Background: Current study aimed to evaluate the effect of different decontamination procedures on micro-shear bond strength (μSBS) of sound (SoD) and caries-affected dentin (CAD) of two universal adhesives after blood-saliva contamination. Methods: One hundred and eighty bovine anterior teeth were prepared and allocated into the respective groups according to tested dentin substrates [SoD, CAD], universal adhesives [Clearfil Bond Universal Quick (UBQ), All-Bond-Universal (ABU)], adhesive contamination stage [none, contamination before and after adhesives light-curing], and according to decontamination procedures [no decontamination, water rinsing, adhesive rebond, Ethylenediaminetetraacetic acid (ETDA) and chlorhexidine (CHX) application]. Universal adhesives were applied according to manufacturer instructions in self-etch (SE) bonding mode. Four composite microrods were built for each tooth. Specimens were kept in distilled water for 24 hours at 37°C before testing μSBS. Four-way ANOVA and Tukey HSD tests were used for data analysis. Results: A statistically significant difference between contamination stages of both universal adhesives at different decontamination procedures for SoD and CAD. Highest μSBS was recorded for UBQ control group at SoD, while the least was recorded for light-cured ABU upon water rinsing decontamination procedure of CAD. Conclusions: Proper cavity isolation is mandatory to avoid possible contamination which can dramatically affect μSBS. CHX is a potent cavity decontaminant that can restore different dentin substrates bond strength. EDTA presents a promising substitute. UBQ adhesive showed better bonding performance than ABU to both dentin substrates. Application of regular cavity decontamination approaches is highly advised in daily practice to avoid possible detrimental effect of accidental cavity contamination.

Objective: Was to evaluate effect of clove, turmeric and garlic nano-herbal extracts on surface roughness and microhardness of demineralized dentin, and their bactericidal effect on Streptococcus mutans and Streptococcus sobrinus with or without diode laser irradiation. Methods: Three 5% nano-formulas were prepared and characterized using transmission electron microscope. MI paste Plus™ was used as control. A total of 100 specimens of demineralized dentin were prepared and treated with 3 W-power diode laser; then, the different tested materials for 10-min before the surface roughness and Vickers microhardness tests were conducted. Eighty coronal cavities were prepared (1-mm diameter × 2-mm depth). Cavities were inoculated with the tested materials with S. mutans or S. sobrinus bacteria, with or without diode laser irradiation for 20-s. Colony-forming unit method was used for counting the viable bacteria. Data were explored for normality using Kolmogorov–Smirnov and Shapiro–Wilk tests and showed parametric distribution for the surface roughness and microhardness tests, and non-parametric distribution for the bactericidal activity test. Results: The herbal formulas had a significant surface roughness and microhardness mean values. It showed a significant antimicrobial effect on the tested bacteria. When they were combined with diode laser, they showed a significantly higher antimicrobial effect. Conclusions: The tested herbal formulas represent potent topical remineralizing and antibacterial agents especially when they are used in conjunction with diode laser irradiation.

Background: Different types of dental laser can be used instead of the traditional hand and rotary files in root canal treatment with highly acceptable performance. Laser devices emit an intense and focused light energy, which interacts with biologic tissues, for pulp removal, shaping and cleaning the dentinal walls to be finally sealed with gutta-percha. Various laser devices with different wavelengths such as CO₂, Er:YAG, Nd: YAG and Diode present the best laser–tissue interaction. Lasers in root canal treatment show more advantages than traditional treatment. Laser is more accurate than conventional root canal treatment that allow minimal removal of healthy dentinal tissue. Lasers have anti-bacterial effect by reduction of more than 99.7% bacterial counts for root canal sterilization. Laser provides less bleeding, inflammation, pain, discomfort and infection than conventional procedures. Laser treatment of root canals results in a good sealing of gutta-percha to root canal walls to prevent infections. Conclusions: Laser application is comfortable to the patients by removing the disturbing sounds of drills and decreasing the need for local anesthesia. It decreases the need for suturing in endodontic surgery due to better hemostasis, thus getting clean and well-sealed surgical wounds.

This study investigated the effect of different polymerization protocols on the degree of conversion (DC%) of various photo-polymerized and dual-polymerized self-etch adhesive resins. Five different photo-polymerized (All-Bond Universal, Bisco; G-ænial Bond, GC; Futurabond M+ LC, VOCO; Single Bond Universal LC, 3M ESPE and Peak Universal Bond, Ultradent) and four dual-polymerized self-etch adhesives (Futurabond U, VOCO; Gradia Core SE, GC; Futurabond M+ DC, VOCO and Single Bond Universal DC, 3 M ESPE) were tested. All adhesives were applied on potassium bromide pellets (KBr) following the manufacturer’s instructions. The KBr pellets were divided into 10 experimental groups for the photo-polymerized adhesives and 12 experimental groups for the dual-polymerized adhesives according to the two levels of the study, Level 1: polymerization protocol and Level 2: adhesive system. For the photo-polymerized adhesives, the adhesives were polymerized either at 1 or 10 mm from the KBr pellets. For the photo-polymerized adhesives, the adhesives were photo-polymerized either at 1 or 10 mm distance or polymerized chemically. The DC% of the unpolymerized and polymerized adhesives was assessed using Fourier transform infrared spectroscopy. Data were analyzed using two-way ANOVA to evaluate the effect of polymerization protocol, adhesive system, and their interaction on the DC% of the self-etch adhesives. For the photo-polymerized and dual-polymerized adhesives, one-way ANOVA and Tukey HSD post hoc test was used to evaluate the effect of adhesive system within each polymerization protocol and the effect of polymerization protocol within each adhesive for the dual-polymerized adhesives (p = 0.05). Student t-test was used to compare the effect of polymerization distances within each photo-polymerized adhesive. For both photo- and dual-polymerized adhesives, the polymerization protocol and adhesive system had a significant effect on the DC (p = 0.000). The interaction between the two factors (polymerization protocol and adhesive system) revealed also a significant effect on the DC% of the different adhesives (p = 0.000). Polymerization distance of 1 mm showed significantly higher DC% compared to 10 mm distance. When the dual-polymerized adhesives were left to set chemically, they showed the lowest DC% among all polymerization protocols. DC varied depending on the chemical composition of the self-etch adhesives. The tip of the polymerization device should be positioned as close as possible to the surface to achieve higher DC% of the tested adhesives. Photo-polymerization of the dual-polymerized self-etch adhesives is a mandatory step to improve their DC.

Background: The aim of the study was to evaluate the remineralizing potential of prepared solutions of eggshell powder (ESP) and nano-hydroxyapatite (nHA) on the surface roughness and microhardness of bleached enamel. Materials and Methods: Fifty bovine anterior teeth were selected and cleaned then bleached using a chemically activated in-office bleaching agent then the teeth were randomly allocated into five groups (n = 10) according to the tested remineralizing agents (10% ESP solution, 10% nHA solution, and MI Paste Plus) into; control, bleached, bleached + ESP solution, bleached + nHA solution, and bleached + MI Paste Plus groups. Then, the teeth were tested for surface roughness and microhardness of the bleached enamel, respectively. Results: There was a statistically significant difference in the surface roughness and microhardness values of the tested groups. The highest surface roughness mean value was found in bleached enamel group, while the least mean value was found in the control group. The highest mean microhardness value was found in the bleached enamel + ESP solution group, while the least mean value was found in the bleached enamel group. Conclusions: The application of the tested remineralizing agents following the bleaching procedure had improved the surface roughness and microhardness of the bleached enamel. ESP and nHA present promising and potent remineralizing agents.