Background: Pit and fissure sealing is an evidence-based preventive measure against dental caries, especially in primary teeth which possess high caries risk, and to give the required benefits of the sealant, a good adaptation, and sealing ability should be present. Purpose: This study aimed to assess and compare the microleakage score of Ionoseal® pit and fissure sealant, when used either alone or with prior surface treatment of erbium-doped yttrium aluminum garnet (Er: YAG) laser, acid etching, or their combination, in primary teeth. Materials and Methods: Forty healthy human molar teeth were randomly chosen and allocated into four study groups according to the surface pretreatment: group I, no surface pretreatment; Group II, 2W Er: YAG laser etching, Group III, combined laser etching and acid etching group, and Group IV, 37% phosphoric acid etching. After surface pretreatment procedures were conducted, the teeth were sealed with Ionoseal®. Subsequent microleakage was assessed through dye penetration under a stereomicroscope. One sample from each group was randomly selected, and scanning electron microscopy (SEM) was carried out on the central slice of the three obtained slices of the samples. Results: Chi-square test revealed a high statistically significant difference between groups (P = 0.00). Similarly, all pairwise comparisons revealed a statistically significant difference. Group I showed the greatest mean of microleakage score (1.5), followed by Group IV (1.4), Group II (0.7), and Group III which showed the least microleakage score (0.6). These findings were supported by the SEM examination results. Conclusions: Using Ionoseal with prior surface treatment by combined 2 W Er: YAG laser etching and 37% phosphoric acid etching can result in the best sealing ability which would significantly enhance the long-term success of pit and fissure sealing in primary teeth.

Purpose: This study was carried out to compare the effect of laser surface treatment on cubic and tetragonal zirconia ceramics regarding; phase transformation tetragonal-monoclinic (T-M), surface topography, mechanical properties and biaxial flexural strength before and after low thermal degradation (LTD) aging. Materials and Methods: sixty discs (N=60) of CAD/CAM zirconia were used in this study. These specimens were divided into two main groups according to type of zirconia. Group I: (n=30) Cubic Zirconia (DD cubeX 2), while Group II: (n=30) Tetragonal zirconia (Superfect-Zir). Then each group further subdivided into two subgroups according to surface treatment, subgroup (1): control without surface treatment, subgroup (2): laser surface treatment .Specimens form each subgroups were tested for the following; Phase transformation, surface topography, and mechanical properties before and after Low Thermal Degradation (LTD) aging test. Results: Statistical analysis revealed that there was a statistical significant difference between the two tested groups regarding the surface topography, biaxial flexural strength, and surface hardness. Also there was a statistical significant difference regarding the surface treatment and before/after LTD and laser among the tested zirconia ceramics. Conclusions: laser surface treatment improved the properties of tetragonal / cubic zirconia, and increases their resistance to low thermal degradation LTD aging.

Purpose:The aim of this in vitro study was to evaluate the microleakage of premixed BioCeramics (BCs) and mineral trioxide aggregate (MTA) for sealing primary molar furcal perforations. Materials and Methods: This study was carried out on 30 extracted mandibular primary molars. Perforations of the furcation areas were created in the pulp chamber floor of the teeth. The molars were then divided randomly in two groups (n=15). Perforations were then repaired with biocompatible materials. After 72 h, the teeth were immersed in 2% basic fuchsine dye solution for 24h. The teeth were then sectioned longitudinally and evaluated for dye leakage. Data analyzed statistically using ANOVA test. Results: There was a statistically significant difference between the micro leakage of MTA (1669.25±140.59 µm) and premixed Bioceramics(1275.21±235.998 µm) groups (P>0.008). Conclusion: Premixed Bioceramics appeared to have superior sealing ability than MTA in perforation repair in primary teeth.An ideal sealing material should be biocompatible, non-toxic, bactericidal or bacteriostatic, radiopaque, non-absorbent, and maintain a good seal. Moreover, it should possess the ability to induce osteogenesis Codex : 01/22.04