Expression of the receptor of advanced glycation end products in gingival tissues of type 2 diabetes patients with chronic periodontal disease: a study utilizing immunohistochemistry and RT-PCR

Investigation on the association between serum lipid levels and periodontitis: a bidirectional Mendelian randomization analysis

OBJECTIVE

Several research has considered the potential correlation between periodontitis and serum lipids. However, serum lipid profiles correlation with periodontitis remains largely unknown. The investigation objective was to examine periodontitis correlation with serum lipid levels using a bidirectional Mendelian randomization (MR) analysis.

METHODS

The study employed a bidirectional MR analysis with two samples, utilizing a freely accessible genome-wide association study (GWAS). Furthermore, the primary analysis employed the inverse variance weighted (IVW) method. To determine whether the lipid profiles were associated with periodontitis, a variety of sensitivity analyses (including MR-Egger regression, MR-PRESSO, and weighted median), as well as multivariable MR, were employed.

RESULTS

MR analysis performed by IVW did not reveal any relationship between periodontitis and low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (TG), or total cholesterol (TC). It was also found that LDL, HDL, TG, and TC were not associated to periodontitis. Furthermore, the MR estimations exhibited consistency with other MR sensitivity and multivariate MR (MVMR) analyses. These results show that the correlation between serum lipid levels and periodontitis could not be established.

CONCLUSION

The finding indicates a negligible link between periodontitis and serum lipid levels were identified, despite previous observational studies reporting a link between periodontitis and serum lipid levels.

Clinical and Radiographic Outcomes of Adjunctive Photodynamic Therapy for Treating Peri-Implant Mucositis Among Cigarette Smokers and Diabetics: A Systematic Review and Meta-Analysis

Objective: This systematic review aimed to assess the influence of antimicrobial photodynamic therapy (aPDT) as an adjunct to mechanical debridement (MD) on peri-implant clinical and radiographic outcomes among cigarette smokers and diabetics with peri-implant mucositis (piM). Methods: Randomized controlled trials, assessing the clinical and radiographic parameters of aPDT versus MD alone among smokers and diabetics with piM, were included in the study. Meta-analyses were conducted to calculate the standard mean difference with a 95% confidence interval. The methodological quality of the included studies was assessed utilizing the modified Jadad quality scale. Results: The meta-analyses found statistically significant differences between the impact of adjunct aPDT and MD alone on the peri-implant plaque index (PI), probing depth (PD), and bleeding on probing among smokers and diabetics with piM at the final follow-up visit. However, no significant differences were found between the impact of adjunct aPDT and MD alone on the peri-implant crestal bone loss among smokers and diabetics with piM at the final follow-up. Conclusions: The application of aPDT as an adjunctive to MD demonstrated improved scores of the peri-implant clinical parameters among smokers and diabetics with piM in comparison with MD alone.

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.

Levels of peri-implant sulcular fluid levels of soluble urokinase plasminogen activator receptor and TNF-α among cigarette smokers and non-smokers with peri-implantitis

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) and tumor necrosis factor-alpha (TNF-α) are inflammatory biomarkers. No studies have yet assessed the suPAR levels in relation with TNF-α in the peri-implant sulcular fluid (PISF) among cigarette smokers and non-smokers with peri-implantitis.

OBJECTIVE

The aim was to evaluate PISF levels of suPAR, and TNF-α among cigarette smokers and non-smokers with and without peri-implantitis.

METHODS

Sixty male patients with peri-implantitis were included. There were 20 cigarette smokers and 20 and non-smokers with peri-implantitis (Groups 1 and 2), and 20 non-smokers without peri-implantitis (Group 3). Demographic data and information related to cigarette smoking was recorded. Peri-implant clinicoradiographic parameters (plaque index [PI], gingival index [GI], probing depth [PD] and crestal bone loss [CBL]) were assessed. The PISF samples were collected and levels of suPAR and TNF-α were measured. Sample-size estimation was performed and all parameters were statistically assessed. Level of significance was set at P< 0.05.

RESULTS

Sixty individuals were included in Groups 1, 2 and 3 (20 in each). Peri-implant PI (P< 0.01), PD (P< 0.01) and mesial (P< 0.01) and distal (P< 0.01) CBL were significantly higher in Group 1 than in Groups 2 and 3. The PISF volume (P< 0.01) and suPAR (P< 0.01) and TNF-α levels (P< 0.01) were significantly higher in Groups 1 and 2 than in Group 3. There was no difference in PISF volume and suPAR and TNF-α levels between patients in Groups 1 and 2. In Group 2, there was a statistically significant correlation between peri-implant PD and PISF suPAR and TNF-α levels (P< 0.01). The suPAR and TNF-α levels are expressed in high concentrations in the PISF of smokers and non-smokers with peri-implantitis compared with non-smokers without peri-implantitis.

CONCLUSION

In non-smokers, PISF suPAR and TNF-α levels are correlated with peri-implant PD.

Comparative analysis of sulfiredoxin and total oxidative stress levels in diabetic individuals with periodontitis: A case-control study

BACKGROUND

The delicate balance between oxidative stress and its antioxidant system can be disrupted in diabetes mellitus (DM), making the tissue susceptible to injury. Hence, this case-control study aims to estimate and correlate the gingival tissue sulfiredoxin and crevicular total oxidative stress (TOS) levels in generalized periodontitis Stage II individuals Grade C (PSII) with and without type II DM.

MATERIAL AND METHODS

A total of 72 individuals were grouped based on their glycosylated hemoglobin (HbA1c) levels and clinical parameters: group I, periodontally healthy non-diabetic (HbA1c < 5.7%) (n = 24); group II, non-diabetic with PSII (n = 24); and group III, diabetic individuals (HbA1c > 6.5%) with PSII (n = 24). Gingival tissues and crevicular fluid samples were collected. The samples with adequate protein concentrations (n = 72) were further estimated for sulfiredoxin and TOS levels by enzyme-linked immunosorbent assay (ELISA) and calorimetric method, respectively.

RESULTS

Tissue sulfiredoxin and crevicular TOS levels are increased significantly in the periodontitis group compared to the non-periodontitis group (p < 0.001).The tissue sulfiredoxin levels did not vary significantly between the two periodontitis groups (p < 0.179). The TOS levels are significantly higher in the diabetic compared to non-diabetic periodontitis group (p < 0.001). Correlation statistics showed a significant positive correlation (r = 0.65 and p < 0.005) between sulfiredoxin and TOS levels in diabetes with PSII group, however, no such significant correlation was observed in the non-diabetic PSII group (r = 0.255 and p < 0.422).

CONCLUSION

Diabetic individuals showed inadequate sulfiredoxin-mediated antioxidant response to an increase in oxidative stress levels in periodontitis Stage II Grade C individuals.

Expression of advanced glycation end products and receptors in gingival tissues of patients with noninsulin-dependent diabetes mellitus-associated periodontitis

Background/purpose

Advanced glycation end products (AGEs) are known to accumulate in the periodontal tissues of patients with diabetes mellitus (DM). Through this study, we aimed to investigate the distribution of AGEs and the receptor of AGEs (RAGE) in the gingival tissues of patients with chronic periodontitis with and without non-insulin-dependent diabetes mellitus (NIDDM).

Materials and methods

Gingival biopsy samples from 13 patients with both NIDDM and periodontitis and 6 patients with both non-DM (NDM) and periodontitis were collected. The tissue sections were processed using immunohistochemical (IHC) staining to detect the distributions of AGEs and RAGE. Spearman correlation coefficients of all samples were calculated (P < 0.05) for the AGE and RAGE rankings of the following clinical parameters: plaque score (PI), probing depth (PD), bleeding on probing (BOP), and tooth loss (TL).

Results

IHC analysis revealed that AGEs among patients with NIDDM had a significantly higher ranking than those of the NDM group (P < 0.05). Positive staining for RAGE was observed in both groups but was not significantly different (P > 0.05). A positive correlation between AGE ranking and TL was observed in the NIDDM group, but not between AGE ranking and PI, PD, or BOP. The distribution of RAGE was not correlated with PI, PD, BOP, or TL.

Conclusion

AGEs were particularly distributed in the highly inflamed gingiva of patients with NIDDM-associated periodontitis and was statistically correlated with the long-term parameter TL.

Impact of Periodontitis on Glycemic Control and Metabolic Status in Diabetes Patients: Current Knowledge on Early Disease Markers and Therapeutic Perspectives

Diabetes mellitus and periodontitis are two of the most common chronic diseases affecting the world's population, and they are intimately linked. For several years, in fact, it has been known that there is an interdependent relationship between the two diseases: Diabetes promotes the destruction of periodontal tissues, and periodontal disease negatively affects glycemic control. In relation to the control of dental plaque and oral dysbiosis responsible for periodontal disease, both nonsurgical and surgical therapy associated with proper home hygiene procedures have emerged as essential for good glycemic control. Moreover, several evidences suggest the essential role played by the control of periodontal disease in preventing the onset of the most common complications of diabetes: cardiovascular diseases, retinopathies, and other systemic diseases. The aim of this study is to update the current knowledge on the bi-univocal relationship between diabetes and periodontitis and the impact of therapy in the optimal management of these two disorders. From the information found in the literature, it has emerged that the correct treatment of periodontal disease in diabetic patients represents one of the main mechanisms and means currently established and valid to control periodontal disease and glucose metabolism and prevent the onset or development of diabetic complications.

The role of oral microbiome in periodontitis under diabetes mellitus

Periodontitis is among most common human inflammatory diseases and characterized by destruction of tooth-supporting tissues that will eventually lead to tooth loss. Diabetes mellitus (DM) is a group of metabolic disorders characterized by chronic hyperglycemia which results from defects in insulin secretion and/or insulin resistance. Numerous studies have provided evidence for the inter-relationship between DM and periodontitis that has been considered as the sixth most frequent complication of DM. However, the mechanisms are not fully understood yet. The impact of DM on periodontitis through hyperglycemia and inflammatory pathways is well described, but the effects of DM on oral microbiota remain controversial according to previous studies. Recent studies using next-generation sequencing technology indicate that DM can alter the biodiversity and composition of oral microbiome especially subgingival microbiome. This may be another mechanism by which DM risks or aggravates periodontitis. Thus, to understand the role of oral microbiome in periodontitis of diabetics and the mechanism of shifts of oral microbiome under DM would be valuable for making specific therapeutic regimens for treating periodontitis patients with DM or preventing diabetic patients from periodontitis. This article reviews the role of oral microbiome in periodontal health (symbiosis) and disease (dysbiosis), highlights the oral microbial shifts under DM and summarizes the mechanism of the shifts.

Are Inflamed Periodontal Tissues Endogenous Source of Advanced Glycation End-Products (AGEs) in Individuals with and without Diabetes Mellitus? A Systematic Review

Advanced glycation end-products (AGEs) are heterogeneous compounds formed when excess sugars condense with the amino groups of nucleic acids and proteins. Increased AGEs are associated with insulin resistance and poor glycemic control. Recently, inflamed periodontal tissues and certain oral bacteria were observed to increase the local and systemic AGE levels in both normoglycemic and hyperglycemic individuals. Although hyperglycemia induced AGE and its effect on the periodontal tissues is known, periodontitis as an endogenous source of AGE formation is not well explored. Hence, this systematic review is aimed to explore, for the first time, whether inflamed periodontal tissues and periodontal pathogens have the capacity to modulate AGE levels in individuals with or without T2DM and how this affects the glycemic load. Six electronic databases were searched using the following keywords: (Periodontitis OR Periodontal disease OR Periodontal Inflammation) AND (Diabetes mellitus OR Hyperglycemia OR Insulin resistance) AND Advanced glycation end products. The results yielded 1140 articles, of which 13 articles were included for the review. The results showed that the mean AGE levels in gingival crevicular fluid was higher in individuals with diabetes mellitus and periodontitis (521.9 pg/mL) compared to healthy individuals with periodontitis (234.84 pg/mL). The serum AGE levels in normoglycemic subjects having periodontitis was higher compared to those without periodontitis (15.91 ng/mL vs. 6.60 ng/mL). Tannerella forsythia, a common gram-negative anaerobe periodontal pathogen in the oral biofilm, was observed to produce methylglyoxal (precursor of AGE) in the gingival tissues. Increased AGE deposition and activate of AGE receptors was noted in the presence of periodontitis in both normoglycemic and hyperglycemic individuals. Hence, it can be concluded that periodontitis can modulate the local and systemic levels of AGE levels even in absence of hyperglycemia. This explains the bidirectional relationship between periodontitis and development of prediabetes, incident diabetes, poor glycemic control, and insulin resistance.

Bioinspired Andrias davidianus-Derived wound dressings for localized drug-elution

Local drug delivery has received increasing attention in recent years. However, the therapeutic efficacy of local delivery of drugs is still limited under certain scenarios, such as in the oral cavity or in wound beds after resection of tumors. In this study, we introduce a bioinspired adhesive hydrogel derived from the skin secretions of Andrias davidianus (SSAD) as a wound dressing for localized drug elution. The hydrogel was loaded with aminoguanidine or doxorubicin, and its controlled drug release and healing-promoting properties were verified in a diabetic rat palatal mucosal defect model and a C57BL/6 mouse melanoma-bearing model, respectively. The results showed that SSAD hydrogels with different pore sizes could release drugs in a controllable manner and accelerate wound healing. Transcriptome analyses of the palatal mucosa suggested that SSAD could significantly upregulate pathways linked to cell adhesion and extracellular matrix deposition and had the ability to recruit keratinocyte stem cells to defect sites. Taken together, these findings indicate that property-controllable SSAD hydrogels could be a promising biofunctional wound dressing for local drug delivery and promotion of wound healing.

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The SSAD is a biologically drawable source with facile production, cost-effective, and safe.

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SSAD increases drug bioavailability with local application.

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The drug release rate can be controlled by regulating SSAD particle size.

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The SSAD-based wound dressing is adhesive.

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SSAD can also promote wound healing.

Pathogenic Molecular Mechanisms in Periodontitis and Peri-Implantitis: Role of Advanced Glycation End Products

Advanced Glycation End Products (AGEs), the products of the non-enzymatic oxidation of proteins, nucleic acids, and lipids, are accumulated in periodontal tissues under hyperglycemic conditions such as Diabetes Mellitus (DM) and are responsible for sustained periodontal destruction. AGEs mediate their intracellular effects either directly or indirectly through receptor binding (via RAGE) in all types of periodontal ligament cells (osteocytes, gingival fibroblasts, stem cells, epithelial cells), indicating an important target for intervention. In combination with lipopolysaccharides (LPS) from Porphyromonas gingivalis (Pg), the negative impact of AGEs on periodontal tissue is further enhanced and accentuated. In addition, AGE accumulation is evident in peri-implantitis, yet through different underlying molecular mechanisms. Novel therapeutic approaches targeting the effects of AGEs in periodontal ligament cells show beneficial effects in pre-clinical studies. Herein, we provide evidence on the detrimental role of AGE accumulation in oral cavity tissues and their associated signaling pathways in periodontitis and peri-implantitis to further highlight the significance of oral or topical use of AGE blockers or inhibitors along with dental biofilms’ removal and DM regulation in patients’ management.

The Complex Interrelationship between Diabetes Mellitus, Oral Diseases and General Health

There is emerging evidence that several oral diseases and conditions can be associated with DM. Dental caries, hyposalivation, fungal diseases and endodontics lesions may represent potential oral complications that can be aggravated by chronic hyperglycemia. Individuals with DM have a low perception of oral diseases which can lead to clinically important oral and systemic complications. This review aims to provide data on the most common oral signs and symptoms related to DM and to explore the mechanisms that might explain associations between DM and oral diseases in order to clarify the risks posed by poor oral health in DM. Since the linkage between oral diseases and DM is part of multifactorial aspects related to chronic hyperglycemic status and several common conditions affecting the whole body, both require rigorous self-control from patients and attention from medical and dental professionals.

The Effect of Diabetes Mellitus on IGF Axis and Stem Cell Mediated Regeneration of the Periodontium

Periodontitis and diabetes mellitus (DM) are two of the most common and challenging health problems worldwide and they affect each other mutually and adversely. Current periodontal therapies have unpredictable outcome in diabetic patients. Periodontal tissue engineering is a challenging but promising approach that aims at restoring periodontal tissues using one or all of the following: stem cells, signalling molecules and scaffolds. Mesenchymal stem cells (MSCs) and insulin-like growth factor (IGF) represent ideal examples of stem cells and signalling molecules. This review outlines the most recent updates in characterizing MSCs isolated from diabetics to fully understand why diabetics are more prone to periodontitis that theoretically reflect the impaired regenerative capabilities of their native stem cells. This characterisation is of utmost importance to enhance autologous stem cells based tissue regeneration in diabetic patients using both MSCs and members of IGF axis.

Prevalence of periodontitis in people clinically diagnosed with diabetes mellitus: a meta-analysis of epidemiologic studies

AIMS

The relationship between diabetes mellitus and periodontitis has long been discussed, but the conclusion of this relationship was controversial. We conducted this meta-analysis to explore the association between diabetes mellitus and the prevalence of periodontitis.

METHODS

PubMed, Embase, Web of Science, and the Cochrane Library were searched for studies reporting associations of periodontitis with diabetes. Gray literature was integrated from the Open-Gray database. Prevalence estimates and odds ratios were extracted by two independent reviewers and synthesized through meta-analyses.

RESULTS

Twenty-seven papers met the inclusion criteria involving 3092 diabetic patients and 23,494 controls. Overall prevalence of periodontitis was 67.8% in diabetics (combined types) and 35.5% in patients without diabetes (OR, 1.85; 95%CI, 1.61-2.11). Probing depth (MD 0.23; 95% CI, 0.17-0.29; I² = 25%) and plaque index (MD, 0.20; 95% CI, 0.18-0.23; P = 0.59; I² = 0%) severity scores were significantly greater among the diabetic group.

CONCLUSIONS

The prevalence and severity of periodontitis are greater in patients with diabetes than in non-diabetic populations.

Diabetic wound healing in soft and hard oral tissues

There is significant interest in understanding the cellular mechanisms responsible for expedited healing response in various oral tissues and how they are impacted by systemic diseases. Depending upon the types of oral tissue, wound healing may occur by predominantly re-eptihelialization, by re-epithelialization with substantial new connective tissue formation, or by a a combination of both plus new bone formation. As a result, the cells involved differ and are impacted by systemic diaseses in various ways. Diabetes mellitus is a prevalent metabolic disorder that impairs barrier function and healing responses throughout the human body. In the oral cavity, diabetes is a known risk factor for exacerbated periodontal disease and delayed wound healing, which includes both soft and hard tissue components. Here, we review the mechanisms of diabetic oral wound healing, particularly on impaired keratinocyte proliferation and migration, altered level of inflammation, and reduced formation of new connective tissue and bone. In particular, diabetes inhibits the expression of mitogenic growth factors whereas that of pro-inflammatory cytokines is elevated through epigenetic mechanisms. Moreover, hyperglycemia and oxidative stress induced by diabetes prevents the expansion of mesengenic cells that are involved in both soft and hard tissue oral wounds. A better understanding of how diabetes influences the healing processes is crucial for the prevention and treatment of diabetes-associated oral complications.

Verbascoside Protects Gingival Cells against High Glucose-Induced Oxidative Stress via PKC/HMGB1/RAGE/NFκB Pathway

Impaired wound healing often occurs in patients with diabetes and causes great inconvenience to them. Aside from the presence of prolonged inflammation, the accumulation of oxidative stress is also implicated in the delayed wound healing. In the present study, we tested the effect of verbascoside, a caffeoyl phenylethanoid glycoside, on the improvement of cell viability and wound healing capacity of gingival epithelial cells under high glucose condition. We showed that verbascoside attenuated the high glucose-induced cytotoxicity and impaired healing, which may be associated with the downregulation of oxidative stress. Our results demonstrated that verbascoside increased the activity of the antioxidant enzyme SOD and reduced the oxidative stress indicator, 8-OHdG, as well as apoptosis. Moreover, verbascoside upregulated the PGC1-α and NRF1 expression and promoted mitochondrial biogenesis, which was mediated by suppression of PKC/HMGB1/RAGE/NFκB signaling. Likewise, we showed the inhibitory effect of verbascoside on oxidative stress was via repression of PKC/HMGB1/RAGE/NFκB activation. Also, our data suggested that the PKC-mediated oxidative stress may lead to the elevated production of inflammatory cytokines, IL-6 and IL-1β. Collectively, we demonstrated that verbascoside may be beneficial to ameliorate impaired oral wound healing for diabetic patients.

Association between periodontal inflammation and serum lipid profile in a healthy population: A cross-sectional study

AIMS

The impact of periodontal inflammation on lipid metabolism is controversial. This study aimed to investigate the association between full-mouth periodontal inflammation and serum lipid levels.

MATERIALS AND METHODS

In this cross-sectional study, we performed periodontal and bacteriological examinations during medical checkup on 131 subjects. The association between the periodontal inflamed surface area (PISA) and the lipid markers was analyzed by multiple linear regression, adjusting for age, sex, smoking, and body mass index.

RESULTS

Overall, 118 medically healthy participants were analyzed. The proportions of none, mild, moderate, and severe periodontitis were 37.3%, 32.2%, 25.4%, and 5.1%, respectively. Multivariate analysis showed that high-density lipoprotein cholesterol was significantly higher in participants with the lowest tertile of PISA values (PISA low, coefficient: 7.94; 95% confidence interval [CI]: 1.63, 14.26, p = .01) compared to those in other tertiles (PISA high). Low-density/high-density lipoprotein cholesterol and total/high-density lipoprotein cholesterol ratios were significantly lower in the PISA-low group than the PISA-high group (coefficient: -0.26 and -0.30; 95% CI: -0.50, -0.02, and -0.59, -0.0002; p = .04 and .0498). Serum high-sensitivity C-reactive protein level, but not serum Porphyromonas gingivalis antibody titer, partly explained the association between PISA and high-density lipoprotein cholesterol. A significant interaction between female sex and PISA values toward high-density lipoprotein cholesterol level was detected.

CONCLUSION

Periodontal inflammation was inversely associated with higher high-density lipoprotein cholesterol, especially in females. Elevated serum C-reactive protein partly explained this association.

Clinical, radiographic and restorative parameters for short tuberosity implants placed in smokers: a retrospective study with 5 year follow-up

This study aimed to estimate and compare the clinical, radiographic, and restorative parameters around short tuberosity implants (STIs) placed in cigarette smokers (CS) and never smokers (NS). In this 60-month follow-up retrospective study, a total of 50 (37 males + 13 females) individuals who had received 82 dental implants were included. These participants were categorized into two groups as follows: (i) Group-1: 25 self-reported systemically healthy CS with 43 STIs; and (ii) Group-2: 25 self-reported systemically healthy NS with 39 STIs. In both groups, peri-implant plaque index (PI), probing depth (PD), bleeding on probing (BOP), and crestal bone loss (CBL) and restorative parameters were measured at 12 and 60 months of follow-up. Group comparisons were performed utilizing the Kruskal-Wallis test. The significance level was set at p < 0.05. In CS and NS, the mean age of participants was 58.5 and 60.7 years, respectively. No statistically significant differences were observed in the overall mean levels of PD and CBL around STIs among CS and NS. However, a statistically significant increase was observed in the mean scores of BOP and PI around STIs in the NS and CS at 12 and 60 months follow-up, respectively. In both groups, the loosening of the implant was the most frequently encountered type of STI failure. The outcomes of the present study suggest that STIs placed in maxillary tuberosity can show reliable clinical, radiographic, and restorative stability among cigarettes smokers and non-smokers. However, the role of smoking status and oral hygiene cannot be disregarded in this scenario.

Effect of spirulina and chlorella alone and combined on the healing process of diabetic wounds: an experimental model of diabetic rats

BACKGROUND

Using chemical agents to cure diabetes mellitus and its complications may be accompanied by complications. New natural agents, such as spirulina and chlorella, could be used as alternative choices in this case.

METHODS

65 male Wistar rats were allocated to 5 groups: A (healthy control), B (diabetic rats with a normal diet), C (diabetic rats supplemented with 50 g/kg/day spirulina), D (diabetic rats supplemented with 50 g/kg/day chlorella) and E (diabetic rats supplemented with 25 g/kg/day chlorella and 25 g/kg/day spirulina). After 21 days, wounds were inflicted on the back of rats. Assessment of blood sugar (BS), high-sensitivity C-reactive protein (hs-CRP), vascular endothelial growth factor (VEGF), granulation tissue formation, vascularization, epithelialization, and percentage of wound healing were determined along with macroscopic examinations.

RESULTS

The microscopic changes at days 3, 7, 14, and 21 showed significant evidence of improved angiogenesis, epithelial proliferation, and granulation tissue formation in the spirulina and chlorella treated rats compared with the controls (p˂0.05). Both spirulina and chlorella treatments of diabetic rats resulted in a significant reduction in BS and weight (p˂0.05), but VEGF and hs-CRP levels did not significantly change (p > 0.05). Percentage of wound healing was 100% on day 21 in all groups, except the control group B (97.8 ± 1.15%).

CONCLUSIONS

The results of this study showed that supplementation with spirulina and chlorella alone and combined could improve wound healing indices in diabetic rats and could therefore be recommended for the management of diabetic ulcer.

Can we improve dental treatment outcomes in patients with high-risk factors?

Aim The aim of the study was to identify best practice in relation to improving the periodontal conditions of patients and increasing the rate of treatment success, through the identification of risk factors and implementation of changes in lifestyle.Methods and materials The study used two search strategies to identify papers describing best practices and important lifestyle changes which improved periodontal conditions and treatment outcomes in patientsResults The study demonstrated that the two most important factors in terms of interventions to improve periodontal conditions and treatment outcomes were to improve the level of diabetes control and remove aggravating factors such as smoking.Conclusion Many studies have focused on improving treatment outcomes in patients with high-risk factors such as smoking and medical conditions. Strategies, guidelines and protocols that reflect the best practices and lifestyle changes to improve the level of treatment success in high-risk patients should be adapted within treatment planning and follow-up. Successful treatment outcomes are best achieved through controlling diseases affecting the oral cavity and supporting structures.

Levels of proinflammatory chemokines and advanced glycation end products in patients with type-2 diabetes mellitus undergoing fixed orthodontic treatment

OBJECTIVES

To explore the effect of diabetic status on the proinflammatory chemokine profile and levels of advanced glycation end products (AGEs) in gingival crevicular fluid (GCF) derived from patients with type 2 diabetes mellitus (T2DM) undergoing fixed orthodontic treatment.

MATERIALS AND METHODS

Two groups, nondiabetic and T2DM, were included. Their demographics, biochemical parameters including hemoglobin A1c, fasting blood glucose, body mass index, and oral hygiene status were recorded. GCF sampling was performed after 2 months of placement of stainless steel archwires and chemokines (primary outcome) were quantified using Human Magnetic Luminex multiplex assay. Secondary outcomes were assessment of clinical periodontal status, unstimulated whole saliva flow rate, and GCF flow rate.

RESULTS

Twenty participants each in the nondiabetic (mean age: 26.4 years) and T2DM (mean age: 27.2 years) groups gave consent to participate. Biochemical analysis showed significantly increased values for hemoglobin A1c (P < .001), fasting blood glucose (P < .0001), body mass index(P = .047), and unstimulated whole saliva flow rate (P = .041) for the T2DM group. Bleeding on probing was significantly higher in participants with T2DM than nondiabetic participants (P = .039). Resistin (P = .034) and AGEs (P = .017) showed significantly higher values in participants with T2DM than nondiabetic participants. Pearson correlation analysis indicated a significant positive correlation between resistin (r = 0.1372; P = .022) and AGEs (r = 0.0194; P = .0186) against bleeding on probing in participants with T2DM.

CONCLUSIONS

The biochemical profile of GCF samples from participants with T2DM after alignment demonstrated higher levels of resistin and AGEs. The data suggest the presence of a proinflammatory response in patients with T2DM undergoing fixed orthodontic treatment.

The association of periodontal diseases with metabolic syndrome and obesity

Periodontitis is a multifactorial chronic inflammatory disease associated with dysbiotic plaque biofilms and characterized by progressive destruction of the tooth-supporting apparatus. Globally, it is estimated that 740 million people are affected by its severe form. Periodontitis has been suggested to be linked to obesity and metabolic syndrome. Obesity, defined as excessive fat accumulation, is a complex multifactorial chronic inflammatory disease, with a high and increasing prevalence. Metabolic syndrome is defined as a cluster of obesity, dyslipidemia, hypertension, and dysglycemia. Obesity, metabolic syndrome and periodontitis are among the most common non-communicable diseases and a large body of evidence from epidemiologic studies supports the association between these conditions. Extensive research has established plausible mechanisms to explain how these conditions can negatively impact each other, pointing to a bidirectional adverse relationship. At present there is only limited evidence available from a few intervention studies. Nevertheless, the global burden of periodontitis combined with the obesity epidemic has important clinical and public health implications for the dental team. In accordance with the common risk factor approach for tackling non-communicable diseases, it has been proposed that oral healthcare professionals have an important role in the promotion of periodontal health and general well-being through facilitation of healthy lifestyle behaviours.

High Mobility Group Box 1 Expression in Oral Inflammation and Regeneration

High mobility group box 1 (HMGB1) is a non-histone DNA-binding protein of about 30 kDa. It is released from a variety of cells into the extracellular milieu in response to inflammatory stimuli and acts on specific cell-surface receptors, such as receptors for advanced glycation end-products (RAGE), Toll-like receptor (TLR)2, TLR4, with or without forming a complex with other molecules. HMGB1 mediates various mechanisms such as inflammation, cell migration, proliferation, and differentiation. On the other hand, HMGB1 enhances chemotaxis acting through the C-X-C motif chemokine ligand (CXCL)12/C-X-C chemokine receptor (CXCR)4 axis and is involved in regeneration. In the oral cavity, high levels of HMGB1 have been detected in the gingival tissue from periodontitis and peri-implantitis patients, and it has been shown that secreted HMGB1 induces pro-inflammatory cytokine expression, such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α, which prolong inflammation. In contrast, wound healing after tooth extraction or titanium dental implant osseointegration requires an initial acute inflammation, which is regulated by secreted HMGB1. This indicates that secreted HMGB1 regulates angiogenesis and bone remodeling by osteoclast and osteoblast activation and promotes bone healing in oral tissue repair. Therefore, HMGB1 can prolong inflammation in the periodontal tissue and, conversely, can regenerate or repair damaged tissues in the oral cavity. In this review, we highlight the role of HMGB1 in the oral cavity by comparing its function and regulation with its function in other diseases. We also discuss the necessity for further studies in this field to provide more specific scientific evidence for dentistry.

Effect of photobiomodulation on cellular migration and survival in diabetic and hypoxic diabetic wounded fibroblast cells

A disrupted wound repair process often leads to the development of chronic wounds, and pose a major physical, social and economic inconvenience on patients and the public health sector. Chronic wounds are a common complication seen in diabetes mellitus (DM), and often the severity necessitates amputation of the lower limbs. Recently, there has been increasing evidence that photobiomodulation (PBM) initiates wound healing, including increased protein transcription for cell proliferation, viability, migration and tissue reepithelialisation. Here, the hypothesis that PBM at a wavelength of 660 nm and energy density of 5 J/cm² regulates wound repair in diabetic wounded and hypoxic diabetic wounded fibroblasts by enhancing cell migration and survival was investigated. PBM increased migration and survival in diabetic wounded and hypoxic diabetic wounded fibroblasts. Our findings suggest that PBM enhances migration and survival in diabetic wounded and hypoxic diabetic wounded fibroblasts, indicating that this therapeutic method may be beneficial against chronic wounds in diabetic patients.

GLP-1 inhibits PKCβ2 phosphorylation to improve the osteogenic differentiation potential of hPDLSCs in the AGE microenvironment

BACKGROUND AND OBJECTIVE

Advanced glycation end products (AGEs) have been hypothesized as the etiologic factors of diabetic periodontitis. The discovery of incretins (including GLP-1 and GIP) provides a novel therapy for the treatment of diabetes. Recent reports have shown that glucagon-like peptide-1 (GLP-1) is an important modulator of bone growth and remodeling. The aim of this study was to clarify the mechanism of how GLP-1 weakens/inhibits the effect of AGEs in hPDLSCs (human periodontal ligament stem cells).

MATERIALS AND METHODS

The hPDLSCs were cultured under simulated conditions of osteogenic culture, AGEs, AGEs + GLP-1, AGEs + GLP-1 + PMA and AGEs + GLP-1 + LY333531. The phenomenon and related mechanism of cell osteogenesis under different microenvironments were evaluated by Alizarin red staining, ALP staining and quantitative activity measurement, RT-qPCR, western blotting and immunofluorescence staining.

RESULTS

RT-qPCR showed that AGEs negatively regulated the expression of osteogenic differentiation markers (ALP, BSP, OPN, and Runx2); in contrast, GLP-1 increased the expression of these markers. Furthermore, the expression of RAGE and pPKCβ (PKC phosphorylation) in the AGE group was upregulated, while the expression of RAGE and pPKCβ was decreased in the GLP-1 group compared with the AGE group.

CONCLUSIONS

AGEs impaired the osteogenic potential of hPDLSCs via PKCβ2. Our phenomenon showed that GLP-1 could reverse the function of AGEs on osteogenic potential. In addition, the mechanism of GLP-1 weakens/inhibits the effect of AGEs in hPDLSCs, possibly by inhibiting PKCβ2 phosphorylation.

6-Shogaol Inhibits Advanced Glycation End-Products-Induced IL-6 and ICAM-1 Expression by Regulating Oxidative Responses in Human Gingival Fibroblasts

Advanced glycation end-products (AGEs) cause diabetes mellitus (DM) complications and accumulate more highly in periodontal tissues of patients with periodontitis and DM. AGEs aggravate periodontitis with DM by increasing the expression of inflammation-related factors in periodontal tissues. 6-Shogaol, a major compound in ginger, has anti-inflammatory and anti-oxidative activities. However, the influence of shogaol on DM-associated periodontitis is not well known. In this study, the effects of 6-shogaol on AGEs-induced oxidative and anti-oxidative responses, and IL-6 and ICAM-1 expression in human gingival fibroblasts (HGFs) were investigated. When HGFs were cultured with 6-shogaol and AGEs, the activities of reactive oxygen species (ROS) and antioxidant enzymes (heme oxygenase-1 [HO-1] and NAD(P)H quinone dehydrogenase 1 [NQO1]), and IL-6 and ICAM-1 expressions were investigated. RAGE expression and phosphorylation of MAPKs and NF-κB were examined by western blotting. 6-Shogaol significantly inhibited AGEs-induced ROS activity, and increased HO-1 and NQO1 levels compared with the AGEs-treated cells. The AGEs-stimulated expression levels of receptor of AGE (RAGE), IL-6 and ICAM-1 and the phosphorylation of p38, ERK and p65 were attenuated by 6-shogaol. These results suggested that 6-shogaol inhibits AGEs-induced inflammatory responses by regulating oxidative and anti-oxidative activities and may have protective effects on periodontitis with DM.

Association of Receptor for advanced glycation end products G82S polymorphism with chronic periodontitis in type II diabetic and non-diabetic South Indians

AIM The current study investigated the association of RAGE G82S polymorphism with chronic periodontitis in South Indians with and without type II Diabetes mellitus.

MATERIALS AND METHODS

405 individuals were enrolled into 3 groups-systemically and periodontally healthy with no attachment loss (n = 135), generalized chronic periodontitis (n = 135)and generalized chronic periodontitis with type II diabetes mellitus(n = 135). Periodontal clinical parameters were recorded. RFLP-PCR was utilized for genotyping.

RESULTS

Frequencies of genotype GG, GA and AA were 133, 2, 0 in group I respectively, 131, 4, 0 in group II respectively and 118, 13, 4 in group III respectively. Pearson's Chi squared test demonstrated a significant difference in the genotype distribution between the three groups (χ² = 19.88,P < 0.001). Fischer exact-test showed that the variant GA/AA genotype was associated with a significantly increased risk for generalized chronic periodontitis in type II diabetics when compared with the GG genotype of systemically and periodontally healthy subjects (OR-9.58, 95% CI 2.168-42.339, P < 0.001) and non-diabetic chronic periodontitis subjects (OR- 4.71, 95% CI: 1.54-14.42, P < 0.05). No association and increased susceptibility to chronic periodontitis was observed in subjects with GA/AA genotype when compared with systemically and periodontally healthy subjects (OR- 2.031, 95% CI: 0.366-11.277 P > 0.05). Furthermore, comparison of clinical parameters based on genotype distribution revealed statistically significant higher mean plaque (P < 0.05) and sulcus bleeding score (P < 0.001) in group-III subjects.

CONCLUSION

RAGE G82S gene polymorphism confers susceptibility to generalized chronic periodontitis in type II diabetic subjects of South Indian Tamilian ethnicity.

Clinical, radiographic, and restorative peri-implant measurements of narrow and standard diameter implants in obese and nonobese patients: A 3-year retrospective follow-up study

BACKGROUND

There is dearth of studies assessing clinical, restorative, and radiographic peri-implant outcomes around narrow diameter implants (NDIs) and standard diameter implants (SDIs) in obese and nonobese subjects.

OBJECTIVE

To assess clinical, restorative, and radiographic parameters of NDIs and SDIs placed in obese and nonobese individuals.

MATERIALS AND METHODS

Obese and nonobese patients requiring NDIs and SDIs in the anterior maxilla/mandible were included. Based on the implant diameter, participants were further divided into two subgroups: (a) NDIs (3.3 mm) and (b) SDIs (4.1 mm). Peri-implant clinical measurements including plaque index (PI), bleeding on probing (BOP), probing depth (PD), and radiographic crestal bone loss (CBL) were evaluated around NDIs and SDIs at 1 and 3-year follow-up.

RESULTS

A total of 70 patients (35 obese and 35 nonobese) were included. Only BOP showed statistically significant differences between both the groups at patient level at 1 and 3-year follow-up (P < .05). There was no statistically significant difference in PI and PD around NDIs and SDIs between obese and nonobase patients. Statistical significant differences were observed in the total CBL around NDIs and RDIs among obese and nonbase subjects at 3 year follow-up (P < .05).

CONCLUSION

Both NDIs and SDIs show consistent clinical stability among obese and nonobase patients. Higher amount of bone loss was observed in obese patients compared to nonobase patients despite regular hygiene maintenance.

Soluble Forms of the Receptor for Advanced Glycation Endproducts (RAGE) in Periodontitis

The receptor for advanced glycation endproducts (RAGE) is critically involved in the pathobiology of chronic inflammatory diseases. Soluble forms of RAGE have been proposed as biomarkers of severity in inflammatory and metabolic conditions, and in monitoring therapeutic responses. The aim of the present study was to determine circulating levels of the soluble forms of RAGE in periodontitis and to evaluate the expression of cell-bound, full-length RAGE and its antagonist AGER1 locally, in gingival tissues. Periodontitis patients and periodontally healthy, sex- and age-matched controls (50 per group) were included. Serum levels of total soluble RAGE and cleaved RAGE (cRAGE) were significantly lower in periodontitis patients. Levels of the endogenous secretory esRAGE were similar in the two groups. cRAGE remained significantly lower in the periodontitis group following multiple adjustments, and had a statistically significant inverse correlation with body mass index and all periodontal parameters. In periodontitis patients, gene expression of full-length RAGE and of AGER1 were significantly higher in periodontitis-affected gingival tissues compared to healthy gingiva. Soluble forms of RAGE, particularly cRAGE, may serve as biomarkers for the presence and severity/extent of periodontitis, and may be implicated in its pathogenesis and its role as a systemic inflammatory stressor.

Periodontal, metabolic, and cardiovascular disease: Exploring the role of inflammation and mental health

Previous evidence connects periodontal disease, a modifiable condition affecting a majority of Americans, with metabolic and cardiovascular morbidity and mortality. This review focuses on the likely mediation of these associations by immune activation and their potential interactions with mental illness. Future longitudinal, and ideally interventional studies, should focus on reciprocal interactions and cascading effects, as well as points for effective preventative and therapeutic interventions across diagnostic domains to reduce morbidity, mortality and improve quality of life.

Role of Osteogenic Coatings on Implant Surfaces in Promoting Bone-To-Implant Contact in Experimental Osteoporosis: A Systematic Review and Meta-Analysis

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the role of osteogenic coatings (placement of a thin film of organic and inorganic osteoinductive and osteoproliferative materials) on implant surfaces in augmenting bone-to-implant contact (BIC) in osteoporotic bone.

DATA SOURCES

To answer the focused question "Do osteogenic coatings on implant surfaces increase BIC in osteoporotic bone?" PubMed/MEDLINE, EMBASE, ISI Web of Knowledge, Scopus, and Google-Scholar databases were searched till June 2017 using different combinations of the following key words: bone-to-implant contact, coating, implant surface, osseointegration, and osteoporosis. Letters to the Editor, review articles, case-reports/case-series, and commentaries were excluded.

RESULTS

Six animal studies were included, in which osteoporosis was induced by bilateral ovariectomy. In all studies, implant surface roughness was increased by various osteogenic surface coatings including alumina, hydroxyapatite, calcium phosphate, and zoledronic acid. Five studies showed that bone volume and BIC are significantly higher around implants with coated surfaces than noncoated implants. In 1 study, there was no difference in BIC around coated and noncoated implants.

CONCLUSION

Although experimental studies have shown that osteogenic coatings are effective in enhancing BIC, their clinical relevance requires further investigations.

Polycystic Ovary Syndrome and Periodontal disease: Underlying Links- A Review

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age, which negatively affects various health systems. There is an extensive literature regarding the association of PCOS and other systemic conditions such as diabetes mellitus, cardiovascular disease, and psychological disorders. However, there is a lack of literature in associating PCOS and periodontal disease. Hence, PubMed search was done for various articles related to PCOS and its association with other comorbidities, including periodontal diseases. Analysis was done and data were synthesized and compiled in a sequential and presentable paradigm. This literature review of the pathophysiological mechanisms linking the two diseases suggests a positive relation between the two comorbidities. However, multicenter studies, with larger sample sizes, are to be conducted to establish a clearer and stronger association.

Cigarette smoke extract induces oral squamous cell carcinoma cell invasion in a receptor for advanced glycation end-products-dependent manner

Oral squamous cell carcinoma (OSCC) affects approximately 30,000 people and is associated with tobacco use. Little is known about the mechanistic effects of second-hand smoke in the development of OSSC. The receptor for advanced glycation end-products (RAGE) is a surface receptor that is upregulated by second-hand smoke and inhibited by semi-synthetic glycosaminoglycan ethers (SAGEs). Our objective was to determine the role of RAGE during cigarette smoke extract-induced cellular responses and to use SAGEs as a modulating factor of Ca9-22 OSCC cell invasion. Ca9-22 cells were cultured in the presence or absence of cigarette smoke extract and SAGEs. Cell invasion was determined and cells were lysed for western blot analysis. Ras and nuclear factor of kappa light polypeptide gene enhancer in B-cells (NF-κB) activation were determined. Treatment of cells with cigarette smoke extract resulted in: (i) increased invasion of OSCC; (ii) increased RAGE expression; (iii) inhibition of cigarette smoke extract-induced OSCC cell invasion by SAGEs; (iv) increased Ras, increased AKT and NF-κB activation, and downregulation by SAGEs; and (v) increased expression of matrix metalloproteinases (MMPs) 2, 9, and 14, and downregulation by SAGEs. We conclude that cigarette smoke extract increases invasion of OSCC cells in a RAGE-dependent manner. Inhibition of RAGE decreases the levels of its signaling molecules, which results in blocking the cigarette smoke extract-induced invasion.

Impact of diabetes on gingival wound healing via oxidative stress

The aim of this study is to investigate the mechanisms linking high glucose to gingival wound healing. Bilateral wounds were created in the palatal gingiva adjacent to maxillary molars of control rats and rats with streptozotocin-induced diabetes. After evaluating postsurgical wound closure by digital imaging, the maxillae including wounds were resected for histological examinations. mRNA expressions of angiogenesis, inflammation, and oxidative stress markers in the surgical sites were quantified by real-time polymerase chain reaction. Primary fibroblast culture from the gingiva of both rats was performed in high glucose and normal medium. In vitro wound healing and cell proliferation assays were performed. Oxidative stress marker mRNA expressions and reactive oxygen species production were measured. Insulin resistance was evaluated via PI3K/Akt and MAPK/Erk signaling following insulin stimulation using Western blotting. To clarify oxidative stress involvement in high glucose culture and cells of diabetic rats, cells underwent N-acetyl-L-cysteine treatment; subsequent Akt activity was measured. Wound healing in diabetic rats was significantly delayed compared with that in control rats. Nox1, Nox2, Nox4, p-47, and tumor necrosis factor-α mRNA levels were significantly higher at baseline in diabetic rats than in control rats. In vitro study showed that cell proliferation and migration significantly decreased in diabetic and high glucose culture groups compared with control groups. Nox1, Nox2, Nox4, and p47 expressions and reactive oxygen species production were significantly higher in diabetic and high glucose culture groups than in control groups. Akt phosphorylation decreased in the high glucose groups compared with the control groups. Erk1/2 phosphorylation increased in the high glucose groups, with or without insulin treatment, compared with the control groups. Impaired Akt phosphorylation partially normalized after antioxidant N-acetyl-L-cysteine treatment. Thus, delayed gingival wound healing in diabetic rats occurred because of impaired fibroblast proliferation and migration. Fibroblast dysfunction may occur owing to high glucose-induced insulin resistance via oxidative stress.

Inhibition of the receptor for advanced glycation promotes proliferation and repair of human periodontal ligament fibroblasts in response to high glucose via the NF-κB signaling pathway

OBJECTIVE

To observe if inhibition of the receptor for advanced glycation endproducts (RAGE) promotes proliferation and repair of human periodontal ligament fibroblasts (hPDLFs) stimulated by high glucose. In addition, we also discuss the effects of the NF-κB signaling pathway in relation to this process.

METHODS

Primary cultured hPDLFs were exposed to either low glucose (5.5 mmol/L) or high glucose (25 mmol/L), and RAGE expression was measured by Western blot analysis. Cells were cultured in high glucose with different concentrations of the RAGE inhibitor, FPS-ZM1. We measured cell proliferation using the Cell Counting Kit-8 and expression of collagen type 1 and fibronectin by real-time PCR and ELISA, respectively. The relative protein expression levels of NF-κB p65 and phosphorylated p65 were measured by Western blot analysis.

RESULTS

High glucose enhanced RAGE expression and suppressed cell growth. While FPS-ZM1 increased proliferation and expression of repair-related factors in high glucose, there was a concurrent decline in the phosphorylation level of NF-κB p65.

CONCLUSION

FPS-ZM1 rescued the proliferative capacity and repair capability of hPDLFs via the RAGE-NF-κB signaling pathway in response to high glucose.

Efficacy of statin delivery as an adjunct to scaling and root planing in the treatment of chronic periodontitis: A meta-analysis

The action of statins in stimulating bone formation and having other pleiotropic effects, such as anti-inflammatory and immunomodulatory effects, has justified their use as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis (CP). The aim of the present study was to evaluate the efficacy of statin delivery as an adjunct to SRP in the treatment of CP. Electronic searches were conducted using the following databases: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register, up until July 2017. The primary outcome was probing depth (PD), while the secondary outcomes were changes in clinical attachment level (CAL) and bone defect (BD) fill. Eleven studies were included, and all showed significant PD reduction, CAL gain, and BD fill with adjunctive statin delivery compared to SRP alone. The meta-analysis showed significant improvement in periodontal parameters for atorvastatin (PD: weighted mean difference [WMD] = -1.84, -2.56 to -1.12, P < .001; CAL: WMD = -2.31, -3.58 to -1.03, P < .001; BD fill: WMD = 2.66, -3.92 to -1.39, P < .001), simvastatin (PD: WMD = -1.91, -2.27 to -1.55, P < .001; CAL: WMD = -1.91, -2.27 to -1.55, P = .001; BD: WMD = -1.52, -2.20 to -0.85, P < .001), and rosuvastatin (PD: WMD = -0.94, -1.32 to -0.55, P < .001; CAL: WMD = -1.00, -1.41 to -0.60, P < .001; BD fill: WMD = -1.30, -1.80 to -0.79, P < .001). Adjunctive statin delivery appears to be effective in reducing PD, CAL gain, and BD fill in CP, and therefore, these drugs could be a promising therapeutic option for periodontal regeneration in future.

Investigation of the effect of astaxanthin on alveolar bone loss in experimental periodontitis

BACKGROUND AND OBJECTIVE

Astaxanthin is a keto-carotenoid that has a strong antioxidant effect. The purpose of this study was to evaluate the effects of astaxanthin on alveolar bone loss and histopathological changes in ligature-induced periodontitis in rats.

MATERIAL AND METHODS

Wistar rats were divided into four experimental groups: non-ligated (C, n = 6); ligature only (L, n = 6); ligature and astaxanthin (1 mg/kg/day astaxanthin, AS1 group, n = 8); ligature and astaxanthin (5 mg/kg/day astaxanthin, AS5 group, n = 8). Silk ligatures were placed at the gingival margin of lower first molars of the mandibular quadrant. The study duration was 11 days and the animals were killed at the end of this period. Changes in alveolar bone levels were clinically measured and tissues were immunohistochemically examined, osteocalcin, bone morphogenic protein-2, inducible nitric oxide synthase, Bax and bcl-2 levels in alveolar bone and tartrate-resistant acid phosphatase-positive osteoclast cells, osteoblast and inflammatory cell counts were determined.

RESULTS

Alveolar bone loss was highest in the L group and the differences among the L, AS1 and AS5 groups were also significant (P < .05). Both doses of astaxanthin decreased tartrate-resistant acid phosphatase-positive+ osteoclast cell and increased osteoblast cell counts (P < .05). The inflammation in the L group was also higher than those of the C and AS1 groups were (P < .05) indicating the anti-inflammatory effect of astaxanthin. Although inducible nitric oxide synthase, osteocalcin, bone morphogenic protein-2 and bax staining percentages were all highest in the AS5 group and bcl-2 staining percentage was highest in the AS1 group, values were close to each other (P > .05).

CONCLUSION

Within the limits of this study, it can be suggested that astaxanthin administration may reduce alveolar bone loss by increasing osteoblastic activity and decrease osteoclastic activity in experimental periodontitis model.

Cigarette smoke extract (CSE) induces RAGE-mediated inflammation in the Ca9-22 gingival carcinoma epithelial cell line

OBJECTIVE

The oral environment is anatomically positioned as a significant gateway for exposure to environmental toxicants. Cigarette smoke exposure compromises oral health by orchestrating inflammation. The receptor for advanced glycation end-products (RAGE) has been implicated in smoke-induced inflammatory effects; however, its role in the oral cavity is unknown. The purpose of this study was to determine RAGE expression by immortalized gingival carcinoma cells and the degree to which RAGE-mediated signaling influences inflammation.

DESIGN

Gingival epithelia cells (Ca9-22) were exposed to 10% cigarette smoke extract (CSE) for six hours and screened for RAGE expression and inflammatory mediators.

RESULTS

Quantitative PCR and immunoblotting revealed increased RAGE expression following exposure. Furthermore, exposure activated RAGE signaling intermediates including Ras and NF-κB. IL-6 and IL-1β were also elevated in cell culture medium from CSE-exposed cells when compared to controls. A family of anionic, partially lipophilic sulfated polysaccharide derivatives known as semi-synthetic glycosaminoglycan ethers (SAGEs) were used in an effort to block RAGE signaling. Co-treatment of CSE and SAGEs ameliorated inflammatory responses.

CONCLUSIONS

These results provide a new perspective on a mechanism of cigarette smoke induced oral inflammation. Further work may show RAGE signaling as a potential target in the treatment of diseases of the oral cavity exacerbated by tobacco smoke exposure.

Effect of Nd:YAG laser-assisted non-surgical mechanical debridement on clinical and radiographic peri-implant inflammatory parameters in patients with peri-implant disease

BACKGROUND AND AIM

The efficacy of neodymium-doped yttrium aluminium garnet (Nd:YAG) laser-assisted non-surgical mechanical debridement (MD) in the treatment of periimplant diseases remains uninvestigated. The aim was to assess the efficacy of Nd:YAG laser-assisted non-surgical MD on clinical and radiographic periimplant inflammatory parameters in patients with periimplant disease.

METHODS

Treatment wise, 63 male patients with periimplant diseases were divided into 2 groups: Group-1 (32 patients): treatment of periimplant disease using MD alone (control group); and Group-2 (n=31 patients): treatment of periimplant disease using MD with a single application of Nd:YAG laser. Peri-implant inflammatory parameters (plaque index [PI], bleeding on probing [BOP] and probing depth [PD]) were measured at baseline and at 3 and 6months' follow-up. Periimplant crestal bone loss (CBL) was measured at baseline and at 6months' follow-up. Statistical analysis was performed using the Kruskall-Wallis and Bonferroni Post hoc tests. P-values<0.05 were considered statistically significant.

RESULTS

In both groups, mean age of patients and baseline scores of periimplant PI, BOP and PD were comparable. At 3-month follow-up, scores of periimplant PI, BOP and PD were higher among patients in Group-1 compared with Group-2. At 6-month follow-up, scores of periimplant PI, BOP and PD were comparable among patients in groups 1 and 2. There was no statistically significant difference in periimplant CBL in both groups at all time intervals.

CONCLUSION

Nd:YAG laser-assisted non-surgical MD is more effective in reducing periimplant soft tissue inflammatory parameters than MD alone in short-term but not in long-term.