To check the influence of different all-ceramic systems on the polymerization of a dual-cured resin cement, evaluated immediately and 24 hours after curing cycle.

A total of 80 resin cement disk specimens (n = 20) were fabricated by polymerization through lithium disilicate disks (group B), leucite-reinforced disks (group C), zirconia disks (group D) and without an intervening ceramic disk (group A). Each group further consisted of two subgroups (n = 10), t₃₀ and t₆₀ according to two different exposure times of 30 and 60 seconds respectively. Each of the 80 resin disk specimens was evaluated for microhardness (VHN) immediately and after 24 hours, giving us a total of 160 readings. One way analysis of variance (ANOVA) test was used for multiple group comparisons followed by Tukey's post-hoc for group-wise comparisons.

Direct activation (group A) of the resin cement showed statistically significant higher mean microhardness values as compared to the experimental groups (groups B, C and D), both immediately and after 24 hours. The mean microhardness for immediate postactivation was always inferior to the 24 hours postactivation test for both direct activation and through different ceramics. For immediate testing time, of both the 30 and 60 seconds curing cycle, there was a significant increase in the microhardness of the resin cement disks cured for 60 seconds through the different ceramics (groups B, C and D) and direct light activation (group A). For the 24 hours testing time, of both the 30 and 60 seconds curing cycle, there was a significant increase in the microhardness of the resin cement disks cured for 60 seconds through the different ceramics except for the direct light-activation group.

Ceramic composition affected the polymerization of dual-cured resin cements. Doubling the light irradiation time significantly increased mean microhardness value. Greater degree of conversion leading to an increase in hardness was observed when the resin cement disks were evaluated after 24 hours.

Jain NV, Dugal R, Madanshetty P, Poplai GR, Gharatkar AA, Shinde PH. Influence of Different Ceramic Systems on the Polymerization of Dual-cured Resin Cement evaluated Immediately and after 24 Hours. An in vitro Study. Int J Prosthodont Restor Dent 2015;5(1):1-9.

The effect of microgravity on gingival epithelial cells (GE1) is unknown; thus, we analyzed cell proliferation as well as the gene expression patterns in GE1 cells cultured under simulated microgravity.

Gingival epithelial cells were seeded and cultured at 10^-3 G in a three-dimensional clinostat to simulate microgravity (group CL) or in normal gravity (group C) for 10 days. Cell proliferation was analyzed by counting the numbers of cells. Real-time polymerase chain reaction was performed to amplify the krt 5, krt 13 and involucrin genes. Additionally, total protein was immunoblotted with anti-krt 13 antibody. Statistical analysis (n = 9, three groups repeated three times) was performed (ANOVA, Tukey's test, p < 0.05).

Cell proliferation was significantly upregulated under microgravity based on the average number of cells. Cell proliferation and differentiation marker expression was significantly increased after culture under simulated microgravity. Western blotting showed intense krt 13 staining under simulated microgravity. The simulated microgravity environment had an accelerating effect on GE1 proliferation and differentiation.

These findings suggest that GE1 cells would be affected by the microgravity environment during space flight. Moreover, these findings also suggest that we could promote regeneration of gingival cells using of a simulated microgravity environment.

Tamura A, Masaki C, Seo Y, Mukai C, Mukaibo T, Kondo Y, Nakamoto T, Hosokawa R. Microgravity might affect Peri-implant Mucosal Epithelial Cells during Space Flight. Int J Prosthodont Restor Dent 2015;5(1):10-16.

Daswani SR, Aras MA, Chitre V, Mysore A. A Simplified Technique for Fabrication and Characterization of a Custom Ocular Prosthesis using Light- cured Stains. Int J Prosthodont Restor Dent 2015;5(1):17-20.

Autologous plasma rich in platelets is derived blood product whose uses in dentistry dates back to the 1990s and it has been gaining popularity ever since.

A systematic review of the available literature to determine the efficacy, safety and success of platelet concentrates in physiological systems as well as describing its vigilant use.

A Medline search with keywords ‘platelet rich plasma dental’ further filtered using Boolean opera- tors (AND, OR, NOT) and combination of specific keywords as follows: ‘platelet rich fibrin’, ‘platelet rich plasma regenerative’, ‘platelet rich plasma periodontal’, ‘platelet rich plasma extraction’ with a custom range of 10 years was performed, which yielded 88 results out of which 32 were selected based on the inclusion criteria.

Significantly, successful outcomes have been wit- nessed in the field of osteoregeneration though it has been evidenced that adequate platelet rich plasma (PrP) additives are essential to bear a therapeutic potential. Favoring blood cell adhesion on the root surface optimizing periodontal healing, PrP has also shown positive effect on gingival repair; though controversial facts have also been reported. In the scope of implant dentistry, PrP has also reported greater implant-bone contact when used in both gel or liquid form. Emerging as a possible pulp capping agent along with properties of decreased chances root growth, PrP has successfully completed apexo- genesis in cases of pulpotomy.

  Research has shown that although clinical results from the comparison of PrP alone vs PrP and resorbable membrane or various graft materials has shown a varied results, additional research in the field is needed.

Platelet rich plasma has shown promising results in the field of regenerative dentistry, with high success rate in implantology, periodontology and oral surgery. Because of conflicting success rates reported in literature further research is warrented.

Platelet rich fibrin has displayed various features of rapid clinical healing, excellent bone density, less surgical time, less resorption during healing and decreased postoperative pain, as compared to guided bone regeneration procedures. Platelet rich plasma has also shown a myriad of applications ranging from hard tissue regeneration to soft tissue management, stretching across to the field of pediatric dentistry and endodontics.

Gada SK, Gupta P. the Clinical Application of Platelet Concentrates: A Systematic Meta- analysis. Int J Prosthodont restor Dent 2015;5(1):21-26.

Metkari SS, Kamble PS, Meena RK, Ramugade MM. Functional Rehabilitation of Mandibular Molar with Separated Instrument and External Root Resorption. Int J Prosthodont Restor Dent 2015;5(1):27-30.