Clinical and Radiographical Evaluation of Bovine Derived Xenograft without or with Calcium Sulphate Hemihydrate in the Treatment of Intrabony Defects in Chronic Periodontitis: A RCT

Introduction: Intrabony periodontal defects respond well to regenerative periodontal therapy. Numerous grafts and non graft materials are available for regeneration. Careful use of nonallogenic bone graft could enhance radiographic defect fill. Aim: To compare the clinical and radiographical evaluation of bovine derived xenograft (OsseograftTM) alone versus a combination of bovine derived xenograft and calcium sulphate hemihydrate (OsseomoldTM) in the treatment of intrabony defects in chronic periodontitis. Materials and Methods: A prospective, single blinded randomised clinical trial was conducted in the department of Periodontics, Nair Hospital Dental College, Mumbai, India (December 2017- August 2019). A total of 42 patients presenting with 43 intrabony defects were randomly assigned to Control Group (CG) (n=21) or Test Group (TG) (n=22). Clinical parameters {Probing Pocket Depth (PPD) and Clinical Attachment Level (CAL)} were assessed at baseline (M0), one month (M1), three months (M3) and six months (M6) and radiographic parameters {Bone Fill (BF)} were measured using Intraoral Periapical Radiograph (IOPA) at baseline (M0) and six months (M6). Two patients (three defects) were lost to follow-up. Descriptive and inferential statistical analyses were performed, results on continuous measurements were presented on Mean±SD. Statistical software IBM SPSS statistics 20.0. Level of significance was fixed at p=0.05. Student’s t-test was used to find the significant difference between and within the groups. Repeated measures Analysis of variance (ANOVA) was used to find the significance of study parameters within the group (at different time intervals). Results: PPD was lowest at six months for TG (3.95±0.61) and CG (3.30±0.66) and it gradually improved from baseline to six- months (p<0.001 for both TG and CG). CAL gain was highest at six-months for TG (4.4±0.50) and CG (3.65±0.75) (p<0.001). Significant reduction in Radiographic Defect Depth (RDD) was noted in both the groups (CG: 6.65±1.08 at M0 and 4.92±1.00 at M6 (p<0.001); TG: 7.06±0.96 at M0 and 5.14±0.77 at M6) (p<0.001). Intergroup analysis was statistically significant for clinical parameters with greater improvement seen in CG control group {PPD and CAL at M3 and M6 (p<0.001)} and statistically insignificant for radiographic parameters (p>0.5). BF was higher at M6 in TG (1.87) as compared to CG (1.72), which was statistically insignificant. Conclusion: Both treatments were clinically effective showing a significant improvement in clinical and radiographic parameters and there was significant difference between the two groups- clinically in terms of reduction in PPD and CAL gain at three months and six months with greater improvement seen in CG as compared to TG, with no difference radiographically. Further studies are needed to show the stability over time of the present results.

Crystallization features of calcium sulfate in the process of “artificial aging”

Gypsum binders are widely used in construction, mining and the oil and gas industry. The use of these binders is conditioned by stability of their technical characteristics, which is achieved by using a technological operation “artificial aging”. The features of artificial aging are: 1) hydration of calcium sulphate hemihydrate in liquid phase deficiency; 2) the resulting dihydrate gypsum crystallizes in a limited volume of micropores of the original binder. From the standpoint of the quataronic concept, the features of the crystallization of gypsum dihydrate in the micropores of the original gypsum binder are considered. The effect of artificial aging conditions and the degree of supersaturation on the growth mechanism and the morphology of gypsum dihydrate crystals was determined. The use of artificial “aging” results in healing of defects in the structure of the original binder, decreasing water demand and increasing strength.

Enhancing the Phase Conversion of Hydroxyapatite from Calcium Sulphate Hemihydrate by Hydrothermal Reaction

Hydroxyapatite (HA) is a well-known biocompatible material which is widely used in orthopedic and dental applications. Because its chemical structure is similar to the human bone so it is compatible to use as a based materials in drug delivery system for treatment of bone infection diseases. In this research we focused on fabrication of HA sphere shape by three dimension printing using calcium sulphate hemihydrate (CaSO4·0.5H2O) as a starting material, then the as-three dimension printed CaSO4·0.5H2O spheres were hydrothermally treated in 1M disodium hydrogenphosphate (Na2HPO4) at 100°C-180°C for 2-8 hr. The reaction was taken place and the conversion of CaSO4·0.5H2O was gradually changed to Ca10(PO4)6(OH)2. Phase analysis by X-ray diffraction indicated that monetite (CaHPO4) was coexisted with HA when hydrothermally treated at pH 9 at low reaction temperature (<180°C). When the pH of 1M Na2HPO4 was adjusted to pH 11, 180°C for 6 hr, the as-three dimension printed calcium sulphate hemihydrate spheres were completely converted to HA spheres without any destruction of the sphere shape. This is confirmed that hydrothermal reaction could enhance the phase conversion of HA and the conversion time was four times faster than the normal conversion.