The antibacterial activity and release of quaternary ammonium compounds in an orthodontic primer

The aim of this study was to evaluate the impact of 10 wt% benzalkonium chloride (TB-BAC) or 10 wt% cetylpyridinium chloride (TB-CPC) on the antimicrobial properties of the orthodontic adhesive primer, Transbond XT™ (TB). Antimicrobial activity was assessed using a zone of inhibition diffusion test and the release of the antimicrobial compounds was monitored by high performance liquid chromatography (HPLC). Shear bond strength (SBS) was tested using bovine enamel. Control, TB, specimens failed to demonstrate intrinsic antibacterial activity at 1, 7 and 14 days; whereas, TB-BAC and TB-CPC showed antibacterial effects at all times. HPLC analysis indicated no significant differences in the release behaviour of TB-BAC and TB-CPC (t-test, p > 0.05), except for the 7-day release which was higher for TB-BAC (p 0.05)

The impact of Er:YAG laser enamel conditioning on the microleakage of a new hydrophilic sealant — UltraSeal XT® hydro™

UltraSeal XT® hydro™ is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XT® hydro™ as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XT® hydro™ was applied to each group of teeth (n=10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50°C with a dwell time of 30s. Microleakage assessments were then carried out using 0.5 % fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, Mann–Whitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p>0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p<0.001). Electron microscopy with energy-dispersive X-ray analysis revealed that the mineral filler component of UltraSeal XT® hydro™ essentially comprises micrometre-sized particles of inorganic silicon-, aluminium- and barium-bearing phases. Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface

Radiological and functional outcomes of ultrasound-guided PRP injections in intrasubstance meniscal degenerations

PubMed: 31204581Aim: This retrospective study is aimed to analyze the effect of ultrasound-guided platelet-rich plasma (PRP) injections on grade 2 intrasubstance meniscal degenerations (IMDs). Materials and Methods: Fifteen patients who underwent PRP injections for symptomatic grade 2 meniscal lesions were included in the study. All injections were performed with ultrasound in the degenerated menisci. Patients were evaluated with Lysholm score and magnetic resonance imaging (MRI) before the injection and after a mean of 32-month follow-up. T2-weighted MRI images were evaluated on sagittal by two authors as double-blind. Results: Lysholm score was found to be statistically significantly increased, and in 67% of the patients, grade 2 degenerations were improved to grade 1. Conclusion: Intra-meniscal PRP injection under ultrasonography guidance provides good functional scores and radiological improvement in the patients with IMD. © the Author(s) 2019

The effect of heat application on fluoride release from antibacterial agent added glass ionomer cement

Objectives: This study aimed to evaluate the effect of heat on the fluoride (F-) releasing ability of glass ionomer cement (GIC) when used in the conventional form and when combined with 5% cetylpryridium chloride (CPC). Materials and Methods: Twenty (n=5; each group) GIC samples were prepared, with the experimental group comprising GIC combined with 5% CPC and the control group comprising GIC without 5% CPC. The samples were prepared by non-heating (NH) procedures (n = 10) or by heating (H) for 60 seconds (n = 10) with a Light Emitting Diode (LED). Flouride releasing pattern was evaluated on days 1, 7, 15 and 30. Repeated measurements using two-way ANOVA and Fisher's LSD test were used for comparisons (p < 0.05). Results: Interactions among the groups, application of heat, and the time at which F- release was evaluated were analyzed (p < 0.001). There was no significant difference in F- release in the NH control and experimental groups on days 1, 7 and 15; however a significant release was evident in the experimental group on day 30 (p=0.01). Significantly higher values were obtained in the H associated control group than in the experimental group on days 1 (p=0.026), 7 (p = 0.001), 15 (p=0.005) and 30 (p=0.028). Significantly increased values were obtained from days 1 to 30 by NH and H procedures for both the groups (p<0.001). Conclusions: Heating in the control and experimental groups showed an increased F- releasing pattern. The fluoride release on 60 seconds of heating GIC containing 5% CPC, can have acceptable values for up to 30 days. The increased F- releasing pattern after the heating is believed to be promising for antibacterial GIC combinations. © 2019 Cumhuriyet Dental Journal

Direct and Transdentinal (Indirect) Antibacterial Activity of Commercially Available Dental Gel Formulations against Streptococcus mutans

**Objective** To evaluate the direct and transdentinal (indirect) agar diffusion antibacterial activity of different commercially available antibacterial dental gel formulations against Streptococcus mutans. Materials and **Methods** The commercially available dental gel formulations were Corsodyl® (COG, 1% chlorhexidine), Cervitec® (CEG, 0.2% chlorhexidine + 0.2% sodium fluoride), Forever Bright® (FOB, aloe vera), Gengigel® (GEG, 0.2% hyaluronic acid), 35% phosphoric acid gel and distilled water (control). Direct agar diffusion was performed by isolating three wells from brain-heart infusion agar plates using sterile glass pipettes attached to a vacuum pump and adding 0.1 ml of the gels to each well. Transdentinal (indirect) agar diffusion was performed by applying gel to 0.2- and 0.5-mm-thick human dentin discs previously etched with phosphoric acid and rinsed with distilled water. Zones formed around the wells and the dentin discs were measured and analyzed using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction (p 0.01). COG and CEG exhibited higher antibacterial effects compared to FOB and GEG (p < 0.01) in both direct and transdentinal (indirect) testing procedures. GEG did not show any antimicrobial activity in transdentinal (indirect) testing. **Conclusion** Commercially available dental gels inhibited S. mutans, which may indicate their potential as cavity disinfectants

The importance of storage time for human dental pulp cells isolation

Objective: The objective of the study was to compare the importance of storage time and the tooth type for isolation of dental pulp stem cells (DPSCs) from extracted human teeth.Materials & Methods: 35 human teeth (premolars, first molars and third molars) were used in this study. The teeth were stored in PBS medium after extraction and divided into two groups randomly according to the time elapsed between extraction and isolation. In group one, the isolation was performed within 2 hours and in the other group it was performed 24 hours after extraction. Results: There were no significant differences between isolation time and total cell counts (p=0.483) and between isolation time and viable cells (p=0.341). Also, there were no significant differences between the first molar and the premolar related cell counts and viable cells, but both teeth groups showed significant higher viability and had higher total cell amounts than third molars after isolation. Statistically significant correlations were found between age of donors and viable cells and viability after 24 hours isolation time.Conclusion: The immediate isolation of DPSCs is not necessary after the tooth extraction. The tooth can be stored in a PBS medium at room temperature up to twenty four hours after the extraction without a significant reduction in cell viability and counts. Also, the cells obtained from younger donors might have more chance for more viability even if storage time was extended

The impact of Er:YAG laser enamel conditioning on the microleakage of a new hydrophilic sealant — UltraSeal XT® hydro™

UltraSeal XT® hydro™ is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XT® hydro™ as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XT® hydro™ was applied to each group of teeth (n=10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50°C with a dwell time of 30s. Microleakage assessments were then carried out using 0.5 % fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, Mann–Whitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p>0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p<0.001). Electron microscopy with energy-dispersive X-ray analysis revealed that the mineral filler component of UltraSeal XT® hydro™ essentially comprises micrometre-sized particles of inorganic silicon-, aluminium- and barium-bearing phases. Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface