Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study.

AIM: The aim of the current investigation was to evaluate the marginal microleakage of various esthetic restorative materials applied to primary teeth. MATERIALS AND METHODS: A total of 75 noncarious primary molars that were removed for orthodontic intervention and teeth nearing exfoliation were chosen. One millimeter (mm) above the cementoenamel junction, on the buccal surface of the teeth, Class V cavities were prepared. William's graded periodontal probe was used to standardize cavity preparation on all teeth. 3 mm was the cavity's length, 2 mm in width, and 2 mm in depth. The teeth were then divided into three groups (25 samples in each group) according to the type of esthetic restorative material used. Group I: Resin-modified glass ionomer cement, Group II: Ormocer, Group III: Giomer. The samples underwent 500 cycles of thermocycling, with an immersion time of 60 seconds and a well time of 15 seconds, between 5 and 55°C. The samples were submerged in methylene blue dye for 24 hours at room temperature and dried. The samples were then divided into sections and examined with a stereomicroscope. Data was recorded and statistically analyzed. RESULTS: The least marginal microleakage was found in the ormocer group (1.22 ± 0.01) followed by resin-modified glass ionomer cement group (1.31 ± 0.07) and the giomer group (1.78 ± 0.03). There was a highly statistically significant difference found between resin-modified glass ionomer cement group and the ormocer group, resin-modified glass ionomer cement group and giomer group. And no significant difference was found between the ormocer group and the giomer group. CONCLUSION: The present study concluded that there was some amount of microleakage in primary teeth in all restorative materials examined in this in-vitro investigation. However, the marginal sealing ability of ormocer was found highest compared to resin-modified glass ionomer cement and Giomer materials. CLINICAL SIGNIFICANCE: The primary reason dental restorations fail, particularly in Class V cavities, is microleakage since the margins of these restorations are typically found in the dentin or cementum. Assessing microleakage is a crucial step in determining the marginal integrity of restorative materials. Developing methods and resources that reduce the adverse effects caused by the restorative marginal seal failing would benefit from this. How to cite this article: Al Ghwainem A, Alqarni AS. Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study. J Contemp Dent Pract 2024;25(1):58-61.

Comparison of the marginal microleakage of a bioactive composite resin and traditional dental restorative materials.

The primary objective of this study was to evaluate the marginal microleakage of Activa Kids BioActive-Restorative used with an adhesive bonding agent (AB+) and compare it with the microleakage of a traditional composite resin (CR), a resin-modified glass ionomer cement (RMGIC), and Activa Kids BioActive-Restorative placed without the use of an adhesive bonding agent (AB-). Standard Class I cavities were prepared in 200 extracted, caries-free permanent molars, which were then restored with 1 of the 4 restorative materials (n = 50 each). The restored teeth were thermocycled for 500 cycles, alternating between 5°C and 55°C with a dwell time of 25 seconds; stained with basic fuchsin dye with a soak time of 24 hours; and sectioned buccolingually. Microleakage was assessed independently by 2 evaluators who viewed specimens under a dissecting microscope at ×30 magnification and assigned scores according to a standardized microleakage scale. Because a Spearman correlation test showed a high correlation between the scores assigned by the 2 evaluators, their ratings for each of the 4 test groups were pooled, and a modified Wilcoxon rank sum test (P < 0.05) was used to analyze the microleakage scores. No difference in microleakage was observed between the AB+ and CR groups (P = 0.8652). Statistically significant differences in microleakage were observed between the AB+ and RMGIC groups (P < 0.0001) as well as between the AB+ and AB- groups (P = 0.0324). The results showed that AB+ had a mean microleakage rate comparable to that of traditional CR. Moreover, AB+ exhibited a lower mean microleakage rate than RMGIC; both the bioactive composite resin and RMGIC are fluoride-releasing materials, so clinicians should consider using AB+, especially in high-caries-risk patients, who are vulnerable to recurrent caries resulting from microleakage and benefit from fluoride release. In this study, AB+ exhibited a significantly lower mean microleakage rate than AB-; therefore, this bioactive material should be used with a bonding agent.

Comparative microleakage outcomes of different techniques used for creating the occlusal anatomy in occlusal direct restorations using the dental operating microscope.

OBJECTIVES: Microleakage in direct dental restorations is a primary causal factor in the restoration's failure. The aim of this study was to evaluate whether the technique for occlusal layering of the composite resin (the use of brush adaptation, the use of magnification, cusp build-up, stamp technique) has any effect on microleakage of direct restorations in occlusal cavities. MATERIALS AND METHODS: One hundred extracted human molars were restored using five restoration techniques (Packable Bulk technique, Occlusal Stamp technique, Successive Cusp Build-up technique, Successive Cusp Build-up technique + Brush adaptation, Successive Cusp Build-up technique + brush adaptation + Dental Operative Microscope magnification). The teeth were subjected to thermal aging for 800 cycles at 5°C and 55°C, infiltrated with basic fuchsin dye for 24 h, and then sectioned buccolingually in the middle of the crown. Infiltration was measured in four areas of the tooth section by five different observers and then given a score from 1 to 3, proportional to infiltration depth. RESULTS: The lowest mean scores for infiltration (meaning less infiltration observed) were present in Group A (1.41 ± 0.878) and Group C (1.46 ± 0.679), while Group D showed the highest infiltration scores (1.75 ± 0.853). When comparing the groups for differences, no statistically significant difference in infiltration was found between any technique p < .586. CONCLUSION: The techniques examined for placing the occlusal layer of composite in direct restorations do not differ significantly in terms of marginal infiltration, although a slight improvement was found when using the bulk technique and the successive cusp build-up.

Evaluation of Bacterial Leakage in Platform-Switching Dental Implant with Morse Taper Connection Under Thermocycling and Loading Effects: In Vitro Study.

PURPOSE: The aim of this study was to test in vitro the bacterial microleakage at the Morse taper implant-abutment connection with switched platform subjected to functional load and thermocycling. MATERIALS AND METHODS: A total of 48 Morse taper implant-abutment connections with switched platforms (12 implants per group) were used. The abutments were attached to implants and presented in four groups: group 1, control; group 2, subjected to thermocycling; group 3, subjected to cyclic compressive loading; and group 4, subjected to thermocycling and cyclic compressive loading. All groups were then inoculated in Eppendorf tubes including three types of bacterial suspensions: Enterococcus faecalis, Staphylococcus aureus, and Pseudomonas aeruginosa for 7 and 14 days to detect possibility of bacterial infiltration from outside to the internal chamber of the implant. RESULTS: Implants not exposed to cyclic loading and thermocycling (group 1) and those exposed to thermocycling (group 2) exhibited no infiltration of E faecalis, S aureus, and P aeruginosa from outside to the inner chamber of the implant, while infiltration of P aeruginosa was only observed in implants subjected to cyclic loading only (group 3) and those subjected to cyclic loading in conjunction with thermocycling (group 4). CONCLUSION: Microbial leakage at the implant-abutment connection is influenced by the applied load alone and in combination with thermocycling; however, E faecalis and S aureus did not leak at the implant-abutment connection even under these circumstances. Only P aeruginosa infiltrated inside the implant-abutment connection, which might be caused by its swarming motility.

The influence of a selected desensitizer on marginal microleakage of a class V composite restoration subjected to thermocycles: an in vitro study.

INTRODUCTION: Dentin hypersensitivity is a painful clinical condition. The frequency of its occurrence varies from 8 to 57%, depending on tested group and different methods of investigations. Recommended desensitizing agents have different mechanism of action and effectiveness. We are still looking for solutions that will improve their effectiveness and simultaneously allow for wider use of e.g. as a base material, counteracting postoperative hypersensitivity, reducing marginal microleakage. The aim of the study was to assess the effect of a selected desensitizing agent occluding dentin tubules with calcium hydroxyapatite on marginal microleakage formation of a class V composite restorations subjected to thermocycles. MATERIALS AND METHODS: In study it was used 40 molars and premolars, which were alternately assigned into two groups. In both groups standardized cavities were prepared. In the study group (study group - SG) before application of bonding agent Teethmate Desensitizer (f. Kuraray, Noritake Dental Inc., Okayama, Japan) was used. In the control group (control group - CG) OptiBond All-in-one (f. Kerr, Bioggio, Switzerland) bonding agent was used and cavities were filled using composite material Gradia Direct (f. GC Europe N.V., Leuven, Belgium). After storage in saline, teeth were subjected to 600 thermocycles, passive dye penetration test was done, teeth were cut in the area of filling, according to its long axis. Under light microscope magnification value of microleakage was measured and marginal microleakage rate (M) was counted. The results of the tests were statistically analyzed using the package STATISTICA 12.0 (StatSoft, USA). RESULTS: The average value of M for the SG group was 0.46 (min 0.05, max 0.76, SD 0.226) and for CG was 0.22 (min 0, max 0.74, SD 0.235). The differences between M values were statistically significant (p = 0.0094). CONCLUSION: A reduction in the number of retention sites for the bonding system, facilitates the formation of microleakage in the experimental conditions and reduces the degree of adhesion of the composite material to the hard tissues of the tooth.

Microfiltración coronal según materiales de restauración temporal empleados en endodoncia / Coronal microleakage according to the temporary restorative materials used in endodontic treatment

RESUMEN Introducción: La microfiltración coronal causada por los materiales de restauración temporal es considerada una de las causas del fracaso de los tratamientos endodónticos. A raíz de ello, en los últimos años se ha buscado crear un material de restauración temporal que sea capaz de evitar este problema. Objetivo: Comparar in vitro la microfiltración coronal de un cemento experimental y cuatro materiales de restauración temporal usados en endodoncia. Métodos: Se realizaron cavidades clase I en 90 premolares, divididos en 10 grupos (n= 9) y evaluados en dos periodos de tiempo (1 y 2 semanas). Se realizó la elaboración del cemento experimental, posteriormente se llevó a cabo el sellado coronal de las piezas dentales con el cemento experimental, Clip F (VOCO), Eugenato (MOYCO), Ketac™ Molar Easymix 3M (ESPE) y Coltosol® F. Los especímenes fueron sumergidos en tinta china (Pelikan) durante 1 y 2 semanas. Se evaluó la microfiltración en la interfase pared dentinaria-restauración temporal utilizando un esteromicroscopio (Leica Microsystems LAS EZ versión 2.0.0). La medición se realizó en milímetros en el programa LAS EZ versión 2.0.0. Resultados: Se encontró diferencias estadísticamente significativas (p < 0,05) al comparar la microfiltración coronal de los cinco materiales de restauración temporal, según el tiempo de exposición en tinta (1 y 2 semanas). Conclusiones: El cemento experimental presentó menor microfiltración que el Coltosol® F y Ketac™ Molar EasyMix 3M (ESPE); sin embargo, ninguno de los cuatro materiales fue capaz de prevenir la microfiltración en su totalidad(AU)

ABSTRACT Introduction: Coronal microleakage caused by temporary restorative materials is viewed as one of the reasons for endodontic failure. Efforts have been made in recent years to create a temporary restorative material capable of preventing that problem. Objective: Compare in vitro coronal microleakage of an "experimental cement" and four temporary restorative materials used in endodontics. Methods: Class I cavities were made in 90 premolar teeth divided into 10 groups (n= 9) and evaluated at two time periods (1 and 2 weeks). The "experimental cement" was prepared and then coronal sealing of the teeth was performed with the experimental Cement, F (VOCO), Eugenato (MOYCO), Ketac™ Molar Easymix 3M (ESPE) and Coltosol® F. The pieces were submerged in India ink (Pelikan)for 1 and 2 weeks. Microleakage was evaluated on the interface dentin wall / temporary restoration using a stereo microscope (Leica Microsystems LAS EZ version 2.0.0). Measurement was made in millimeters using the software LAS EZ version 2.0.0. Results: Statistically significant differences were found (p < 0.05) when comparing coronal microleakage in the five temporary restorative materials according to exposure time in ink (1 and 2 weeks). Conclusions: The experimental cement had less microleakage than Coltosol® F and Ketac™ Molar EasyMix 3M (ESPE). However, none of the four materials was capable of completely preventing microleakage(AU)

Influence of Cavity Dimensions on Microleakage of Two Bulk-Fill Composite Resins

Objective: To evaluate the effect of cavity dimensions on the amount of microleakage in two different types of bulk-fill composite resins. Material and Methods: Forty class II cavities were prepared in the mesial and distal surfaces of human molars without any carious lesions. The samples were divided into 4 groups (n=10): Group 1: cavities with 3 mm of buccolingual width (known as the smaller cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 2: cavities with 6 mm of buccolingual width (larger cavity), filled with Tetric N-Ceram Bulk Fill composite resin; Group 3: cavities with 3 mm of buccolingual width, filled with X-Tra Base composite resin; and Group 4: cavities with 6 mm of buccolingual width, filled with X-Tra Base composite. After the specimens were thermocycled for 500 cycles at 5/55°C, they were immersed in 1% methylene blue for 24 hours, and then cut into sections mesiodistally in the longitudinal axis of each tooth. Then, the samples were scored regarding the amount of dye penetration in two occlusal and gingival areas under a stereomicroscope (x32). Data was submitted to Kruskal- Wallis and Mann-Whitney tests. Results: The highest degrees of microleakage in larger cavities filled with X-Tra Base among the four groups. There was a significant statistic difference (p=0.012) between large and small cavities filled with X-Tra Base (Groups 3 and 4); however, there was no significant difference between the two cavity sizes of Tetric N-Ceram Bulk-filled groups. Conclusion: Microleakage of composite resins depends on the dimension of the cavity and the type of composite resin used.

Coronal Microleakage of Teeth Restored with Cast Posts and Cores Cemented with Four Different Luting Agents after Thermocycling.

PURPOSE: The apical seal provided by a root canal filling may be breached via coronal leakage. This study aimed to compare the teeth restored with custom-made cast metal posts and cores cemented with different luting agents in terms of coronal microleakage after thermocycling. MATERIALS AND METHODS: This in vitro study was conducted on 32 extracted single-canal teeth. Root canals were prepared by step-back technique and filled with gutta percha and sealer. The coronal 7 mm of gutta percha was removed, and post space was prepared using peeso reamers #2 and #3 consecutively. After fabricating the acrylic resin patterns of the posts and cores, they were cast using Ni-Cr metal alloy. The specimens were divided into 4 groups in which the castings were cemented using one of the following luting agents: zinc phosphate (ZP), glass ionomer (GI), Panavia F 2.0, and Speed CEM. After cementation, the teeth were immersed in distilled water and incubated for 7 days. Then, the teeth were subjected to thermocycling, immersed in silver nitrate for 6 hours, and finally sectioned. The degree of dye penetration into the coronal part of the specimens was measured using a stereomicroscope. Data were analyzed using Kruskal-Wallis and Mann-Whitey U tests with significance level of 0.05. RESULTS: The median microleakage in ZP, Speed CEM, GI, and Panavia were 171.89, 114.76, 26.51, and 20.02 µm, respectively. Pairwise comparisons among GI and ZP, GI, and Speed CEM, ZP and Panavia, ZP and Speed CEM, and Panavia and Speed CEM groups yielded significant differences (p < 0.05). CONCLUSION: Complete coronal seal was not achieved with any of the luting agents. The highest and the lowest degree of microleakage was yielded by ZP and Panavia luting agents, respectively.

Evaluating the microleakage between dentin and composite materials.

BACKGROUND: For successful restoration, it is necessary to minimize the microleakage between dentin and the composite material. OBJECTIVES: The purpose of this study was to evaluate the microleakage of 2 different resin cements (self-adhesive and conventional) on dentin treated with acid, sodium hypochlorite (NaOCl), the acid-NaOCl mixture, the erbium-doped yttrium aluminum garnet (Er:YAG) laser, and their combination. MATERIAL AND METHODS: Seventy dentin specimens were divided into 7 groups (n = 10) according to the surface treatment. Then, the specimens were divided into 2 subgroups (n = 35) according to the resin cement used during cementation with prepared composite resin blocks 5 mm × 11 mm × 3 mm: self-adhesive resin cement or conventional resin cement. Microleakage was scored and recorded at the occlusal and gingival levels, along the resin-dentin interfaces. The data was analyzed with the use of univariate analysis of variance (two-way ANOVA) and the Kruskal-Wallis test for both resin subgroups. RESULTS: The obtained results revealed that self-adhesive resin cement and conventional resin cement showed similar microleakage. Etching with sodium hypochlorite, the Er:YAG laser, the acid-NaOCl mixture, and their combination resulted in microleakage comparable to that achieved in acid etching, which is the conventional method of surface treatment. CONCLUSIONS: Microleakage exhibited by self-adhesive resin cement was similar as in the case of conventional resin cement.

Evaluation of marginal leakage after mechanical fatigue cycling of composite inlays luted with different cements.

This in vitro study evaluated the marginal microleakage of composite inlays luted with 3 different cement systems. The null hypothesis was that the luting materials would not influence dye penetration, showing the same degree of microleakage. Thirty-six sound molars were selected, mesio-occlusodistal cavities were prepared, and the teeth were randomly divided into 3 groups (n = 12). Composite resin inlay restorations were made and cemented using a dual-curing resin cement (Calibra), a light-curing flowable composite (Charisma Flow), or a self-adhesive resin cement (RelyX Unicem). The restored teeth were subjected to fatigue cycles and immersed in 0.5% basic fuchsin dye for 24 hours. Two orthogonal cuts were made to enable evaluation of dye penetration at the cervical and occlusal margins. The sections were evaluated with a 4-point scale ranging from 0 (no penetration) to 3 (penetration up to the cavity floor [occlusal margins] or axial wall [cervical margins]). The Calibra and Charisma Flow groups showed greater microleakage, notably at the cervical margins, whereas RelyX Unicem specimens showed the least dye penetration. Significant differences were found between the Calibra and Charisma Flow groups and between the Charisma Flow and RelyX Unicem groups (P < 0.05). No statistically significant differences were detected between the Calibra and RelyX Unicem groups. The microleakage associated with the flowable composite was significantly greater than that associated with both resin cements, results that discourage its use for luting of Class II composite inlays.

Assessment of Shear Bond Strength and Marginal Sealing Ability of Pit and Fissure Sealants: An in vitro Study.

AIM: The aim of the present study was to compare the shear bond strength and marginal sealing ability of self-adhering flow-able composite and conventional fissure sealant. MATERIALS AND METHODS: The samples consisted of 30 healthy premolar teeth which were extracted due to orthodontic reasons and randomly divided into two groups of 15, i.e., group I (Fissurit F) and group II (Dyad Flow). Shear bond strength and marginal sealing ability of both the groups were evaluated in Statistical Package for the Social Sciences (SPSS) version 16. RESULTS: The mean shear bond strength of Dyad Flow (group II) was found to be 1.4 ± 0.87 MPa and in Fissurit F (group I), it was 1.3 ± 1.4 MPa. Differences between the groups were statistically significant. In group II, 53.3% of specimens demonstrated score 0; 33.3% showed score 1; and 13.3% showed score 2. In group I, scores 0 and 1 showed 33.3% of dye penetration respectively. Scores 2 and 3 demonstrated 26.6 and 6.6% of dye penetration respectively. But there was no significant difference between both the sealant groups. CONCLUSION: The present study concluded that self-adhering flowable composite was found to have better shear bond strength and marginal sealing ability than conventional fissure sealant. CLINICAL SIGNIFICANCE: Self-adhering flowable composite can be effectively used in pediatric patients in whom isolation is difficult and exclusion of bonding agent leads to decrease in time consumption.

Evaluation of the marginal integrity of a bioactive restorative material.

This in vitro study evaluated the marginal microleakage of a bioactive restorative with other restorative materials in standard Class V preparations. Sixty previously extracted, noncarious human molars were randomly assigned to 3 experimental groups (n = 20): a bioactive composite resin, a universal hybrid composite resin, and a resin-modified glass ionomer restorative. Class V cavities were prepared on the facial or lingual surface of each tooth so that coronal margins were located in enamel and apical margins in cementum (dentin). After the cavity preparations were restored with the appropriate material, the specimens were artificially aged in water baths. The root apices were sealed with utility wax, the tooth surfaces were coated with nail varnish to within 1 mm of the restoration, and specimens were immersed in 1% methylene dye solution for 8 hours. The teeth were invested in clear polymer resin, sectioned longitudinally, and examined under a stereomicroscope to assess dye penetration. Nonparametric scores indicated that microleakage was significantly greater at the apical margins than the coronal margins for all groups (P > 0.0001). The specimens restored with the bioactive material exhibited greater microleakage at both the coronal and apical margins than did specimens restored with the composite resin or resin-modified glass ionomer material, although the differences were not statistically significant (P > 0.05). Based on the results of the present study, the type of restorative material did not appear to have a significant influence on microleakage. Rather, the marginal position (coronal versus apical) of the restoration was the determining factor in microleakage.

Effect of Er,Cr:YSGG Laser and Ascorbic Acid on the Bond Strength and Microleakage of Bleached Enamel Surface.

BACKGROUND: The available evidence of Er,Cr:YSGG lasers on bleached enamel is limited and controversial. It is assumed that Er,Cr:YSGG laser will be effective in reversing the effect of bleaching on adhesive bond integrity of enamel to resin composite. OBJECTIVE: The study aimed to evaluate the efficacy of Er,Cr:YSGG laser on bond strength and microleakage of bleached enamel. MATERIALS AND METHODS: From the 80 samples, 60 samples were bleached (40% hydrogen peroxide) and divided into three subgroups. Twenty bleached samples in each subgroup were exposed to 10% sodium ascorbate (Gp A), Er,Cr:YSGG laser (50 Hz and 4.5 W) (Gp L), and no treatment (Gp B), respectively. Twenty samples were not bleached (Control-C). Using etch and rinse technique, resin composite was built-up on enamel and photopolymerized. Ten specimens in each group were tested for shear bond strength at a crosshead speed of 1 mm/min. Ten specimens in each group were tested for microleakage using 2% methylene blue. Data were analyzed using analysis of variance (ANOVA) and Tukey post hoc multiple comparisons test. RESULTS: The mean bond strength of specimens in group L (30.83 ± 1.7000) was comparable with group A (31.38 ± 2.03) and was significantly higher than bleached specimens (9.49 ± 0.86) (p < 0.001). The highest mean microleakage values were observed in bleached group (630.32 ± 156.58). The mean microleakage among control (36.66 ± 27.33) and laser group specimens (55.32 ± 34.98) was comparable (p > 0.05). CONCLUSIONS: Treatment of bleached enamel with erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser showed a significant reversal effect on the enamel bond strength and microleakage scores. CLINICAL SIGNIFICANCE: Er,Cr:YSGG laser (50 Hz, 4.5 W) treatment has the potential to restore the bond strength of bleached enamel to resin composite.

Effect of At-home and In-office Bleaching on Marginal Microleakage in Composite Resin Restorations using Two Adhesive Systems.

AIM: The aim of this study is to assess marginal microleakage of cervical cavities restored with composite resins and two different adhesive techniques subjected to at-home and in-office bleaching. MATERIALS AND METHODS: In this randomized, blind laboratory experiment, 60 bovine teeth recently extracted were collected and divided into six groups (n = 10 each group). The teeth received cervical cavity preparations (2 mm × 3 mm × 1 mm) with enamel margins. Two different adhesive systems were used (Single Bond 2 and Clearfil SE Bond), in addition to composite resin (Z250). Restored teeth received two different bleaching gels (Opalescence PF and Opalescence Boost). Teeth were thermo-cycled and analyzed under confocal laser scanning microscopy. RESULTS: No significant differences were observed (p > 0.05) in microleakage scores between the two groups not subjected to bleaching nor between the four groups that received bleaching treatment (p > 0.05), regardless of the gel and adhesive system employed. However, when comparing nonbleached with bleached teeth, those not subjected to bleaching showed statistically lower marginal microleakage scores (p < 0.05). Data were statistically analyzed using the Kruskal-Wallis test followed by Student-Newman-Keuls post hoc test, with significance set at 5%. CONCLUSION: Marginal microleakage in composite resin restorations is influenced by the action of bleaching agents used both at-home and in-office, regardless of the adhesive system employed (total-etch or self-etch). CLINICAL SIGNIFICANCE: Both at-home and in-office bleaching agents have an influence on the adhesive interface of resin restorations, producing changes and inducing marginal leakage.

Microleakage of Different Adhesive Systems in Primary Molars Prepared by Er: YAG Laser or bur.

BACKGROUND AND AIM: This study aimed to examine the microleakage of class V cavities of primary molars prepared by either a conventional dental bur or Er:YAG laser and one of two different adhesive systems. METHODS: A total of 50 tooth samples from primary molars were used in this study. They were randomly assigned into five experimental groups of 10 samples each, according to the cavity preparation technique and the type of adhesive system applied to the cavities. Following cavity preparation, etching, bonding, and filling steps, samples were dyed using basic fuchsine and were sectioned longitudinally in buccolingual direction. Percentages of dye penetration at gingival and occlusal margins were calculated for each group. RESULTS: Overall, microleakage scores of gingival margins were significantly higher than those of occlusal margins (P < 0.001). The group that underwent laser preparation, laser etch, and self-etch bonding procedures had worse microleakage scores for gingival margins. However, all groups had similar occlusal scores (P > 0.05). CONCLUSION: Self-etch bonding systems and cavity preparation with Er:YAG laser may be an alternative to conventional restoration of primary molars with compomers. Further studies are warranted to fully elucidate the effect of laser-based etching techniques in cavities prepared by laser.

Effect of erosive challenges on deciduous teeth undergoing restorative procedures with different adhesive protocols - an in vitro study.

To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 µm, 50 µm, and 100 µm from the eroded surface and at 25 µm, 75 µm, and 125 µm from the enamel bond interface. Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).

Gingival microleakage of class II bulk-fill composite resin restorations.

BACKGROUND: Bulk-fill composites were developed to simplify composite placement and minimize polymerization shrinkage stresses, which can improve gingival marginal adaptation in deep class II cavities. OBJECTIVES: The objective of this study was to compare the gingival microleakage of class II cavities restored with bulk-fill composites to that of incrementally restored ones with a conventional composite at 2 storage periods. MATERIAL AND METHODS: Forty freshly extracted intact molars were employed. Two standardized class II slot cavities, 3-millimeter-wide buccolingually, with the gingival floor 0.5 mm below the cementoenamel junction (CEJ) and the axial wall depth of 1.3 mm were prepared in each tooth (80 cavity preparations). The prepared teeth were divided equally into 3 bulk-fill groups (Tetric EvoCeram® Bulk Fill, X-tra Fil® and QuiXX®) and 1 control group (TPH Spectra® HV). Each group was subdivided into 2 equal subgroups (n = 10) according to the storage period in distilled water (24 h and 6 months). The Adper® Single Bond Plus adhesive was used with all the restorative materials. The cavities in the experimental groups were restored with 4-millimeter bulk-fill composites in 1 increment, while the cavities in the control group were restored with 2 increments of the thickness of 2 mm. The polymerization light was applied from the occlusal surfaces. The teeth were then immersed in 2% procion red dye solution, sectioned and examined under a stereomicroscope to determine the extent of dye penetration. The data was statistically analyzed using the Kruskal-Wallis test and the Mann-Whitney U test. RESULTS: The Kruskal-Wallis test revealed no significant differences in the mean microleakage scores among all the groups after 24-hour and 6-month storage (p = 0.945 and p = 0.928, respectively). The Mann-Whitney U test revealed an increase in the mean microleakage scores in all the groups after 6-month storage; however, the scores were not significantly different from the means obtained after 24 h (p = 0.259 for Tetric EvoCeram Bulk Fill; p = 0.205 for X-tra Fil; p = 0.166 for QuiXX; p = 0.155 for TPH Spectra HV). CONCLUSIONS: Gingival microleakage of bulk-fill composites in class II cavities was not significantly different from that of incrementally restored ones with a conventional composite. The increase in the mean gingival microleakage of the specimens stored for 6 months was not statistically significantly different in comparison to the values obtained after the 24-hour storage period for each composite.

Effect of erosive challenges on deciduous teeth undergoing restorative procedures with different adhesive protocols - an in vitro study

ABSTRACT Objective: To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Material and Methods: Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 μm, 50 μm, and 100 μm from the eroded surface and at 25 μm, 75 μm, and 125 μm from the enamel bond interface. Results: Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). Conclusions: We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).

Comparison of Microleakage of Class V Cavities restored with the Embrace WetBond Class V Composite Resin and Conventional Opallis Composite Resin.

PURPOSE: This study was undertaken to compare the micro-leakage of class V cavities restored with the newly introduced Embrace WetBond class V (EWC) composite resin and conventional Opallis composite resin. MATERIALS AND METHODS: In this in vitro study, class V cavities were prepared on 30 extracted bovine incisors, with the gingival floor and the coronal margin of the cavities 1 mm apical and coronal to the cementoenamel junction (CEJ) respectively. The cavities measured 3 mm in length, 2 mm in width, and 1.5 mm in depth. The teeth were randomly divided into two groups. In group I, the cavities were restored with Opallis composite resin in association with ExciTE adhesive system (total-etch); in group II, the EWC composite resin was used for restorations. After 500 thermocycling procedures, the teeth were immersed in 0.5% fuchsin solution for 24 hours. Then, the samples were placed within a polyester model and sectioned in the buccolingual direction. The samples were evaluated under a stereomicroscope at ×30 for the penetration of dye. The enamel and dentin margins were evaluated separately. To test ordinal results, we used nonparametric statistical methods. To find out whether each independent composite groups I and II came from the same populations, we used Mann-Whitney U test and to compare two related samples' coronal margin and gingival margin, Wilcoxon signed-rank test was used. RESULTS: There was significantly more microleakage in group II at both the enamel and dentin margins (coronal margin: p = 0.04; gingival margin: p = 0.21). In both groups, microleakage at gingival margins was significantly higher than that at coronal margins (group I: p = 0.008; group II: p = 0.26). CONCLUSION: Despite the high speed and the short process of restoration with Embrace WetBond, it is not a reliable restorative material for class V cavities due to its inadequate marginal seal.

Evaluation of the Sealing Capability of the Internal Conical Connections of Implants with Titanium and Zirconia Abutments.

AIM: The purpose of this in vitro investigation was to evaluate the sealing capability of the conical implant-abutment interfaces under different abutment screw torque values using titanium and zirconia abutments with Morse taper designs. MATERIALS AND METHODS: A total of 42 dental implants (n = 21 for titanium abutments and n = 21 for zirconia abutments) were inoculated internally with three bacteria. These assemblies were divided into four test groups (n = 10) based on screw fixation torques of 35 or 20 Ncm and placed in sterile broth; the remaining abutments were used as positive controls and torqued to 10 Ncm. Microleakage was quantified by enumerating the bacteria from the colony-forming units. An analysis of variance for the estimates of bacteria enumerated and microgaps was used with a post hoc analysis as indicated. A p-value of 0.05 was used as the level of significance. RESULTS: There was no statistically significant difference in microleakage among the four test groups; there were no significant effects of screw torque or abutment type on the bacteria enumerated. There was a significantly smaller mean microgap with the zirconia abutments. CONCLUSION: The results of this study indicated no statistically significant difference in the sealing capabilities between titanium and zirconia abutments, having internal conical connections, after increasing the abutment screw torque. CLINICAL SIGNIFICANCE: It is important for clinicians to follow the guidelines suggested by the implant companies to avoid biomechanical complications over time.