Clinical effect of subgingivally delivered simvastatin in the treatment of patients with chronic periodontitis: a randomized clinical trial

Mycobacterium tuberculosis : a new hitchhiker in the etiopathogenesis of periodontitis

Periodontitis, a chronic inflammatory disease of the gums affects both the ligament and alveolar bone. A severe form of periodontal disease affects a strikingly high number of one billion adults globally. The disease permutes both the soft and hard tissues of the oral cavity leading to localized and systemic diseases. Periodontitis has a deleterious impact on systemic health causing diabetes, cardiovascular diseases (CVD), and other disease. The cause of the enhanced inflammatory process is due to dysbiosis and an unregulated immune response. Innate immune response and T cells trigger uninhibited cytokine release causing an unwarranted inflammatory response. The RANK- RANKL interaction between osteoblasts, immune cells, and progenitor osteoclasts results in the maturation of osteoclasts, which promote bone resorption. It is well established that dysbiosis of the oral cavity has been implicated in periodontitis. But emerging reports suggest that the pulmonary pathogen, Mycobacterium tuberculosis (Mtb), causes extrapulmonary diseases such as periodontitis. Many clinical case reports advocate the involvement of Mtb in periodontitis, which poses a threat with the surge of tuberculosis in HIV and other immunocompromised individuals. Fostering a better understanding of the mechanism, causative agents and control on inflammatory response is imperative in the prevention and treatment of periodontitis.

The Use of Statins as an Adjunctive Periodontal Disease Treatment: Systematic Review and Meta-Analysis

BACKGROUND

the purpose of this systematic review was to assess the clinical and radiographic effect of subgingival-administered statins as an adjunct periodontal treatment in patients with periodontitis.

METHODS

Electronic literature searches in Medline/PubMed and the Cochrane Library were conducted to identify all relevant articles. Eligibility was based on inclusion criteria which included Randomized Controlled Trials (RCTs) published after 2010, where the periodontal variables were assessed before and after periodontal treatment in combination with a statin administration. The risk of bias was assessed with the ROBINS-2 tool. The outcome variables were probing depth, clinical attachment level, bleeding on probing, and bone fill in systematically healthy patients, patients with type 2 diabetes, and smokers.

RESULTS

Out of 119 potentially eligible articles, 18 randomized controlled trials were included with a total of 1171 participants. The data retrieved from the meta-analysis showed the positive effect that statins have as an adjunctive periodontal disease treatment. When comparing the different types of statins, the PD reduction in the Simvastatin group was significantly higher than the Atorvastatin group at 6 months and at 9 months, while no differences between statins were found for the rest of the outcomes. Over 66% of the articles presented an overall risk of bias with some concerns, making this a limitation of this present RCT.

CONCLUSIONS

The adjunct administration of statins has proven to have a positive effect on the periodontium by improving both clinical and radiographic parameters by a considerable margin.

Effectiveness of Topical Oxygen Therapy in Gingivitis and Periodontitis: Clinical Case Reports and Review of the Literature

Gingivitis and periodontitis are common oral pathological conditions. Several optional adjunctive local therapies are used clinically. While antibiotics and chlorhexidine are the most common agents of choice, their long-term use is associated with several adverse effects. Some of these include staining of teeth and restorations, cellular cytotoxicity and hypersensitivity. Topical oxygen therapy has been recently introduced and could be clinically capable of inhibiting plaque bacterial biofilm growth. Available as a mouthwash, toothpaste and oral gel, this formulation comprises cellulose, glycerol and sodium peroxoborate, and releases topical oxygen in a controlled manner. Moreover, it releases topical oxygen, in a controlled manner, and lactoferrin, which are capable of antibacterial action and stimulation of bone cells, respectively. The aim of this paper is to report a case of gingivitis and another case of periodontitis, both of which were successfully treated clinically with adjunctive local oxygen therapy (blue®m). Additionally, this paper aims to review the relevant literature in terms of adjunct topical or local therapies used in the treatment of gingivitis and periodontitis, in order to understand how local therapies are helpful and to know if local oxygen therapy is a suitable clinical alternative.

Statins and oral biofilm: Simvastatin as a promising drug to control periodontal dysbiosis

OBJECTIVES

This study evaluated antimicrobial activity of atorvastatin, pravastatin, rosuvastatin, and simvastatin against oral bacteria, and the interaction of simvastatin with standard antimicrobials (amoxicillin and metronidazole).

METHODS

Minimal inhibitory concentration assays were performed with Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinomyces odontolyticus, Streptococcus oralis, Streptococcus mitis, Streptococcus salivarius, Streptococcus sanguinis, and Streptococcus gordonii; checkerboard microdilution assays between simvastatin and standard antimicrobials; monospecies and multispecies biofilms.

RESULTS

Simvastatin showed the best antimicrobial activity against most species (MIC range from 3.12 to 25 μg/ml), highlighting the sensitivity of P. gingivalis. In the checkerboard assay, synergistic interaction was found between simvastatin and amoxicillin against S. oralis and S. sanguinis. P. gingivalis biofilm was inhibited by simvastatin at 10 and 50× Minimal inhibitory concentration, with similar effects to metronidazole. For multispecies biofilm, SMV reduced the biofilm metabolic activity (79%) and total counts (87%), comparable to amoxicillin. Simvastatin also reduced bacterial counts of Veilonnella parvula, P. gingivalis, Streptococcus mutans, Actinomyces naeslundii, P. intermedia, and Capnocytophaga ochracea in the multispecies biofilm.

CONCLUSIONS

Simvastatin showed antimicrobial and antibiofilm activity against oral bacteria and may contribute to the control of dysbiosis, and may be considered in clinical studies as an adjuvant in the treatment of periodontitis.

Comparative Evaluation of Tetracycline Hydrochloride Fiber and Simvastatin Gel as an Adjunct to Scaling and Root Planing in Periodontitis Patients

Inflammation of oral soft tissues, caused by periodontal disease, results in the loss of attachment to supporting therapy and is a severe threat to dental health. Although there are a number of therapeutic options available, mechanical debridement continues to be the gold standard. Scaling and root planing is the gold standard therapy for periodontitis, but this research aims to examine the efficacy of tetracycline fibers and simvastatin gel as local drug delivery methods. We evaluated 60 sites, splitting them into three groups: 20 sites received just scaling and root planing; 20 sites received scaling and root planing plus simvastatin gel; and 20 sites received scaling and root planing plus tetracycline fibers. Clinical indicators such as the gingival index, the modified sulcular bleeding index, and the probing depth were measured at the start of the study, after one week, after one month, after three months, and after six months. After six months, the simvastatin group reduced the gingival index and modified sulcular bleeding index more than the tetracycline group, whereas the tetracycline group reduced probing depth more than the simvastatin group.

Gels as adjuvant to non-surgical periodontal therapy: A systematic review and meta-analysis

Objective

This systematic review and meta-analysis evaluated the effect of the use of available drugs loaded gels used as adjunct to non-surgical periodontal therapy.

Methods

Systematic research on PubMed/MEDLINE, Cochrane Central register of Controlled Trials, and Embase databases up to December 2021 was performed. Randomized clinical trials (RCT) which compared the outcomes of scaling and root planing (SRP) + local adjuvant administration (gel) versus SRP + placebo or SRP alone in Humans were included. The primary outcome measures were PPD and CAL changes at 3 months.

Results

After articles screening, 77 articles were included and assessed for quality. Then, a meta-analysis was conducted in studies with at least 3 months of follow-up. Clinical improvements were found to be significant for tetracyclines (-0.51 [-0.71;-0.31] p < 0.001), macrolides (-0.71 [-1.04;-0.38] p < 0.001), statins (-0.84 [-0.98;-0.70] p < 0.001), metformin (-1.47 [-1.66;-1.29] p < 0.001) and hyaluronan (-1.61 [-2.28;-0.94] p < 0.001) loaded gels, but non-significant for chlorhexidine (-0.48 [-1.10; 0.14] p = 0.13), metronidazole (-0.50 [-1.20; 0.20] p = 0.16) and bisphosphonates (-0.42 [-1.39; 0.54] p = 0.539) gels.

Conclusion

Adjunctive use of drugs loaded gels to non-surgical periodondal treatment could improve PPD reduction at 3 months. However, huge disparities remain when comparing the outcomes of the differents drugs used. Future comparative studies should be considered to determine precisely short and long term benefits of such treatments.

Adjunctive use of locally delivered host-modulators in intra-bony defects as part of step 2 periodontal therapy: systematic review, meta-analysis and trial sequential analysis

BACKGROUND

This systematic review and meta-analysis aimed at investigate the role of locally delivered host-modulators in combination with step 2 of periodontal therapy in reducing probing pocket depth, improving clinical attachment level and reducing bone defect depth in intra-bony defects.

HIGHLIGHT

RCT with at least 6 months follow-up were included in this study. Risk of bias assessment was performed with Cochrane collaboration tool and Grade GRADEpro. In addition, meta-analysis and trial sequential analysis were used to aggregate the available evidence. 22 studies met the inclusion criteria and were included in this systematic review. At 6 months locally delivered host-modulators significantly improved PD and CAL and bone defect depth.

CONCLUSION

Considering the emerging role of host-inflammatory response in the treatment of periodontitis, several studies are exploring the role of locally delivered host modulators as an adjunct to step 2 of periodontal therapy.

Evaluation of efficacy of simvastatin in bone regeneration following local application in third molar extraction socket: A randomized control trial

Aims and Objectives

The aim of this study is to study the efficacy of simvastatin in bone regeneration following the local application in third molar extraction sockets.

Materials and Methods

This is a randomized controlled trial done on 50 patients involving 100 third molar teeth extraction sockets. The patients were randomly divided based on the placement of simvastatin. Extraction sockets which were treated with simvastatin were considered study sockets and without simvastatin were considered control sockets. The study socket was assigned for the placement of simvastatin (10 mg) powder along with gelfoam as carrier moistened with normal saline solution and control socket was assigned for the placement of gelfoam moistened with saline. Intraoral periapical radiographs were taken on the 1st, 4th, 8th, and 12th weeks, and mean gray scale values indicating bone density were evaluated for both the groups. Cone-beam computed tomography (CBCT) was taken by the end of the 12th week to further evaluate the osseous regeneration. Patients were compared and evaluated for bone density, pain, and swelling. Pain and swelling were evaluated on postoperative days 1 and 7.

Results

The mean gray-level histogram values (bone density) were statistically highly significant in the study group compared to the control group in the 1st, 4th, 8th, and 12th weeks, and CBCT also showed statistically significant difference between the control and study group by the end of the 12th week.

Conclusion

The present data suggest that the local application of simvastatin promotes and enhances bone formation in the extraction sockets, which provides a very cost-effective way for faster bone regeneration.

Controlled release devices as adjuvants in nonsurgical periodontal therapy: A systematic review

Controlled release devices (CRD) have been widely studied regarding their application in periodontal therapy. Therefore, the present study aims to evaluate the use and effectiveness of controlled-release devices in nonsurgical periodontal therapy through a systematic review. The research was carried out in six different databases, namely: Online Medical Literature Search and Analysis System (Medline-PubMed), Web of Science, Science Direct, Scopus, Scielo, and Google Scholar. The descriptors "Delayed-Action Preparation," "Therapeutics," and "Periodontitis," were used with their EntryTerms and connected through the Boolean operators AND and OR. A total of 2847 studies were found, and after applying the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist flowchart, 34 were selected using the eligibility criteria. After that, the qualitative results were tabulated and the risk of bias in each of them was evaluated. It can be observed that the use of CRD presents itself as a successful alternative for adjuvant treatment to periodontal therapy, a fact due to its availability and local concentration in the crevicular fluid. However, further clinical research is still needed to develop devices that are effective, with an easy and quick application, as well as available at a good cost-benefit ratio.

Sub-gingival delivery of simvastatin and rosuvastatin for treatment of chronic periodontitis with diabetes mellitus: A randomized controlled clinical-radiographic pilot study

Background

Statins are lipid-lowering medications that work by blocking rate-limiting enzyme in cholesterol formation. In patients with Chronic periodontitis (CP) and Diabetes mellitus (DM), subgingival delivery of simvastatin (SMV) and rosuvastatin (RSV) have demonstrated to have bone-stimulatory and anti-inflammatory properties. The current study intended to assess and compare the efficacy of sub-gingivally delivered SMV gel and RSV gel as an adjunctive medication to scaling and root planing (SRP) in the management of intrabony defects in CP patients with type 2 DM.

Methods

30 patients with CP and type 2 DM were classified into three treatment groups - SRP + placebo, SRP +1.2% SMV and SRP +1.2% RSV. Clinical parameters: site-specific plaque index, modified sulcus bleeding index (mSBI), pocket probing depth (PPD), and relative attachment level (RAL) were documented at baseline, 3 and 6 months and radiographic parameter: intrabony defect depth (IBD) at baseline and 6 months post-treatment.

Results

- LDD of 1.2% SMV and 1.2% RSV demonstrated greater clinical and radiographic improvement than placebo, the improvement being statistically significant for PI, mSBI, and PPD for 1.2% SMV and statistically significant for all clinical and radiological parameters for the 1.2% RSV. 1.2% RSV demonstrated greater IBD fill and RAL gain than 1.2% SMV.

Conclusion

- Localized sub-gingival delivery of statins was beneficial in the treatment intrabony defects in patients with CP and well-controlled type 2 DM. IBD fill and RAL gain were higher with 1.2% RSV than with 1.2% SMV.

Comparison of simvastatin 1.2% gel and alendronate 1% gel in chronic periodontitis as local drug delivery: A randomized clinical trial

Introduction

Simvastatin (SMV) is used for the treatment of hypercholesterolemia. Long-term systemic administration of SMV has been shown to result in increased bone mineral density. Alendronate (ALN) is known to inhibit osteoclastic bone resorption and has osteostimulative properties.

Aim

To compare percentile changes in gain in clinical attachment level and reduction of pocket depth, and to radiographically evaluate osseous defect fill with subgingival local drug delivery of 1.2% SMV gel and 1% ALN gel.

Materials and Methods

A split-mouth study was conducted with 40 infrabony defects from 20 patients diagnosed with chronic periodontitis. The sites were assigned as test site 1 (SMV gel) or test site 2 (ALN gel). After phase I therapy, a single application of SMV gel or ALN gel was done into periodontal pockets. Clinical periodontal parameters and percentage of bone fill were evaluated at baseline, 3 and 6 months.

Results

There was a statistically significant reduction in pocket depth, plaque index, and bleeding index scores, gain in Clinical attachment level (CAL) and bone defect fill from baseline to 6 months at both sites. On comparison between the groups, test site 2 showed significant improvement in clinical attachment level than in test site 1 at 6-month follow-up. Test site 2 showed more percentage bone fill than test site 1.

Conclusion

Usage of both SMV and ALN gels in periodontal intra bony defects can lead to significant improvements in clinical and radiographic parameters; however, ALN showed better osseous defect fill.

Bone-Targeting Nanoparticles of a Dendritic (Aspartic acid)3-Functionalized PEG-PLGA Biopolymer Encapsulating Simvastatin for the Treatment of Osteoporosis in Rat Models

Simvastatin (SIM) is a lipid-lowering drug that also promotes bone formation, but its high liver specificity may cause muscle damage, and the low solubility of lipophilic drugs limits the systemic administration of SIM, especially in osteoporosis (OP) studies. In this study, we utilized the bone-targeting moiety of dendritic oligopeptides consisting of three aspartic acid moieties (_dAsp₃) and amphiphilic polymers (poly(ethylene glycol)-block-poly(lactic-co-glycolic acid); PEG-PLGA) to create _dAsp₃-PEG-PLGA (APP) nanoparticles (NPs), which can carry SIM to treat OP. An in vivo imaging system showed that gold nanocluster (GNC)-PLGA/APP NPs had a significantly higher accumulation rate in representative bone tissues. In vivo experiments comparing low-dose SIM treatment (0.25 mg/kg per time, 2 times per week) showed that bone-targeting SIM/APP NPs could increase the bone formation effect compared with non-bone-targeting SIM/PP NPs in a local bone loss of hindlimb suspension (disuse) model, but did not demonstrate good bone formation in a postmenopausal (ovariectomized) model of systemic bone loss. The APP NPs could effectively target high mineral levels in bone tissue and were expected to reduce side effects in other organs affected by SIM. However, in vivo OP model testing showed that the same lower dose could not be used to treat different types of OP.

The Effect of Locally Applied Simvastatin on Clinical Attachment Level and Alveolar Bone in Periodontal Maintenance Patients: Randomized Clinical Trial

BACKGROUND

The purpose of this double-masked, randomized, controlled trial was to determine if the local application of simvastatin (SIM), combined with minimally invasive papilla reflection and root preparation (PR/RP), is effective in improving clinical attachment level (CAL), probing depth (PD) reduction, and increasing interproximal bone height (IBH) in persistent 6-9 mm periodontal pockets in patients receiving periodontal maintenance therapy (PMT).  METHODS: : Fifty patients with Stage III, Grade B periodontitis presenting with a 6-9 mm interproximal PD with a history of bleeding on probing (BOP) were included in the study. Experimental [PR/RP+SIM/methylcellulose (MCL); n=27] and control (PR/RP + MCL; n=23) therapies were randomly assigned.  Root surfaces were accessed via reflection of interproximal papillae, followed by root planing assisted with endoscope evaluation, acid etching, and SIM/MCL or MCL application.  CAL, PD, BOP, plaque presence and IBH (using standardized vertical bitewing radiographs) were evaluated at baseline and 12 months. Measurements were compared by group and time using Chi-square, Wilcoxon rank sum, and t-tests.

RESULTS

Both PR/RP+SIM/MCL and PR/RP+MCL, respectively, resulted in improvements in clinical outcomes (CAL: -1.9 ± 0.3 mm, p<0.0001; -1.0 ± 0.3 mm, p<0.003; PD:  -2.3 mm ± 0.3, p<0.0001; -1.3 mm ± 0.3, p<0.0001; BOP: -58.7%; -41.7%, p<0.05) and stable IBH (-0.2 ± 0.12, -0.4 ± 0.2, p=0.22) from baseline to 12 months post-therapy. PR/RP+SIM/MCL had more improvement in CAL (p=0.03), PD (p=0.007), and BOP (p=0.047).

CONCLUSIONS

The addition of SIM/MCL to PR/RP improved CAL, PD, and BOP compared to PR/RP alone in periodontal maintenance patients. This article is protected by copyright. All rights reserved.

The evaluation of cytotoxicity and cytokine IL-6 production of root canal sealers with and without the incorporation of simvastatin: an invitro study

Background

Freshly mixed root canal sealers when proximate the periapical tissues, trigger varying degrees of cytotoxicity/inflammatory reactions. Simvastatin, a class of the drug statin, is a widely used cholesterol-lowering agent with additional anti-inflammatory activities. This study assessed the effects of simvastatin on cytotoxicity and the release of IL-6 (Interleukin-6) production when incorporated in zinc oxide eugenol and methacrylate resin-based sealers.

Methods

Experimental groups consisted of conventional zinc oxide eugenol and methacrylate based-EndoREZ sealers (ZE & ER respectively) and 0.5 mg/mL simvastatin incorporated sealers (ZES & ERS). L929 mouse fibroblast cells were exposed to freshly mixed experimental sealers and evaluated for cytotoxicity (MTT assay) and inflammation levels (inflammatory marker IL-6 for ELISA) at various time intervals (0h, 24h and 7th day). The values were compared to the cell control (CC; L929 cells alone) and solvent control (SC; L929 cells + DMSO) groups. All the experiments were conducted in triplicates and subjected to statistical analysis using IBM SPSS Statistics software. Non parametric tests were conducted using Kruskal-Wallis and Friedman tests for inter-group and intra-group comparisons respectively. Pairwise comparison was conducted by post hoc Dunn test followed by Bonferroni correction. P values < 0.05 were considered statistically significant.

Results

All the experimental groups (ZE, ER, ZES, ERS) exhibited varying degree of cytotoxicity and IL-6 expression compared to the control groups CC and SC. The cell viability for ZE and ER decreased on day 7 as compared to 24 h. ZES and ERS had higher viable cells (75.93% & 79.90%) compared to ZE and ER (54.39% & 57.84%) at all time periods. Increased expression of IL-6 was observed in ZE & ER (25.49 pg/mL & 23.14 pg/mL) when compared to simvastatin incorporated ZE & ER (ZES-12.70 pg/mL & ERS-14.68 pg/mL) at all time periods. Highest level of cytotoxicity and inflammation was observed in ZE compared to all the other groups on day 7.

Conclusions

Addition of 0.5 mg/mL of simvastatin to the sealers (ZES and ERS) decreased the cytotoxicity in the freshly mixed state and reduces their inflammatory effect.

Preparation and characterization of poly (lactic-co-glycolic acid) nanofibers containing simvastatin coated with hyaluronic acid for using in periodontal tissue engineering

Periodontal diseases can lead to soft tissue defects. Tissue engineering can provide functional replacements for damaged tissues. Recently, electrospun nanofibers have attracted great interest for tissue engineering and drug delivery applications. This has been revealed that statins exhibit positive impacts on the proliferation and regeneration of periodontal tissues. Electrospun simvastatin loaded poly (lactic-co-glycolic acid) (SIM-PLGA-NF) were prepared using electrospinning technique. Optimal conditions for preparation of SIM-PLGA-NF (PLGA concentration of 30 wt%, voltage of 15 kV, and flow rate of 1.5 ml h^-1 ) were identified using a 2³ factorial design. The optimized SIM-PLGA-NFs (diameter of 640.2 ± 32.5 nm and simvastatin entrapment efficacy of 99.6 ± 1.5%) were surface modified with 1% w/v hyaluronic acid solution (1%HA- SIM-PLGA-NF) to improve their compatibility with fibroblasts and potential application as a periodontal tissue engineering scaffold. HA-SIM-PLGA NFs were analyzed using SEM, FTIR, and XRD. 1%HA-SIM-PLGA-NF had uniform, bead-free and interwoven morphology, which is similar to the extracellular matrix. The mechanical performance of SIM-PLGA-NFs and release profile of simvastatin from these nanofibers have been also greatly improved after coating with HA. In vitro cellular tests showed that the proliferation, adhesion, and differentiation of fibroblast cells positively enhanced on the surface of 1%HA- SIM-PLGA-NF. These results demonstrate the potential application of 1%HA-SIM-PLGA-NFs as a scaffold for periodontal tissue engineering.

STATINSWITH POTENTIAL TO CONTROL PERIODONTITIS: FROM BIOLOGICAL MECHANISMS TO CLINICAL STUDIES

BACKGROUND

Statins are widely used for the treatment of hyperlipidemia. However, these drugs have pleiotropic effects that can be promising for the prevention and treatment of oral diseases, such as periodontitis.

HIGHLIGHT

This review aimed to identify preclinical, observational, and clinical studies that evaluate the effects and biological mechanisms of statins on oral cells and tissues and those using these drugs to treat periodontitis. A LITERATURE SURVEY HAS BEEN CONDUCTED IN PUBMED USING COMBINATIONS OF THE UNITERMS: "statins," "dentistry," "periodontal disease," and "periodontal treatment." In vitro findings showed positive statin results in cell lines related to alveolar bone metabolism by altering the signaling pathway Osteoprotegerin/Receptor Activator of Nuclear Factor Kappa B/Receptor Activator of Nuclear Factor Kappa B Ligand (OPG/RANK/RANKL), stimulating the production of alkaline phosphatase and osteocalcin, and reducing the production of matrix metalloproteinases (MMPs). Animal studies have shown a reduction in alveolar bone loss and osteoclastic activity, in addition to a reduction in inflammatory markers, such as IL-1, IL-6, and TNF-α, when statins were used prophylactically. Clinical trials showed a positive impact on clinical parameters, leading to a higher reduction in probing depth and gain in clinical attachment when a local statin was adjunctively associated with mechanical therapy.

CONCLUSION

Statins were shown to be promising for regenerating and stimulating bone activity, with great potential for treating chronic periodontitis. However, further studies are required to confirm its effectiveness.

Connection between Periodontitis-Induced Low-Grade Endotoxemia and Systemic Diseases: Neutrophils as Protagonists and Targets

Periodontitis is considered a promoter of many systemic diseases, but the signaling pathways of this interconnection remain elusive. Recently, it became evident that certain microbial challenges promote a heightened response of myeloid cell populations to subsequent infections either with the same or other pathogens. This phenomenon involves changes in the cell epigenetic and transcription, and is referred to as ''trained immunity''. It acts via modulation of hematopoietic stem and progenitor cells (HSPCs). A main modulation driver is the sustained, persistent low-level transmission of lipopolysaccharide from the periodontal pocket into the peripheral blood. Subsequently, the neutrophil phenotype changes and neutrophils become hyper-responsive and prone to boosted formation of neutrophil extracellular traps (NET). Cytotoxic neutrophil proteases and histones are responsible for ulcer formations on the pocket epithelium, which foster bacteremia and endoxemia. The latter promote systemic low-grade inflammation (SLGI), a precondition for many systemic diseases and some of them, e.g., atherosclerosis, diabetes etc., can be triggered by SLGI alone. Either reverting the polarized neutrophils back to the homeostatic state or attenuation of neutrophil hyper-responsiveness in periodontitis might be an approach to diminish or even to prevent systemic diseases.

Clinical efficacy of simvastatin gel combined with polypropylene membrane on the healing of extraction sockets: A triple-blind, randomized clinical trial

OBJECTIVES

This study aimed to evaluate dimensional changes, level of soft tissue healing, and pain/discomfort perception in post-extraction sockets filling with 1.2% simvastatin (SIM) gel covered with polypropylene membranes (PPPM).

MATERIAL AND METHODS

Twenty-six post-extraction sockets of posterior teeth were randomly allocated in two groups: (a) socket filling with 1.2% SIM gel and covered with PPPM (n = 13) and (b) socket filling with placebo gel and covered with PPPM (n = 13). Cone-beam computed tomography (CBCT) images before and 90 days after the extraction enabled alveolar bone dimensional changes calculation using horizontal and vertical measurements. The measurements occurred at three different levels for thickness located 1, 3, and 5 mm from the top of the bone crest. The vertical (depth) measure was assessed from the most apical portion of the socket to the bone crest's most coronal portion. Seven days after the extractions, the level of soft tissue healing and pain perception were also analyzed.

RESULTS

After 90 days of extractions, the dimensional changes in thickness in the test group were significantly smaller in sections A (p = .044), B (p = .036) and C (p = .048) when compared to the control group. The test group showed a significantly lower height-dimensional change than the control group (p < .0001). Soft tissue healing index (p = .63), perception of pain (p = .23), and number of analgesics consumed (p = .25) were similar between groups.

CONCLUSIONS

Simvastatin at 1.2% compared with placebo effectively reduced the dimensional changes in post-extraction sockets covered with PPPM. There was no significant difference in the level of soft tissue healing and postoperative pain between the test and control groups.

Thermoresponsive Hydrogel-Based Local Delivery of Simvastatin for the Treatment of Periodontitis

Except for routine scaling and root planing, there are few effective nonsurgical therapeutic interventions for periodontitis and associated alveolar bone loss. Simvastatin (SIM), one of the 3-hydroxy-3-methylglutaryl-cosenzyme A reductase inhibitors, which is known for its capacity as a lipid-lowering medication, has been proven to be an effective anti-inflammatory and bone anabolic agent that has shown promising benefits in mitigating periodontal bone loss. The local delivery of SIM into the periodontal pocket, however, has been challenging due to SIM's poor water solubility and its lack of osteotropicity. To overcome these issues, we report a novel SIM formulation of a thermoresponsive, osteotropic, injectable hydrogel (PF127) based on pyrophosphorolated pluronic F127 (F127-PPi). After mixing F127-PPi with F127 at a 1:1 ratio, the resulting PF127 was used to dissolve free SIM to generate the SIM-loaded formulation. The thermoresponsive hydrogel's rheologic behavior, erosion and SIM release kinetics, osteotropic property, and biocompatibility were evaluated in vitro. The therapeutic efficacy of SIM-loaded PF127 hydrogel on periodontal bone preservation and inflammation resolution was validated in a ligature-induced periodontitis rat model. Given that SIM is already an approved medication for hyperlipidemia, the data presented here support the translational potential of the SIM-loaded PF127 hydrogel for better clinical management of periodontitis and associated pathologies.

The adjunctive use of host modulators in non-surgical periodontal therapy. A systematic review of randomized, placebo-controlled clinical studies

BACKGROUND

Considering the role of the inflammatory host response in the pathogenesis of periodontitis, different host modulators have been proposed to enhance the outcomes of non-surgical periodontal therapy (NSPT), but their efficacy has not been fully clarified.

OBJECTIVES

This systematic review investigated the efficacy of host modulators combined with NSPT in reducing probing pocket depth (PPD) in periodontitis patients.

MATERIALS AND METHODS

Placebo-controlled RCTs with ≥6 months follow-up were searched. Meta-analysis was conducted when ≥5 studies using the same host modulator were identified.

RESULTS

Fifty eight studies met the inclusion criteria. After 6 months, local administration of 1.2% statin gels as adjuncts to NSPT significantly improved PPD reduction (1.83 mm) in infrabony defects and systemic administration of sub-antimicrobial dose doxycycline (SDD) in addition to NSPT improved PPD reduction of deep pockets. Administration of probiotics conferred limited clinical benefits. Local bisphosphonate and metformin gels showed potential for clinical use in infrabony defects, which needs to be confirmed.

CONCLUSIONS

Local delivery of statins in infrabony defects and systemic SDD for deep pockets may confer additional clinical benefits to NSPT. Their long-term effectiveness and safety need to be confirmed in independent multi-centred studies. Further studies are needed to confirm the benefit of other host modulators.

Local delivery of simvastatin maintains tooth anchorage during mechanical tooth moving via anti-inflammation property and AMPK/MAPK/NF-kB inhibition

Simvastatin (SMV) could increase tooth anchorage during orthodontic tooth movement (OTM). However, previous studies on its bone‐specific anabolic and anti‐inflammation properties were based on static in vitro and in vivo conditions. AMPK is a stress‐activated kinase that protects tissue against serious damage from overloading inflammation. Rat periodontal ligament cells (PDLCs) were subjected to a serial of SMV concentrations to investigate the optimization that promoted osteogenic differentiation. The PDLCs in static and/or tensile culturing conditions then received the proper concentration SMV. Related factors expression was measured by the protein array, real‐time PCR and Western blot. The 0.05UM SMV triggered osteogenic differentiation of PDLCs. The inhibition of AMPK activation through a pharmacological approach (Compound C) caused dramatic decrease in osteogenic/angiogenic gene expression and significant increase in inflammatory NF‐κB phosphorylation. In contrast, pharmacological activation of AMPK by AICAR significantly inhibited inflammatory factors expression and activated ERK1/2, P38 MAPK phosphorylation. Moreover, AMPK activation induced by SMV delivery significantly attenuated the osteoclastogenesis and decreased the expression of pro‐inflammatory TNF‐α and NF‐κB in a rodent model of OTM. The current studies suggested that SMV could intrigue intrinsic activation of AMPK in PDLCs that promote attenuate the inflammation which occurred under tensile irritation through AMPK/MAPK/NF‐kB Inhibition.

Core-Shell poly-(D,l-Lactide-co-Glycolide)-chitosan Nanospheres with simvastatin-doxycycline for periodontal and osseous repair

This study aimed to evaluated the potential of core-shell poly(D,l-lactide-co-glycolide)-chitosan (PLGA-chitosan) nanospheres encapsulating simvastatin (SIM) and doxycycline (DOX) for promoting periodontal and large-sized osseous defects. SIM, and/or DOX were encapsulated in PLGA-chitosan nanospheres using double emulsion technique and were delivered to sites of experimental periodontitis and large-sized mandibular osseous defects of rats for 1-4 weeks. The resultant nanospheres were ~ 200 nm diameter with distinct core-shell structure and released SIM and DOX sustainably for 28 days. DOX and SIM-DOX nanospheres significantly inhibited P. gingivalis and S. sanguinis. In experimental periodontitis sites, SIM-DOX nanospheres significantly down-regulated IL-1b and MMP-8 and significantly reduced bone loss. In mandibular osseous defects, VEGF was up-regulated, and osteogenesis was significantly augmented with SIM nanospheres treatment. In conclusion, core-shell PLGA-chitosan nanospheres released SIM and DOX sustainably. SIM-DOX and SIM nanospheres could be considered to promote the repair of infected periodontal sites and non-infected osseous defects respectively.

The effects of statins on dental and oral health: a review of preclinical and clinical studies

The statin family of drugs are safe and effective therapeutic agents for the treatment of arteriosclerotic cardiovascular disease (CVD). Due to a wide range of health benefits in addition to their cholesterol lowering properties, statins have recently attracted significant attention as a new treatment strategy for several conditions, which are not directly related to normalizing a lipid profile and preventing CVD. Statins exert a variety of beneficial effects on different aspects of oral health, which includes their positive effects on bone metabolism, their anti-inflammatory and antioxidant properties, and their potential effects on epithelization and wound healing. Additionally, they possess antimicrobial, antiviral, and fungicidal properties, which makes this class of drugs attractive to the field of periodontal diseases and oral and dental health. However, to the best of our knowledge, there has been no comprehensive study to date, which has investigated the effects of statin drugs on different aspects of dental and oral health. Therefore, the primary objective of this paper was to review the effect of statins on dental and oral health. Results of our extensive review have indicated that statins possess remarkable and promising effects on several aspects of dental and oral health including chronic periodontitis, alveolar bone loss due to either extraction or chronic periodontitis, osseointegration of implants, dental pulp cells, orthodontic tooth movement, and orthodontic relapse, tissue healing (wound/bone healing), salivary gland function, and finally, anti-cancer effects. Hence, statins can be considered as novel, safe, inexpensive, and widely-accessible therapeutic agents to improve different aspects of dental and oral health.

Recent advances in periodontal regeneration: A biomaterial perspective

Periodontal disease (PD) is one of the most common inflammatory oral diseases, affecting approximately 47% of adults aged 30 years or older in the United States. If not treated properly, PD leads to degradation of periodontal tissues, causing tooth movement, and eventually tooth loss. Conventional clinical therapy for PD aims at eliminating infectious sources, and reducing inflammation to arrest disease progression, which cannot achieve the regeneration of lost periodontal tissues. Over the past two decades, various regenerative periodontal therapies, such as guided tissue regeneration (GTR), enamel matrix derivative, bone grafts, growth factor delivery, and the combination of cells and growth factors with matrix-based scaffolds have been developed to target the restoration of lost tooth-supporting tissues, including periodontal ligament, alveolar bone, and cementum. This review discusses recent progresses of periodontal regeneration using tissue-engineering and regenerative medicine approaches. Specifically, we focus on the advances of biomaterials and controlled drug delivery for periodontal regeneration in recent years. Special attention is given to the development of advanced bio-inspired scaffolding biomaterials and temporospatial control of multi-drug delivery for the regeneration of cementum-periodontal ligament-alveolar bone complex. Challenges and future perspectives are presented to provide inspiration for the design and development of innovative biomaterials and delivery system for new regenerative periodontal therapy.

Effect of Simvastatin on Bone Regeneration: A Histologic and Histomorphometric Analysis

PURPOSE

The purpose of the present study was to evaluate the efficacy of simvastatin administration as an osteoinductive agent combined with bovine bone material (BBM) for augmentation of human maxillary sinuses.

MATERIALS AND METHODS

In the present randomized clinical trial with a split-mouth design, 24 maxillary sinuses in 12 patients were augmented using BBM alone or BBM combined with simvastatin. Biopsy samples were taken 9 months after maxillary sinus floor augmentation for histologic and histomorphometric analyses. A total of 44 implants were placed in the augmented bone.

RESULTS

The results of the microscopic assessment of most samples revealed no inflammation or only mild chronic inflammation. Lamellation was detectable in old bone trabeculae under polarized light microscopy but was not observed in newly formed bone. Osteocytes were found with a lower frequency in the lacunae of newly formed bone compared with normal bone. No significant differences were found in the amount of newly formed bone and the amount of residual particles between the 2 groups.

CONCLUSIONS

Despite the greater mean percentage of newly formed bone in the test group, the histomorphometric analysis results did not show a significant positive effect for the use of simvastatin in maxillary sinus augmentation.

Periodontal regeneration: a bibliometric analysis of the most influential studies

Aim: The aim of the present study is to identify the most influential research articles and their main characteristics in the specialty of periodontal regeneration. Materials & methods: The Web of Science database advance search was performed in the subject category of 'Dentistry, Oral surgery and medicine' from January 2004 to October 2018 to retrieve citations data. Results: The majority of the articles were published in journals dedicated to the specialty of periodontology. Among the top-cited articles most emphasized study types were randomized control trials (n = 25) and reviews (n = 20). Conclusion: The present bibliometric analysis provides comprehensive information regarding the contributions made in the advancement of regenerative periodontal research. The authors from developed countries and affiliated with interdisciplinary/multicenter institutions have predominantly contributed.

Guided tissue regeneration of intrabony defects with perforated barrier membranes, simvastatin, and EDTA root surface modification: A clinical and biochemical study

BACKGROUND

Perforated barrier membranes (PBM) were suggested to enhance periodontal regeneration by allowing positive charity of wanted elements from the gingival tissue side. The present study was designed to evaluate clinically and biochemically the use of PBM combined with simvastatin (SMV) gel with and without an associated EDTA gel root surface etching as a suggested option that could improve SMV availability and clinical outcomes of PBM.

METHODS

Forty patients having moderate-to-severe chronic periodontitis with 40 intrabony defects were randomly divided into four treatment groups (10 sites each). Patients in group 1 received 1.2% SMV gel and covering the defect with occlusive membrane (OM). Patients in group 2 received 1.2% SMV gel and covering the defect with PBM. Group 3 received 24% EDTA root surface etching, 1.2% SMV gel, and defect coverage with OM (eOM). Patients in group 4 were treated as in group 3 but the defect was covered with PBM (ePBM). Clinical parameters were recorded at baseline before surgical procedures and were reassessed at 6 and 9 months after therapy. The mean concentration of SMV in gingival crevicular fluid (GCF) was estimated by reverse-phase high-performance liquid chromatography at days 1, 7, 14, 21, and 30.

RESULTS

At 6- and 9-month observation periods, groups 3 and 4 showed a statistically significant improvement in PD reduction and CAL gain compared with groups 1 and 2. Group 4 showed a statistically significant more defect fill compared with groups 1, 2, and 3 (P ≤ .05). Group 2 showed statistically significant higher defect fill compared with group 1 and group 3 (P < .05). Bone density was significantly increased with no significant difference between the four groups at 6- and 9-month observation periods. SMV-GCF concentration in group 4 showed the highest mean concentration with no significant difference than that of group 3.

CONCLUSION

The use of perforated barrier membranes in association with SMV enhances the clinical hard tissue parameters compared with occlusive ones in treating intrabony periodontal defects. Moreover, EDTA root surface treatment could enhance SMV availability in the defect area.

Efficacy of locally-delivered statins adjunct to non-surgical periodontal therapy for chronic periodontitis: a Bayesian network analysis

BACKGROUND

Studies indicate locally-delivered statins offer additional benefits to scaling and root planning (SRP), however, it is still hard to say which type of statins is better. This network meta-analysis aimed to assess the effect of locally-delivered statins and rank the most efficacious statin for treating chronic periodontitis (CP) in combination with SRP.

METHODS

We screened four literature databases (Pubmed, Embase, Cochrane Library, and Web of Science) for randomized controlled clinical trials (RCTs) published up to June 2018 that compared different statins in the treatment of chronic periodontitis. The outcomes analyzed were changes in intrabony defect depth (IBD), pocket depth (PD), and clinical attachment level (CAL). We carried out Bayesian network meta-analysis of CP without systemic diseases. Traditional and Bayesian network meta-analyses were conducted using random-effects models.

RESULTS

Greater filling of IBD, reduction in PD, and gain in CAL were observed for SRP treated in combination with statins when compared to SRP alone for treating CP without systemic diseases. Specifically, SRP+ Atorvastatin (ATV) (mean difference [MD]: 1.5 mm, 1.4 mm, 1.8 mm, respectively), SRP + Rosuvastatin (RSV) (MD: 1.8 mm, 2.0 mm, 2.1 mm, respectively), and SRP + Simvastatin (SMV) (MD: 1.1 mm, 2.2 mm, 2.1 mm, respectively) were identified. However, no difference was found among the statins tested. In CP patients with type 2 diabetic (T2DM) or in smokers, additional benefits were observed from locally delivered statins.

CONCLUSION

Local statin use adjunctive to SRP confers additional benefits in treating CP by SRP, even in T2DM and smokers. RSV may be the best one to fill in IBD. However, considering the limitations of this study, clinicians must use cautious when applying the results and further studies are required to explore the efficacy of statins in CP with or without the risk factors (T2DM comorbidity or smoking history).

Efficacy of Locally Administered 1.2% Rosuvastatin Gel in Patients with Periodontitis: A Randomized Placebo Controlled Clinical Trial

Objective Periodontitis initiation and progression are a result of host immune inflammatory response to oral pathogens. Several pharmacological agents are being delivered locally, to improve periodontal health. Hence, the present randomized placebo controlled clinical trial is designed to check the clinical and antimicrobial efficacy of locally delivered 1.2% rosuvastatin (RSV) in intrabony defects (IBD) in periodontitis patients.

Materials and Methods One-hundred patients were randomly allotted into two treatment groups: group A received 1. 2% RSV gel, scaling and root debridement and group B received placebo gel, scaling and root debridement. Clinical parameters, including modified sulcus bleeding index (mSBI), probing depth (PD), clinical attachment level (CAL), and plaque index (PI), were recorded at baseline before phase 1 and after 6 months. Radiographic assessment of IBD was done by cone beam computed tomography at baseline and after 6 months. Anaerobic colony count was done at baseline and after 180 days.

Results On intragroup comparison, there is a significant improvement in periodontal parameters in both the groups. On intergroup comparison, there is significant gain in CAL in group A than group B ( p = 0.04). There is significant decrease in PD in group A, compared to group B. There is significant bone fill in group A ( p = 0.034), compared to group B. With respect to mSBI, PI, and anaerobic colony count, there is no significant difference between the two groups after 6 months. No adverse effect was noticed in any subjects.

Conclusion The author concludes that 1.2% RSV gel when delivered locally into IBD improved periodontal clinical parameters such as PD and CAL and showed significant bone fill.

Contribution of Statins towards Periodontal Treatment: A Review

The pleiotropic effects of statins have been evaluated to assess their potential benefit in the treatment of various inflammatory and immune-mediated diseases including periodontitis. Herein, the adjunctive use of statins in periodontal therapy in vitro, in vivo, and in clinical trials was reviewed. Statins act through several pathways to modulate inflammation, immune response, bone metabolism, and bacterial clearance. They control periodontal inflammation through inhibition of proinflammatory cytokines and promotion of anti-inflammatory and/or proresolution molecule release, mainly, through the ERK, MAPK, PI3-Akt, and NF-κB pathways. Moreover, they are able to modulate the host response activated by bacterial challenge, to prevent inflammation-mediated bone resorption and to promote bone formation. Furthermore, they reduce bacterial growth, disrupt bacterial membrane stability, and increase bacterial clearance, thus averting the exacerbation of infection. Local statin delivery as adjunct to both nonsurgical and surgical periodontal therapies results in better periodontal treatment outcomes compared to systemic delivery. Moreover, combination of statin therapy with other regenerative agents improves periodontal healing response. Therefore, statins could be proposed as a potential adjuvant to periodontal therapy. However, optimization of the combination of their dose, type, and carrier could be instrumental in achieving the best treatment response.

Platelet derived growth factor-BB levels in gingival crevicular fluid of localized intrabony defect sites treated with platelet rich fibrin membrane or collagen membrane containing recombinant human platelet derived growth factor-BB: A randomized clinical and biochemical study

BACKGROUND

Development of autologous and recombinant growth factor/matrix combination products represent a new emerging trend in regenerative therapeutics and have gained increasing attention as a strategy to optimize tissue regeneration. The aim of the present study was to evaluate the levels of platelet derived growth factor-BB (PDGF-BB) in gingival crevicular fluid (GCF) during early healing period after the regenerative treatment of intrabony defects using beta tricalcium phosphate (β-TCP) as a bone regeneration material with either platelet rich fibrin (PRF) membrane or collagen membrane (CM) treated with recombinant human PDGF-BB (rhPDGF-BB).

METHODS

Twenty patients (13 males and 7 females) with chronic periodontitis participated in this prospective, randomized clinical and biochemical study. Each patient was randomly assigned to PRF membrane (group A) or CM incorporated with rhPDGF-BB (group B). GCF samples were obtained on days 3, 7, 14, and 30 for evaluation of PDGF-BB levels and alkaline phosphatase (ALP) levels.

RESULTS

On days 3 and 7 following surgery, mean levels of PDGF-BB at sites treated with PRF membrane or CM incorporated with rhPDGF-BB as a barrier membrane were not significantly different. PDGF-BB levels decreased significantly in samples collected on days 14 and 30 with significant differences between both the groups. ALP levels significantly increased from day 3 to day 30 but there was no difference between two groups.

CONCLUSION

Within the limitations of the study, both PRF membrane and CM incorporated with rhPDGF-BB showed comparable GCF levels of PDGF-BB initially with PRF showing more sustained levels throughout the study period.

Identification of Genes Differentially Expressed in Simvastatin-Induced Alveolar Bone Formation

Local delivery of simvastatin (SIM) has exhibited potential in preventing inflammation and limiting bone loss associated with experimental periodontitis. The primary aim of this study was to analyze transcriptome changes that may contribute to SIM's reduction of periodontal inflammation and bone loss. We evaluate the global genetic profile and signaling mechanisms induced by SIM on experimental periodontitis bone loss and inflammation. Twenty mature female Sprague Dawley rats were subjected to ligature-induced experimental periodontitis around maxillary second molars (M2) either unilaterally (one side untreated, n = 10) or bilaterally (n = 10). After the ligature removal at day 7, sites were injected with either carrier, pyrophosphate (PPi ×3), 1.5-mg SIM-dose equivalent SIM-pyrophosphate prodrug, or no injection. Three days after ligature removal, animals were euthanized; the M1-M2 interproximal was evaluated with μCT, histology, and protein expression. M2 palatal gingiva was harvested for RNA sequencing. Although ligature alone caused upregulation of proinflammatory and bone catabolic genes and proteins, seen in human periodontitis, SIM-PPi upregulated anti-inflammatory (IL-10, IL-1 receptor-like 1) and bone anabolic (insulin-like growth factor, osteocrin, fibroblast growth factor, and Wnt/ β-catenin) genes. The PPi carrier alone did not have these effects. Genetic profile and signaling mechanism data may help identify enhanced pharmacotherapeutic approaches to limit or regenerate periodontitis bone loss. © 2018 The Authors. JBMR Plus Published by Wiley Periodicals, Inc. on behalf of the American Society for Bone and Mineral Research.

Combination of a Bioceramic Scaffold and Simvastatin Nanoparticles as a Synthetic Alternative to Autologous Bone Grafting

The fragile nature of porous bioceramic substitutes cannot match the toughness of bone, which limits the use of these materials in clinical load-bearing applications. Statins can enhance bone healing, but it could show rhabdomyolysis/inflammatory response after overdosing. In this study, the drug-containing bone grafts were developed from poly(lactic acid-co-glycolic acid)-polyethylene glycol (PLGA-PEG) nanoparticles encapsulating simvastatin (SIM) (SIM-PP NPs) loaded within an appropriately mechanical bioceramic scaffold (BC). The combination bone graft provides dual functions of osteoconduction and osteoinduction. The mechanical properties of the bioceramic are enhanced mainly based on the admixture of a combustible reverse-negative thermoresponsive hydrogel (poly(N-isopropylacrylamide base). We showed that SIM-PP NPs can increase the activity of alkaline phosphatase and osteogenic differentiation of bone marrow stem cells. To verify the bone-healing efficacy of this drug-containing bone grafts, a nonunion radial endochondral ossification bone defect rabbit model (N = 3/group) and a nonunion calvarial intramembranous defect Sprague Dawley (SD) rat model (N = 5/group) were used. The results indicated that SIM-PP NPs combined with BC can improve the healing of nonunion bone defects of the radial bone and calvarial bone. Therefore, the BC containing SIM-PP NPs may be appropriate for clinical use as a synthetic alternative to autologous bone grafting that can overcome the problem of determining the clinical dosage of simvastatin drugs to promote bone healing.

The sole and combined effect of simvastatin and platelet rich fibrin as a filling material in induced bone defect in tibia of albino rats

Statins like simvastatin (SIM) have demonstrated to have pleiotropic actions other than their conventional use as antilipidemic drugs. Also, nowadays natural scaffolds like platelets rich fibrin (PRF) showed promising results on bone regeneration. Aim This study compare the regenerative power of SIM and PRF added locally each as a sole filling material on induced bone defect and evaluate the combined effect using PRF loaded with SIM. MATERIALS AND METHODS: A critical size bone defect was induced in 48 male albino rats of average weight 150-200 g and were divided into 4 groups according to the filling material. Control, PRF, SIM, and SIM/PRF group. Each group was subdivided according to the sacrificing period into two subgroups (one and two-months postoperatively). Tibial specimens were evaluated histologically using masson trichrome (MT) special stain to detect areas of new bone formation, immunohistochemically using anti- BMP2 and anti-VEGF, serum levels of Osteoprotegerin (OPG), RANKL, osteocalcin and alkaline phosphatase enzyme (ALP) were measured one and two months postoperatively using ELISA, Finally bone mineral density (BMD) at the bone defect area was analyzed using digital X-ray one and two-months postoperatively. RESULTS: The percentage of newly formed bone increased significantly in the three groups vs the control group with the highest significant increase (p < 0.001) in the SIM/PRF group one month postoperatively. Also, SIM/PRF group was the only group which showed significant bone maturation two-months postoperatively compared to the other groups. Immunohistochemical analysis showed significant increase in positively stained BMP-2 and VEGF expression (p < 0.001) in the three groups vs the control group with the highest significant increase (p < 0.001) in the SIM/PRF group. Serum bone anabolic markers increased significantly in the SIM and SIM/PRF groups. In contrast, RANKL serum level decreased significantly in the SIM and SIM/PRF group one month postoperatively with no significant decrease in the PRF group vs the control group. Digital X-ray results revealed the highest BMD percent change was found in the SIM/PRF group and showed complete bone healing two-months postoperatively.

Simvastatin attenuates tibial bone loss in rats with type 1 diabetes and periodontitis

Background

Diabetes induces long bone loss and aggravation of periodontitis-induced alveolar bone loss. Simvastatin (SIM), which is a lipid-lowering agent is known to have an anabolic effect on bone. Therefore, we investigated effect of SIM on tibial and alveolar bone loss in type 1 diabetic rats with periodontitis.

Methods

Rats were divided into control (C), diabetes with periodontitis (DP), and diabetes with periodontitis treated with SIM (DPS) groups. DP and DPS groups were intravenously injected with streptozotocin (50 mg/kg), and C group was injected with citrate buffer. Seven days later (day 0), periodontitis was induced by ligatures of mandibular first molars. DP and DPS groups were orally administered vehicle or SIM (30 mg/kg) from day 0 to days 3, 10, or 20. Alveolar and tibial bone loss was measured using histological and m-CT analysis alone or in combination. Osteoclast number and sclerostin-positive osteocytes in tibiae were evaluated by tartrate-resistant acid phosphatase and immunohistochemical staining, respectively. Glucose, triglyceride (TG), cholesterol (CHO), and low-density lipoprotein (LDL) were evaluated.

Results

Consistent with diabetes induction, the DP group showed higher glucose and TG levels at all timepoints and higher CHO levels on day 20 than C group. Compared to the DP group, the DPS group exhibited reduced levels of glucose (day 3), TG (days 10 and 20), CHO, and LDL levels (day 20). Bone loss analysis revealed that the DP group had lower bone volume fraction, bone mineral density, bone surface density, and trabecular number in tibiae than C group at all timepoints. Interestingly, the DPS group exhibited elevation of these indices at early stages compared to the DP group. The DPS group showed reduction of osteoclasts (day 3) and sclerostin-positive osteocytes (days 3 and 20) compared with the DP group. There was no difference in alveolar bone loss between DP and DPS groups.

Conclusions

These results suggest that SIM attenuates tibial, but not alveolar bone loss in type 1 diabetic rats with periodontitis. Moreover, attenuation of tibial bone loss by SIM may be related to inhibition of osteoclast formation and reduction of sclerostin expression.

Progranulin is highly expressed in patients with chronic periodontitis and protects against experimental periodontitis in rats

BACKGROUND

The autocrine growth factor progranulin (PGRN) plays a crucial role in the physiological and pathological processes. However, its function in chronic periodontitis (CP) remains unclear.

METHODS

Forty-five CP patients and 43 healthy controls were recruited. Expressions of PGRN in gingival biopsies were assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry, respectively. The levels of PGRN, tumor necrosis factor alpha (TNF-α), and interleukin-1 beta (IL-1β) in the gingival crevicular fluid (GCF) before and after non-surgical periodontal treatment were quantified by ELISA. In addition, recombinant human PGRN (rhPGRN) or its vehicle was injected into the gingiva of rats with ligature-induced experimental periodontitis to test its influence on the disease process. Local inflammatory cell infiltration and alveolar bone loss were assessed by histomorphometric analysis, and the expression levels of TNF-α and IL-1β in the gingiva were determined by RT-qPCR and ELISA.

RESULTS

PGRN expression was increased in the gingiva and GCF of patients with CP compared with healthy controls. With the decline of periodontal clinical indices, the molar ratio of PGRN to TNF-α in GCF at 1 month after non-surgical treatment was significantly higher than at baseline (35.31 ± 22.09 vs 25.67 ± 16.19, P < 0.01). In rats with experimental periodontitis, local administration of rhPGRN attenuated inflammatory cell infiltration (P < 0.05), inhibited alveolar bone loss (P < 0.05) and decreased TNF-α and IL-1β levels (both P < 0.01) compared with the vehicle treatment group.

CONCLUSION

These findings suggest that progranulin is highly expressed in the gingiva and GCF of patients with CP and protects against experimental periodontitis in rats.

The effect of local and systemic statin use as an adjunct to non-surgical and surgical periodontal therapy-A systematic review and meta-analysis

OBJECTIVES

To evaluate the effect of local and/or systemic statin use as an adjunct to non-surgical and/or surgical periodontal therapy.

DATA

Literature search according to PRISMA guidelines with the following eligibility criteria: (a) English or German language; (b) interventional studies; (c) statins as monotherapy or as an adjunct to non-surgical and/or surgical treatment of periodontitis; (d) clinical and/or radiographic treatment effect size of statin intake reported.

SOURCES

Medline (PubMed), Embase (Ovid), CENTRAL (Ovid).

STUDY SELECTION

Thirteen clinical studies regarding local application and 2 with systemic administration of statins as an adjunct to non-surgical treatment (SRP) and 4 studies regarding intrasurgical statin application with a maximum follow-up of 9 months could be included; simvastatin, atorvastatin, and rosuvastatin were used. Local but not systemic statin application as an adjunct to SRP yielded significantly larger probing pocket depth (PD), radiographic defect depth (RDD), and bleeding index reduction, and larger clinical attachment level gain, and less residual PD and RDD (p≤0.016); rosuvastatin appeared as the most efficacious. Three of 4 studies reported a significant positive effect of intrasurgical statin application. No adverse events were reported after statin use. The vast majority of the included studies were from the same research group.

CONCLUSIONS

Significant additional clinical and radiographic improvements are obtained after local, but not systemic, statin use as an adjunct to SRP in deep pockets associated with intrabony defects and seemingly with furcation defects; intrasurgical statin application seems similarly beneficial. Confirmation of these results, and especially of the effect size, from other research groups is warranted.

Local Application of Pyrophosphorylated Simvastatin Prevents Experimental Periodontitis

PURPOSE

Simvastatin (SIM), a HMG-CoA reductase inhibitor widely prescribed for hypercholesterolemia, has been reported to ameliorate inflammation and promote osteogenesis. Its clinical applications on these potential secondary indications, however, have been hampered by its lack of osteotropicity and poor water solubility. To address this challenge, we propose to design and evaluate the therapeutic efficacy of a novel simvastatin prodrug with better water solubility and bone affinity.

METHOD

The prodrug (SIM-PPi) was synthesized by directly conjugating a SIM trimer to a pyrophosphate (PPi). It was characterized and evaluated in vitro for its water solubility, osteotropicity, toxicity, anti-inflammatory and osteoinductive properties. It was then tested for anti-inflammatory and osteoinductive properties in vivo by three weekly injections into gingiva of a ligature-induced experimental periodontitis rat model.

RESULTS

In vitro studies showed that SIM-PPi has greatly improved water-solubility of SIM and shows strong binding to hydroxyapatite (HA). In macrophage culture, SIM-PPi inhibited LPS-induced pro-inflammatory cytokines (IL-1β, IL-6). In osteoblast culture, it was found to significantly increase alkaline phosphatase (ALP) activity with accelerated mineral deposition, confirming the osteogenic potential of SIM-PPi. When tested in vivo on an experimental periodontal bone-loss model, SIM-PPi exhibited a superior prophylactic effect compared to dose equivalent SIM in reducing inflammatory cells and in preserving alveolar bone structure, as shown in the histological and micro-CT data.

CONCLUSION

SIM-PPi may have the potential to be further developed for better clinical management of bone loss associated with periodontitis.

The effect of statins on periodontal treatment-a systematic review with meta-analyses and meta-regression

OBJECTIVE

This study aimed to systematically review clinical trials about the effect of statins as adjunct to mechanical periodontal therapy, on probing pocket depth, clinical attachment level, and intrabony defects, in comparison to mechanical periodontal therapy alone or in association with placebo.

MATERIAL AND METHODS

Three databases were searched for controlled clinical trials that used any locally delivered or systemically statin as a sole adjunctive therapy to mechanical periodontal treatment. Weighted mean differences between baseline and 6 months after periodontal treatment for clinical attachment level (CAL), probing pocket depth (PPD), and intrabony defect (IBD) were calculated. A high heterogeneity was detected. Therefore, a meta-regression adjusted for type of statin and year of publication was performed.

RESULTS

Fifteen studies were included in the systematic review, and ten studies were included in the meta-analysis. In the meta-regression, the adjunct use of simvastatin, rosuvastatin, and atorvastatin additionally reduced PPD in comparison to mechanical periodontal therapy and a placebo gel (2.90 ± 0.35, 3.90 ± 0.77, 3.06 ± 0.71 mm, respectively; p < 0.05). Regarding the resolution of IBD, simvastatin and rosuvastatin significantly improved in comparison to control group (0.89 ± 0.35 and 1.93 ± 0.77 mm, respectively; p < 0.05). No statistically significant difference was found between the statins for both PPD and IBD (p < 0.05). Regarding CAL gain, simvastatin provided a statistically significant improvement as compared to the control group (2.02 ± 0.79 mm; p = 0.043).

CONCLUSIONS

The use of statins, used as sole adjuncts to mechanical periodontal treatment, improved the periodontal parameters. In the quantitative analyses, simvastatin was the only drug that showed additional benefits in all evaluated parameters.

CLINICAL RELEVANCE

Statins promote significantly clinical periodontal improvements when administered in association with non-surgical scaling and root planning (SRP), when compared to SRP alone or in association with a placebo.

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.

Efficacy of Acacia arabica gum as an adjunct to scaling and root planing in the treatment of chronic periodontitis: A randomized controlled clinical trial

Aim

The aim of the present study was to explore the adjunctive use of Acacia arabica gel in the treatment of chronic periodontitis.

Methods

Single centre, randomised, triple blind, controlled trial on mild to moderate chronic periodontitis patients; Group I (SRP + Acacia arabica, n = 40) and Group II (SRP + placebo, n = 40); were analysed for clinical improvements in periodontal pocket depth (PPD) and clinical attachment levels (CAL) at baseline, 15 and 90 days on application of gels. Gingival index and plaque index were assessed as secondary parameters.

Results

Statistically significant PPD reduction (p < .05) and CAL gain (p < .05) was observed with use of Acacia arabica gel. The reduction in sites with moderate PPD was observed more among Group I than Group II and the difference was statistically significant (p = .001). Secondary outcome variables; Plaque Index and Gingival Index showed better resolution with Acacia arabica gel.

Conclusion

Acacia arabica leads to better clinical outcomes in patients with mild to moderate chronic periodontitis with effective antiplaque and anti-gingivitis action. It may be recommended adjunct to SRP for maintenance in patients with mild to moderate chronic periodontitis.

Does the adjunctive use of statins provide additional benefits to nonsurgical periodontal treatment? A systematic review and meta-analysis

Adjunctive therapeutic agents may be used to improve the response to nonsurgical periodontal therapy. Local delivery of statins (simvastatin, artovastatin and rosuvastatin) is a promising adjunct to scaling and root planing (SRP). Thus, the aim of this review is to evaluate if adjunctive local delivery of statins is more effective than SRP alone. Randomized clinical trials that presented a test group evaluating local delivery of statins as adjuncts in healthy, diabetic and smoking patients were included. Medline and the Cochrane library database were searched up to November 2016. Random effects meta-analyses were conducted for pocket depth change and clinical attachment gain. One hundred and twenty-five studies potentially related to the aim of this review were screened, but only 10 were included. The majority of the trials reported additional clinical benefits in the groups that were treated with adjunctive local delivery of statins. Pooled calculations showed that local delivery of statins resulted in additional reduction of pocket depth and clinical attachment gain in healthy people, smokers and diabetic patients. Local statins may offer additional clinical benefits to SRP, even in smokers and diabetics.

Evaluations of clinical-grade bone substitute-combined simvastatin carriers to enhance bone growth: In vitro and in vivo analyses

We demonstrated in a value-added study that the combination of calcium phosphate–based bone substitute (MaxiBone® bioceramics) and simvastatin/poly lactic- co-glycolic acid (SIMm) carriers which were fabricated by GMP pharmaceutical company and underwent our patterned double-emulsion technique can promote bone growth. The average size distribution of SIMm, the encapsulation efficacy, and the in vitro release profile of simvastatin in SIMm over 14 days were investigated in this study. Based on the results of Alizarin Red S staining and alkaline phosphatase activity, the released simvastatin of SIMm can effectively induce osteogenesis of bone marrow mesenchymal stem cells (D1 cells). In the non-union fracture model of animal study, the MaxiBone bioceramics group and MaxiBone bioceramics with SIMm group showed a significant increase in the percentages of new bone matrix compared with the control group and SIMm groups at the 8th and 10th weeks. Moreover, the MaxiBone bioceramics with SIMm group showed the strongest effect in new bone formation among these groups. We concluded that the calcium phosphate–based ceramics of MaxiBone combined with SIMm can accelerate osteogenic differentiation and bone growth in vitro and in vivo. Our results provide a proof of concept that SIMm can play as an osteoinductive material and the combination with bone substitutes with osteoconductive property effectively enhance bone growth, and this treatment is value added for clinical application, especially in the healing of large bone defects or non-union.

Graphical abstract. The clinical-grade calcium phosphate–based bone substitute combined SIM/PLGA/HAp microspheres were fabricated by GMP pharmaceutical company to promote bone growth in bone defect model of mice.

Efficacy of 1% Metformin Gel in Patients With Moderate and Severe Chronic Periodontitis: A Randomized Controlled Clinical Trial

BACKGROUND

The aim of this study is to investigate efficacy of metformin (MF) 1% gel as an adjunct to scaling and root planing (SRP) in the treatment of moderate and severe chronic periodontitis (CP).

METHODS

Seventy patients were categorized into two treatment groups: 1) SRP plus 1% MF and 2) SRP plus placebo. Clinical parameters were recorded at baseline and 3, 6, and 9 months. They included plaque index (PI), modified sulcus bleeding index (mSBI), probing depth (PD), and clinical attachment level (CAL). Radiologic assessment of intrabony defects (IBDs) and percentage defect depth reduction (DDR%) was done at baseline and 6- and 9-month intervals using computer-aided software. PD, CAL, and DDR% were evaluated in two subgroups in both the placebo and MF group: 1) initial PD of 5 to 7 mm and 2) initial PD of >7 mm.

RESULTS

Mean PD reduction and mean CAL gain was found to be greater in the MF group than the placebo group at all visits. Clinical parameters (PD, CAL) in both subgroups, with initial PDs of 5 to 7 and >7 mm, showed significant improvement in the 1% MF group compared with the placebo group. A significantly greater mean DDR% was found in the MF group than the placebo group at 6 and 9 months in both subgroups, 5 to 7 and >7 mm of initial PD.

CONCLUSION

There was a greater decrease in PD and more CAL gain with significant IBD depth reduction at sites treated with SRP plus locally delivered MF in patients with CP in both initial PD = 5 to 7 and >7 mm subgroups compared with placebo.