Dental implants in diabetic patients: retrospective cohort study reporting on implant survival and risk indicators for excessive marginal bone loss at 5 years

Nano-Based Approaches in Surface Modifications of Dental Implants: A Literature Review

Rehabilitation of fully or partially edentulous patients with dental implants represents one of the most frequently used surgical procedures. The work of Branemark, who observed that a piece of titanium embedded in rabbit bone became firmly attached and difficult to remove, introduced the concept of osseointegration and revolutionized modern dentistry. Since then, an ever-growing need for improved implant materials towards enhanced material-tissue integration has emerged. There is a strong belief that nanoscale materials will produce a superior generation of implants with high efficiency, low cost, and high volume. The aim of this review is to explore the contribution of nanomaterials in implantology. A variety of nanomaterials have been proposed as potential candidates for implant surface customization. They can have inherent antibacterial properties, provide enhanced conditions for osseointegration, or act as reservoirs for biomolecules and drugs. Titania nanotubes alone or in combination with biological agents or drugs are used for enhanced tissue integration in dental implants. Regarding immunomodulation and in order to avoid implant rejection, titania nanotubes, graphene, and biopolymers have successfully been utilized, sometimes loaded with anti-inflammatory agents and extracellular vesicles. Peri-implantitis prevention can be achieved through the inherent antibacterial properties of metal nanoparticles and chitosan or hybrid coatings bearing antibiotic substances. For improved corrosion resistance various materials have been explored. However, even though these modifications have shown promising results, future research is necessary to assess their clinical behavior in humans and proceed to widespread commercialization.

AMPK activation enhances osteoblast differentiation on a titanium disc via autophagy

PURPOSE

The acquisition of osseointegration during implant therapy is slower and poorer in patients with diabetes compared with healthy persons. The serum concentration of adiponectin in patients with type II diabetes is lower than that of healthy persons via the suppression of AMP-activated protein kinase (AMPK). Therefore, we hypothesized that the AMPK activation enhances bone formation around implants, resulting in the improved acquisition of osseointegration. The purpose of this study was to evaluate the impact of AMPK activation on osteoblast differentiation and its mechanism of downstream signaling on titanium disc (Ti).

METHODS

Confluent mouse pre-osteoblasts (MC3T3-E1) cells (1 × 105 cells/well) were cultured with BMP-2 for osteoblast differentiation, in the presence or absence AICAR, an AMPK activator. We examined the effects of AMPK activation on osteoblast differentiation and the underlying mechanism on a Ti using a CCK8 assay, a luciferase assay, quantitative RT-PCR, and western blotting.

RESULTS

Although the proliferation rate of osteoblasts was not different between a Ti and a tissue culture polystyrene dish, the addition of AICAR, AMPK activator slightly enhanced osteoblast proliferation on the Ti. AICAR enhanced the BMP-2-dependent transcriptional activity on the Ti, leading to upregulation in the expression of osteogenesis-associated molecules. AICAR simultaneously upregulated the expression of autophagy-associated molecules on the Ti, especially LC3-II. AdipoRon, an adiponectin receptor type1/type2 activator activated AMPK, and upregulated osteogenesis-associated molecules on Ti.

CONCLUSIONS

AMPK activation enhances osteoblast differentiation on a Ti via autophagy, suggesting that it promotes the acquisition of osseointegration during implant therapy.

Systemic Diseases and Biological Dental Implant Complications: A Narrative Review

The relationship between periodontitis and such systemic disorders as diabetes, cardiovascular disease and obesity has been extensively investigated. There is less scientific evidence available, however, regarding the influence of systemic diseases on the risk of late failure of dental implant rehabilitation due to peri-implantitis. The aim of the present study was to review the literature on the role of several common systemic disorders (diabetes, obesity, cardiovascular disease, hypertension and osteoporosis) in the onset of peri-implantitis. A database search initially yielded 2787 studies of potential interest published up to 1 March 2022 (993 in PubMed; 908 in Web of Science; and 886 in Scopus). After removing 1190 duplicate articles and checking the titles, abstracts and full texts for relevance, 70 articles were selected for the present analysis. Only cohort, case-control studies and clinical case series were considered. Most of the literature concludes for no association between diabetes, cardiovascular disease, hypertension or osteoporosis and the risk of peri-implantitis. On the other hand, almost all the studies that investigated obesity as a risk factor for implant rehabilitation found a positive association between the two. Further longitudinal studies are needed to better understand the effects of systemic diseases on rehabilitation with dental implants.

Dental implants in patients suffering from autoimmune diseases: A systematic critical review

PURPOSE

This systematic review aimed to evaluate complications and survival rates of dental implants placed in patients suffering from autoimmune diseases.

MATERIALS AND METHODS

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses systematic review guidelines (PRISMA), using Google scholar and PubMed electronic databases with a stop date of September 2021. The eligibility criteria included all full text human studies in the English language literature reporting on patients with autoimmune diseases treated with dental implants.

RESULTS

Fifty-five studies reporting on nine distinct autoimmune diseases were analyzed: 17 on Sjögren's syndrome (SS), 11 on oral lichen planus (OLP), 8 on Type 1 diabetes, 6 on rheumatoid arthritis (RA), 4 on systemic scleroderma (SSc), 3 on Crohn's disease (CD), 3 on systemic lupus erythematosus (SLE), 2 on mucous membrane pemphigoid (MMB) and 1 on pemphigus vulgaris (PV). Despite the heterogeneity and methodological limitations of most of the studies, results showed that dental implant survival rates were comparable to those reported in the general population. However, patients with secondary SS or erosive OLP were more susceptible to developing peri-mucositis and increased marginal bone loss.

CONCLUSION

This review suggested that dental implants may be considered as a safe and viable therapeutic option in the management of edentulous patients suffering from autoimmune diseases. Nevertheless, scrupulous maintenance of oral hygiene and long-term follow-up emerge as being the common determinants for uneventful dental implant treatment.

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.

Effectiveness of dental implantation with the partial split-flap technique on vertical guided bone regeneration: a retrospective study

PURPOSE

This study aimed to evaluate the effectiveness of the partial split-flap technique with a K-incision on vertical guided bone regeneration (vGBR) and to retrospectively analyze the clinical and radiographic outcomes of dental implantation using this approach.

METHODS

In total, 78 patients who received 104 dental implants with vGBR, categorized as (1) pre-GBR and post-implantation and (2) simultaneous GBR and implantation, were enrolled. Data analysis was based on periapical radiographs, clinical photos, and dental records. The 2-sample t-test was used to compare the 2 surgical procedures.

RESULTS

The baseline vertical bone level, augmented bone height (ABH), and treatment duration were significantly higher in the pre-GBR procedure group. The survival rates of the implants were 96.1% and 94.8% in implant- and patient-based analyses, respectively. In Cox regression analysis, high rates of implant failure were found in the presence of ABH of ≥4 mm, smoking, and diabetes.

CONCLUSIONS

Within the limitations of this retrospective study, the partial split-flap technique using a K-incision for vGBR showed stable clinical outcomes and favorable dental implant survival.

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.

Adiponectin regulates osteocytic MLO-Y4 cell apoptosis in a high-glucose environment through the AMPK/FoxO3a signaling pathway

Clinical studies have shown that persistent hyperglycemia following oxidative stress is associated with the apoptosis of osteocytes in diabetics. Adiponectin (APN) can ameliorate oxidative stress, and its receptors have been identified in bone-forming cells. However, the relationship between APN and osteocyte apoptosis has not been fully elucidated. This study aimed to investigate whether APN could prevent osteocyte apoptosis and regulate reactive oxygen species (ROS) generation in a high-glucose environment. Hoechst staining and fluorescence microscopy were used to observe the apoptosis of osteocytic MLO-Y4 cells. Real-time quantitative polymerase chain reaction and Western blot analysis were used to detect the expression of Caspase 3, Caspase 8, and Bcl-2. ROS generation was investigated with an active oxygen kit and fluorescence microscopy. Furthermore, the expression of proteins in the AMPK/FoxO3A signaling pathway was also studied by Western blot analysis. In a high-glucose environment, APN promoted the proliferation of MLO-Y4 osteocytes and the expression of Bcl-2 but inhibited the expression of Caspase 3, Caspase 8, and ROS in a dose-dependent manner. APN promoted the activation of p-AMPK and p-AMPK/AMPK, which reached their highest levels at 10 min and returned to baseline at 30 min. The expression of p-FoxO3A/FoxO3A in both the cytoplasm and nucleus peaked at 15 min, and this expression was returned to baseline at 60 min. In summary, APN has an antiapoptotic effect and regulates ROS generation in MLO-Y4 osteocytes in a high-glucose environment. The AMPK/FoxO3A signaling pathway might be a key signaling pathway that participates in the effect of APN on regulating osteocyte apoptosis in diabetics.

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.

A Prognostic Model for the Outcome of Nobel Biocare Dental Implants with Peri-Implant Disease after One Year

Background: This investigation, based on a 1-year retrospective cohort study, aimed to estimate and validate a prognostic model for ailing and failing implants due to peri-implant disease. Methods: A total of 240 patients (male: 97; female: 143; average age of 57.3 years) with at least one ailing or failing implant were included: 120 patients for model derivation and 120 patients for model validation. The primary outcome measure was the implant status: success, defined as the arrest of the disease, or failure defined as implant extraction, prevalence or re-incidence of peri-implant disease). Potential prognostic risk indicators were collected at the baseline evaluation. The relative risk (RR) was estimated for the predictors through logistic regression and the c-statistic (95% confidence interval) was calculated for both derivation and validation sets. The significance level was set at 5%. Results: The risk model retrieved the prognostic factors age (RR = 1.04), history of Periodontitis (RR = 3.13), severe peri-implant disease status (RR = 3.26), implant length (RR = 3.52), early disease development (RR = 3.99), with good discrimination in both the derivation set (0.763 [0.679; 0.847]) and validation set (0.709 [0.616; 0.803]). Conclusions: A prognostic risk model for estimating the outcome of implants with peri-implant disease is available, with a good performance considering the c-statistic evaluation.