Effect of calcium and Vitamin D supplementation on residual ridge resorption in edentulous patients: An open-label randomized study.

AIM: Complete dentures (CDs) are fabricated to rehabilitate the edentulous. Severe residual ridge resorption (RRR) compromises CD functionality, adversely affecting function, appearance, systemic health, and quality of life. SETTINGS AND DESIGN: The purpose of this study was to assess the benefit, if any, of calcium and Vitamin D supplementation on the rate of RRR. Retarding RRR would improve treatment prognosis and make CD fabrication less demanding. MATERIALS AND METHODS: This longitudinal, parallel, open-label randomized study was conducted in the Department of Prosthodontics of the institute. One hundred and fifty edentulous subjects underwent bone mineral density (BMD) assessment followed by CD fabrication to measure RR height and width with computerized tomographic (CT) scans. Subjects were randomized to oral supplementation group - S, given combined Vitamin D and calcium daily, and nonsupplementation group - NS. Subjects from both the groups were followed up with repeat BMD test and CT scan after 12 months. Mean BMD, RR height and width, and RRR values were collected, analyzed, and compared for the two groups using STATA 17. STATISTICAL ANALYSIS USED AND RESULTS: Baseline mean T-score, RR height, and RR width were - 1.84, 22.30 mm, and 4.25 mm, respectively, for the sample. In both Groups S and NS, a statistically significant decrease in mandibular RR height (P = 0.000 for both) and width (P = 0.027 and 0.003, respectively) was observed at 1-year follow-up. There was a statistically insignificant difference between Groups S and NS for mean BMD, T-score, RR height and width, and RRR at both baseline and 12-month follow-up. One-year RRR rate for Group S (1.30 mm) was insignificantly lesser than for group NS (1.33 mm). CONCLUSION: Short-term oral calcium and Vitamin D supplementation was ineffective in reducing RRR and improving BMD.

A quantitative method to determine osteogenic differentiation aptness of scaffold.

Osteogenic differentiation of Mesenchymal stem cells (MSCs) on scaffold is crucial for bone tissue engineering. Alkaline phosphatase (ALP) assay is an important method of assessing osteogenesis. Here, a very simple and innovative procedure is being described for quantification of osteogenic differentiation of MSCs in presence of scaffold using ALP assay. Different concentrations of the scaffold particles with the same number of MSCs were assayed for alkaline phosphatase activity using p-NPP as substrate for ALP activity. G-bone scaffold was used in concentrations of 5, 20, 60 and 100 mg/ml and same number of MSCs were seeded. Any scaffold which can be grind and weighed may be used. It was found that100 mg/ml G-bone graft was most useful for promoting osteogenesis and addition of growth factors further promoted. So, we were able to ascertain the concentration of scaffold which promotes osteogenesis the most.

Hydroxyapatite-collagen augments osteogenic differentiation of dental pulp stem cells.

The objectives of this study were to isolate and culture dental pulp stem cells (DPSCs) and to investigate their proliferation and osteogenic differentiation on hydroxyapatite-collagen (HA-Col) scaffold. DPSCs were characterized by fluorescence-activated cell sorting (FACS). Cultured cells were CD73+, CD90+, CD105+ and CD31-, CD45-. A commercially available HA-Col scaffold was used for culture of DPSCs. Cell attachment and viability of DPSCs cultured on scaffold was studied by sulforhodamine assay. Osteoblast differentiation capacity was studied by alkaline phosphatase assay and the effects of growth factors such as PDGF, IGF1 and FGF2 were further studied. Scanning electron microscopy (SEM) of cell seeded scaffolds was also performed. We found that DPSCs cultured exhibited the characteristic mesenchymal stem cells (MSCs) morphology and differentiation properties. Scaffold was found to be non-cytotoxic and had good biocompatibility in vitro. Osteoblast differentiation ability was found to increase at higher concentration of scaffold and additive effects were observed with the use of growth factors. In SEM, cells appeared to cover the entire surface of the scaffold forming continuous cell layer and extending filopodial extensions. HA-Col scaffold is apt for MSCs attachment and proliferation in vitro. Their unique self-renewal and multilineage differential potential make them ideal for use in regenerative medicine. The limitations of currently available bone graft materials have led to the emergence of tissue engineering using mesenchymal stem cells (MSCs). Since, HA-Col scaffold potentiated the proliferation and osteogenic differentiation of DPSCs, this biomimetic material may be an ideal one for maxillofacial and alveolar bone regeneration.

Antioxidant enzymes in periodontitis.

Periodontitis is basically an inflammatory disease initiated by the subgingival biofilm and modified by the individual's aberrant inflammatory/immune response. Various studies have pointed toward the role of oxidative stress in periodontitis. As the reactive oxygen species and antioxidants are in dynamic equilibrium, any disturbance in one would lead to changes in the other. As studying, individual antioxidants is a vast field, this review focuses on the role of antioxidant enzymes in periodontitis and in other related systemic conditions. It is highlighted that oxidative stress may be the missing link in these associations of periodontitis and other conditions. Also, the antioxidant enzymes may be considered a useful biomarker for periodontal diseases and antioxidant supplementation may be of help to reduce the burden of periodontal destruction without having much extra effort.

Association of salivary lipid peroxidation levels, antioxidant enzymes, and chronic periodontitis.

This study assessed the activities of antioxidant enzymes superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) and free radical damage marker malondialdehyde (MDA) levels in saliva of 30 patients with chronic periodontitis (CP) compared to 30 healthy controls by spectrophotometry. MDA levels were significantly elevated in the CP group, whereas the SOD, CAT, and GR activities were significantly reduced compared to healthy controls. MDA levels demonstrated a significant direct correlation with all periodontal parameters, whereas all antioxidant enzymes studied (SOD, CAT, and GR) showed an inverse correlation. These findings support the idea that oxidative stress has a role in periodontal disease pathogenesis.

Evaluation of antioxidant enzymes activity and malondialdehyde levels in patients with chronic periodontitis and diabetes mellitus.

BACKGROUND: The aim of this study is to investigate the impact of diabetes, a known risk factor for periodontitis, on activities of antioxidant enzymes superoxide dismutase (SOD), glutathione reductase (GR), and catalase (CAT) as well as levels of free radical damage marker malondialdehyde (MDA) in blood and saliva of individuals with chronic periodontitis (CP). METHODS: Sixty patients with CP (30 patients with type 2 diabetes mellitus [DMCP] and 30 systemically healthy patients [CP]) and 60 periodontally healthy individuals (30 patients with type 2 diabetes mellitus and 30 systemically healthy patients [PH]) were included in this study. After clinical measurements, blood and saliva samples were collected. SOD, GR, and CAT activities in red blood cell lysate and saliva and MDA levels in plasma and saliva samples were spectrophotometrically assayed. An analysis of variance test followed by a post hoc test was used to compare the intragroup and intergroup variances among the study groups. RESULTS: MDA levels in both the periodontitis groups were higher than in the periodontally healthy groups, but the difference between the CP and DMCP groups did not reach statistical significance (P >0.05). There was a highly significant difference between the CP and PH groups for all the enzymes studied except for SOD in blood. Only salivary SOD and GR activities were significantly different in the CP and DMCP groups. CONCLUSIONS: This study favors the role of oxidative stress in both diabetes and periodontitis. It shows that the compensatory mechanism of the body is partially collapsed because of excessive production of free radicals during periodontitis and is not able to cope with increased free radical generation attributable to diabetes, thereby worsening the situation.

Finite element analysis: A boon to dentistry.

The finite element analysis (FEA) is an upcoming and significant research tool for biomechanical analyses in biological research. It is an ultimate method for modeling complex structures and analyzing their mechanical properties. In Implantology, FEA has been used to study the stress patterns in various implant components and also in the peri-implant bone. It is also useful for studying the biomechanical properties of implants as well as for predicting the success of implants in clinical condition. FEA of simulated traumatic loads can be used to understand the biomechanics of fracture. FEA has various advantages compared with studies on real models. The experiments are repeatable, there are no ethical considerations and the study designs may be modified and changed as per the requirement. There are certain limitations of FEA too. It is a computerized in vitro study in which clinical condition may not be completely replicated. So, further FEA research should be supplemented with clinical evaluation.