion) and long-term (≥5 years after implant placement) visits, interproximal (mesial and distal) MBL were radiographically evaluated. To analyze factors predicting MBL change, the site (either mesial or distal) showing the highest MBL change (hChMBL site) was identified for each implant. Multilevel regression models were built to explain MBL change as well as the probability for a bone loss ≥2 mm at long-term.

RESULTS

942 implants in 312 patients with a mean follow-up of 8.02 ± 2.5 years were analyzed. MBL change was significantly predicted by baseline MBL, oral bisphosphonate (BP) intake, history of periodontitis, diabetes, and super-hydrophilic implant surface. Higher risk for a bone loss ≥2 mm was observed in patients with history of periodontitis (OR = 9.52, 95% CI 0.72-3.79) and taking BP (OR = 6.84, 95% CI 0.21-3.63). Mandibular implants had higher odds for bone loss ≥2 mm compared to maxillary implants (OR = 3, 95% CI 0.39-1.87).

CONCLUSIONS

The findings of the present study contribute to the identification of specific clinical scenarios at higher risk for implant-supporting bone loss that need to be strictly monitored during maintenance.

Prediabetes and poorly controlled type-2 diabetes as risk indicators for peri-implant diseases:A systematic review and meta-analysis

OBJECTIVE

The study answers the PECO question: "In adults with dental implants (P), do subjects suffering from type-2 diabetes or prediabetes (E) have worse peri-implant conditions (O) than subjects without type-2 diabetes and prediabetes (C)?". Prediabetes (5.7-6.4 % HbA1c), and the different qualities of glycemic control in type-2 diabetes; well-controlled (>8 % HbA1c), and poorly controlled (>8 % HbA1c) individuals; were classified according to the recommendations of the American Diabetes Association.

DATA

Predefined search keys were used with search terms including: Dental implant, diabetes mellitus, glycemic control and HbA1c.

SOURCES

An electronic search in the MEDLINE, Embase, and Cochrane libraries were conducted without any filters or language restrictions. Additionally, manual search of the reference lists were carried out to identify all relevant articles.

STUDY SELECTION

Eligibility criteria were cohort, case-control and cross-sectional studies that answerd our PECO question with at least 1 year of follow-up. From a total of 2660 records, 35 articles (1761 individuals) were included in the analysis. Meta-analytic difference in means for crestal bone loss was 1.2 mm [95 % CI=0.4; 2.1] in patients with prediabetes, 1.8 mm [CI=1.0; 2.7] in poorly controlled patients, whereas 0.4 mm [CI=-0.3; 1.1] in well-controlled individuals. Meta-regression showed that 1 % increase in HbA1c increased crestal bone loss by 0.24 mm.

CONCLUSIONS

Within the limitations of the study, patients with poorly controlled type-2 diabetes or prediabetes may have worse peri-implant conditions compared to patients without diabetes and well-controlled type-2 diabetes. Well-controlled type-2 diabetes is not a risk indicator for peri-implant diseases.

CLINICAL SIGNIFICANCE

Clinicians should measure blood HbA1c levels when planning implant-supported restorations, thus patients with undiagnosed or poorly controlled type-2 diabetes can be identified, that allows for glycemic level adjustment prior to dental implant surgery, ensuring peri-implant health. PROTOCOL REGISTRATION NUMBER: (CRD42022375263).

Clinical and radiographic outcomes around 4 mandibular implant-retained overdentures in individuals with type 2 diabetes: A long-term retrospective study

OBJECTIVES

To report the implant survival rates, clinical, and radiographic status after a period of more than 5 years in the function of 4 inter-foraminal implants retaining mandibular overdentures (OVDs) in individuals with T2DM.

METHODS

78 completely edentulous participants with type 2 diabetic mellitus (T2DM) who had worn mandibular OVDs retained by 4 inter-foraminal implants for long-term functional life were selected for this study. The participants were divided into 2 groups according to glycosylated haemoglobin A1c (HbA1c) levels before implant placement: group I with an HbA1c value > 6.5 % (inadequately controlled T2DM), and group II with an HbA1c value ≤6.5 % (well-controlled T2DM). The inadequately controlled T2DM was further subdivided into 2 groups: Group IA with an HbA1c value > 6.5 % and ≤8 % (moderately controlled), and Group IB has an HbA1c value > 8 % (poorly controlled). Implant survival rate, plaque index (PI), bleeding on probing (BOP), probing depth (PD), and radiographic crestal bone level (CBL) around implants were measured.

RESULTS

Among 312 implants, 6 failed, 4 in well-controlled diabetics, and 2 in inadequately controlled diabetics. The overall survival rate was 98.07 %. The mean PI in group Ι was 36.4 (group IA =37.76, group IB = 34.27), and in group ΙΙ it was 19. The mean BOP in group Ι was 45.5 (group IA =47.84, group IB = 41.76), and in group ΙΙ it was 22. The mean PD in group Ι was 4.1 (group IA =4.3, group IB = 3.85) and in group ΙΙ was 2.2. The mean radiographic CBL in group Ι was 3.4 (group IA =3.7, group IB = 2.9), and in group ΙΙ was 1.5. Group IA exhibited a significantly greater level of PI, BOP, PD, and CBL compared to group IB and group IΙ (P1=0.017, P2=0.001).

CONCLUSIONS

Individuals with T2DM can benefit from 4 inter-foraminal implants retained mandibular OVDs, and their inability to maintain proper glucose control may not exclude implant success.

CLINICAL SIGNIFICANCE

This study is a significant step toward improving knowledge of options available for treatment and anticipated outcomes for T2DM completely edentulous populations undergoing implant therapy.

Sustained Release of Salicylic Acid for Halting Peri-Implantitis Progression in Healthy and Hyperglycemic Systemic Conditions: A Gottingen Minipig Model

To develop a peri-implantitis model in a Gottingen minipig and evaluate the effect of local application of salicylic acid poly(anhydride-ester) (SAPAE) on peri-implantitis progression in healthy, metabolic syndrome (MS), and type-2 diabetes mellitus (T2DM) subjects. Eighteen animals were allocated to three groups: (i) control, (ii) MS (diet for obesity induction), and (iii) T2DM (diet plus streptozotocin for T2DM induction). Maxillary and mandible premolars and first molar were extracted. After 3 months of healing, four implants per side were placed in both jaws of each animal. After 2 months, peri-implantitis was induced by plaque formation using silk ligatures. SAPAE polymer was mixed with mineral oil (3.75 mg/μL) and topically applied biweekly for up to 60 days to halt peri-implantitis progression. Periodontal probing was used to assess pocket depth over time, followed by histomorphologic analysis of harvested samples. The adopted protocol resulted in the onset of peri-implantitis, with healthy minipigs taking twice as long to reach the same level of probing depth relative to MS and T2DM subjects (∼3.0 mm), irrespective of jaw. In a qualitative analysis, SAPAE therapy revealed decreased levels of inflammation in the normoglycemic, MS, and T2DM groups. SAPAE application around implants significantly reduced the progression of peri-implantitis after ∼15 days of therapy, with ∼30% lower probing depth for all systemic conditions and similar rates of probing depth increase per week between the control and SAPAE groups. MS and T2DM conditions presented a faster progression of the peri-implant pocket depth. SAPAE treatment reduced peri-implantitis progression in healthy, MS, and T2DM groups.

Impact of diabetes mellitus on the poor prognosis in patients with osseointegrated dental implants: a meta-analysis of observational studies

This meta-analysis aimed to explore the correlation between diabetes mellitus (DM) and peri-implant diseases in patients with osseointegrated dental implants. Relevant studies were searched in multiple databases from the available date of inception through 26 August 2021. The odds ratios (ORs) were used as the effect indicator for measurement data, and each effect size was given estimates and 95% confidence intervals (CIs). Begg's test was used for publication bias. Twenty-one observational studies with 24,953 participants were selected. No significant association was shown between DM and peri-implant mucositis (OR: 0.739, 95% CI: 0.394-1.383, P = 0.344). The results demonstrated that the risk of peri-implantitis was higher in DM than in non-DM (OR: 1.553, 95% CI: 1.084-2.226, P = 0.016). Smokers had higher risk of peri-implantitis than non-smoking patients (OR: 1.754, 95% CI: 1.620-1.899, P < 0.001). In addition, no significant association was shown between DM and peri-implantitis among non-smokers. The association between periodontal history (OR: 2.538, 95% CI: 0.814-7.921, P = 0.109), poor plaque control (OR: 1.700, 95% CI: 0.334-8.648, P = 0.523) and peri-implantitis was not statistically significant. No publication bias was observed for each outcome. DM increases the risk of poor outcomes in osseointegrated dental implant patients. The findings of the present study further elucidate the need for longitudinal investigations regarding risk variables that affects peri-implant tissues.

Effectiveness of two photosensitizer-mediated photodynamic therapy for treating moderate peri-implant infections in type-II diabetes mellitus patients: A randomized clinical trial

PURPOSE

This study evaluated the impact of Fox Green (FG) against methylthioninium chloride (MTC)-facilitated photodynamic therapy (PDT) as an adjunctive to manual scaling (MS) on the peri‑implant clinical and cytokine parameters in type-2 diabetes mellitus (DM) patients with peri‑implantitis.

METHODS

Patients were divided into group-A comprising 13 patients who received adjunctive FG-PDT using a diode laser (wavelength: 810 nm; irradiation power: 300 mW; irradiation time: 30 s; fluence: 56 Jcm-2), group-B comprising 12 patients who received adjunctive MTC-PDT using a diode laser (wavelength: 660 nm; irradiation power: 100 mW; irradiation time: 120 s/site; fluence: 30 Jcm-2), and group-C comprising 13 patients who received MS alone [control group]). After diagnosing the diabetics with peri‑implantitis (established on eligibility criteria), a structured questionnaire was used to gather the information of the participants. Plaque (PS) and bleeding scores (BS), along with peri‑implant probing scores (PPS) and peri‑implant bone loss (PIBL), together with immunological variables (interleukin [IL]-6, tumor necrosis factor-alpha [TNF-α], and advanced glycation end products [AGEs]) were measured in all study group participants at baseline, 3-month, and 6-month follow-ups.

RESULTS

A significant reduction was observed for PS, BS, and PPS within all tested groups at each follow-up visits compared from their baseline values (p<0.05). However, a substantial decrease in PIBL was observed in all study group patients at 6-month follow-up as compared to 3-month follow-up (p<0.05). Regarding the levels of IL-6 and TNF-α, a substantial reduction was observed in all study groups until 6-month from their baseline scores (p<0.05). However, no changes were observed in the levels of AGEs in any group at either visit (p>0.05).

CONCLUSION

In DM patients with periimplantitis, adjunctive FG-PDT and MTC-PDT exhibited comparable outcomes in terms of peri‑implant clinical as well as pro-inflammatory characteristics than MS alone among peri‑implantitis patients with DM.

Clinical and radiographic outcomes of adjunctive photodynamic therapy for treating peri-implantitis among diabetics and cigarette smokers: a systematic review of randomized controlled trials

Photodynamic therapy (PDT) has been suggested as an adjunctive therapeutic approach for peri-implantitis. This systematic review aimed to assess the clinical and radiographic outcomes of adjunctive PDT (aPDT) for the treatment of peri-implantitis among diabetics and cigarette smokers. Randomized controlled trials (RCTs), which assessed the clinical and radiographic outcomes of aPDT versus other intervention(s) and/or MD alone among diabetics and smokers with peri-implantitis, were considered eligible for the review. Meta-analysis was performed for calculating the standard mean difference (SMD) with a 95% confidence interval (CI). The methodological quality of the included studies was evaluated using the modified Jadad quality scale. The meta-analysis revealed no significant differences between the influence of aPDT and other intervention/MD alone on the peri-implant PI among diabetics at the final follow-up. However, statistically significant improvements in the peri-implant PD, BOP, and CBL were observed after the application of aPDT among diabetics. Similarly, no significant differences were found between the influence of aPDT and other interventions/MD alone on the peri-implant PD among smokers with peri-implant diseases at the final follow-up. However, statistically significant improvements in the peri-implant PI, BOP, and CBL were observed after the application of aPDT among smokers. Significant improvements in the peri-implant PD, BOP, and CBL among diabetics and the peri-implant PI, BOP, and CBL among smokers after the application of aPDT at the final follow-up. However, large-scale, well-designed, and long-term RCTs are recommended in this domain.

The Effect of Hyperlipidemia on Peri-implant Health: A Clinical and Radiographical Prospective Study

High levels of cholesterol and triglycerides may have a negative effect on the immune system and bone health, leading to lower bone mineral density, an increased risk of osteoporosis, and bone fractures, and could therefore also be related to a significant worsening of peri-implant health. The purpose of the following study was to evaluate whether the altered lipid profile in patients who undergo implant insertion surgery represents a prognostic factor capable of influencing clinical outcomes. This prospective observational study was conducted on 93 subjects; patients were required to have taken blood tests to obtain triglycerides (TG), total cholesterol, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels prior to the surgical procedure to classify them according to current American Heart Association guidelines. The outcomes considered were marginal bone loss (MBL) 3 years after implant placement, full-mouth plaque score (FMPS), and full-mouth bleeding score (FMBS) 3 years after surgery. A statistically significant correlation was found between hypertriglyceridemia and MBL as well as between total cholesterol and MBL. There is no statistically significant correlation between the variables analyzed and the secondary outcomes 3 years after implant placement. Peri-implant marginal bone loss may be influenced by hyperlipidemia. However, further studies are needed, with larger samples and more extensive follow-ups, to confirm these results.

Preoperative HbA1c and Blood Glucose Measurements in Diabetes Mellitus before Oral Surgery and Implantology Treatments

Diabetes mellitus has become a worldwide epidemic and is frequently accompanied by a number of complications proportional to the duration of hyperglycemia. The aim of this narrative review is to assess the most up-to-date guidelines on DM provided by both diabetes and dental associations. Furthermore, to gather evidence on the uni/bidirectional relationships of elevated HbA1c levels on dental surgery, implantology, bone augmentation, and periodontology and to demonstrate the importance of measuring HbA1c levels before invasive dental treatments. HbA1c and blood glucose measurements are a minimally invasive method for preventing complications in diabetes mellitus. The authors conducted a literature review to determine which oral conditions are affected by diabetes mellitus. MEDLINE served as a source with the use of a specific search key. Regarding oral complications of diabetes, prevention is the most vital factor. With this publication, we hope to assist physicians and dentists to make prompt diagnoses and to help in recognizing various oral manifestations of diabetes and follow the existing guidelines.

Primordial and primary prevention of peri-implant diseases: A systematic review and meta-analysis

AIM

This systematic review and meta-analysis aims to assess the efficacy of risk factor control to prevent the occurrence of peri-implant diseases (PIDs) in adult patients awaiting dental implant rehabilitation (primordial prevention) or in patients with dental implants surrounded by healthy peri-implant tissues (primary prevention).

MATERIALS AND METHODS

A literature search was performed without any time limit on different databases up to August 2022. Interventional and observational studies with at least 6 months of follow-up were considered. The occurrence of peri-implant mucositis and/or peri-implantitis was the primary outcome. Pooled data analyses were performed using random effect models according to the type of risk factor and outcome.

RESULTS

Overall, 48 studies were selected. None assessed the efficacy of primordial preventive interventions for PIDs. Indirect evidence on the primary prevention of PID indicated that diabetic patients with dental implants and good glycaemic control have a significantly lower risk of peri-implantitis (odds ratio [OR] = 0.16; 95% confidence interval [CI]: 0.03-0.96; I² : 0%), and lower marginal bone level (MBL) changes (OR = -0.36 mm; 95% CI: -0.65 to -0.07; I² : 95%) compared to diabetic patients with poor glycaemic control. Patients attending supportive periodontal/peri-implant care (SPC) regularly have a lower risk of overall PIDs (OR = 0.42; 95% CI: 0.24-0.75; I² : 57%) and peri-implantitis compared to irregular attendees. The risk of dental implant failure (OR = 3.76; 95% CI: 1.50-9.45; I² : 0%) appears to be greater under irregular or no SPC than regular SPC. Implants sites with augmented peri-implant keratinized mucosa (PIKM) show lower peri-implant inflammation (SMD = -1.18; 95% CI: -1.85 to -0.51; I² : 69%) and lower MBL changes (MD = -0.25; 95% CI: -0.45 to -0.05; I² : 62%) compared to dental implants with PIKM deficiency. Studies on smoking cessation and oral hygiene behaviors were inconclusive.

CONCLUSIONS

Within the limitations of available evidence, the present findings indicate that in patients with diabetes, glycaemic control should be promoted to avoid peri-implantitis development. The primary prevention of peri-implantitis should involve regular SPC. PIKM augmentation procedures, where a PIKM deficiency exists, may favour the control of peri-implant inflammation and the stability of MBL. Further studies are needed to assess the impact of smoking cessation and oral hygiene behaviours, as well as the implementation of standardized primordial and primary prevention protocols for PIDs.

Soft tissue features of peri‐implant diseases and related treatment

BACKGROUND

The need for soft tissue grafting at implant sites for preventing and treating peri-implant diseases is a currently investigated and debated topic.

PURPOSE

The aim of this manuscript is to explore the inflammatory mechanisms at the peri-implant soft tissue compartment, to distinguish the structural components of the peri-implant soft tissue phenotype and their role on peri-implant health, and to appraise the clinical indications and expected outcomes of soft tissue augmentation procedures at peri-implant diseased sites.

MATERIALS AND METHODS

This narrative review depicts the inflammatory biomarkers and mediators in the peri-implant crevicular fluid utilized to diagnose peri-implant disease and that have been shown to be associated with peri-implant soft tissue phenotype modification and disease resolution. The impact of the peri-implant soft tissue phenotype, involving keratinized mucosa (KM) width, attached mucosa (AM), mucosal thickness (MT), and supracrestal tissue height (STH), on peri-implant health, esthetic, patient's comfort and disease prevention are discussed. The manuscript also illustrates the use of ultrasonography for the detection of peri-implant health/disease and the evaluation of the treatment outcomes following surgical therapies.

RESULTS

Current evidence indicates that soft tissue phenotype modification at implant sites with inadequate KM width, AM and MT can be beneficial for promoting peri-implant health and improving patient's comfort and hygiene procedures. Treatment approaches and outcomes from the available literature on soft tissue phenotype modification in combination with conventional techniques at sites with peri-implant mucositis or peri-implantitis are presented and discussed in detail.

CONCLUSIONS

Soft tissue grafting can be beneficial in preventing and treating peri-implant diseases. Clinical recommendations based on the disease, soft tissue phenotype characteristics and bone defect morphology are provided for a comprehensive hard- and soft-tissue-oriented treatment of peri-implant disease.

From Bench to Bedside in Precision Medicine: Diabetes Mellitus and Peri-Implantitis Clinical Indices with a Short-Term Follow-Up: A Systematic Review and Meta-Analysis

Background and objective: Diabetes mellitus (DM) refers to a group of metabolic disorders characterized by hyperglycemia resulting from impaired secretion or action of insulin. The high levels of glucose in the blood can negatively affect the healing processes through alterations in vascularization, bone remodeling, and with increased susceptibility to infections. Diabetes mellitus is therefore a risk factor not only for many systemic diseases, but also for localized problems such as peri-implantitis. The objective of this systematic review was to identify a clear relationship between peri-implant inflammation indices and glycemic levels, through the investigation of prospective studies that report data on a short-term follow-up period. Our hypothesis was that peri-implant inflammatory indices may already present themselves in a statistically significant way as altered in patients with DM compared to patients without DM. Materials and methods: This review was reported according to the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA). Results: More than 992 records were identified in the PubMed, Scopus, and Cochrane Central Register of Controlled Trial electronic databases and only seven studies were included in the meta-analysis. The results of the meta-analysis report worse outcomes in patients with DM, even in the short period of six months, for peri-implatitis inflammation indices, such as Marginal bone loss (standardized (Std). mean difference (MD) 12\6 months 0.81 [0.45, 1.17]\1.82 [0.53, 3.10]), Bleeding on probing (Std. MD 12\6 months 2.84 [1.34, 4.34]\3.44 [1.41, 5.50]), Probing depth (Std. MD 12\6 months 1.14 [0.60, 1.68]\2.24 [0.66, 3.83]), and the plaque index (Std. MD 12 months 2.83 [0.09, 5.57]). Conclusion: The literature linking glycaemic control to peri-implant disease is highly heterogeneous due to lack of consistency of the definition of peri-implantitis and its clinical indicators among studies. Therefore, interpretation of finding and relevance to clinical practice should be considered on individual bases. In the era of personalized medicine, the clinician should utilize individualized information from translational researches and analyze all risk factors to provide the patient with evidence-based treatment options.

Systematic review on diabetes mellitus and dental implants: an update

Purpose

Dental implant surgery was developed to be the most suitable and comfortable instrument for dental and oral rehabilitation in the past decades, but with increasing numbers of inserted implants, complications are becoming more common. Diabetes mellitus as well as prediabetic conditions represent a common and increasing health problem (International Diabetes Federation in IDF Diabetes Atlas, International Diabetes Federation, Brussels, 2019) with extensive harmful effects on the entire organism [(Abiko and Selimovic in Bosnian J Basic Med Sci 10:186–191, 2010), (Khader et al., in J Diabetes Complicat 20:59–68, 2006, 10.1016/j.jdiacomp.2005.05.006)]. Hence, this study aimed to give an update on current literature on effects of prediabetes and diabetes mellitus on dental implant success.

Methods

A systematic literature research based on the PRISMA statement was conducted to answer the PICO question “Do diabetic patients with dental implants have a higher complication rate in comparison to healthy controls?”. We included 40 clinical studies and 16 publications of aggregated literature in this systematic review.

Results

We conclude that patients with poorly controlled diabetes mellitus suffer more often from peri-implantitis, especially in the post-implantation time. Moreover, these patients show higher implant loss rates than healthy individuals in long term. Whereas, under controlled conditions success rates are similar. Perioperative anti-infective therapy, such as the supportive administration of antibiotics and chlorhexidine, is the standard nowadays as it seems to improve implant success. Only few studies regarding dental implants in patients with prediabetic conditions are available, indicating a possible negative effect on developing peri-implant diseases but no influence on implant survival.

Conclusion

Dental implant procedures represent a safe way of oral rehabilitation in patients with prediabetes or diabetes mellitus, as long as appropriate precautions can be adhered to. Accordingly, under controlled conditions there is still no contraindication for dental implant surgery in patients with diabetes mellitus or prediabetic conditions.

Should the Quality of Glycemic Control Guide Dental Implant Therapy in Patients with Diabetes? Focus on Implant Survival

INTRODUCTION

Optimal glycemic control is crucial to dental implant long-term functional and esthetic success. Despite HbA1c levels of 7% or lower used is as an indicator for good glycemic control, however, this level may not be attainable for all diabetic patients. Most dentists do not consider patients with poor glycemic control candidates for implant therapy due to higher implant failure, infection or other complications.

AIM

This review challenges the concept of one size fits all and aims to critically appraise the evidence for the success or failure rate of dental implants and peri-implant health outcomes in patients with less than optimal glycemic control.

DISCUSSION

Evidence suggests that estimating glycemic control from HbA1c measurement alone is misleading. Moreover, elevated preoperative HbA1c was not associated with increased mortality and morbidity after major surgical procedures. Literature for the survival or success of implants in diabetic patients is inconsistent due to a lack of standardized reporting of clinical data collection and outcomes. While a number of studies report that implant treatment in patients with well controlled diabetes has a similar success rate to healthy individuals, other studies suggest that the quality of glycemic control in diabetic patients does not make a difference in the implant failure rate or marginal bone loss. This discrepancy could indicate that risk factors other than hyperglycemia may contribute to the survival of implants in diabetic patients.

CONCLUSION

In the era of personalized medicine, the clinician should utilize individualized information and analyze all risk factors to provide the patient with evidence-based treatment options.

Clinical performance of hydrophilic, titanium-zirconium dental implantsin patients with well-controlled and poorly-controlledtype 2 diabetes: One-Year results of a dual-centerprospectivecohort study

BACKGROUND

This study assessed the clinical performance of hydrophilic dental implants in a patient cohort with type 2 diabetes mellitus (T2DM).

METHODS

Subjects with T2DM of ≥ 2-years duration were allocated to either the well-controlled (WC; HbA1c ≤ 7.0%,) or poorly-controlled (PC; 7.5 < HbA1c < 10%) groups in a dual-center, prospective cohort study. Each subject received a single, titanium-zirconium (Ti-Zr) dental implant with a chemically-modified, hydrophilic (modSLA) surface in a posterior mandibular site. Postoperatively, subjects were followed at 1, 2, 4, 8 and 12-week intervals. Post-loading, subjects were followed at 3, 6 and 12-months. Clinical and radiographic parameters of implant success, and dental patient-reported outcomes were collected.

RESULTS

Twenty-one dental patients (N_WC = 11; N_PC = 10; mean age: 66.8 ± 7.5 years) were enrolled and the 1-year implant success rate was 100%. Peri-implant bone levels were stable with 0.15 ± 0.06 mm mean marginal loss at one year without significant inter-group differences (p = 0.79). Postoperative pain was minimal at 1-week, and OHIP-5 scores decreased significantly over time as compared with preoperative levels (p < 0.001) suggesting significant improvement in patient-perceived oral health following implant therapy.

CONCLUSIONS

Elevated HbA1c levels> 7.5% did not compromise 1-year successrates, or oral health-related quality of lifein PC patients receiving modSLA, Ti-Zr implants. This article is protected by copyright. All rights reserved.

microRNA-491-5p regulates osteogenic differentiation of bone marrow stem cells in type 2 diabetes

OBJECTIVES

Osseointegration of oral implants has a low success rate in patients with type 2 diabetes. This is because of the inhibition of osteogenic differentiation in the jawbone marrow mesenchymal stem cells, in which the expression of microRNA(miR)-491-5p is significantly downregulated, as ascertained through gene chip screening. However, the underlying mechanisms are unclear. Here, we aimed to clarify the mechanisms involved in the influence of miR-491-5p on osteogenic differentiation.

SUBJECTS AND METHODS

Jawbone marrow mesenchymal stem cells were isolated from jawbones of patients with type 2 diabetes and subjected to bioinformatics and functional analyses. Osteogenesis experiments were conducted using the isolated cells and an in vivo model.

RESULTS

Knockdown and overexpression experiments revealed the positive effects of miR-491-5p expression on osteogenic differentiation in vivo and in vitro. Additionally, a dual-luciferase assay revealed that miR-491-5p targeted the SMAD/RUNX2 pathway by inhibiting the expression of epidermal growth factor receptor.

CONCLUSIONS

miR-491-5p is vital in osteogenic differentiation of jawbone mesenchymal stem cells; its downregulation in type 2 diabetes could be a major cause of decreased osteogenic differentiation. Regulation of miR-491-5p expression could improve osteogenic differentiation of jawbone mesenchymal stem cells in patients with type 2 diabetes.

Survival rate and peri-implant evaluation of immediately loaded dental implants in individuals with type 2 diabetes mellitus: a systematic review and meta-analysis

Objectives

To evaluate the survival rate, success rate, and peri-implant biological changes of immediately loaded dental implants (ILs) placed in type 2 diabetic patients (DM2).

Materials and methods

The present study was registered on PROSPERO and followed the PRISMA checklist. The search was performed by the first reviewer in January 2021. The electronic databases used were MEDLINE via PubMed, Cochrane, BVS, Web of Science, Scopus, LIVIVO, and gray literature. The risk of bias analysis was performed using an instrument from the Joanna Briggs Institute.

Results

A total of 3566 titles and abstracts were obtained. The qualitative synthesis included 7 studies, while the quantitative synthesis included 5 studies. The meta-analysis of IL in individuals with DM2 compared to nondiabetic individuals showed no significant difference among the groups regarding the survival rate of dental implants (RR = 1.00, 95% CI 0.96–1.04; p = 0.91; I² = 0%), even if the patient had poor glycemic control (RR = 1.08, 95% CI 0.87–1.33; p = 0.48; I² = 70%). Meta-analysis of marginal bone loss in IL compared to conventional loading in DM2 patients also showed no significant difference (mean difference =  − 0.08, 95% CI − 0.25–0.08; p = 0.33; I² = 83%).

Conclusions

Type 2 diabetes mellitus does not seem to be a risk factor for immediately loaded implants if the glycemic level is controlled, the oral hygiene is satisfactory, and the technical steps are strictly followed.

Clinical relevance

Rehabilitation in diabetic individuals is more common due to the highest prevalence of edentulism in this population. It is essential to establish appropriate protocols for loading dental implants.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04154-6.

Glycemic fluctuation exacerbates inflammation and bone loss and alters microbiota profile around implants in diabetic mice with experimental peri-implantitis

BACKGROUND

The impact of glycemic fluctuation under diabetic condition on peri-implantitis in diabetic patients remains unclear. We hypothesized that glycemic fluctuation has greater adverse effect on experimental peri-implantitis, compared with sustained high blood glucose in diabetes.

RESULTS

Maxillary left first and second molars of diabetic db/db mice were extracted and were replaced with one dental implant in the healed edentulous space. Glycemic control or fluctuation were managed by constant or interrupted oral administration of rosiglitazone to these mice. Meanwhile, experimental peri-implantitis was induced by ligation around implants. After 14 weeks, inflammatory responses, and peri-implant bone loss, together with oral microbiota profile were analyzed. Diabetic mice with glycemic fluctuation showed greater peri-implant bone loss, inflammatory cell infiltration, and osteoclastogenesis, compared with mice with sustained hyperglycemia. Compared to sustained hyperglycemia, glycemic fluctuation led to further increase in IL-1β, TNFα, RANKL, TLR2/4, IRAK1, and TRAF6 mRNA expression in peri-implant gingival tissues. Both rosiglitazone-induced glycemic control and glycemic fluctuation caused microbiota profile change in diabetic mice compared to that in uncontrolled hyperglycemic mice.

CONCLUSIONS

This study suggests that glycemic fluctuation may aggravate peri-implantitis inflammation and bone loss, which may be associated with a shift in peri-implant microbial profile towards dysbiotic changes and the activation of TLR2/4-IRAK1-TRAF6 signaling.

Clinical, bacterial, and inflammatory outcomes of indocyanine green-mediated photodynamic therapy for treating periimplantitis among diabetic patients: A randomized controlled clinical trial

Background This 6-months randomized controlled clinical trial aimed to assess the efficacy of indocyanine green mediated photodynamic therapy (ICG-PDT) as an adjunct to peri‑implant manual debridement (PIMD) versus PIMD alone among Diabetes Mellitus (DM) patients in the treatment of peri‑implantitis. Methods A total of 48 DM patients having 64 implants were treated with either ICG-PDT + PIMD (n = 35 implants) or PIMD alone (n = 29 implants). Clinical (probing depth [PD], bleeding on probing [BOP], and plaque index [PI]) and radiographic (peri‑implant crestal bone loss [PCBL]) peri‑implant variables were recorded. Bacterial species including Porphyromonas gingivalis and Treponema denticola were evaluated from peri‑implant plaque biofilms. Levels of interleukin (IL)-1β and IL-6 were assessed after the collection of peri‑implant sulcular fluid. All the evaluations were carried out at baseline, 3- and 6-months. The significance level was set to p < 0.05. Results All clinical parameters significantly reduced within both treatment groups (P<0.05). Intra-group comparison indicates that there was statistically significant reduction in PD and suppuration for ICG-PDT group (P<0.05). There was a statistically significant difference in the BOP between ICG-PDT and PIMD groups at both follow-up periods (P<0.001). However, there was a significant difference for PD (P = 0.001), suppuration (P = 0.01), and PCBL (P = 0.04) on 6 months follow-up between ICG-PDT and PIMD groups, respectively. Only ICG-PDT showed a significant reduction in P. gingivalis and T. denticola on both 3 months and 6 months follow-up compared to baseline. PIMD showed a statistically significant reduction only on 3 months follow-up compared to baseline. This reduction was maintained for both the species when dental implants were treated with ICG-PDT. However, PIMD failed to maintain this reduction until 6 months. Only at 3 months assessment that both treatment groups showed statistically significant reduction in IL-1β and IL-6 with no significant difference between the groups. Both biomarkers failed to maintain the reduction in both groups and significantly increased levels for IL-1β was noted at 6 months follow up Conclusion Multiple application of indocyanine-green mediated photodynamic therapy resulted in improved clinical and microbial parameters among type 2 DM subjects in the treatment of peri‑implantitis. This clinical trial was registered in the ClinicalTrials.gov Protocol Registration and Results System with registration record number: NCT04833569.

Impact of hyperglycemia on the rate of implant failure and peri-implant parameters in patients with type 2 diabetes mellitus: Systematic review and meta-analysis

BACKGROUND

The impact of hyperglycemia on dental implant therapy remains unclear. In this systematic review and meta-analysis, the authors compared the rates of implant failure and peri-implant bleeding on probing (BOP), probing depth (PD), and peri-implant bone loss (PIBL) among patients with type 2 diabetes mellitus and nondiabetic patients. The authors performed subgroup analyses based on glycemic level to evaluate whether patients with higher glycemic levels were more prone to peri-implant inflammation.

TYPE OF STUDIES REVIEWED

The authors searched 4 databases for original clinical studies. Studies in which the researchers provided information on the rate of implant failure or peri-implant parameters were included.

RESULTS

Nine clinical studies were identified on the basis of the inclusion criteria. No significant differences were found in rates of implant failure (P = .46) and PD (P = .1) between diabetic and nondiabetic patients. Significant differences in BOP (P < .00001) and PIBL (P = .02), favoring nondiabetic patients, were observed. Results of subgroup analyses indicated that the increase in glycemic level did not significantly influence BOP, PD, and PIBL values among diabetic patients.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Patients with type 2 diabetes mellitus seem to be able to achieve a rate of implant survival similar to that of healthy patients. Regarding peri-implant parameters, BOP and PIBL were higher in patients with type 2 diabetes mellitus, indicating that hyperglycemia is an important risk factor for peri-implant inflammation. No association was found between peri-implant parameters and glycemic level among patients with type 2 diabetes mellitus, providing oral hygiene was strictly maintained.

DOES GLYCEMIC CONTROL HAVE A DOSE-RESPONSE RELATIONSHIP WITH IMPLANT OUTCOMES? A COMPREHENSIVE SYSTEMATIC REVIEW AND META-ANALYSIS

OBJECTIVES

To comprehensively evaluate implant survival, clinical and biochemical parameters, as well as possible dose-response relationship with hemoglobin A1c (HbA1c) in patients with differing diabetic control.

METHODOLOGY

Five electronic databases were searched for studies that compared implant outcomes in patients with differing HbA1c values. Research quality was evaluated using Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool. Narrative synthesis and meta-analysis were performed for survival rate, plaque index (PI), bleeding on probing (BOP), probing pocket depth, and marginal bone loss (MBL). Categorical dose-response meta-analysis (DRMA) was conducted according to length of follow-up.

RESULTS

Twenty-two studies met the inclusion criteria. Prospective studies were mostly of moderate quality, but non-prospective papers had serious to critical risk of bias. Survival rate was high for the first 3 years (92.6%-100%) for patients with HbA1c less than 8%. Meta-analysis revealed worsening clinical parameters with increasing HbA1c. DRMA further established a significant dose-response relationship between glycemic control with BOP (10% more bleeding, 95% CI 0.05-0.16, P = .008) and MBL (0.05 mm more bone loss, 95% CI 0.01-0.09, P = .002) per HbA1c category, but no association with probing pocket depth. Osseointegration progressed at a slower rate, and inflammatory cytokines and bone biomarkers were adversely affected in patients with HbA1c above 8%.

CONCLUSION

Moderate evidence suggests a high short-term survival but possible dose-response trend of worsening BOP and MBL in association with glycemic control. Clinically, HbA1c values must be considered for risk assessment before placement and throughout the lifespan of the implant placed in a patient with diabetes.

Association between diabetes and dental implant complications: a systematic review and meta-analysis

OBJECTIVES

The aim of this study was to explore the possible association between diabetes mellitus and dental implant complications.

MATERIAL AND METHODS

A systematic literature review was conducted to answer the following PICO (Participants, Intervention, Comparison, and Outcome) question: Is there association between diabetes mellitus and dental implant complications? Two independent searchers performed a literature search of the PubMed/MEDLINE, Web of Science, Cochrane Library and EMBASE databases for studies published until February 2020, focussing on studies including continuous outcomes, marginal bone loss (primary outcome), probing depth, and bleeding upon probing (secondary outcomes).

RESULTS AND CONCLUSIONS

A final total of 10 published studies were included in this systematic review. There were statistically significant differences between the groups with regard to marginal bone loss (p < .00001), probing depth (p < .00001) and bleeding around dental implants (p < .00001), and subjects without diabetes had lower complication rates. Additionally, in the subgroup analysis performed with loading time and HbA1c levels, a more evident association was found in immediate loading for probing depth. Moreover, the analysis results of bleeding around dental implants suggested that as HbA1c level increases, the bleeding of the tissues surrounding the implant will also increase. With regard to dental implant complications, there were statistically significant differences favouring patients without diabetes mellitus.

Breaking the wave of peri-implantitis

Peri-implant diseases are prevalent with a weighted mean prevalence rate of 43% across Europe and 22% across South and North America. Although the main etiologic agent is bacterial biofilm, a myriad of factors influence the initiation and progression of the disease. Unfortunately, the treatment of peri-implant diseases is at best favorable in the short term with a high rate of persistent inflammation and recurrence. Therefore, it is sensible to consider and control all potential factors that may predispose an implant to peri-implant tissue inflammation in an attempt to avoid the disease. This paper reviews recent evidence on factors that may predispose implants to peri-implantitis and measures that can be taken to prevent it.

Obesity/Metabolic Syndrome and Diabetes Mellitus on Peri-implantitis

Literature has reported that up to 50% of dental implants may be affected by peri-implantitis, a bacteria-induced chronic inflammatory process, which promotes osteoclast-mediated bone resorption and inhibits bone formation, leading to progressive bone loss around implants. Current evidence points toward an increased risk for the development of peri-implantitis in both obesity/metabolic syndrome (MetS) and diabetes mellitus (DM) conditions relative to the healthy population. Currently, there is no effective treatment for peri-implantitis and the 50% prevalence in MetS and DM, along with its predicted increase in the worldwide population, presents a major concern in implant dentistry as hyperglycemic conditions are associated with bone-healing impairment; this may be through dysfunction of osteocalcin-induced glucose metabolism. The MetS/DM proinflammatory systemic condition and altered immune/microbiome response affect both catabolic and anabolic events of bone-healing that include increased osteoclastogenesis and compromised osteoblast activity, which could be explained by the dysfunction of insulin receptor that led to activation of signals related with osteoblast differentiation. Furthermore, chronic hyperglycemia along with associated micro- and macro-vascular ailments leads to delayed/impaired wound healing due to activation of pathways that are particularly important in initiating events linked to inflammation, oxidative stress, and cell apoptosis; this may be through deactivation of AKT/PKB protein, which possesses a pivotal role in drive survival and eNOS signaling. This review presents an overview of the local and systemic mechanisms synergistically affecting bone-healing impairment in MetS/DM individuals, as well as a rationale for hierarchical animal model selection, in an effort to characterize peri-implantitis disease and treatment.

Comparative Evaluation of Dental Implant Failure among Healthy and Well-Controlled Diabetic Patients-A 3-Year Retrospective Study

Diabetes mellitus is known to compromise the various aspects of homeostasis, including the immune response and the composition of oral microflora. One of the oral manifestations of diabetes mellitus is tooth loss and the survival rate of dental implants chosen as a treatment modality for its rehabilitation is controversial. The current study aims to evaluate and compare the failure rate of dental implants between well-controlled diabetic and healthy patients. A retrospective study of case-control design was conceptualized with 121 well-controlled diabetic and 136 healthy individuals. Records of subjects who had undergone oral rehabilitation with dental implants between the periods of January 2013 to January 2016 were retrieved. Post-operative evaluation was carried out for all patients for about three years to assess the immediate and long-term success of the procedure. From a total of 742 dental implants, 377 were placed in well-controlled diabetic patients (case group) and 365 in healthy subjects (control group). A comparable (9.81%), but non-significant (p = 0.422) failure rate was found in the case group in comparison to the control group (9.04%). A non-significant (p = 0.392) raised number (4.98%) of failure cases were reported among females in comparison to males (4.44%). In respect to arch, the mandibular posterior region was reported as the highest failure cases (3.09%; p = 0.411), with 2.29% of cases reported in the mandibular anterior (p = 0.430) and maxillary posterior (p = 0.983) each. The maxillary anterior region was found to have the least number (1.75%; p = 0.999) of failure cases. More (4.98%; p = 0.361) cases were reported to fail during the functional loading stage in contrast to osseointegration (4.44%; p = 0.365). A well-controlled diabetic status does not impose any additional risk for individuals undergoing dental implant therapy.

Influence of Diabetes on Implant Failure and Peri-Implant Diseases: A Retrospective Study

Diabetes is an important modifying factor of periodontitis, but its association with peri-implant diseases has not been fully explored and the existing literature reports controversial results. The aim of this retrospective study was to evaluate the influence of diabetes on peri-implantitis and implant failure. Smoking status, history of periodontal disease, presence of diabetes, diabetes type, therapy and glycaemia levels were collected in a total of 204 subjects treated with 929 implants, with a mean follow-up time of 5.7 ± 3.82 years after loading. Odds ratio (OR) for diabetes as a direct cause of peri-implantitis and implant failure were calculated, adjusted for smoking status and history of periodontitis. Nineteen patients were diabetic and most of them presented a good control of the disease at the time of surgery. The overall patient-level prevalence of peri-implantitis was 11.3%. Among diabetic patients, one developed peri-implantitis, whereas one experienced multiple implant failures. The calculated ORs, adjusted for smoking status and periodontitis, were not statistically significant. The results revealed no association between diabetes and peri-implantitis or implant failure coherently with the existing scientific literature. The actual influence of hyperglycemia on implant failure is still uncertain and new studies with larger cohorts of patients are needed.

TiO2 Nanotubes Alleviate Diabetes-Induced Osteogenetic Inhibition

Background

Patients with diabetes mellitus (DM) have a higher failure rate of dental implant treatments. However, whether titanium (Ti) implants with TiO₂ nanotubes (TNT) surface can retain their biocompatibility and osteogenetic ability under DM conditions has not been investigated; in addition, their behavior in DM conditions is not well characterized.

Materials and Methods

Pure Ti discs were surface treated into the polishing (mechanically polished, MP), sandblasted and acid-etched (SLA), and TNT groups. Scanning electron microscopy was used to examine the surface morphology. The cell adhesion and proliferation ability on different modified Ti surfaces at various glucose concentrations (5.5, 11, 16.5, and 22 mM) was detected by the CCK-8 assay. The osteogenetic ability on different modified Ti surfaces under high-glucose conditions was evaluated by alkaline phosphatase (ALP), osteopontin (OPN) immunofluorescence, Western blot, and Alizarin Red staining in vitro. Detection of cell apoptosis and intracellular reactive oxygen species (ROS) was undertaken both before and after N-acetylcysteine (NAC) treatment to assess the oxidative stress associated with different modified Ti surfaces under high-glucose conditions. An in vivo study was conducted in DM rats with different modified Ti femoral implants. The osteogenetic ability of different modified Ti implants in DM rats was assessed using a micro-CT scan.

Results

High-glucose conditions inhibited cell adhesion, proliferation, and osteogenetic ability of different modified Ti surfaces. High-glucose conditions induced higher apoptosis rate and intracellular ROS level on different modified Ti surfaces; these effects were alleviated by NAC. Compared with the SLA surface, the TNT surface alleviated the osteogenetic inhibition induced by high-glucose states by reversing the overproduction of ROS in vitro. In the in vivo experiment, micro-CT scan analysis further confirmed the best osteogenetic ability of TNT surface in rats with DM.

Conclusion

TNT surface modification alleviates osteogenetic inhibition induced by DM. It may provide a more favorable Ti implant surface for patients with DM.

Osteogenic inducer sustained-release system promotes the adhesion, proliferation, and differentiation of osteoblasts on titanium surface

OBJECTIVE

Biomaterial can be locally applied to promote the osseointegration of dental implants. This study aimed to fabricate an osteogenic inducer (OI) sustained-release system and to evaluate its effects on the adhesion, proliferation, and differentiation of osteoblasts on titanium surfaces.

METHODS

First of all, different contents of OI solution were added to the poly (lactic-co-glycolic acid) (PLGA) gel individually to investigate the best physical properties and drug-release rate. Moreover, osteoblasts were isolated from the calvaria of two-month-old New Zealand rabbits through sequential enzymatic digestion. Osteoblasts were seeded onto the surface of Ti disks (control group), Ti coated with PLGA gel (PLGA group), and Ti coated with the OI sustained-release system (PLGA+OI group). Cell adhesion was observed by scanning electron microscopy. Cell proliferation was analyzed by cell counting kit-8. Cell differentiation was tested by alizarin red staining, alkaline phosphatase (ALP) activity and osteogenic-related gene expression.

RESULTS

The OI sustained-release system contained 15% OI solution had appropriate physical properties and drug-release rate. The osteoblasts in the PLGA+OI group were in a typical spindle shape with a considerable number indicating the promotion of adhesion and proliferation. The expression of early and late stage osteoblast differentiation genes in the PLGA+OI group were significantly higher than that of the control group and PLGA group at each time point. The PLGA group showed accelerated adhesion and differentiation but reduced proliferation compared with the control.

CONCLUSION

The OI sustained-release system promotes the adhesion, proliferation, and differentiation of osteoblasts on titanium surfaces. This system is a cost-effective osteoconductive biomaterial that might be promising for use in dental implantation.

Analysis of the Survival of Dental Implants Installed in Reconstructed Maxilla with Autogenous Iliac Crest Graft: 7- to 9-Year Follow-Up

The aim of this study was to analyze the survival of dental implants installed in maxillae reconstructed with autogenous iliac crest grafts and to assess patient satisfaction with the treatment by means of a questionnaire. The study conducted medical record reviews and clinical/radiographic assessments of 10 patients with severe maxillary atrophy who had undergone reconstruction with autogenous iliac crest grafts and rehabilitation with dental implants between 2008 and 2011. Patients were assessed for the survival of the implants, considering implant diameter and length, smoking status, diagnosis of diabetes, type of loss, and region of implant loss. In addition, a questionnaire with specific questions on the patients' satisfaction with the treatment was administered. Seventy-six implants were installed in the sampled patients, and only 1 loss was observed (late loss in the anterior maxilla region) after an average follow-up of 7.9 years, which corresponds to a 98.60% survival rate. The installed implants were of the most frequently used dimension (3.75 × 10 mm). One sampled patient was diabetic, and a second patient was both diabetic and a smoker. No loss of implants was observed in these 2 patients. All patients reported being completely satisfied with the treatment and would undergo the procedure again or refer it to a friend/relative. Six patients reported regular maintenance of the prosthesis, and only 3 had changed the prosthesis prior to the time of questionnaire administration. The results of this limited study with a restricted sample population suggest that the reconstruction of the maxilla with an autogenous iliac crest graft provides both adequate implant survival and patient satisfaction.

The effects of hyperglycaemia on peri-implant tissues after osseointegration

PURPOSE

We assessed the effects of hyperglycaemia induced by streptozotocin (STZ) on peri-implantitis developing after implant osseointegration.

METHODS

Thirty-six male Wistar rats (4 weeks old) were used. We placed titanium implants 4 weeks after extraction of the maxillary first molars. Healing abutments were attached 4 weeks later. After osseointegration was confirmed, the rats were divided into control, hyperglycaemia (STZ), and STZ with insulin (STZ+INS) groups. Hyperglycaemia was induced by a single injection of 50mg/kg STZ. Silk ligatures were placed on only the right sides (i.e. ligature sides), not on the left sides. Peri-implant tissues extracted at 4 weeks post-ligation were analysed both radiologically (via micro-computed tomography) and histologically (via toluidine blue staining). Total RNA was also extracted and analysed by quantitative PCR to detect TNF-α, IL-1β and the receptor of advanced glycation end products (RAGE). Additionally, advanced glycation end products (AGEs) were measured by ELISA.

RESULTS

Radiological and histological analyses showed that bone loss on the non-ligature sides was significantly greater in the STZ than the control group. However, on the ligature sides, bone loss was greater than on the non-ligature sides, and no significant difference was evident among the three groups. The levels of mRNAs encoding TNF-α, IL-1β, RAGE, and AGEs on the ligature sides were significantly upregulated (all P<0.05) in the STZ compared to the control group.

CONCLUSIONS

Although hyperglycaemia could be associated with bone loss around implants with increased AGE production and RAGE expression, hyperglycaemia does not become a triggering factor of ligature induced peri-implantitis.

Peri-implant mucositis

OBJECTIVES

This narrative review was prepared for the 2017 World Workshop of the American Academy of Periodontology and European Federation of Periodontology to address key questions related to the clinical condition of peri-implant mucositis, including: 1) the definition of peri-implant mucositis, 2) conversion of peri-implant health to the biofilm-induced peri-implant mucositis lesion, 3) reversibility of peri-implant mucositis, 4) the long-standing peri-implant mucositis lesion, 5) similarities and differences between peri-implant mucositis at implants and gingivitis at teeth, and 6) risk indicators/factors for peri-implant mucositis.

METHODS

A literature search of MEDLINE (PubMed) and The Cochrane Library up to and including July 31, 2016, was carried out using the search strategy (peri-implant[All Fields] AND ("mucositis"[MeSH Terms] OR "mucositis"[All Fields])) OR (periimplant[All Fields] AND mucosits[All Fields]). Prospective, retrospective, and cross-sectional studies and review papers that focused on risk factors/indicators for peri-implant mucositis as well as experimental peri-implant mucositis studies in animals and humans were included.

FINDINGS

Peri-implant mucositis is an inflammatory lesion of the soft tissues surrounding an endosseous implant in the absence of loss of supporting bone or continuing marginal bone loss. A cause-and-effect relationship between experimental accumulation of bacterial biofilms around titanium dental implants and the development of an inflammatory response has been demonstrated. The experimental peri-implant mucositis lesion is characterized by an inflammatory cell infiltrate present within the connective tissue lateral to the barrier epithelium. In long-standing peri-implant mucositis, the inflammatory cell infiltrate is larger in size than in the early (3-week) experimental peri-implant mucositis lesion. Biofilm-induced peri-implant mucositis is reversible at the host biomarker level once biofilm control is reinstituted. Reversal of the clinical signs of inflammation may take longer than 3 weeks. Factors identified as risk indicators for peri-implant mucositis include biofilm accumulation, smoking, and radiation. Further evidence is required for potential risk factors, including diabetes, lack of keratinized mucosa, and presence of excess luting cement.

CONCLUSIONS

Peri-implant mucositis is caused by biofilm accumulation which disrupts the host-microbe homeostasis at the implant-mucosa interface, resulting in an inflammatory lesion. Peri-implant mucositis is a reversible condition at the host biomarker level. Therefore, the clinical implication is that optimal biofilm removal is a prerequisite for the prevention and management of peri-implant mucositis. An understanding of peri-implant mucositis is important because it is considered a precursor for peri-implantitis.

Chronic hyperglycemia as a risk factor in implant therapy

It has been estimated that by 2030, the number of patients with diabetes aged > 64 years will be > 82 million in underdeveloped countries, and > 48 million in developed countries. Chronic hyperglycemia delays wound healing by reducing the expression of growth factors in the wound fluid and re-epithelialization. Impaired wound healing in patients with diabetes has also been associated with inhibition of the production of stromal cell-derived factor-1alpha by several tissues including bone marrow, brain, heart, spleen, and gingivae. Chronic hyperglycemia interferes with the osseointegration of implants by deferring the expression of fibronectin and integrins. Results from experimental studies have shown a significantly higher bone-to-implant contact around implants placed in healthy animals compared with animals with streptozotocin-induced diabetes. Moreover, persistent hyperglycemia plays a role in abnormal differentiation of osteoclasts, thereby making bone tissue more susceptible to resorption. Furthermore, persistent hyperglycemia has also been associated with increased peri-implant soft tissue inflammation (increased peri-implant bleeding on probing and probing depth) and crestal bone loss. Clinical studies have shown that under optimal glycemic control dental implants can show success and survival rates of up to 100% in patients diagnosed with diabetes. Although patients with diabetes can undergo dental implant therapy and can exhibit implant survival similar to those in systemically healthy individuals, the contribution of glycemic control and regular oral hygiene maintenance cannot be disregarded.

Risk indicators for marginal bone resorption around implants in function for at least 4 years: A retrospective longitudinal study

BACKGROUND

Marginal bone stability is considered one of the most important issues in implant dentistry. It is essential to understand how various factors influence bone resorption around implants. The purpose of this retrospective longitudinal study was to identify potential risk indicators associated with marginal bone resorption around implants in function for at least 4 years.

METHODS

Several systemic-related, intraoral-related, implant-related factors were collected. Marginal bone level change (MBLC) was determined by comparing intraoral radiographs taken at baseline (1 year after prosthesis delivery), and at follow-up (over 3 years from baseline). A hierarchical regression analysis using liner mixed-effects models was performed to examine correlations between MBLC and various factors.

RESULTS

Overall, 514 patients with 1535 implants were analyzed. The mean age of the participants was 62.9 years. Mean annual MBLC was 0.048 mm, and mean functional time was 5.96 years. The result showed that the following explanatory variables had significant effects on MBLC: functional time, plaque control record > 20%, Eichner index C1-3, maxilla, cement-retained superstructure, and keratinized mucosa width < 2 mm. We did not find statistically significant associations between bone resorption and some variables known as risk factors, such as diabetes, smoking, and history of periodontitis.

CONCLUSIONS

Within the limits of this study, longer functional time, poor oral hygiene, loss of occlusal support, location in the maxilla, cement-retained superstructure, and less keratinized mucosa should be considered as risk indicators for bone resorption around implants.

Peri-implant mucositis

OBJECTIVES

This narrative review was prepared for the 2017 World Workshop of the American Academy of Periodontology and European Federation of Periodontology to address key questions related to the clinical condition of peri-implant mucositis, including: 1) the definition of peri-implant mucositis, 2) conversion of peri-implant health to the biofilm-induced peri-implant mucositis lesion, 3) reversibility of peri-implant mucositis, 4) the long-standing peri-implant mucositis lesion, 5) similarities and differences between peri-implant mucositis at implants and gingivitis at teeth, and 6) risk indicators/factors for peri-implant mucositis.

METHODS

A literature search of MEDLINE (PubMed) and The Cochrane Library up to and including July 31, 2016, was carried out using the search strategy (peri-implant[All Fields] AND ("mucositis"[MeSH Terms] OR "mucositis"[All Fields])) OR (periimplant[All Fields] AND mucosits[All Fields]). Prospective, retrospective, and cross-sectional studies and review papers that focused on risk factors/indicators for peri-implant mucositis as well as experimental peri-implant mucositis studies in animals and humans were included.

FINDINGS

Peri-implant mucositis is an inflammatory lesion of the soft tissues surrounding an endosseous implant in the absence of loss of supporting bone or continuing marginal bone loss. A cause-and-effect relationship between experimental accumulation of bacterial biofilms around titanium dental implants and the development of an inflammatory response has been demonstrated. The experimental peri-implant mucositis lesion is characterized by an inflammatory cell infiltrate present within the connective tissue lateral to the barrier epithelium. In long-standing peri-implant mucositis, the inflammatory cell infiltrate is larger in size than in the early (3-week) experimental peri-implant mucositis lesion. Biofilm-induced peri-implant mucositis is reversible at the host biomarker level once biofilm control is reinstituted. Reversal of the clinical signs of inflammation may take longer than 3 weeks. Factors identified as risk indicators for peri-implant mucositis include biofilm accumulation, smoking, and radiation. Further evidence is required for potential risk factors, including diabetes, lack of keratinized mucosa, and presence of excess luting cement.

CONCLUSIONS

Peri-implant mucositis is caused by biofilm accumulation which disrupts the host-microbe homeostasis at the implant-mucosa interface, resulting in an inflammatory lesion. Peri-implant mucositis is a reversible condition at the host biomarker level. Therefore, the clinical implication is that optimal biofilm removal is a prerequisite for the prevention and management of peri-implant mucositis. An understanding of peri-implant mucositis is important because it is considered a precursor for peri-implantitis.

Evaluation of biologic implant success parameters in type 2 diabetic glycemic control patients versus health patients: A meta-analysis

AIM

The aim of the present systematic literature review was to evaluate bleeding on probing (BOP), pocket depth (PD), and marginal bone loss (MBL) in type 2 diabetes mellitus (T2DM) control patients.

METHODS

An electronic literature search was conducted through PubMed, Web of Science, Cochrane, Embase, and ScienceDirect. The search included prospective human clinical studies that analyzed the success of dental implants in T2DM control patients. For inclusion, studies should have had a minimum of 1-year follow up and should have assessed the following parameters: MBL, BOP and PD. Prior to meta-analysis, all of the studies were assessed for quality, bias, and heterogeneity.

RESULTS

Risk of bias analysis indicated that all studies were of moderate quality. After a full-text evaluation, only seven studies met the inclusion criteria for this meta-analysis, with a combined total of 443 patients and 530 dental implants. The meta-analysis indicated a statistically significant difference between parameters of implants placed in the glycemic-controlled group and healthy group in MBL (P < .001), BOP (P < .04), and PD (P < .001).

CONCLUSION

The results of the present study indicated that, despite being glycemic controlled, patients with T2DM were associated with a higher risk of peri-implant disease.

Cinaciguat in combination with insulin induces a favorable effect on implant osseointegration in type 2 diabetic rats

The osseointegration process of implant is seriously impaired in type 2 diabetes mellitus (T2DM) that causes high failure rate, and insufficiency exists in current insulin therapy, creating a demand for new bone-synergistic agent. Cinaciguat, a novel type of soluble guanylate cyclase (sGC) activator, plays a vital role in glucose metabolism, inflammation control and bone regeneration. We hypothesized that the combined application of cinaciguat and insulin could reverse poor implant osseointegration in diabetes. To test this hypothesis, streptozotocin-induced diabetic rats were placed implants in the femur, and divided into five groups: control, T2DM, cinaciguat-treated T2DM (7 μg/kg), insulin-treated T2DM (12 IU/kg), cinaciguat plus insulin combination-treated T2DM (7 μg/kg and 12 IU/kg respectively), according to different treatment received. The weight and glucose levels of rats were evaluated at fixed times, and plasma level of cyclic guanosine monophosphate (cGMP) was determined before euthanasia. Three months after therapy, the femurs were isolated for pull-out test, environmental scanning electron microscope observation, microscopic computerized tomography evaluation and various histology analysis. Results revealed that diabetic rats showed the highest blood glucose level and lowest cGMP content, which led to the worst structural damage and least osseointegration. Combined treatment could attenuate the diabetes induced hyperglycemia to be normal, restore the cGMP content, protein kinase G II (PKG II) expression, phosphodiesterase-5 (PDE5) activity and ameliorate the mechanical strength, the impaired bone microarchitecture and osseointegration to the highest level. Meanwhile, monotreatment (insulin or cinaciguat) also showed restorative effect, but less. Our findings demonstrated that the cGMP/PKG II signaling pathway activated by cinaciguat mediated the favorable effects of the combined application on improving implant fixation under T2DM condition.

Molecular mechanisms linking peri-implantitis and type 2 diabetes mellitus revealed by transcriptomic analysis

Aims

To explore molecular mechanisms that link peri-implantitis and type 2 diabetes mellitus (T2DM) by bioinformatic analysis of publicly available experimental transcriptomic data.

Materials and methods

Gene expression data from peri-implantitis were downloaded from the Gene Expression Omnibus database, integrated and differentially expressed genes (DEGs) in peri-implantitis were identified. Next, experimentally validated and computationally predicted genes related to T2DM were downloaded from the DisGeNET database. Protein–protein interaction network (PPI) pairs of DEGs related to peri-implantitis and T2DM related genes were constructed, “hub” genes and overlapping DEG were determined. Functional enrichment analysis was used to identify significant shared biological processes and signaling pathways. The PPI networks were subjected to cluster and specific class analysis for identifying “leader” genes. Module network analysis of the merged PPI network identified common or cross-talk genes connecting the two networks.

Results

A total of 92 DEGs overlapped between peri-implantitis and T2DM datasets. Three hub genes (IL-6, NFKB1, and PIK3CG) had the highest degree in PPI networks of both peri-implantitis and T2DM. Three leader genes (PSMD10, SOS1, WASF3), eight cross-talk genes (PSMD10, PSMD6, EIF2S1, GSTP1, DNAJC3, SEC61A1, MAPT, and NME1), and one signaling pathway (IL-17 signaling) emerged as peri-implantitis and T2DM linkage mechanisms.

Conclusions

Exploration of available transcriptomic datasets revealed IL-6, NFKB1, and PIK3CG expression along with the IL-17 signaling pathway as top candidate molecular linkage mechanisms between peri-implantitis and T2DM.

Clinical and radiographic indices around narrow diameter implants placed in different glycemic-level patients

BACKGROUND

Studies assessing peri-implant clinical and marginal bone resorption (MBR) around narrow diameter implants (NDIs) placed in different glycemic levels are uninvestigated.

OBJECTIVE

The present 3-year retrospective follow-up investigation was designed to explore clinical and radiographic status of NDIs placed in individuals with different glycemic control levels.

MATERIALS AND METHODS

Patients with serum hemoglobin A1c (HbA1c) levels ≥6.5% (Group-1), 5.7%-6.4% (Group-2), and 4.0%-5.0% (Group-3) were included. Clinical indices evaluating bleeding on probing (BOP), plaque scores (PI), peri-implant probing depth (PD), and MBR were recorded around NDIs at 1-, 2-, and 3-year follow-up. Serum HbA1c test was carried out for all patients to assess the profile of glycosylated hemoglobin at 1 and 3 years of follow-up.

RESULTS

A significant reduction in mean HbA1c levels from year 1 to year 3 follow-up period was seen in Group-1 only. PI varied from 0.40 in Group 1 at 2 year and 0.42 at 3-year follow-up to 0.18 at 2-year (P = 0.032) and 0.17 at 3-year (P = 0.018) follow-up, respectively. Greater BOP was noted in Group 1 (0.53) as compared with Group 2 (0.42) and Group 3 (0.21) (P = 0.048) at 3-year follow-up. PD after 3 year ranged from 2.04 mm in Group 3 to 2.32 mm in Group 1 that showed statistically significant difference (P = 0.037). No statistical significant differences were observed in MBR at any time point between the groups.

CONCLUSION

The results of this short-term follow-up study indicate that NDIs show clinical and radiographic stability, provided oral cleanliness and glycemic levels are relatively maintained. Further long-term clinical studies are needed to evaluate implant stability over the period along with controlled glycemic status.

Evaluating All Potential Oral Complications of Diabetes Mellitus

Diabetes mellitus (DM) is associated with several microvascular and macrovascular complications, such as retinopathy, nephropathy, neuropathy, and cardiovascular diseases. The pathogenesis of these complications is complex, and involves metabolic and hemodynamic disturbances, including hyperglycemia, insulin resistance, dyslipidemia, hypertension, and immune dysfunction. These disturbances initiate several damaging processes, such as increased reactive oxygen species (ROS) production, inflammation, and ischemia. These processes mainly exert their damaging effect on endothelial and nerve cells, hence the susceptibility of densely vascularized and innervated sites, such as the eyes, kidneys, and nerves. Since the oral cavity is also highly vascularized and innervated, oral complications can be expected as well. The relationship between DM and oral diseases has received considerable attention in the past few decades. However, most studies only focus on periodontitis, and still approach DM from the limited perspective of elevated blood glucose levels only. In this review, we will assess other potential oral complications as well, including: dental caries, dry mouth, oral mucosal lesions, oral cancer, taste disturbances, temporomandibular disorders, burning mouth syndrome, apical periodontitis, and peri-implant diseases. Each oral complication will be briefly introduced, followed by an assessment of the literature studying epidemiological associations with DM. We will also elaborate on pathogenic mechanisms that might explain associations between DM and oral complications. To do so, we aim to expand our perspective of DM by not only considering elevated blood glucose levels, but also including literature about the other important pathogenic mechanisms, such as insulin resistance, dyslipidemia, hypertension, and immune dysfunction.

1α,25-dihydroxyvitamin D3 promotes osseointegration of titanium implant via downregulating AGEs/RAGE pathway in T2DM

Diabetes-induced advanced glycation end products (AGEs) overproduction would result in compromised osseointegration of titanium implant and high rate of implantation failure. 1α,25-dihydroxyvitamin D3 (1,25VD3) plays a vital role in osteogenesis, whereas its effects on the osseointegration and the underlying mechanism are unclear. The purpose of this study was to investigate that 1,25VD3 might promote the defensive ability of osseointegration through suppressing AGEs/RAGE in type 2 diabetes mellitus. In animal study, streptozotocin-induced diabetic rats accepted implant surgery, with or without 1,25VD3 intervention for 12 weeks. After sacrificed, the serum AGEs level, bone microarchitecture and biomechanical index of rats were measured systematically. In vitro study, osteoblasts differentiation capacity was analyzed by alizarin red staining, alkaline phosphatase assay and western blotting, after treated with BSA, AGEs, AGEs with RAGE inhibitor and AGEs with 1,25VD3. And the expression of RAGE protein was detected to explore the mechanism. Results showed that 1,25VD3 could reverse the impaired osseointegration and mechanical strength, which possibly resulted from the increased AGEs. Moreover, 1,25VD3 could ameliorate AGEs-induced damage of cell osteogenic differentiation, as well as downregulating the RAGE expression. These data may provide a theoretical basis that 1,25VD3 could work as an adjuvant treatment to against poor osseointegration in patients with type 2 diabetes mellitus.

PLGA film/Titanium nanotubues as a sustained growth factor releasing system for dental implants

Ti-based implants sometimes fail to integrate with surrounding bone tissue due to insufficiency of new bone formation and surface bonding. To overcome this problem, this research focused on establishing a sustained bone growth factor delivery system by applying anodized TiO2 nanotube arrays and PLGA film on the titanium implant surface. TiO2 nanotube arrays were made by anodic oxidation method, and were then filled with rhBMP2 by vacuum freeze-drying. Next, PLGA was deposition on the surface of this material. The designed system was characterized, pharmacokinetic release rate of rhBMP2 was determined. Adhesion, proliferation, and differentiation activity of osteoblasts cultured on the new surfaces and traditional titanium surfaced were compared. SEM showed that a surface of TiO2 nanotube arrays were successfully generated. PLGA membranes of 50 nm, 250 nm, 800 nm thickness were successfully deposited on the surfaces of TiO2 nanotube layers by using 1%, 3%, 10% PLGA solutions. PLGA film of 250 nm thickness showed ideally controlled release of rhBMP2, lasting for 4 weeks. Furthermore, 250 nm thickness PLGA film improved osteoblast adhesion, proliferation, and levels of alkaline phosphatase. In conclusion, the PLGA film / TiO2 nanotube growth factor delivery system can effectively sustain the release of rhBMP-2, and promote proliferation and differentiation of MC3T3-E1 osteoblasts.