Enamel Margins Research Articles

Effect of strong tooth-bleaching with 38% hydrogen peroxide on marginal seal of dental restorations using self-etch and total-etch adhesives.

The negative control or leakage-free group is very important when discussing the effects of bleaching on marginal seal or microleakage. Bleaching using 38% H2 O2 increases the microleakage distance and dye penetration area of cementum/dentin margin more than that of enamel margin. The bleached tooth is not a good substrate for reliable bonding and complete seal and it is also a channel for external stimuli reaching the pulp.

Flowable composites for restoration of non-carious cervical lesions: Results after five years

ObjectivesTo evaluate the clinical performance of two flowable composites for restoration of Class-V non-carious cervical lesions (NCCLs), one with novel (N’Durance® Dimer Flow, Septodont; ND) and one with modified conventional matrix composition (Filtek™ Supreme XTE Flow, 3M-ESPE; FS). The null hypothesis was that both flowable composite materials perform equally regarding clinical quality and survival. Methods50 patients received one ND and one FS restoration of NCCLs in premolars using Clearfil Protect Bond (Kuraray) as an adhesive without additional selective enamel etching. Restorations were evaluated at baseline (BL), after 30 and 60 months employing selected original FDI criteria and refined FDI criteria by separate evaluation of enamel and dentine margins. Non-parametric statistical analyses and χ2 tests were applied (α=0.05). Results38 patients with both restorations under risk were available for the 60-mo recall (recall rate: 76%). At 60-mo, 94.7% of ND and 84.2% of FS restorations were rated clinically acceptable. No significant differences for all selected FDI criteria were recorded between ND and FS at each examination time point except for the criteria surface lustre at 60-mo, where FS showed significantly better results. No significant differences over time could be detected for both materials. There was a trend for more deterioration along the enamel margins than along the dentine margins (criteria marginal staining and marginal adaptation). SignificanceWithin the limitations of the study, the null hypothesis that materials perform equally could not be rejected. Both flowable composites performed similarly regarding clinical performance.

SHEAR BOND STRENGTH AND INTERFACIAL MICROSCOPIC EXAMINATION OF TWO TYPES OF FLOWABLE RESIN-COMPOSITE TO ENAMEL SURFACE OF DECIDUOUS MOLARS

Aim: Evaluation of shear bond strength of a self-adhering flowable resin-composite versus total-etch one to enamel surface of deciduous molars. Interfaces between these restorations and primary enamel were also microscopically investigated. Materials and Methods: Twenty freshly extracted human deciduous molars were used. For the shear bond strength, twelve molars were embedded in acrylic blocks, such that their buccal surfaces were aligned with the acrylic. The enamel surfaces were subjected to minimal grinding. The teeth were randomly divided into two groups, Group I: Self-adhering flowable resin-composite (Dyad™-flow, Kerr, USA); Group II: Total-etch flowable resin-composite necessitate etching and bonding (Filtek™Z350-XT, 3M-ESPE, USA). A specially designed holed-split Teflon mold was used for constructing resin-composite cylinders (3x3mm) over the buccal surfaces of the mounted teeth. For group I, resin-composite was applied directly on teeth surfaces using the mold and light-cured for 20seconds. For group II, using the mold the following steps were performed: acid etching (15 seconds), 2) bonding agent (light-curing 20 seconds) and 3) resin-composite (light-curing 20 seconds). The teeth were stored in 37°C distillate water for 24 hours. The shear bond strength was recorded and statistically analyzed. Modes of failure were studied using digital microscope. For interfacial examination, cavities (class V) were prepared in buccal surface of eight teeth, filled by the two flowable composites as previous (n=4/group) and scanned using scanning electron microscope. For each group, two teeth were examined from buccal aspect, while the other two were sectioned and inspected.Results: Mean bond strength values for groups I and II were 5 and 21.6 MPa respectively with highly significant difference P=0.005 (P value ≤ 0.01). Modes of failure for groups I and II were [100%adhesive] and [16.7%cohesive within tooth + 83.33%mixed] respectively. SEM micrographs of group I revealed a gap at enamel-restoration interface, while group II showed cohesive failure within enamel at the margins. Conclusions: The bonding performance of the self-adhering resin-composite “Dyad™-flow” still needs further enhancement. Modifications may be required to prevent marginal enamel cracks with the use of Total-etch “Filtek™Z350-XT” flowable resin-composite.

Glass ionomer cement inhibits secondary caries in an in vitro biofilm model.

The objective of this study was to investigate the effect of different glass ionomer cements on secondary caries inhibition in a fully automated in vitro biofilm model. One hundred and twenty-four extracted third molars received class V cavities and were filled with one conventional (Ketac Molar/KM), and two resin-modified glass ionomer cements (Photac Fil/PF, Ketac N100/KN, 3M Espe). A bonded resin composite (Single Bond Plus/Filtek Supreme XTE) served as control. After 14days water storage at 37°C, specimens were thermocycled (10,000×5/55°C). Over a period of 10days, specimens were subjected to cariogenic challenge for 3/4/6h/day. Demineralization was caused by Streptococcus mutans (DSM 20523) alternatingly being rinsed over specimens using artificial saliva. After biological loading, teeth were cut longitudinally and demineralization depths were evaluated at the margins and at a distance of 0.5mm from the margins using fluorescence microscopy. Marginal quality was investigated under a SEM at ×200 magnification. Four-hour demineralization depths were for enamel margins (EM), enamel (E), dentin margin (DM), and dentin (D) (μm±SD): KM: EM 12±8, E 33±7, DM 56±11, D 79±6; PF: EM 19±13, E 34±13, DM 53±10, D 77±12; and KN: EM 26±5, E 38±6, DM 57±11, D 71±7. For all glass ionomer cements (GICs), demineralization depth at the margins was less compared to 0.5mm distance, with demineralization depth having been correlated to duration of cariogenic challenge (ANOVA [mod. LSD, p<0.05]). Compared to the bonded resin composite, all GICs exhibited caries inhibition at restoration margins in enamel and dentin. Fluoride-releasing GIC materials exhibit a secondary caries inhibiting effect in vitro. Glass ionomer cements have a higher secondary caries inhibiting effect than resin composites.

Effect of Finishing Techniques on the Junction Between the Composite Restoration and the Dental Enamel

The aim of this in vitro study was to to evaluate the impact of finishing procedures on the enamel adjacent to composite restorations and to assess if the resistance of the enamel-resin junction to leakage is affected by the use of these instruments. The surfaces of enamel at the joint with composite were observed by scanning electron microscopy, then the microleakages at the enamel margin was assessed using an optical microscope. Finishing with extra-/ ultra-fine carbide burs and extra-fine diamond burs produced a superficial abrasion to the adjacent enamel and did not seem to have a significant influence on the sealing ability of composite resin.

Non-operative control of cavitated approximal caries lesions in primary molars: a prospective evaluation of cases.

The effect of non-operative caries control at cavity level is often questioned. This prospective study of cases aimed to evaluate the suitability of non-operative treatment of active cavitated approximal caries lesions in primary molars by assessing clinical changes of lesions over time. Further, we evaluate children's and parents' attitudes in response to non-operative cavity treatment. Thirty-nine children attending a community dental service, aged 5-11 years, joined the evaluation based on the following criteria: (i) the presence of at least one active cavitated caries lesion in the distal surface of first primary molar or mesial surface of the second primary molar extending up to two-thirds into dentin assessed radiographically, (ii) the absence of spontaneous pain, (iii) the absence of pulpal or periapical pathology. After informed consent, one randomly selected lesion per child had overhanging enamel margins adjusted and was treated non-operatively by the child/parent performing daily site-specific oral hygiene with a fluoridated toothpaste, supplemented by professional topical fluoride treatment and dietary advice. Nine lesions/children dropped out. Fifteen lesions survived without pulpal or periapical pathology for an average of 26 m (range 9-44). Lesion failure was associated with poor compliance or lesions not suited for the method. Children and parents were highly satisfied with the treatment. Our study identifies key factors in the performance of non-operative cavity treatment in a dental practice setting. It is concluded that non-operative cavity treatment can be a helpful method to control caries lesion progression in primary teeth and may familiarise the child with dental treatment.

Microleakage and Shear Bond Strength of Composite Restorations Under Cycling Conditions.

The aim of this study was to evaluate microleakage and shear bond strength of composite restorations under different cycling conditions. Class V cavities were prepared in the buccal and lingual surfaces of 30 human molars (n=60). A further 60 molars were used to prepare flat enamel and dentin specimens (n=60 each). Cavities and specimens were divided into six groups and pretreated with an adhesive (self-etch/Clearfil SE Bond or etch-and-rinse/Optibond FL). Composite was inserted in the cavities or adhered to the specimens' surfaces, respectively, and submitted to cycling (control: no cycling; thermal cycling: 10,000 cycles, 5°C to 55°C; thermal/erosive cycling: thermal cycling plus storage in hydrochloric acid pH 2.1, 5 minutes, 6×/day, 8 days). Microleakage was quantified by stereomicroscopy in enamel and dentin margins after immersion in silver nitrate. Specimens were submitted to shear bond strength testing. Statistical analysis was done by two-way analysis of variance and Kruskal-Wallis tests (p<0.05). Microleakage in enamel margins was significantly lower in the control group compared with thermal cycling or thermal/erosive cycling. Erosive conditions increased microleakage compared with thermal cycling (significant only for Clearfil SE Bond). No significant differences were observed in dentin margins. Bond strength of enamel specimens was reduced by thermal cycling and thermal/erosive cycling when Clearfil SE Bond was used and only by thermal/erosive cycling when Optibond FL was used. No differences were observed among dentin specimens. Thermal/erosive cycling can adversely affect microleakage and shear bond strength of composite resin bonded to enamel.

In vitro microleakage of class v composite restorations prepared by Er,Cr:YSGG laser and carbide bur

Background: The aim of this in vitro study was to compare the degree of microleakage on enamel and dentin margins of class V cavities prepared with either a high-speed drill or an Er,Cr:YSGG laser (2780 nm) and to associate their use with a beveling method for the margin. Method and Materials: Sixty bovine incisors were randomly distributed into three groups. Group 1 (G1) cavities were laser prepared and bur beveled, group 2 (G2) cavities were bur prepared and beveled, while cavities of group 3 (G3) were laser prepared and beveled. Cavities were restored with selective enamel etching, using the same bonding agent and nano-hybrid resin composite for all groups. After thermocycling, microleakage was assessed using a methylene blue dye penetration method. Results: Statistical analysis (Mann-Whitney, Kruskal-Wallis and post-hoc Dunn’s multiple comparison tests) demonstrated significantly higher microleakage for dentin compared to enamel margins in G1. Enamel margin microleakage was found to be significantly higher at G3 compared to G1 (p=0.032) and G2 (p=0.001), while no significant differences were found between G1 and G2 (p=0.850). Regarding dentin margins, G2 group performed significantly better than G1 and G3 (p&lt;&lt;0.001), while there was no significant difference among G1 and G3 scores (p=1.000). Conclusions: The conventional cavity preparation method seems to perform better in terms of microleakage than the Er,Cr;YSGG laser. Laser-prepared cavities could perform better in terms of microleakage if an additional step of enamel bur-beveling is performed prior to restoration.

Comparison of microleakage of Scotchbond™ Universal Adhesive with methacrylate resin in Class V restorations by two methods: Swept source optical coherence tomography and dye penetration.

One of the most important factors in restoration failure is microleakage at the restoration interface. Furthermore, a new generation of bonding, Scotchbond Universal (multi-mode adhesive), has been introduced to facilitate the bonding steps. The aim of this study was to compare the microleakage of Class V cavities restored using Scotchbond™ Universal with Scotchbond Multi-Purpose in two procedures. Eighteen freshly extracted human molars were used in this study. Thirty-six standardized Class V cavities were prepared on the buccal and lingual surfaces. The teeth were divided into three groups: (1) Group A: Scotchbond Universal with "self-etching" procedure and nanohybrid composite Filtek Z350. (2) Group B: Scotchbond Universal with "total etching" procedure and Filtek Z350. (3) Group C: Scotchbond Multi-Purpose and Filtek Z350. Microleakage at enamel and dentinal margins was evaluated after thermocycling under 5000 cycles by two methods of microleakage assay: swept source optical coherence tomography (OCT) and dye penetration. Wilcoxon's signed-rank test and Kruskal-Wallis test were used to analyze microleakage. In silver nitrate dye penetration method, group A exhibited the minimum microleakage at dentin margins and group C exhibited the minimum microleakage at enamel margins (P < 0.05). Furthermore, in OCT method, group C demonstrated the minimum microleakage at enamel margins (P = 0.047), with no difference in the microleakage rate at dentin margins. Scotchbond Universal with "self-etching" procedure at dentin margin exhibited more acceptable performance compared to the Scotchbond Multi-Purpose with the two methods.

Effect of disinfecting the cavity with chlorhexidine on the marginal gaps of Cl V giomer restorations.

BackgroundConsidering the effect of cavity disinfecting agents on the bonding and sealing ability of restorations bonded to dentin, the aim of this study was to evaluate the effect of chlorhexidine (CHX) disinfecting agent on the marginal gaps of Cl V giomer restorations.Material and MethodsCl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors in this in vitro study, with the occlusal and gingival margins in enamel and dentin, respectively. The teeth were randomly divided into two groups (n=30). The teeth in groups 1 and 2 were restored without and with the use of the disinfecting agent in the cavity, respectively, before applying the adhesive. BeautiBond one-step self-etch adhesive and Beautifil II giomer were used to restore the cavities in both groups. After thermocycling and sectioning of the samples, the sizes of marginal gaps at gingival margins were measured in µm under a stereomicroscope. Mann-Whitney U test was used to compare marginal gaps at P<0.05 level of significance.ResultsThe means of marginal gaps were significantly different between the two study groups (U=180, P<0.001), with higher means of marginal gaps in group 2 (with CHX disinfection) compared to group 1 (without CHX disinfection) (P<0.0005).ConclusionsApplication of CHX for the disinfection of cavities in giomer restorations resulted in an increase in gingival margin gaps. Key words:Chlorhexidine, dental marginal adaptation, dental restorations.

Effect of Cavity Contamination by Blood and Hemostatic Agents on Marginal Adaptation of Composite Restorations.

To determine the effects of contamination of tooth cavities by hemostatic agents applied after blood contamination on marginal adaptation of composite restorations bonded with etch-and-rinse and self-etch adhesives. Cervical cavities (n = 10 per group) were contaminated with blood and subsequently treated with aluminum chloride (Racestyptine) or ferric sulfate (Astringedent, ViscoStat) hemostatic agents. After water rinsing, composite restorations were placed using either an etch-and-rinse (OptiBond FL) or self-etch (OptiBond All-in-One) adhesive. EDS-based elemental surface analysis was performed, and marginal integrity was evaluated using SEM both before and after thermomechanical loading. The percentage of continuous margins in enamel (%CEM) and dentin (%CDM) was statistically analyzed (p < 0.05). No statistically significant differences in %CEM and %CDM were observed between hemostatic-contaminated groups and uncontaminated controls after thermomechanical loading, irrespective of the adhesive used. Specimens contaminated with aluminum-chloride-based Racestyptine showed a significantly higher final %CEM when the etch-and-rinse adhesive was applied (OptiBond FL) than with the self-etch adhesive (OptiBond All-in-One). Cavity contamination with hemostatic agents, applied after blood contamination and removed with water spray, does not compromise marginal adaptation in enamel and dentin. In the case of contamination by an aluminum-chloride hemostatic agent, the tested etch-and-rinse approach resulted in a higher percentage of continuous enamel margins of composite restorations than did the self-etch approach.

Influence of Hand Instrumentation and Ultrasonic Scaling on the Microleakage of various Cervical Restorations: An in vitro Study.

In cervical lesions, various restorative materials can be inserted, which can be affected by the application of periodontal scalers. This study evaluated and compared the marginal seal of class V glass ionomer, composite resin, and amalgam restorations after subjecting them to hand instrumentation and ultrasonic scaling. In this experimental study, 30 sound human first premolars were selected. In each tooth, buccal and lingual cavities (4 mm mesiodistal width, 3 mm occlusogingival height, and 2 mm depth) were made. The teeth were randomly assigned to three groups of 10 teeth: (1) Glass ionomer group, (2) composite group, and (3) amalgam group. Teeth were subjected to thermocycling procedure for 1,000 cycles between 5 and 55°C water baths and a 1-minute dwell time. Then, each group was randomly subdivided: (1) Margins of 30 restorations were exposed to hand instrumentation procedures by applying 10 working strokes, (2) margins of 30 restorations were exposed to a periodontal tip mounted on a piezoelectric ultrasonic handpiece working at 25 kHz for 10 seconds. The specimens were serially sectioned mesiodistally. Each section was examined under a stereomicroscope. The extent of microleakage was ranked using a 0 to 4 scale at both occlusal and cervical margins of the restorations. Data were analyzed initially using the Kruskal-Wallis test, followed by multiple comparisons using the Mann-Whitney and Wilcoxon test. The type of restorative material had a significant influence on dye penetration, whether in the enamel margin or in the dentinal margin (p < 0.001). The microleakage of glass ionomer group was the highest. No statistical differences were found in dye penetration between scaling groups (hand instrumentation and ultrasonic scaling) (p > 0.05). Type of restorative material had a significant influence on microleakage. No statistical differences were found in dye penetration between scaling groups. The microleakage of glass ionomer restoration is greater than amalgam and composite restorations after subjecting them to hand instrumentation and ultrasonic scaling.

Factors affecting marginal integrity of class II bulk-fill composite resin restorations.

Background. Bulk-fill composite resins are a new type of resin-based composite resins, claimed to have the capacity to be placed in thick layers, up to 4 mm. This study was carried out to evaluate factors affecting gap formation in Cl II cavities restored using the bulk-fill technique. Methods. A total of 60 third molars were used in this study. Two Cl II cavities were prepared in each tooth, one on the mesial aspect 1 mm coronal to the CEJ and one on the distal aspect 1 mm apical to the CEJ. The teeth were divided into 4 groups: A: The cavities were restored using the bulk-fill technique with Filtek P90 composite resin and its adhesive system and light-cured with quartz tungsten halogen (QTH) light-curing unit. B: The cavities were restored similar to that in group A but light-cured with an LED light-curing unit. C: The cavities were restored using the bulk-fill technique with X-tra Fil composite resin and Clearfil SE Bond adhesive system and light-cured with a QTH curing unit. D: The cavities were restored similar to that in group C but light-cured with an LED light-curing unit. The gaps were examined under a stereomicroscope at ×60. Data were analyzed with General Linear Model test. In cases of statistical significance (P<0.05), post hoc Bonferroni test was used for further analyses. Results. The light-curing unit type had no effect on gap formation. However, the results were significant in relation to the composite resin type and margin location (P<0.001). The cumulative effects of light-curing unit*gingival margin and light-curing unit*composite resin type were not significant; however, the cumulative effect of composite rein type*gingival margin was significant (P=0.04) Conclusion. X-tra Fil composite exhibited smaller gaps compared with Filtek P90 composite with both light-curing units. Both composite resins exhibited smaller gaps at enamel margins.

The effect of oxalate-based desensitizers on the microleakage and shear bond strength of resin modified glass ionomer.

BackgroundThe first line of intervention to alleviate tooth sensitivity is to use dentin desensitizers such as oxalate-based desensitizers. When the dentin sensitivity continues even after application of desensitizers the next intervention would be restoration of the lesion. The aim of this in vitro study was to investigate the effect of prior application of oxalate-based desensitizer on the marginal microleakage and shear bond strength of resin modified glass ionomer (RMGI) restorations.Material and MethodsIn order to prepare the specimens for microleakage test standard class v cavities were prepared on buccal surfaces of 45 teeth. The specimens were randomly divided into three equal groups. In control group, the cavities were restored with RMGI. In group 2, oxalate-based desensitizer was applied and the specimens were kept in distilled water for 14 days before restoration. In group 3 the specimens were prepared similar to group 2 and the surface of the cavities were slightly cut with bur before restoration. Methyleneblue penetration was evaluated using stereomicroscope. The data were analyzed using non-parametric tests. For shear bond strength test cervical dentin specimens were prepared and were divided into 3 groups. Surface treatments were similar to microleakage test. RMGI was packed into cylindrical plastic molds which were placed on the cut surface of the tooth and light cured. The data were analyzed by one-way ANOVA.ResultsThere was not any significant difference in dye penetration in dentin margins among the groups, but microleakage in enamel margins of group 2 and 3 was higher than group 1. There was no significant difference in shear bond strength among the groups (p =0.285).ConclusionsNon carious cervical lesions which were treated for hypersensitivity with oxalate-based desensitizers could be restored with resin modified glass ionomer if the hypersensitivity persists. Key words:Dentin hypersensitivity, oxalate-based desensitizers, microleakage, shear bond strength.

Effect of Bioactive Primers on Bacterial-Induced Secondary Caries at the Tooth-Resin Interface.

Secondary caries at the tooth-resin interface is the primary reason for replacement of resin composite restorations. The tooth-resin interface is formed by the interlocking of resin material with hydroxyapatite crystals in enamel and collagen mesh structure in dentin. Efforts to strengthen the tooth-resin interface have identified chemical agents with dentin collagen cross-linking potential and antimicrobial activities. The purpose of the present study was to assess protective effects of bioactive primer against secondary caries development around enamel and dentin margins of class V restorations, using an in vitro bacterial caries model. Class V composite restorations were prepared on 60 bovine teeth (n=15) with pretreatment of the cavity walls with control buffer solution, an enriched fraction of grape seed extract (e-GSE), 1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide/N-hydroxysuccinimide, or chlorhexidine digluconate. After incubating specimens in a bacterial model with Streptococcus mutans for four days, dentin and enamel were assessed by fluorescence microscopy. Results revealed that only the naturally occurring product, e-GSE, significantly inhibited the development of secondary caries immediately adjacent to the dentin-resin interface, as indicated by the caries inhibition zone. No inhibitory effects were observed in enamel margins. The results suggest that the incorporation of e-GSE into components of the adhesive system may inhibit secondary caries and potentially contribute to the protection of highly vulnerable dentin-resin margins.

Effect of various grit burs on marginal integrity of resin composite restorations.

The purpose of this study was to evaluate the generation of enamel cracks and gaps at the cavosurface margin of resin composite restorations using various burs. Saucer-shaped cavities with a bevel were prepared on mid-coronal buccal or lingual surfaces of extracted human molars using a regular-grit round diamond bur, a fine-grit diamond bur, a superfine-grit diamond bur or a six-bladed tungsten carbide bur with an air turbine handpiece. The enamel margin of the cavity in each group was observed by a light microscope. Cavities were restored with a self-etching adhesive and a light-cured composite resin. After thermocycling, enamel cracks and gaps at the cavosurface margins were observed and scored. Specimens were sectioned longitudinally in two halves, and the resin-cavity interface was observed by means of a light microscope. In cavity preparation, the regular-grid diamond bur and the tungsten carbide bur caused more cracks in the marginal enamel than other groups. From the surface and sectioned surface observation of restored teeth, the superfine-grit diamond bur generated fewer cracks and gaps than the other burs.

Shear Bond Strength and Tooth-Composite Interaction With Self-Adhering Flowable Composites.

To evaluate the tooth-composite interaction (A) and shear bond strength (SBS; B) of self-adhering flowables. (A) Thirty-two human molars with one Class V cavity were restored with Vertise Flow (VF), Fusio Liquid Dentin (FLD), an experimental self-adhering flowable (EF), or Adper Prompt-L-Pop/Filtek Supreme XT Flowable (PLP). Teeth were prepared according to laboratory standard and stored in water (24 hours, 37°C). Microleakage (ML; percentage interface length at enamel [E]/dentin [D]) and tooth-composite interaction were investigated. (B) The buccal surface of 160 embedded human molars was abraded to expose an enamel/dentin area of diameter ≥3 mm. Composite specimens were produced on enamel/dentin with VF, FLD, EF, or PLP. Prior to loading, 80 samples were water stored (24 hours, 37°C) and 80 thermocycled (5°C-55°C, 1500 cycles). The SBS was measured, and failure modes were classified by scanning electron microscopy. Kruskal-Wallis, Mann-Whitney U, and Fisher exact tests were performed (α=0.05). (A) At enamel margins, EF and VF showed significantly lower ML than did FLD and PLP (pi≤0.009; 81%-89%); in dentin, lower values resulted with FLD and VF compared with PLP and EF (pi≤0.01; 77%-94%). Adhesive tags at E were consistently verifiable with EF and VF but irregularly with FLD and PLP. At D, tags were detectable with all systems. (B) In all groups, SBS decreased by up to 97% after thermocycling. It was generally diminished with self-adhering flowables (E: 50%-98%, D: 59%-98%; pi<0.02). More cohesive defects were observed with PLP (pi<0.009). Tooth-composite morphology and bond strength indicate that the clinical use of self-adhering flowables must be pursued cautiously.

Analiza microinfiltraţiei marginale asociate unor sisteme adezive cu strategii de adeziune diferite

Aim. The purpose of this in vitro study was to evaluate microleakage of two different adhesive systems: self-etch and etch-and-rinse, using the optic microscopy. Materials and methods. Six sound upper premolar teeth had MOD cavities prepared. The teeth were divided into two groups of three teeth each and two restorative systems were used: 1) Filtek™ Silorane/Silorane System Adhesive (3M ESPE); 2) Premise™ Packable /OptiBond FL (KERR). All restorative materials were placed following manufacturers’ recommendations. After restoring them, the teeth were stored for 5 years in an oven in distilled water at 37°C. Before the tests, the apex was sealed with wax and the teeth were covered with nail polish except 1 mm around the edge restorations. Then, they were immersed in 0.5% alkaline solution of fuchsin for 24 hours. After sectioning, the microleakage evaluation at enamel margin was made using an optical microscope Olympus KCX41 (Olympus America Inc.) at a magnification of 4x and 10x, the method of granting a semiquantitative score of dye penetration on a scale from 0-3. Data were statistically analyzed using Kruskal-Wallis test. Results, conclusions. Microleakage was present in both groups, scores 2 (infiltration dye the entire length threshold cervical enamel) and 3 (infiltration threshold cervical enamel and expanding axial wall towards the pulp chamber), registering only in the Filtek Silorane (FS) group who applied to Silorane system, adhesive Self-etch adhesive system. The most effective adhesive system to reduce the microleakage at marginal threshold cervical MOD restorations on enamel, was etch-and-rinse system, OptiBond FL.

The role of surface-sealant application on bond effectiveness of all-in-one self-etch adhesives

Purpose: To examine microleakage around Class-V restorations bonded with 3 current all-in-one adhesive systems in the presence or absence of surface-sealant in different evaluation groups.Materials and Methods: Clearfil S3 Bond, G-Aenial Bond, and Optibond All-in-One (AiO), were used in the Class-V cavities in accordance with the manufacturer’s instructions (control group) or were additionally combined with Fortify Plus surface-sealant (surface-sealant group). The two main treatment groups of the dentin adhesives were subdivided into four different evaluation groups (24 h, 6 months, 12 months, and 12 months with two applications); the teeth were immersed in 0.5% methylene blue dye solution for 24 h. Samples were then sectioned longitudinally in a bucco-lingual direction and evaluated for microleakage under a stereomicroscope. Dye penetration was scored at the enamel (occlusal) and dentin (gingival) margins.Results: Microleakage scores were greater at the dentin margins compared with the enamel margins for Clearfil S3 Bond in all evaluation groups, whereas no difference was observed between enamel and dentin microleakage for Optibond AiO. Using Fortify Plus in the enamel margins decreased the microleakage scores of Clearfil S3 Bond. When the control and surface-sealant groups were compared in the G-Aenial Bond enamel margins, the application of surface-sealant significantly reduced microleakage after 6 and 12 months. For Optibond AiO, no statistically significant differences in enamel and dentin margins were observed between the control and surface-sealant application groups.Conclusion: The application of surface-sealant could be considered appropriate for reducing microleakage in composite resin restorations, but this effect might depend on the dentin adhesive.

A radio-odontometric analysis of sexual dimorphism in deciduous dentition

ObjectiveIt has been suggested that the level of sexual dimorphism in deciduous dentition is relatively lower than that in permanent dentition. However, in sub adult skeletal remains whose osseous morphological traits of the sex have not defined yet, predicting sex on the basis of odontometric features may be the most precise technique. The aim of the present study was to assess the degree of sexual dimorphism in marginal enamel, dentin and pulp dimensions of second molar deciduous teeth in a pediatric population. Method and materialsThe present study was conducted on bitewing radiographs of 64 males and 60 females. The greatest width of enamel, dentin and pulp on mandibular and maxillary second molar deciduous teeth were measured. Student's t-test and discriminant analysis were used to compare the differences in the odontometric parameters between females and males. ResultsAmong the second molar measurements, only the maxillary pulp width did significantly discriminate the sex groups. The accuracy of sex identification of a case based on deciduous second molar tooth was approximately 68%. ConclusionsThe application of second molar deciduous teeth in sex prediction showed moderate level of sexual dimorphism. In this respect, the maxillary pulp width had the greatest amount of contribution in sex discrimination. Therefore, these odontometric traits, in conjunction with other skeletal features, can be used as a supplementary sexing tool for gender prediction in forensic anthropology.