Marginal Microleakage Of Class Research Articles

Evaluation of Marginal Microleakage in Class II Composite Restorations Using Open Sandwich and Snowplow Techniques

Introduction: Adaptation of posterior composites to dental walls has been questioned for various reasons and polymerization shrinkage is one example. Thus, the present study investigated microleakage ocurring from different class II composite restorations techniques.
 Materials and Methods: In this in-vitro study class II cavities with cervical margins 1 mm below the CEJ (Cementoenamel junction) were prepared in 64 extracted human premolars. The teeth were randomly divided into two groups. Group 1 (open sandwich): Glass ionomer was injected on the floor of the cavity and the rest of the cavity was restored using composite resin using incremental technique. Group 2 (Snowplow) one layer of flowable composite was placed in the bottom of the cavity and was co-cured with the first layer of composite resin. The rest of the cavity was restored the same as group 1. To evaluate the microleakage, the specimens were thermocycled for up to 3000 cycles and immersed in 1% methylene blue solution for 72 hours. Then they were sectioned mesiodistally and evaluated under a stereomicroscope. Data were analyzed via Mann-Whitney and Fishers exact test and p value < 0.05 was considered significant.
 Results: The mean value for microleakage in group 1 (795.74 ± 494.04 mμ) was lower than group 2 (972.99 ± 457.8 mμ), but the results were not statistically significant (p value = 0.117).
 Conclusion: It appears that microleakage in both open sandwich technique and Snowplow technique did not portray statistical significance, so both of them can be used.

Microleakage in class II restorations of two bulk fill resin composites and a conventional nanohybrid resin composite: an in vitro study at 10,000 thermocycles

BackgroundThe contraction presented by resin composites causes an increase in stress at the tooth-resin interface, causing micro-gaps that allow microleakage. This study aims to evaluate the degree of in vitro marginal microleakage in class II restorations with two bulk fill resin composites compared to a conventional nanohybrid resin composite.MethodsThe present study was an in vitro experimental design. A total of 30 standardized class II cavities were prepared in 15 human molars (mesially and distally). These cavities were later distributed in 3 groups according to the type of resin. Groups A and B were restored with bulk fill resin composites (Filtek—3 M/ESPE and Tetric N-Ceram—Ivoclar/Vivadent respectively) in a single increment of 4 mm. Group C was restored with the Filtek Z350 XT – 3 M/ESPE resin composite and two increments of 2 mm. Later, the restorations were subjected to 10,000 thermocycles between 5 °C to 55 °C and immersed in a silver nitrate solution (1 M for 24 h). The crowns were then sectioned mesiodistally and observed under the stereomicroscope to determine the degree of marginal microleakage at the occlusal and cervical areas. The results were analyzed with the Kruskal–Wallis and the Mann–Whitney U statistical tests.ResultsThere were no statistically significant differences regarding the degree of microleakage between the three types of resin composites in the occlusal and cervical areas (p > 0.05). Similarly, there were no significant differences after comparing each resin type in its occlusal and cervical area (p > 0.05).ConclusionFiltek Bulk Fill and Tetric N-Ceram Bulk Fill resin composites showed no statistically significant differences with the conventional nanohybrid resin composite Filtek Z350XT at both occlusal and cervical areas.

Influence of laser deproteinization of acid-etched dentin on marginal microleakage of class V composite restoration

Aim: Recent reports indicate that deproteinization of acid-etched dentin surface can extend penetration depth of adhesive agents. The main goal of the present research was to investigate the deproteinization effect of Nd:YAG and diode 940 lasers on acid-etched dentin and microleakage grade in class V composite restorations. Methods: 36 extracted human premolar teeth were selected to make standard buccal and lingual class V cavities. These samples were randomly split into three sub-groups: 1.Control group, in which composite was applied for restoration after etch and bonding process without deproteinization; 2.Nd:YAG laser group, in which the teeth were deproteinized with Nd:YAG laser after etching and painting internal surfaces of cavities with Van Geison stain and then composite restorations applied just as control group; 3.Diode laser group, in which the process was similar to Nd:YAG laser group, but instead, diode 940 laser was irradiated. The teeth were bisected into two equal longitudinal buccal and lingual halves. Marginal microleakage of samples was scored by using a stereomicroscope. Kruskal- Wallis, Mann-Whitney U and Fisher’s statistical tests were employed for analysis of the obtained data. Results: A significant reduction in marginal microleakage was observed for both groups treated with laser (Nd:YAG and diode 940)compared to control (p=0.001 & p=0.047). There was no significant difference in marginal microleakage between Nd:YAG laser and diode 940groups (P = 0.333). Conclusion: Nd:YAG and diode 940 laser deproteinization of acid-etched dentin decreased the marginal microleakage of in-vitro class V resin composite restorations.

Comparing marginal microleakage in Class V cavities restored with flowable composite and Cention-N using confocal microscope-an in-vitro study.

Class V cavity presents a clinical challenge in the field of restorative dentistry as the margin placement is partially in enamel and partly in cementum, and the trouble associated with this design is the microleakage at the tooth restoration interface. To evaluate and compare marginal microleakage in Class V cavities when restored with flowable composite and Cention-N restorative material. This in-vitro study was performed on 30 human maxillary premolars, which were extracted for orthodontic reasons. Class V cavities were prepared on the buccal surfaces of each tooth. After application of seventh-generation bonding agent (3M ESPE, Single Bond Universal Adhesive), the teeth were divided into two groups of 15 each and restored with flowable composite (3M ESPE Filtek Z350 XT) and Cention-N (Ivoclar Vivadent) and were subjected to thermocycling. The teeth were then immersed in 0.1% Rhodamine B dye for 48 h. They were sectioned longitudinally into mesial and distal parts with the help of an isomet diamond saw. The sections were observed under a confocal laser scanning microscope (CLSM). The results were subjected to statistical analysis using the Mann-Whitney U test and Pearson's Chi-square test. The analysis showed statistically significant results among the groups. Cention-N showed lesser microleakage, which was statistically significant when compared to flowable composite (P = 0.005). Cention-N showed significantly lesser leakage and better adaptation than flowable composite.

Estimation of the Gingival microleakage of Two Composite Resins with Three Insertion Techniques for Class V Restorations (In-Vitro Comparative Study)

Objective: Evaluating the marginal microleakage of two different composite resins with three different restorative techniques in class V cavities with the cervical margins within the cementoenamel junction. 
 Methods: Sixty standardized box-shaped class V cavities of 2×2×3 mm (depth, length, width) prepared on the buccal and lingual surfaces of 30 freshly extracted healthy human premolars. The teeth randomly divided into two equal groups: group A (FiltekTM Z250 XT) and group B (BeautifilTM II LS giomer). Then each group is subdivided into 3 equal subgroups: group I (bulk technique-10 cavities), group II ( split horizontal technique-10 cavities) and group III (vertical technique-10 cavities) and filled according to the manufacturer’s instructions. The samples were subjected to thermocycling (5°C ±2°C & 55°C ±2°C with a 30 seconds dwell time) and immersed in 2% buffered Methylene blue solution at 37°C for 24 hours. The restorations were sectioned longitudinally in buccolingual direction through the centers of the restoration. Then evaluated for microleakage using a stereomicroscope at 10x magnification and scored as 0, 1, 2, and 3. Non-parametric Mann-Whitney and Kruskal-Wallis tests were used and p value ≤ 0.05 considred statistically significant.
 Results: Split increment horizontal layering technique showed statistically significant lower microleakage than vertical layering and bulk technique. While giomer showed less microleakage than Z250 but statistically not significant.
 Conclusions: The use of split horizontal technique and giomer composite offers better and less marginal microleakage in class V restorations.

Effect of Trypsin/EDTA Conditioning on Marginal Microleakage of Class V Composite Restorations Bonded With a One-Step Selfetch Adhesive

Background: Sodium hypochlorite and EDTA solutions are used in the preparation of dentin surfaces, which may increase the bond strength of the composite restorations and decrease their microleakage scores. This in-vitro experimental study aimed to assess the effect of dentin surface conditioning with EDTA/trypsin solution prior to bonding procedure with Clearfil S3 Bond on the microleakage of class V composite restorations. Methods: Class V cavities were prepared on the buccal and lingual surfaces of 18 human premolars (n=18) and randomly assigned into two groups. In the control group, Clearfil S3 Bond was applied on the dentin surfaces. While in the experimental group, before applying Clearfil S3 Bond, the surfaces were conditioned with EDTA/trypsin solution. The cavities on the teeth were then incrementally filled with Filtek Z250 light-cure composite. Afterward, all the samples were thermocycled for 500 cycles. Next, the specimens were immersed in methylene blue solution for 72 hours. The restorations were sectioned buccolingually through the center of the restorations with a diamond disk. Then, microleakage at the tooth- restoration interface was evaluated in the enamel and dentin margins blindly using dye penetration under a stereomicroscope at ×40 magnification. Finally, data were statistically analyzed by Mann-Whitney U test. Results: The results showed no significant differences between two groups regarding the microleakage scores of the enamel and dentin edges. In addition, in all sections and edges of the experimental group, decreased microleakage scores were attained compared to the control specimens (P<0.03). Conclusions: Regarding the limitations of the present study, the preparation of dentin surfaces with EDTA/trypsin solution before applying Clearfil S3 Bond resulted in the decreased microleakage scores compared to unprepared surfaces.

Evaluation of Diode laser (940 nm) irradiation effect on microleakage in class V composite restoration before and after adhesive application

Introduction: Nowadays, the main focus of dental studies is on adhesive dental materials; since clinical long-term success of bonded restorations depended more on marginal microleakage minimization. So, the aim of this study was Evaluation of Diode laser irradiation effect on microleakage in class V composite restoration before and after adhesive application. Materials and methods: In this in vitro-experimental study, standard class V cavity was prepared on lingual and buccal surfaces of 60 premolar teeth. For evaluation of microleakage, 60 teeth were divided randomly into four groups A, B, C, D (n=15): A) primer + adhesive (Clearfil TM SE Bond), B) primer + Diode laser + adhesive (940nm wave-length, 21J total energy, 0.7W power, 30s irradiation time) C) primer + adhesive + Diode laser D) primer + Diode laser + adhesive + Diode laser. Then, restoration was completed by Z250 composite. For data analyzing, we used SPSS 16 software. For statistical analysis, we used Non-parametric Kruskal-Wallis & Mann-Whitney tests at 0.05% significance level. Results: According to non-parametric Kruskal-Wallis test, microleakage scores had not significant difference before and after laser irradiation on gingival margins (p=0.116). But, in occlusal margins the results were significant among the groups (p=0.015). Also according to non-parametric Mann-Whitney tests among the occlusal microleakage scores, group B and D (Diode laser irradiation after primer and Diode laser irradiation after primer and adhesive) showed significant results. Conclusion: This study findings showed that in 6th generation adhesives, Diode laser irradiation on self-etch primer before bonding have significant effect on reduction of occlusal marginal microleakage in class V cavities although there was no significant positive effect of Diode laser on gingival margins.

Effect of Proteolytic Agents on Microleakage of Etch and Rinse Adhesive Systems

Objective: this study aimed to assess the effect of treatment of phosphoric acid etched dentin surface with 5% bromelain enzyme and Nd:YAG laser prior to the use of etch and rinse adhesive systems on microleakage margins of class V composite restorations. Materials and Methods: sixty sound premolar teeth were selected. Standard class V cavities were prepared in the buccal and lingual surfaces of each teeth. Preparation in that way 1 mm of the cavity was above and 1 mm of it was below the cementoenamel junction. The teeth were then randomly divided into three groups including 20 teeth(40cavities in each gorup). Two ethanol base etch and rinse system (Adper Single Bond and OptiBond Solo) was applied in each group. In the control group, cavities were etched with 37% phosphoric acid. Adper Single Bond was applied to 20 and OptiBond Solo was applied to the remaining 20 cavities and they were restored with Z250 composite (n=40). The same procedures were performed in bromelain and Nd:YAG laser groups with the difference that prior to the application of adhesive, aqueous 5% bromelain was applied in bromelain group while Nd:YAG laser was irradiated in laser group. All teeth were thermocycled and their apices were sealed with sticky wax. The tooth surfaces were coated with nail varnish except for 1 mm around the restoration margins, and the teeth were then immersed in fuchsine and sectioned by a diamond disc into mesial and distal halves. Marginal microleakage at both sides was determined and scored under a stereomicroscope at x40 magnification. Then data were analyzed using the Kruskal Wallis and Mann Whitney tests (α=0.05). Results: according the result of Mann Whitney test, Cervical margins showed significantly higher microleakage than the occlusal margins (P=0.000) but no significant difference was noted in microleakage of occlusal (P=0.362) or gingival (P=0.147) margins among the three groups by Kruskal Wallis test. Conclusion: in conclusion, application of proteolytic agents(5% bromelain solution and Nd:YAG laser) on acid-etched dentin surface prior to the application of adhesive has no significant effect on marginal microleakage of class V composite restorations.

Investigation of the Er: YAG laser and diamond bur cavity preparation on the marginal microleakage of Class V cavities restored with different flowable composites.

The purpose of this study was to evaluate the efficiency of the Er:YAG laser and diamond bur cavity preparation on the marginal microleakage of Class V cavities. Group 1: bur preparation (bp) + Vertise Flow (VF); Group 2: laser preparation (lp) + VF; Group 3: bp + Adper Easy One (AEO) + Filtek Ultimate Flowable Composite (FUFC); Group 4: lp + AEO + FUFC; Group 5: bp + Clearfil S3 Bond (CSB) + Clearfil Majesty Flow (CMF); Group 6: lp + CSB + CMF. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests (p < .05). More microleakage was observed in cervical regions compared to occlusal regions in all groups (p < .05). No significant difference was observed among all groups in terms of occlusal and cervical surfaces, respectively (p > .05). The use of the Er:YAG laser for cavity preparation with different adhesive systems and flowable composites did not influence microleakage.

Influence of Different Photoinitiators on Polymerization Kinetics and Marginal Microleakage in Restorations using Photopolymerizable Dental Composites

Objective: To evaluate the influence of four different photoinitiators on the polymerization kinetics and marginal microleakage in class V restorations using photopolymerizable dental composites. Material and Methods: Four photopolymerizable dental composites based on Bis-GMA (14.5 wt %), UDMA (6.5 wt %) and silanized filler particles (79 wt %) containing different photoinitiators were formulated. Camphorquinone (CQ)/amine, phenyl-propanedione (PPD), monoacylphosphine oxide (Lucirin ® TPO) and bisacylphosphine oxide (Irgacure ® 819) were used as photoinitiators. Sixteen intact human third molars were selected and divided into four groups. All teeth received class V cavity preparations in their buccal and lingual surfaces and were submitted to a dye leakage test. Data were independently analyzed for both enamel and dentin, and the results were assessed by a Kruskal-Walis test. The polymerization reactions of the four composites were evaluated by differential scanning calorimeter coupled with photocalorimeter accessory. Results: Lucirin ® TPO presented the highest scores for microleakage in enamel, whereas the other photoinitiators have not demonstrated statistical differences. The lowest scores were obtained for PPD in dentin while the highest scores have been achieved by Irgacure ® 819 and Lucirin ® TPO. Photocalorimetric measurements demonstrated a correlation between polymerization reaction rate and marginal leakage, showing that faster reactions cause greater marginal leakage. Conclusion : Marginal microleakage scores in photopolymerizable dental composites can be greatly influenced by different types of photoinitiators through their distinct reaction rates.

Comparison of total-etch, self-etch, and selective etching techniques on class V composite restorations prepared by Er:YAG laser and bur: a scanning electron microscopy study.

The purpose of this study was to compare total-etch, self-etch, and selective etching techniques on the marginal microleakage of Class V composite restorations prepared by Er:YAG laser and bur. Class V cavities prepared on both buccal and lingual surfaces of 30 premolars by Er:YAG laser or bur and divided into six groups. The occlusal margins were in enamel, and the cervical margins were in cementum. Group-1: bur preparation(bp)+Adper Single Bond 2 (ASB)+Filtek Z550 (FZ); Group-2: laser preparation(lp)+(ASB)+(FZ); Group-3: bp + Clearfil S3 Bond Plus (CSBP)+(FZ); Group-4: lp+(CSBP) (FZ); Group-5: bp + acid etching+(CSBP)+(FZ); Group-6: lp + acid etching+(CSBP)+(FZ). All teeth were stored in distilled water at 37°C for 24hr, and then thermocycled 1000 times (5-55°C). Five teeth from each group were chosen for the microleakage investigation, and two teeth for the scanning electron microscope evaluation. Teeth which were prepared for the microleakage test were immersed in .5% methylene blue dye for 24hr. After immersion, the teeth were sectioned and observed under a stereomicroscope for dye penetration. Data were analyzed using Kruskal-Wallis and Mann-Whitney U tests (p < .05). More microleakage was observed in the cervical regions compared to the occlusal regions in Groups 3, 5, and 6, respectively (p < .05). There is no statistically significant difference in Groups 1, 2, and 4, in terms of cervical regions versus occlusal regions (p > .05). No significant differences were observed among any groups in terms of occlusal and cervical surfaces, separately (p > .05). Different etching techniques did not influence microleakage of Class V restorations prepared by Er:YAG laser and bur.

Effect of different parameters of Er:YAG laser irradiations on class V composite restorations: A scanning electron microscopy study

The purpose of this study was to compare different parameters of Er:YAG laser irradiations on the marginal microleakage of Class V resin composite restorations. A total of 45 extracted premolars were selected for the study. Class V cavities prepared on both buccal and lingual surfaces of teeth by Er:YAG laser or bur and divided into nine groups. The occlusal margins were in enamel and the cervical margins were in cementum. Group-1: bur preparation; Group-2: laser preparation (lp) (600 mJ/5 Hz); Group-3: lp (300 mJ/10 Hz); Group-4: lp (200 mJ/15 Hz); Group-5: lp (150 mJ/20 Hz); Group-6: lp (200 mJ/20 Hz); Group-7: lp (300 mJ/14 Hz); Group-8: lp (400 mJ/10 Hz); Group-9: lp (700 mJ/5 Hz). All teeth were stored in distilled water at 37°C for 24 h, then thermocycled 1,000 times (5-55°C). Five teeth from each group were chosen for the microleakage investigation and two teeth for the scanning electron microscope (SEM) evaluation. Teeth, which were prepared for the microleakage test were immersed in 0.5% methylene blue dye for 24 h. After immersing, the teeth were sectioned and observed under a stereomicroscope for dye penetration. Data were analyzed by Kruskal-Wallis and Mann-Whitney U tests (p < 0.05). More microleakage was observed in cervical regions compared to occlusal regions in all groups (p < 0.05) except for Group 6 (p > 0.05). No significant difference was observed among groups in terms of occlusal and cervical surfaces, separately (p > 0.05). It may be concluded that the cavities prepared by Er:YAG laser showed higher degree of microleakage than bur prepared at cervical regions. Different parameters of Er:YAG laser irradiations affected microleakage. SCANNING 38:434-441, 2016. © 2016 Wiley Periodicals, Inc.

Marginal microleakage of class V resin-based composite restorations bonded with six one-step self-etch systems

This study compared the microleakage of class V restorations bonded with various one-step self-etching adhesives. Seventy class V resin-based composite restorations were prepared on the buccal and lingual surfaces of 35 premolars, by using: Clearfil S3 Bond, G-Bond, iBond, One Coat 7.0, OptiBond All-In-One, or Xeno IV. The Adper Single Bond etch-and-rinse two-step adhesive was employed as a control. Specimens were thermocycled for 500 cycles in separate water baths at 5°C and 55°C and loaded under 40 to 70 N for 50,000 cycles. Marginal microleakage was measured based on the penetration of a tracer agent. Although the control showed no microleakage at the enamel margins, there were no differences between groups (p = 0.06). None of the adhesives avoided microleakage at the dentin margins, and they displayed similar performances (p = 0.76). When both margins were compared, iBond® presented higher microleakage (p < 0.05) at the enamel margins (median, 1.00; Q3-Q1, 1.25-0.00) compared to the dentin margins (median, 0.00; Q3-Q1, 0.25-0.00). The study adhesives showed similar abilities to seal the margins of class V restorations, except for iBond®, which presented lower performance at the enamel margin.

Effect of light-curing units on gap formation and microleakage of class II composite restorations

Aim: This in vitro study evaluated gap width formation and marginal microleakage in Class II composite restorations light-cured with three different light-curing units. Methods: Standardized cavities in the proximal surfaces of 36 human third molars were made with margins located below the cementoenamel junction. Cavities were restored with Filtek P60 (3M ESPE), inserted with a photocondenser tip and light-cured with three different methods: GI - Optilux401 (halogen); GII – ColtoluxLED (LED) and GIII –UltraLumeLED5 (LED). After finishing the restorations, teeth were subjected to a thermal cycling regimen of 500 cycles (5o C ± 2o C and 55o C ± 2o C), totalizing 500 cycles. Thereafter, the teeth were sectioned in a buccolingual direction and in the center of the restorations. Half of the specimens (18) were used to evaluate marginal microleakage, by measuring of dye penetration in cross-sectioned specimens, and the other half was used to analyzed the gap formation width by SEM observations (1000X). Data were submitted to Kruskal-Wallis (α=0.05). Results: The mean values of gap width (µm) were: GI 3.28±3.34; GII 1.48±1.89 and GIII 3.11±3.45, and microleakage was not affected by the light-curing units. Conclusions: There were no differences between the light-curing methods in gap formation and marginal microleakage.

Effect of the erbium:yttrium-aluminum-garnet laser or diamond bur cavity preparation on the marginal microleakage of class V cavities restored with different adhesives and composite systems

The aim of this in vitro study was to compare the microleakage of Er:YAG laser and diamond bur on different bonding systems in class V restorations. Class V cavities were prepared with Er:YAG laser or diamond bur on 80 intact human molars. Teeth were randomly distributed into ten groups and cavities were restored with CeramX duo (DENTSPLY) or Filtek Silorane (3M/ESPE) using different bonding materials (One Coat 7.0 (Coltène), XP Bond (DENTSPLY), Clearfil Protect Bond (Kuraray), AdperSE (3M/ESPE), and Silorane System Adhesive (3M/ESPE). All specimens were subjected to thermocycling and load cycling. After being immersed in silver nitrate dye, the specimens were sectioned. Microleakage was evaluated by stereomicroscope and SEM. Data were statistically analyzed by one-way ANOVA, Kruskal-Wallis, and Mann-Whitney tests. Statistically differences were found between groups (p > 0.05) and cavities prepared with the Er:YAG laser showed higher microleakage than diamond bur. The microleakage of different bonding systems was influenced by the choice of diamond bur or Er:YAG laser for class V composite cavity preparation.

Effect of Four Different Placement Techniques on Marginal Microleakage in Class II Composite Restorations: An in vitro Study

ABSTRACT Background and objectives This study was undertaken to evaluate the effect of different placement techniques (bulk, oblique incremental, centripetal and split horizontal) on marginal microleakage in class II composite restoration. Method Standardized class II preparations were made in 40 caries-free extracted molars and randomly assigned to four groups (n = 10): (1) Bulk technique (2) oblique incremental insertion technique,(3) centripetal incremental insertion technique and (4) split horizontal incremental insertion. The teeth were restored with a total-etch adhesive and nanocomposite resin. The specimens were immersed in a solution of 2% methylene blue for 24 hours, and subsequently evaluated for leakage. The microleakage scores (0 to 4) obtained from the occlusal and cervical walls were analyzed with Kruskal-Wallis and Mann-Whitney tests (p &lt; 0.05). Results Microleakage scores indicated that incremental technique was better than bulk for composite placement and among incremental techniques split incremental technique showed best results. Conclusion Incremental placement technique showed lower microleakage compared to bulk, and lower microleakage was seen at occlusal margin compared to gingival margin. Split horizontal incremental technique showed the least microleakage scores among incremental techniques

Influence of varying light intensity on microleakage of Class II restorations

The purpose of this in vitro study was to evaluate the marginal microleakage of Class II restorations photo activated with varying light intensity. Class II preparations with gingival margins were made in 80 sound human third molars. The teeth were divided into 2 groups and restored with two different resin composites (P60 and Z100). Each group was further subdivided into four subgroups, which were submitted to distinct light intensity during the polymerization process. Groups 1A and 1B received a light intensity of 550 mW/cm2 in each of the three layers. Groups 2A and 2B received an exponential light intensity from 0 to 600 mW/cm2 in each layer. Groups 3A and 3B received 300 mW/cm2 in the first layer and 550 mW/cm2 in the other two layers. Groups 4A and 4B were submitted to a light intensity of 100 mW/cm2 for 10 seconds followed by 550 mW/cm2 for 30 seconds in each layer. The specimens were immersed in a 2% buffered aqueous solution of methylene blue for 2 hours. The penetration of the dye was then measured under a stereomicroscope with X20 magnification. Data were submitted to the Kruskall-Wallis test and results demonstrated no statistically significant differences between the groups when differentiated by the resin composites or the light intensity, at a p-value of 0.05. In conclusion, the variation in light intensity did not significantly affect the marginal microleakage of the resin composites tested.

Effect of Surface Sealants on Marginal Microleakage in Class V Resin Composite Restorations

Surface sealants may reduce or avoid problems related to the marginal interface. The aim of this study was to evaluate the microleakage in resin composite Class V restorations sealed with an adhesive system (Xeno III [Dentsply, Konstanz, Germany]), a sealant for exposed dentin (Seal & Protect [Dentsply]), and two surface sealants (Fortify [Bisco, Lombard, IL, USA]; Optiguard [Kerr, Orange, CA, USA]). Fifty cavities with margins in enamel were prepared on crowns of bovine teeth and restored with an adhesive system (Prime and Bond NT/Dentsply) and resin composite (Esthet X/Dentsply). They were separated into four groups for the application of the surface sealants, and a control group (without surface sealing). Thermal cycling with baths of 5 degrees C +/- 2 degrees C and 55 degrees C +/- 2 degrees C were performed in 600 cycles. The teeth were made impermeable, except for a 3-mm window around the restoration and immersed in a 50% silver nitrate solution for 8 hours. The crown was sectioned longitudinally and the cuts were analyzed by three independent evaluators, using a stereoscopic loupe with 10x magnification that attributed representative scores. Agreement among the examiners was evaluated by the Kappa test. The Kruskal-Wallis test and Dunn Method showed that there was significant difference between the Control and Seal & Protect groups. The Seal & Protect group presented the lowest degree of microleakage, followed by the Optiguard and Xeno III groups. The highest scores were obtained in the Control group. The sealant materials evaluated presented different rates of effectiveness, and Seal & Protect was the most effective in decreasing the degree of marginal microleakage. CLINICAL SIGNIFICANCE Although surface sealants or covering agents have been used to diminish microleakage, they may present different rates of effectiveness with regard to reducing the degree of marginal leakage. (J Esthet Restor Dent 21:397-406, 2009).

COMMENTARY. effect of surface sealants on marginal microleakage in class v resin composite restorations

COMMENTARY. <scp>effect of surface sealants on marginal microleakage in class v resin composite restorations</scp>

Marginal Microleakage in Class II Cavities Restored with Conventional and Resin- Modified Glass Ionomer Cements: a Comparative Study

Objetivo: Avaliar o grau de microinfiltracao em cavidades classe II preparadas em molares deciduos humanos, restauradas com dois cimentos de ionomero de vidro convencional (Maxxion R e Vidrion R) e dois resinosos (Vitremer e Vitro Fill LC). Metodo: Foram selecionados dezenove molares deciduos humanos a partir de um Banco de Dentes. Nas faces mesial e distal de cada dente foram preparadas, com brocas diamantadas cilindricas, cavidades classe II com dimensoes padronizadas. A seguir, as cavidades foram restauradas com dois cimentos de ionomero de vidro convencionais: Maxxion R (G1) e Vidrion R (G2); e dois cimentos de ionomero de vidro resinosos Vitremer (G3) e Vitro Fill LC (G4). Depois de restaurados, os dentes foram cobertos com dupla camada de esmalte (Colorama®), e, apos a secagem do mesmo, imersos em solucao de nitrato de prata a 50% por vinte e quatro horas. Em seguida, todos foram seccionados longitudinalmente atraves do centro das restauracoes e observados em lupa estereoscopica, sendo a microinfiltracao avaliada segundo criterio qualitativo baseado na atribuicao de escores. Resultados: Todos os materiais testados apresentaram graus variaveis de microinfiltracao, no entanto, o Vitremer (G3) apresentou os melhores resultados. Nao foram observadas diferencas estatisticamente significantes entre os seguintes materiais: MaxxionR (G1), Vidrion R (G2) e Vitro Fill LC (G4). Conclusao: Nenhum dos cimentos testados foi capaz de impedir completamente a microinfiltracao, no entanto, o Vitremer destacou-se por apresentar os menores escores de microinfiltracao, enquanto que os materiais Vidrion R, Maxxion R e Vitro Fill LC nao apresentaram diferencas estatisticamente significantes entre si.