The response of human osteoblasts on bovine xenografts with and without hyaluronate used in bone augmentation.

The aim of the in vitro study was to asses the effect of hyaluronate in conjunction with bovine derived xenografts on the viability, proliferation on day 4, 7 and 10, expression of early osteogenic differentiation marker Alkaline phosphatase on day 14 and 21, collagen, calcium deposition on day 14, 21 and 28 and cellular characteristics, as assessed through live cell image analysis, confocal laser scanning microscopy and scanning electron microscopy, in primary human osteoblasts compared to three bovine xenografts without hyaluronate. All experiments were performed in triplicates. Data were compared between groups and timepoints using one-way analysis of variance (ANOVA). Bonferroni post hoc test were further used for multiple comparison between groups (p < .05) An increase in cell viability (p < .05) and enhanced ALP activity was observed in all xenografts. Specimens containing hyaluronate showed a highest significant difference (23755 ± 29953, p < .0001). The highest levels of calcium (1.60 ± 0.30) and collagen (1.92 ± 0.09, p < .0001) deposition were also observed with hyaluronate loaded groups. The osteoblasts were well attached and spread on all xenograft groups. However, a higher number of cells were observed with hyaluronate functionalized xenograft (76.27 ± 15.11, (p < .0001) in live cell image analysis and they migrated towards the graft boundaries. The biofunctionalization of xenografts with hyaluronate improves their in vitro performance on human osteoblasts. This suggests that hyaluronate might be able to improve the bone regeneration when using such xenografts.

The potential of nano graphene oxide and chlorhexidine composite membranes for use as a surface layer in functionally graded membranes for periodontal lesions.

Membranes have been used for treating periodontal defects and play a crucial role in guided bone regeneration applications. Nano graphene oxide have been exploited in tissue engineering due to its biomechanical properties. Its composite formulations with hydroxyapatite and chitosan with controlled degradation could aid in becoming part of a surface layer in a functionally graded membrane. The aim of the study was to synthesize chitosan and composite formulations of nano graphene oxide, hydroxyapatite and chlorhexidine digluconate using solvent casting technique and to characterize the physiochemical, mechanical, water vapor transmission rate (barrier), degradation and antimicrobial potential of the membranes. Altogether four different membranes were prepared (CH, CCG, 3511 and 3322). Results revealed the chemical interactions of hydroxyapatite, chitosan and nanographene oxide due to inter and intra molecular hydrogen bonding. The tensile strength of 3322 (33.72 ± 6.3 MPa) and 3511 (32.06 ± 5.4 MPa) was higher than CH (27.46 ± 9.6 MPa). CCG showed the lowest water vapor transmission rate (0.23 ± 0.01 g/h.m2) but the highest weight loss at day 14 (76.6 %). 3511 showed a higher drug release after 72 h (55.6 %) Significant biofilm growth inhibition was observed for all membranes. 3511 showed complete inhibition against A. actinomycetemcomitans. Detailed characterization of the synthesized membranes revealed that 3511 composite membrane proved to be a promising candidate for use as a surface layer of membranes for guided bone regeneration of periodontal lesions.

The Effect of Nanosilver Sodium Fluoride on the Mechanical and Physiochemical Properties of Artificially Demineralised Dentin.

PURPOSE: To synthesise and characterise nanosilver sodium fluoride (NSSF) and assess the effect of applying this formulation in vitro on artificially demineralised root dentin lesions, compared with the application of silver diamine fluoride (SDF), sodium fluoride (NAF) or no treatment, in terms of mechanical, chemical and ultrastructural properties. MATERIALS AND METHODS: NSSF was prepared using 0.5 wt% chitosan solution. On 40 extracted human molars, the buccal aspect of the cervical thirds of roots were prepared and divided into 4 groups of 10 each: control (no treatment), NSSF, SDF and NaF (n = 10). The specimens were examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR), surface and cross-sectional microhardness and nano-indentation tests were performed to determine the mineral and carbonate content, microhardness, and nanohardness, respectively. Statistical analysis was performed to determine the differences between the different treatment groups for the set parameters using parametric and non-parametric tests. Tukey's and Dunnet's T3 post-hoc tests were further used for multiple comparisons between groups (α = 0.05). RESULTS: The control group (no treatment) was found to have statistically significantly lower mean scores for surface and cross-sectional microhardness compared with all other test groups (NaF, NSSF and SDF) (p < 0.05). Spearman's rank correlation test showed statistically insignificant differences between the mineral-to-matrix ratio (M:M) and carbonate content of all groups (p < 0.05). CONCLUSIONS: Treatment of root lesions with NSSF yielded comparable results to SDF and NaF under in-vitro conditions.

In-vitro evaluation of the effectiveness of polyphenols based strawberry extracts for dental bleaching.

To formulate a dental bleaching agent with strawberry extract that has potent bleaching properties and antimicrobial efficacy. Enamel specimens (3 × 3 × 2 mm3) were prepared. Quaternary Ammonium Silane (CaC2 enriched) was homogenized with fresh strawberries: Group 1: supernatant strawberry (10 g) extract < Group 2: supernatant strawberry (10 g) extract + 15%HA (Hydroxyapatite) < Group 3: supernatant strawberry (10 g) extract + 15% (HA-2%k21) < Group 4: supernatant strawberry (20 g) extract only (20 g strawberries) < Group 5: supernatant strawberry (20 g) extract + 15% HA < Group 6: supernatant strawberry (20 g) extract + 15% (HA-2%K21) < Group 7: In-office Opalescence Boost 35%. Single-colony lactobacillus was examined using confocal microscopy identifying bacterial growth and inhibition in presence of bleaching agents using 300 µL aliquot of each bacterial culture. Images were analysed by illuminating with a 488 nm argon/helium laser beam. Colour difference (∆E00) was calculated using an Excel spreadsheet implementation of the CIEDE2000 colour difference formula and colour change measured between after staining and after bleaching. Scanning electron microscope was used to image specimens. Raman spectra were collected, and enamel slices were used for STEM/TEM analysis. HPLC was used for strawberry extract analysis. Nano-indentation was performed and X-ray photoelectron spectroscopy. Antioxidant activity was determined along with molecular simulation. hDPSCs were expanded for Alamar Blue Analysis and SEM. Mean colour change was significantly reduced in group 1 compared to other groups (p < 0.05). CLSM showed detrimental effects of different strawberry extracts on bioflms, especially with antimicrobial (p < 0.05). Groups 1, 2 and 3 showed flatter/irregular surfaces with condensation of anti-microbial in group 3. In strawberry specimens, bands predominate at 960 cm-1. HPLC determined the strawberry extracts content. Molecular simulation verified interaction between calcium and polyphenol components. XPS peak-fitted high-resolution corresponding results of Ca2p3/2 and Ca2p1/2 for all k21 groups. Combination of 10 g strawberry extract supernatant and 15% (hydroxyapatite 2%k21) improved the whiteness and provided additional antimicrobial potential. The novel strawberry extract and antimicrobial based dental formulation had immediate bleaching effect without promoting significant changes in enamel morphology.

Differences in Mechanical and Physicochemical Properties of Several PTFE Membranes Used in Guided Bone Regeneration.

Non-resorbable PTFE membranes are frequently used in dental-guided bone regeneration (GBR). However, there is a lack of detailed comparative studies that define variations among commonly used PTFE membranes in daily dental clinical practice. The aim of this study was to examine differences in physicochemical and mechanical properties of several recent commercial PTFE membranes for dental GBR (CytoplastTM TXT-200, permamem®, NeoGen®, Surgitime, OsseoGuard®-TXT, OsseoGuard®-NTXT). Such differences have been rarely recorded so far, which might be a reason for the varied clinical results. For that reason, we analyzed their surface architecture, chemical composition, tensile strength, Young's modulus, wettability, roughness, density, thickness and porosity. SEM revealed different microarchitectures among the non-textured membranes; the textured ones had hexagonal indentations and XPS indicated an identical spectral portfolio in all membranes. NeoGen® was determined to be the strongest and OsseoGuard®-TXT was the most elastic. Wettability and roughness were highest for Surgitime but lowest for OsseoGuard®-NTXT. Furthermore, permamem® was the thinnest and NeoGen® was identified as the thickest investigated GBR membrane. The defect volumes and defect volume ratio (%) varied significantly, indicating that permamem® had the least imperfect structure, followed by NeoGen® and then Cytoplast TM TXT-200. These differences may potentially affect the clinical outcomes of dental GBR procedures.

Role of mineral trioxide aggregate in dentistry: A bibliometric analysis using Scopus database.

OBJECTIVES: Mineral trioxide aggregate (MTA) has a long history of providing predictable clinical outcomes in dental applications especially in endodontic procedures. This bibliometric analysis aimed at evaluating the advancements of research in mineral trioxide aggregate and its use in the field of dentistry, together with the detection of most significant authors, organizations, countries, journals, papers, and the exploration of commonly used keywords using a structured approach. MATERIALS AND METHOD: The search was conducted using the Elsevier's Scopus database, gathering publication information related to MTA published from 1993 and 2021 July. Metadata comprising of titles, abstracts, keywords, authors, organizations, and countries were obtained. Bibliometric evaluators with respect to authors, articles published, journals, keywords, and top countries were scrutinized. Data was analyzed using VOS viewer. RESULTS: Between 1993 and 2021, an uptrend in the research performed on MTA was identified. Researchers from United States, Brazil, and Iran actively contributed on MTA, while papers from USA were highly cited. The Journal of Endodontics along with International Endodontic Journal were the top contributing academic journals. Hacettepe University, Turkey and Cardiff University from United Kingdom were the top most contributing organizations. Mahmoud Torabinejad was the most cited author. Most commonly used keywords included Mineral trioxide aggregate, silicate, oxide, root canal filling material. CONCLUSION: The global rise in the number of publications on mineral trioxide aggregate, tremendous networking and citations have been identified amongst various organizations, authors, and nations through this bibliometric analysis.

Tooth-implant connection with fixed partial dentures in partially edentulous arches. A retrospective cohort study over an 11.8 year observation period.

BACKGROUND: The fixed tooth-implant connection remains a controversial issue. This private practice-based retrospective study aimed to evaluate the clinical outcomes of a contemporary fixed partial denture (FPD) design for connecting natural teeth and implants (TI-FPD), over an 11.8 years observation period. MATERIAL AND METHODS: The data of 91 partially edentulous patients (44 males and 47 females, mean age of 47.7 years) treated with a newly designed TI-FPD retained on 1 implant and 1 natural tooth were analyzed retrospectively. Teeth were covered with electroformed copings and a CAD/CAM made bridge was fixed over the abutments with provisional cement. Two different implant systems were used: Camlog (N=22; anterior areas) and Straumann tissue level (N=69; posterior areas). RESULTS: The survival rate for both implants and teeth was 100%. 19/21 (90%, 95%CI 82-95%), 16/21 (66%, 95%CI 66-84%), and 16/21 (66%, 95%CI 66-84%) patients were free of biological complications after 5 years, 10 years, and 15 years post-loading, respectively. 23/35 (90%, 95%CI 54-74%), 21/35 (61%, 95%CI 50-70%), and 21/35 (61%, 95%CI 50-70%) were free of technical complications following 5 years, 10 years, and 15 years post loading, respectively. CONCLUSIONS: Despite limitations of the study, the findings demonstrated that the use of a recently designed TI-FPD could be used for the tooth-implant connection in cases of partial edentulism and this may widen the treatment modalities by reducing the cost and need for extensive bone tissue augmentations. Further controlled longitudinal studies with larger patient groups are needed. Key words:Tooth-implant connection, dental implant, fixed partial dentures, complications, implant prosthodontics.

The Efficacy and Adverse Events of Delafloxacin for Treating Acute Bacterial Skin and Skin Structure Infections: A Systematic Review and Meta-Analysis.

BACKGROUND: Acute bacterial skin and skin structure infections (ABSSSI) cause significant morbidity and mortality in hospitalized patients and outpatients as well. Newer fluoroquinolones such as delafloxacin might be a useful medication for treating infections of skin caused by gram-positive bacterial species that are resistant. AIMS AND OBJECTIVES: The aim of this study was to evaluate all the literature on delafloxacin in databases and make comparisons of its efficacy with antimicrobial drugs routinely used to treat skin infections. MATERIALS AND METHODS: A detailed search on different databases was conducted using, Cochrane Central Register of Controlled Trials, PubMed, and Embase. Primary outcome was microbiological cure at the end of the follow-up period. Absence of the signs and symptoms at the termination of the follow-up period and clinical response to medications was regarded as the secondary outcome. RESULTS: The pooled efficacy of delafloxacin was at 80% (95% confidence interval 1.01 [0.97, 1.06]; P = 0.51). No statistically significant difference was found between intravenous delafloxacin and comparator drugs. CONCLUSION: The effectiveness of delafloxacin was found to be non-inferior to tigecycline and linezolid. Efficacy and pooled cure rate of delafloxacin was also found to be superior to vancomycin.

Functionally graded biomimetic biomaterials in dentistry: an evidence-based update.

Design and development of novel therapeutic strategies to regenerate lost tissue structure and function is a serious clinical hurdle for researchers. Traditionally, much of the research is dedicated in optimising properties of scaffolds. Current synthetic biomaterials remain rudimentary in comparison to their natural counterparts. The ability to incorporate biologically inspired elements into the design of synthetic materials has advanced with time. Recent reports suggest that functionally graded material mimicking the natural tissue morphology can have a more exaggerated response on the targeted tissue. The aim of this review is to deliver an overview of the functionally graded concept with respect to applications in clinical dentistry. A comprehensive understanding of spatiotemporal arrangement in fields of restorative, prosthodontics, periodontics, orthodontics and oral surgery is presented. Different processing techniques have been adapted to achieve such gradients ranging from additive manufacturing (three dimensional printing/rapid prototyping) to conventional techniques of freeze gelation, freeze drying, electrospinning and particulate leaching. The scope of employing additive manufacturing technique as a reliable and predictable tool for the design and accurate reproduction of biomimetic templates is vast by any measure. Further research in the materials used and refinement of the synthesis techniques will continue to expand the frontiers of functionally graded membrane based biomaterials application in the clinical domain.

Systematic review and meta-analysis on efficacy of cefixime for treating gonococcal infections.

BACKGROUND: Neisseria gonorrhea is known to have developed a high level of resistance against different classes of antimicrobials. Patients with coagulation disorders where intramuscular injections are contraindicated, oral cefixime in combination therapy can be utilized as an alternative regimen. Cefixime in combination with another macrolide might be considered as an alternative treatment option. The aim of this systematic review is to assess the efficacy of 400 mg cefixime against a range of comparator drugs. METHODOLOGY: Extensive literature search for randomized controlled trials was performed using Medline, Cochrane Registry of Controlled Trials, Embase, and Clinical trials registers. The trials assessed the efficacy of cefixime against a range of comparator drugs. Primary outcome of the study was the clinical resolution of signs and symptoms and negative culture at the end of follow-up period. RESULTS: After screening for a total of 1184, only 8 studies were eligible for a meta-analysis. Risk ratio random effects model was used with a 95% confidence interval (CI). The pooled efficacy of Cefixime was at 97% at 95 CI 1.01 (0.98, 1.05). No statistically significant difference was found between oral cefixime and comparator drugs. CONCLUSION: A total of 11 studies were included following a review of 1184 publications. 8 randomized controlled trials for 400 mg oral cefixime were included in meta-analysis. Despite a high grade of evidence, a high risk of bias was found among studies. Hence, more high quality randomized controlled trials on cefixime needs to be performed in future to guide the treatment of gonococcal infections.