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

Assessment of vascular endothelial growth factor and matrix metalloproteinase-9 in the periodontium of rats treated with atorvastatin

BACKGROUND

The aim of this study is to examine, for the first time, the role of systemic and local atorvastatin application on periodontium using histomorphometric and immunohistochemical analysis during and after experimental periodontitis induction with or without the presence of microbial dental biofilm.

METHODS

One hundred ten male Wistar rats were used. Silk ligatures were placed around the cervical area of the mandibular first molars; rats in the healthy control group received no ligatures (n = 10). In experimental periodontitis groups (n = 90), systemic and local atorvastatin and saline were administered in three different periods; the control periodontitis group (n = 10) received no treatment. Histomorphometric analysis, which included alveolar bone area, alveolar bone level, and attachment loss, and immunohistochemical analysis, which included immunoreactivity of vascular endothelial growth factor (VEGF) and matrix metalloproteinase (MMP)-9, were performed after the rats were sacrificed at the end of the experimental procedure.

RESULTS

There was a greater increase in alveolar bone area and VEGF immunoreactivity, as well as a greater decrease in alveolar bone and attachment loss and MMP-9 immunoreactivity, with systemic and local atorvastatin application during and after induction of experimental periodontitis. Local atorvastatin application showed better results on periodontium with regard to alveolar bone findings.

CONCLUSIONS

Systemic and local atorvastatin application showed beneficial effects on periodontium during and after induction of experimental periodontitis. Within the limits of this study, it can be concluded that atorvastatin, which is used for hypercholesterolemia treatment, can also be used as a protective and therapeutic agent for periodontal disease.

Controlling the proliferation and differentiation stages to initiate periodontal regeneration

The success of periodontal regeneration depends on the coordination of early cell proliferation and late cell differentiation. The aim of this study was to investigate whether the proliferation or differentiation stage predominantly promotes the initiation of periodontal regeneration. Critical-sized periodontal defects were surgically created on rat maxillae and filled with poly-(D,L-lactide-co-glycolide)-poly-d,l-lactide hybrid microspheres encapsulating platelet-derived growth factor (PDGF, a promoter of mitogenesis), simvastatin (a promoter of osteogenic differentiation), or bovine serum albumin (a control). The encapsulation efficiency and in vitro release profiles of the microspheres were determined by high-performance liquid chromatography and enzyme-linked immunosorbent assay. The maxillae were harvested after 10 or 14 days and assessed by micro-computed tomography, histology, and immunohistochemistry for regeneration efficacy and cell viability. The rapid release of PDGF was observed within the first week, whereas a slow release profile was noted for simvastatin. The PDGF-treated specimens demonstrated a significantly higher bone volume fraction compared with bovine serum albumin- (p < 0.05) or simvastatin-treated (p < 0.05) specimens at day 14. Histologically, active bone formation originating from the defect borders was noted in both the PDGF- and the simvastatin-treated specimens, and functionally aligned periodontal ligament fiber insertion was only observed in the PDGF-treated specimens. The significant promotion of mitogenesis by PDGF treatment was also noted at day 14 (p < 0.05). In conclusion, increased mitogenesis or osteogenic differentiation may stimulate osteogenesis, and the upregulation of mitogenesis by PDGF appears to play a role in the initiation of periodontal regeneration.

Comparative evaluation of autologous platelet-rich fibrin and platelet-rich plasma in the treatment of mandibular degree II furcation defects: a randomized controlled clinical trial

BACKGROUND

The treatment of molar furcation defects remains a considerable challenge in clinical practice. The identification of clinical measurements influential to treatment outcomes is critical to optimize the results of surgical periodontal therapy. The present study aimed to explore the clinical and radiographical effectiveness of autologous platelet-rich fibrin (PRF) and autologous platelet-rich plasma (PRP) in the treatment of mandibular degree II furcation defects in subjects with chronic periodontitis.

MATERIAL AND METHODS

Seventy-two mandibular degree II furcation defects were treated with either autologous PRF with open flap debridement (OFD; 24 defects) or autologous PRP with OFD (25), or OFD alone (23). Clinical and radiological parameters such as probing depth, relative vertical clinical attachment level and horizontal clinical attachment level along with gingival marginal level were recorded at baseline and 9 mo postoperatively.

RESULTS

All clinical and radiographic parameters showed statistically significant improvement at both the test sites (PRF with OFD and PRP with OFD) compared to those with OFD alone. Relative vertical clinical attachment level gain was also greater in PRF (2.87 ± 0.85 mm) and PRP (2.71 ± 1.04 mm) sites as compared to control site (1.37 ± 0.58 mm), and relative horizontal clinical attachment level gain was statistically significantly greater in both PRF and PRP than in the control group.

CONCLUSIONS

The use of autologous PRF or PRP were both effective in the treatment of furcation defects with uneventful healing of sites.

Statins: A new era in local drug delivery

Periodontitis is an inflammatory disease of the supporting tissues of the teeth, caused by a group of specific microorganisms. Aggressive forms of periodontitis can be localized or generalized. The concept that localized problem sites may be treated by local drug delivery appears attractive as the antimicrobial agent is delivered within periodontal pockets and the therapy is targeted on specific pathogenic microorganisms. Periodontitis can result in bone resorption creating bony defects, which may cause tooth loss. Various drugs have been studied using local delivery to improve the periodontal health and to achieve periodontal regeneration. Local delivery of antimicrobial agents using controlled release systems should be considered as adjunctive to mechanical debridement for the treatment of localized forms of periodontal destruction. Pharmacological agents offer great promise in this direction. Simvastatin, used for the treatment of hypercholesterolemia, is a universally accepted and relatively inexpensive drug. Local application of simvastatin has been shown to stimulate bone formation in rodents both in vitro and in vivo and in human periodontal ligament cells in vitro. This article reviews the effects of simvastatin as a local delivery and examines its potential role in periodontal regenerative therapy.

Novel and often bizarre strategies in the treatment of periodontal disease

Treatment of periodontal disease involves complex mechanical, surgical, and medical modalities. Some of the treatment regimens are patient centered, some involve a great amount of technical expertise and competence from a practitioner, and often involve complex procedures like use of tissue-engineered products. In spite of several advances, treatment of periodontal disease depends on scaling and root planing and various surgical procedures as the mainstay, but results of treatment are not always predictable and are often frustrating. The ultimate aim of periodontal treatment is regeneration of periodontal tissues and more particularly lost alveolar bone support. The treatment options include a myriad of approaches and scientists and researchers have tried various tools and agents to improve alveolar bone status and improve periodontal health. These approaches vary from simple monotherapy with systemic antibiotic usage to exotic and novel procedures like shock wave therapy, photodynamic therapy and application.

Clinical evaluation of a biphasic calcium phosphate grafting material in the treatment of human periodontal intrabony defects

Purpose

The aim of this study was to compare the clinical outcome of open flap debridement (OFD) with a biphasic calcium phosphate (BCP) graft to that of OFD without BCP graft for the treatment of intrabony periodontal defects (IBDs).

Methods

The study included 25 subjects that had at least one intrabony defect of 2- or 3-wall morphology and an intrabony component≥4 mm as detected radiographically. Subjects were randomly assigned to treatment with (BCP group, n=14) or without BCP (OFD group, n=11). Clinical parameters were recorded at baseline and 6 months after surgery and included the plaque index, gingival index, probing depth (PD), clinical attachment level (CAL), and gingival recession (REC). A stringent plaque control regimen was enforced for all of the patients during the 6-month observation period.

Results

In all of the treatment groups, significant PD reductions and CAL gains occurred during the study period (P<0.01). At 6 months, patients in the BCP group exhibited a mean PD reduction of 3.7±1.2 mm and a mean CAL gain of 3.0±1.1 mm compared to the baseline. Corresponding values for the patients treated with OFD were 2.5±0.8 mm and 1.4±1.0 mm, respectively. Compared to OFD group, the additional CAL gain was significantly greater in the patients in BCP group (P=0.028). The additional PD reduction was significant for the BCP group (P=0.048). The REC showed a significant increase in both groups, and the amount of recession was significantly smaller in the BCP group than OFD group (P=0.023). In radiographic evaluation, the height of the bone fill in the BCP group was significantly greater than OFD group.

Conclusions

The clinical benefits of BCP found in this study indicate that BCP may be an appropriate alternative to conventional graft materials.

Treatment modalities and evaluation models for periodontitis

Periodontitis is the most common localized dental inflammatory disease related with several pathological conditions like inflammation of gums (gingivitis), degeneration of periodontal ligament, dental cementum and alveolar bone loss. In this perspective, the various preventive and treatment modalities, including oral hygiene, gingival irrigations, mechanical instrumentation, full mouth disinfection, host modulation and antimicrobial therapy, which are used either as adjunctive treatments or as stand-alone therapies in the non-surgical management of periodontal infections, have been discussed. Intra-pocket, sustained release systems have emerged as a novel paradigm for the future research. In this article, special consideration is given to different locally delivered anti-microbial and anti inflammatory medications which are either commercially available or are currently under consideration for Food and Drug Administration (FDA) approval. The various in vitro dissolution models and microbiological strain investigated to impersonate the infected and inflamed periodontal cavity and to predict the in vivo performance of treatment modalities have also been thrashed out. Animal models that have been employed to explore the pathology at the different stages of periodontitis and to evaluate its treatment modalities are enlightened in this proposed review.

Impact of local and systemic alendronate on simvastatin-induced new bone around periodontal defects

BACKGROUND

Simvastatin has been shown to stimulate new bone growth on rat mandibles, but much of the bone is lost over time. The purpose of this study is to evaluate the impact of a locally or systemically applied antiresorptive agent (alendronate) on simvastatin-induced bone formation in and adjacent to a rat periodontal defect.

METHODS

Fenestration defects were created over mandibular molar roots in 65 mature female Sprague-Dawley rats. Two weeks later, animals were divided into eight groups of eight to nine rats, and three weekly injections around the defect were applied: 1) 0.5 mg simvastatin in ethanol (SIM-EtOH); 2) 0.5 mg simvastatin in alendronate-cyclodextrin conjugate (SIM-ALN-CD); 3) EtOH alone; 4) ALN-CD alone; or 5) no injections. Twenty-four animals were evaluated for new bone width around the defect 21 days after the last injections (short-term) and 41 rats were followed for 48 days (long-term). Three SIM-EtOH groups of long-term rats also were subjected to 2 weeks of daily systemic ALN or saline either during or 3 to 4 weeks after SIM-EtOH injections. Decalcified, hematoxylin-and-eosin-stained cross-sections of the defect area were analyzed for new bone width and groups were compared using mixed-model analyses of variance.

RESULTS

All groups showed nearly 100% bone fill, with no differences among the short-term groups. However, in the long-term animals, two-fold to three-fold more new bone width (≤ 0.004) was seen around the periphery of the defect with the use of systemic ALN after SIM-EtOH injections (0.93 ± 0.12 and 0.78 ± 0.11 mm with early and late systemic ALN, respectively) compared to local SIM/ALN-CD preparations (0.32 ± 0.10 mm) or short-term SIM-EtOH injections (0.35 ± 0.10 mm). No significant new cementum formation or ankylosis was noted.

CONCLUSION

The use of a short course of systemic ALN during the healing period after bone anabolic SIM injections has the potential to enhance local bone augmentation.

Clinical efficacy of subgingivally delivered 1.2-mg simvastatin in the treatment of individuals with Class II furcation defects: a randomized controlled clinical trial

BACKGROUND

Simvastatin (SMV) assists in bone regeneration and has an anti-inflammatory effect when delivered or applied locally. The present clinical trial is designed to investigate the effectiveness of 1.2-mg SMV as a local drug delivery system as an adjunct to scaling and root planing (SRP) for the treatment of Class II furcation defects.

METHODS

Seventy-two patients with mandibular buccal Class II furcation defects were randomized and categorized into two treatment groups: SRP plus placebo (group 1) and SRP plus 1.2-mg SMV (group 2). Clinical parameters were recorded at baseline before SRP and at 3 and 6 months; they included modified sulcus bleeding index (mSBI), probing depth (PD), and relative vertical (RVAL) and horizontal (RHAL) attachment levels. At baseline and after 6 months, radiologic assessment of bone defect fill was performed.

RESULTS

Both therapies resulted in significant improvements. The decrease in mSBI score at 6 months was greater in group 2 (2.02 ± 0.23) compared with group 1 (1.80 ± 0.22). The mean decrease in PD at 6 months was 1.30 ± 1.0 and 4.05 ± 1.31 mm in groups 1 and 2, respectively. A significantly greater gain in mean RVAL and RHAL was found in group 2 than in group 1 (P <0.05). Furthermore, significantly greater mean percentage of bone fill was found in group 2 (25.16%) compared with group 1 (1.54%).

CONCLUSION

Locally delivered SMV provides a comfortable and flexible method to improve clinical parameters and also to enhance bone formation.

Cholesterol, C-Reactive Protein, and Periodontitis: HMG-CoA-Reductase Inhibitors (Statins) as Effect Modifiers

Common risk factors of periodontitis and cardiovascular diseases fuel the debate on interrelationships between them. The aim is to prove whether statins may influence periodontal parameters by affecting either of these factors. Out of the 4,290 subjects of SHIP (Study of Health in Pomerania), we included subjects aged >30 years (219 with statins, 2937 without) and excluded edentulous. We determined periodontal measures, cholesterol fractions, and inflammation markers. Statin use and periodontal risk factors were assessed. Gingival plaque and periodontal attachment loss were associated with systemic LDL cholesterol (P < 0.001) and C-reactive protein CRP (P = 0.019) revealing interaction with statin use. When adjusted for age, sex, smoking, diabetes, education, and dental service, statins were identified as effect modifiers abolishing the relationship between attachment loss and LDL and between gingival plaque and LDL (interactions P < 0.001). No statin-related interaction was detected with increase in CRP. The interaction supports the view of inter-relationships between periodontal and systemic inflammatory mediators.

Clinical effect of autologous platelet-rich fibrin in the treatment of intra-bony defects: a controlled clinical trial

AIM

Platelet-rich fibrin (PRF) may be considered as a second-generation platelet concentrate widely used to accelerate soft and hard tissue healing because of presence of many growth factors. The present study aimed to investigate the clinical and radiological effectiveness of autologous PRF in the treatment of intra-bony defects of chronic periodontitis patients.

MATERIAL AND METHODS

Thirty-two intra-bony defects (one site/patient) were treated either with autologous PRF or a conventional open flap debridement alone. Clinical parameters such as plaque index (PI), sulcus bleeding index (SBI), probing depth (PD), clinical attachment level (CAL) and gingival marginal level (GML) were recorded at baseline and 9 months post-operatively. In both the groups, by using the image analysis software intra-bony defect fill was calculated on standardized radiographs (from the baseline and 9 months).

RESULTS

For all clinical and radiographic parameters test group was performed better than control group, and the difference was found to be statistically significant. Furthermore, images analysis revealed significantly greater bone fill in the test group compared with control (46.92%versus 28.66 %). Mean PD reduction (4.56 ± 0.37>3.56 ± 0.27) and CAL gain (3.69 ± 0.44>2.13 ± 0.43) in test group was found to be more compared with that of control group. In the test group, PD of >4 mm has highest percentage of PD reduction (68.9%) and CAL gain (61.6%). On frequency distribution analysis, there was no more difference for PD reduction in both the groups but CAL gain was much more in the test group than the control group.

CONCLUSIONS

Within the limit of the present study, there was greater reduction in PD, more CAL gain and greater intra-bony defect fill at sites treated with PRF than the open flap debridement alone.

Statins therapy: a review on conventional and novel formulation approaches

BACKGROUND AND OBJECTIVE

High levels of cholesterol lead to atherosclerosis, a factor predisposing to the development of coronary artery disease. Statin drugs, i.e. HMG-CoA reductase inhibitors, have been known since the end of the last century for their benefits against cardio- and cerebrovascular diseases and are widely used clinically. This review aims at compiling the research inputs being made for developing therapeutically efficacious dosage forms that have the potential to surmount the limitations of conventional dosage forms of statins.

KEY FINDINGS

Statin drugs can reduce the endogenous synthesis of cholesterol and prevent the onset and development of atherosclerosis, and are therefore used as an effective treatment against primary hypercholesterolemia. At present, statin drugs are most often administered orally, on a daily basis. After administration, the bioavailability and the general circulation of statin drugs is fairly low due to the first-pass metabolism in the liver and clearance by the digestive system. Extensive pharmaceutical research in understanding the causes of low oral bioavailability has led to the development of novel technologies to address these challenges.

SUMMARY

These technologies vary from conventional dosage forms to nanoparticulate drug-delivery systems, and have the potential to cause improvements in bioavailability and consequently therapeutic efficacy.

Autologous platelet-rich fibrin in the treatment of mandibular degree II furcation defects: a randomized clinical trial

BACKGROUND

Platelet-rich fibrin (PRF), an intimate assembly of cytokines, glycan chains, and structural glycoproteins enmeshed within a slowly polymerized fibrin network, has the potential to accelerate soft and hard tissue healing. This double-masked randomized study is designed to evaluate the effectiveness of autologous PRF in the treatment of mandibular degree II furcation defects compared with open flap debridement (OFD).

METHODS

Using a split-mouth design, 18 patients with 36 mandibular degree II furcation defects were randomly allotted and treated either with autologous PRF and OFD or OFD. Plaque index, sulcus bleeding index, probing depth, relative vertical and horizontal clinical attachment level, gingival marginal level, and radiographic bone defect were recorded at baseline and 9 months postoperatively. Comparison between indices between the test and control groups was performed using the paired t test except for plaque index and sulcus bleeding index data, which used the χ(2) test.

RESULTS

All clinical and radiographic parameters showed statistically significant improvement at the sites treated with PRF and OFD compared to those with OFD alone.

CONCLUSION

Within the limitation of this study, significant improvement with autologous PRF implies its role as a regenerative material in the treatment of furcation defects.