Comparing cytocompatibility of two fluoride-containing solutions and two resin-based restorative materials-a pilot study.

Background: Cytocompatibility should always be considered, especially if the surface of treated carious lesions is close to soft tissue or is accidentally exposed to the oral soft tissue by the clinician. Methods: The aim of the present study was to compare the cytocompatibility of two fluoride-containing liquids and two resin-containing restorative materials with buccal mucosa fibroblasts. The fluoride-containing materials were silver diamine fluoride and water-based silver fluoride. Results: The statistical analysis was completed by comparing the positive control growth of the buccal mucosa fibroblasts to the growth of cells exposed to various materials. The one-way ANOVA with Tukey's HSD result was completed. All the assessed materials compared to the control wells for both the 24 and 48 h time intervals indicated a significant cytocompatibility result, except for the test wells with Stela (SDI) at the 24 h time interval. There was no significant difference between the step 2 liquids and the two dental materials in cytocompatibility at the 24 h interval. All four materials indicated no significant differences between the cytocompatibility of any dental materials for 48 h. Conclusion: The cytocompatibility assessment for Riva Star and Riva Star Aqua with the direct method in a full dispensing drop is not viable for step 1 of the fluoride-containing liquids. The use of Stela Light Cure is a suitable material that will be in contact with buccal mucosa as it showed potential for increased cytocompatibility compared to Riva Light Cure. Riva Star Aqua is more cytocompatible than Riva Star.

Penetration of SDF and AgF from the infected dentine towards the unaffected tooth structure.

Background: The use of SEM-EDS line scan analysis to evaluate the movement of ions from dental materials towards the tooth structure and the concept of ion movement is well established. This analysis technique was used to determine the ion movement of two commercially available silver- and fluoride-containing products. Methods: This study aimed to compare the elemental analysis of primary molar teeth treated with silver diamine fluoride (SDF) and water-based silver fluoride (AgF) and to analyse the penetration of SDF and AgF from the infected dentine towards the healthy dentine. The teeth were cleaned from debris and contaminants off the roots and stored until use. A total of 15 primary molars with large active cavitated lesions, not extending into the pulp (specimens), were divided into three test groups: silver diamine fluoride (SDF) (n = 5), water-based silver fluoride (AgF) (n = 5), and deionised water (W) (n = 5) as the control group. The teeth were sectioned, embedded, and received SEM-EDS line scans. The line scan had a total length of 82.65 µm. The visible end of the infected dentine and the start of the more affected dentine were chosen as the starting point to ensure that the infected caries' line distribution towards the affected dentine's transition area was as standardized as possible. Therefore, the infected dentine length of the scan was 22.80 µm (8 scan points of 2.85 µm apart), and the affected dentine, including the healthy dentine, was 59.8 µm (21 scan points). The SEM-EDS line scan from each specimen determined the average fluoride, iodide, and silver weight percentage for that specimen. Results: The 15 sample SEM-EDS line scans were used to determine the average ion movement in wt%. The Kruskall-Wallis test and Tukey's HSD test were completed at a p < 0.05. SDF and AgF presented no significant fluoride movement in terms of the weight percentage. There was, however, significantly more fluoride movement from infected caries to the healthy dentine with SDF and AgF (p = 0.0010053) compared to the control specimens treated with deionised water. There was no significant difference between SDF and AgF for the movement of the iodide (p = 0.5953) and silver (p = 0.3708) from infected caries to the healthy dentine. Conclusion: SDF and AgF easily penetrated through infected caries and affected tooth structure to the healthy dentine for the line scan of 82.65 µm. There was no significant difference between SDF and AgF for the movement of ions within the infected dentine nor in the affected/healthy dentine.

Correction: Noordien et al. In Vivo Study of Aerosol, Droplets and Splatter Reduction in Dentistry. Viruses 2021, 13, 1928.

There was an error of omission in the original publication [...].

In Vivo Study of Aerosol, Droplets and Splatter Reduction in Dentistry.

Oral health care workers (OHCW) are exposed to pathogenic microorganisms during dental aerosol-generating procedures. Technologies aimed at the reduction of aerosol, droplets and splatter are essential. This in vivo study assessed aerosol, droplet and splatter contamination in a simulated clinical scenario. The coolant of the high-speed air turbine was colored with red concentrate. The red aerosol, droplets and splatter contamination on the wrists of the OHCW and chests of the OHCW/volunteer protective gowns, were assessed and quantified in cm2. The efficacy of various evacuation strategies was assessed: low-volume saliva ejector (LV) alone, high-volume evacuator (HV) plus LV and an extra-oral dental aerosol suction device (DASD) plus LV. The Kruskal-Wallis rank-sum test for multiple independent samples with a post-hoc test was used. No significant difference between the LV alone compared to the HV plus LV was demonstrated (p = 0.372059). The DASD combined with LV resulted in a 62% reduction of contamination of the OHCW. The HV plus LV reduced contamination by 53% compared to LV alone (p = 0.019945). The DASD demonstrated a 50% reduction in the contamination of the OHCWs wrists and a 30% reduction in chest contamination compared to HV plus LV. The DASD in conjunction with LV was more effective in reducing aerosol, droplets and splatter than HV plus LV.

In Vitro Analysis of Techniques that Alter the Surface Hardness of a Glass Ionomer Restorative Material.

AIM: The aim of this in vitro study was to compare the effect of different manipulation techniques on the surface hardness of ChemFil Rock glass ionomer. MATERIALS AND METHODS: The changes in Vickers surface hardness (VH) of ChemFil Rock were evaluated after the application of five manipulation techniques and compared with one control group (n = 60). The manipulation techniques included: finger pressure set, electronic piezo producing a high frequency set, air piezo producing a low frequency set, heat-set achieved with a curing light and the last technique was a combination of electronic piezo followed by heat-set. Standard set was the control. RESULTS: The average surface hardness for the standard set was 49.5 VH. No statistical differences were demonstrated when the means were compared for finger pressure set (49.2 VH) or the air piezo set (48.49 VH) with standard set. The electronic piezo (54.21 VH) and the heat-set (57.5 VH) had an increased mean surface hardness when compared to other techniques. Heat-set had the highest surface hardness demonstrating a significant statistical difference when compared with standard set, finger pressure set, air piezo set as well as the combination of electronic piezo (p < 0.05). CONCLUSION: The surface hardness of the glass ionomer cement (GIC) material assessed in this study can be predictably improved by applying the heat-set technique. A command set can be achieved with the electronic piezo or the air piezo, however, the surface hardness will only increase with the use of the electronic piezo. CLINICAL SIGNIFICANCE: The clinical advantage of using the air piezo as well as the electronic piezo technique would lie in preventing moisture contamination and dissolution of the GIC due to the command set effect of the ultrasonic vibrations within 15 seconds. The heat technique with the LED curing light will reduce the setting time to 90 seconds.