Effect of enamel preparation method on in vitro marginal microleakage of a flowable composite used as pit and fissure sealant

Three dimensional evaluation of marginal microleakage at the adhesive interface between different fissure sealants and enamel: Micro-CT analysis

Background/Aim: Sealing ability and adhesion to enamel of fissure sealants are quite critical in prevention of dental caries. The objective of the present study was to assess the marginal microleakage of different material-based pit and fissures with non-invasive and invasive techniques by using the Micro-CT method. Material and Methods: 30 extracted human permanent molars were randomly assigned to three sealant groups (n=10) as resin-based ClinPro, giomer-based BeautiSealant, and glass ionomer-based Fuji IX-GP. Half of each group was randomly divided into two parts as non-invasive and invasive techniques. The volumetric analysis of marginal microleakage between the enamel-material interface was performed by using Micro-CT. The results were analyzed with Student's t, One-Way ANOVA, Tukey and Games-Howell tests. Statistical significance level was considered as 0.05. Results: In non-invasive technique, Fuji IX-GP showed statistically significantly lower marginal microleakage values than Clinpro (p=0.022). Other comparisons were not significant (p>0.05). However, in invasive technique, microleakage values both of Fuji IX-GP and BeautiSealant were significantly lower than Clinpro (p<0.001, p<0.001). Besides, regardless of the sealant material, the invasive technique showed significantly superior results than non-invasive technique regarding marginal microleakage. Conclusions: Considering the clinical conditions, it was concluded that glass ionomer-based Fuji IX-GP and giomer-based BeautiSealant could be used as alternative to resin based sealants. Additionally, invasive technique (fissure preparation) can be recommended to reduce marginal microleakage.

Three Dimensional Evaluation of Marginal Microleakage at the Adhesive Interface between Different Fissure Sealants and Enamel: Micro-CT Analysis

Background/Aim: Sealing ability and adhesion to enamel of fissure sealants are quite critical in prevention of dental caries. The objective of the present study was to assess the marginal microleakage of different material-based pit and fissures with non-invasive and invasive techniques by using the Micro-CT method.

Material and Methods: 30 extracted human permanent molars were randomly assigned to three sealant groups (n=10) as resin-based ClinPro, giomer-based BeautiSealant, and glass ionomer-based Fuji IX-GP. Half of each group was randomly divided into two parts as non-invasive and invasive techniques. The volumetric analysis of marginal microleakage between the enamel-material interface was performed by using Micro-CT. The results were analyzed with Student’s t, One-Way ANOVA, Tukey and Games-Howell tests. Statistical significance level was considered as 0.05.

Results: In non-invasive technique, Fuji IX-GP showed statistically significantly lower marginal microleakage values than Clinpro (p=0.022). Other comparisons were not significant (p>0.05). However, in invasive technique, microleakage values both of Fuji IX-GP and BeautiSealant were significantly lower than Clinpro (p<0.001, p<0.001). Besides, regardless of the sealant material, the invasive technique showed significantly superior results than non-invasive technique regarding marginal microleakage.

Conclusions: Considering the clinical conditions, it was concluded that glass ionomer-based Fuji IX-GP and giomer-based BeautiSealant could be used as alternative to resin based sealants. Additionally, invasive technique (fissure preparation) can be recommended to reduce marginal microleakage.

An In Vitro Microleakage Study for Comparative Analysis of Two Types of Resin-based Sealants Placed by Using Three Different Types of Techniques of Enamel Preparation

BACKGROUND

Clinicians always experience dilemmas while choosing the type of pit and fissure sealant and the method of enamel preparation before the application of sealant. This study was accomplished using the unfilled and filled types of resin sealant deploying three different techniques of enamel preparation.

AIM AND OBJECTIVE

To do a comparative analysis of unfilled and filled sealants by deploying three techniques of enamel preparation.

MATERIALS AND METHODS

The total number of 60 extracted teeth were divided into 3 groups, each containing 20 samples. Conventional acid etching of enamel was labeled as (group I), laser application as (group II), and fissurotomy bur (group III). The samples of group I were prepared by conventional acid etching, the group II was subjected to Er:YAG lasing, while in group III fissurotomy followed by acid etching was done. The sealant placement was done using split tooth design in all the samples. Dye penetration using 5% methylene blue was used for microleakage assessment.

RESULTS

The highest microleakage was found with Gr. II whereas Gr. I exhibited the least microleakage. No statistical difference was observed between the unfilled and filled sealant (p = 0.652).

CONCLUSION

Conventional acid etching alone or with fissurotomy weighed up appropriate option regardless of the type of sealant material used.

CLINICAL SIGNIFICANCE

In regard to the selection of material and proper technique of enamel preparation, this study will be useful to clinicians.

HOW TO CITE THIS ARTICLE

Shingare P, Chaugule V. An In Vitro Microleakage Study for Comparative Analysis of Two Types of Resin-based Sealants Placed by Using Three Different Types of Techniques of Enamel Preparation. Int J Clin Pediatr Dent 2021;14(4):475-481.

Laser Tooth Preparation for Pit and Fissure Sealing

Objectives: Various approaches are available for pit and fissure sealing, including: the use of sealants, with or without mechanical preparation; the use of etching, with or without bonding; and the use of lasers as an alternative to mechanical preparation. The objective of this study is to evaluate pit and fissure sealing by comparing the retention and microleakage of sealants, between mechanical and Er:Yag laser enamel preparation. Methods: Sixty extracted sound third molars are classified into six groups: A, bur mechanical preparation and sealant application; B, bur mechanical preparation, etching and sealant; C, bur mechanical preparation, etching, bonding and sealant; D, laser mechanical preparation and sealant; E, laser mechanical preparation, etching and sealant application; F, laser mechanical preparation, etching, bonding, and sealant. Statistical analysis methods include Fisher’s exact test, a general linear model for one-way analysis of variance (ANOVA) of multiple comparisons, and Bonferroni multiple comparison tests. Results: All the groups showed dye microleakage beneath the sealants. Less microleakage was observed for those that used bur rather than laser, 41 versus 44 specimens, respectively. The number of specimens without microleakage decreased as follows: group E (24), group A (18), groups B and F (17), group C (14), and group D (5). Retention was 100% in all groups except group D. Conclusion: Mechanical preparation increases retention of sealants, especially when etching material is used; additionally, bonding can help the retention. The best technique is mechanical preparation via laser and subsequent use of etching, without bonding prior to application of the dental sealant.

Microleakage and penetration depth of different fissure sealant materials after cyclic thermo-mechanic and brushing simulation

The aim of the study was to evaluate microleakage and the penetration-depths of different fissure-sealant materials applied with/without enameloplasty after cyclic aging. One-hundred-sixty mandibular molars were divided into non-invasive and enameloplasty preparation groups and eight material subgroups, including: flowable composites (microhyrid, nanohybrid, and nanofilled), three resin-based (unfilled, filled, and highly-filled), a giomer-based, and a glass-ionomer-based fissure sealant. Specimens were subjected to two-year cyclic chewing and brushing simulation. After 5% basic-fuchsin dye penetration, specimens were sectioned and scored under stereomicroscope. Kruskal-Wallis statistical data showed that preparation type significantly affected the penetration of all tested materials (p<0.05), but not significantly affected microleakage (p>0.05). Flowable composites showed the best and the glass-ionomer-based sealant showed the worst penetration and microleakage. Slight preparation of fissures is not important in microleakage. However, enameloplasty significantly enhanced the depth of penetration of the sealants. Flowable composites offer promising results at the fissure sealing.

Effect of Er:YAG laser enamel conditioning and moisture on the microleakage of a hydrophilic sealant

For a given sealant, successful pit and fissure sealing is principally governed by the enamel conditioning technique and the presence of moisture contamination. A new generation of hydrophilic resin sealants is reported to tolerate moisture. This study investigates the impact of Er:YAG laser pre-conditioning and moisture contamination on the microleakage of a recent hydrophilic sealant. Occlusal surfaces of extracted human molars were either acid etched (n = 30), or successively lased and acid etched (n = 30). Ten teeth from each group were either air-dried, water-contaminated, or saliva-contaminated prior to sealing with UltraSeal XT^® hydro™. Samples were inspected for penetration of fuchsin dye following 3000 thermocycles between 5 and 50 °C, and the enamel–sealant interfaces were observed by scanning electron microscopy (SEM). Significant differences in microleakage were evaluated using the Mann–Whitney U test with Bonferroni adjustment (p = 0.05). Laser pre-conditioning significantly reduced dye penetration irrespective of whether the enamel surface was moist or dry. Microleakage of water-contaminated acid etched teeth was significantly greater than that of their air-dried or saliva-contaminated counterparts. SEM analysis demonstrated good adaptation in all groups with the exception of water-contaminated acid etched teeth which exhibited relatively wide gaps. In conclusion, this hydrophilic sealant tolerates the presence of saliva, although water was found to impair its sealing ability. Laser pre-conditioning significantly decreases microleakage in all cases.

A comparative evaluation of retention of pit and fissure sealants placed with conventional acid etching and Er,Cr:YSGG laser etching: A randomised controlled trial

Aim: The aim of this study was to compare the retention rates of sealant placed either with conventional acid etching or Er,Cr:YSGG laser pretreatment of enamel surface. Materials and methods: This is a prospective, single blind randomised controlled clinical trial enrolling 200 permanent first molars in 50 patients, aged 6-12 years for sealant placement. Study followed split mouth design where each side of the arch was randomly allocated to the two treatment group. Group A(Acid etch group): 37 % phosphoric acid (Scotchbond, 3M ESPE, Seefeld, Germany) was applied for 15 seconds, rinsed with water for 20 seconds and then air-dried using air spray. Group L(Laser etch group): Fissures were prepared with an Er,Cr:YSGG laser system (Waterlase, BIOLASE Technology, San Clemente, CA, USA) emitting photons at a wavelength of 2.78 µm. Laser irradiation at 1.5 W (60% air and 40% water), in a noncontact mode, with a repetition rate of 20 Hz for 10seconds was used. Pit and fissure sealant (3M ESPE, Clinpro) was applied and cured for 20 seconds. One blinded, calibrated examiner, who was unaware of which preparation method has been used and who was not involved in the treatment procedures, evaluated the sealant at baseline and at 3, 6, 9 and 12 month follow-up visits. Results: It was observed that overall retention rate in group A was slightly higher as compared to group L at all time periods, however, the difference was statistically non-significant (p-value>0.05).

CONCLUSION

Er,Cr:YSGG laser etching is comparable to acid etching in terms of retention and patient acceptability.

Evaluating the Microshear Bond Strength and Microleakage of Flowable Composites Containing Zinc Oxide Nano-particles

INTRODUCTION

Preventive resin restorations (PRR) are the conservative choice for the most common carious lesions in children. Thus, new age flowable resin composites with higher filler content are readily used. The aim of this study was to evaluate the microshear bond strength and microleakage of two flowable resin composites containing different percentages of nano zinc oxide (NZnO) particles, which have proven to have antimicrobial properties.

METHODS

This experimental in-vitro study was carried out in the Dental Material Research Center of Babol University of Medical Sciences in 2015. One nanohybrid and one nanofill flowable resin composite were chosen and modified with the incorporation of 1% and 3% Wt NZnO particles. Six groups (n=10, 0%, 1%, and 3%) of resin composite sticks on dental enamel (2×2mm) were prepared to be placed in the microtensile tester. The microshear bond strength magnitude (MPa) was recorded at the point of failure. A class I box (3×0.8×1 mm) was prepared on 60 premolars and filled using the resin composites (6 groups, n=10). The specimens were immersed in a 5% basic fuschin solution and sectioned bucco-lingually to view the microleakage using a stereomicroscope. One-way ANOVA and Tukey tests for microshear and Wilcoxon and Kruskal-Wallis tests for microleakage were used to analyze the data in the IBM SPSS Statistics version 22 software.

RESULTS

The bond strength of the 3% clearfill group significantly decreased while no significant change occurred in the bond strength in other groups. The Z-350 group had significantly lower microleakage as nanoparticles increased. No significant difference was observed in the clearfill group.

CONCLUSION

Up to 3% Wt incorporation of NZnO particles will not diversely alter the bond strength, but it will be beneficial in providing antimicrobial effects with lower microleakage rates.

The impact of Er:YAG laser enamel conditioning on the microleakage of a new hydrophilic sealant--UltraSeal XT hydro

UltraSeal XT® hydro™ is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XT® hydro™ as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XT® hydro™ was applied to each group of teeth (n = 10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50 °C with a dwell time of 30 s. Microleakage assessments were then carried out using 0.5 % fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, Mann–Whitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p > 0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p < 0.001). Electron microscopy with energy-dispersive X-ray analysis revealed that the mineral filler component of UltraSeal XT® hydro™ essentially comprises micrometre-sized particles of inorganic silicon-, aluminium- and barium-bearing phases. Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface.

Flowable Resin Composites: A Systematic Review and Clinical Considerations

BACKGROUND

Little is known about flowable composite materials. Most literature mentions conventional composite materials at large, giving minimal emphasis to flowables in particular. This paper briefly gives an in depth insight to the multiple facets of this versatile material.

AIM

To exclusively review the most salient features of flowable composite materials in comparison to conventional composites and to give clinicians a detailed understanding of the advantages, drawbacks, indications and contraindications based on composition and physical/mechanical properties.

METHODOLOGY

DATA SOURCES

A thorough literature search from the year 1996 up to January 2015 was done on PubMed Central, The Cochrane Library, Science Direct, Wiley Online Library, and Google Scholar. Grey literature (pending patents, technical reports etc.) was also screened. The search terms used were "dental flowable resin composites".

SEARCH STRATEGY

After omitting the duplicates/repetitions, a total of 491 full text articles were assessed. As including all articles were out of the scope of this paper. Only relevant articles that fulfilled the reviewer's objectives {mentioning indications, contraindications, applications, assessment of physical/mechanical/biological properties (in vitro/ in vivo /ex vivo)} were considered. A total of 92 full text articles were selected.

CONCLUSION

Flowable composites exhibit a variable composition and consequently variable mechanical/ physical properties. Clinicians must be aware of this aspect to make a proper material selection based on specific properties and indications of each material relevant to a particular clinical situation.

Comparative evaluation of microleakage of nano-filled resin-modified glass ionomer: An in vitro study

Objective:

This in vitro study evaluated the microleakage of a nano-filled resin-modified glass ionomer and a high viscosity glass-ionomer restorations in class V cavities.

Materials and Methods:

Thirty-two class V cavities prepared on the buccal and lingual surfaces of 16 sound, third molar teeth were randomly assigned into two groups and restored by one of the glass ionomer material; Group A: A high viscosity (Ketac Molar, 3M ESPE) Group B: A nano-filled resin-modified (Ketac N100, 3M ESPE) glass ionomer. One clinician prepared all the cavities. The materials were used according to the manufacturers’ recommendations. The restored teeth were then stored in distilled water at 37°C for 24 h, thermocycled at 5-55°C for 1000 cycles. The specimens were immersed in aqueous solution of Indian ink dye for 48 h at room temperature. They were embedded in resin polyester and sectioned longitudinally in a buccolingual direction. Microleakage was assessed according to the depth of dye penetration along the restoration. The extent of dye penetration at the occlusal and gingival margins was assessed using a stereo microscope. Randomly selected samples from each group were prepared for scanning electron microscope evaluation. The data were statistically analyzed with Friedman and Wilcoxon signed ranks tests.

Results:

There were statistically significant differences between the microleakage scores of the two groups for both occlusal and gingival scores (P = 0.001). Occlusal and gingival scores for high viscosity glass ionomer (P = 0.024) and nanoionomer (P = 0.021) using Wilcoxon signed ranks tests showed statistically significant differences. High viscosity glass ionomer showed significantly less microleakage compared to the nano-filled resin-modified glass-ionomer (RMGIs) at occlusal margin (P = 0.001). No significant differences were found between the groups at gingival margin (P = 0.0317).

Conclusion:

Within the limitations of this in vitro study, nano-filled RMGIs restorations did not perform better than high viscosity glass ionomer in class V cavities in terms of microleakage assessment.

Enamel pretreatment with Er:YAG laser: effects on the microleakage of fissure sealant in fluorosed teeth

Objectives

The purpose of this in vitro study was to evaluate the microleakage and penetration of fissure sealant in permanent molar teeth with fluorosis after pretreatment of the occlusal surface.

Materials and Methods

A total of 120 third molars with mild dental fluorosis were randomly divided into 6 groups (n = 20). The tooth surfaces were sealed with an unfilled resin fissure sealant (FS) material. The experimental groups included: 1) phosphoric acid etching (AE) + FS (control); 2) AE + One-Step Plus (OS, Bisco) + FS; 3) bur + AE + FS; 4) bur + AE + OS + FS; 5) Er:YAG laser + AE + FS; and 6) Er:YAG laser + AE + OS + FS. After thermocycling, the teeth were immersed in 0.5% fuchsin and sectioned. Proportions of mircoleakage (PM) and unfilled area (PUA) were measured by digital microscope.

Results

Overall, there were significant differences among all groups in the PM (p = 0.00). Group 3 showed the greatest PM, and was significantly different from groups 2 to 6 (p < 0.05). Group 6 showed the lowest PM. Pretreatment with Er:YAG with or without adhesive led to less PM than bur pretreatment. There were no significant differences among groups in PUA.

Conclusions

Conventional acid etching provided a similar degree of occlusal seal in teeth with fluorosis compared to those pretreated with a bur or Er:YAG laser. Pretreatment of pits and fissures with Er:YAG in teeth with fluorosis may be an alternative method before fissure sealant application.

Shear bond strength and SEM morphology evaluation of different dental adhesives to enamel prepared with ER:YAG laser

CONTEXT

Early observations of enamel surfaces prepared by erbium lasers motivated clinicians to use laser as an alternative to chemical etching.

AIMS

Evaluate shear bond strength (SBS) values of different dental adhesives on Erbium:Yttrium Aluminum Garnet (Er:YAG) laser prepared enamel and to evaluate possible etching patterns correlations between dental adhesives and SBS values.

SUBJECTS AND METHODS

One hundred bovine incisors were randomly assigned to SBS tests on enamel (n = 15) and to enamel morphology analysis (n = 5) after Er:YAG laser preparation as follows: Group I - 37% phosphoric acid (PA)+ ExciTE(®); Group II - ExciTE(®); Group III - AdheSE(®) self-etching; Group IV - FuturaBond(®) no-rinse. NR; Group V - Xeno(®) V. Teeth were treated with the adhesive systems and subjected to thermal cycling. SBS were performed in a universal testing machine at 5 mm/min.

STATISTICAL ANALYSIS USED

One-way ANOVA and post-hoc tests (P < 0.05). For the morphology evaluation, specimens were immersed in Ethylenediamine tetraacetic acid (EDTA) and the etching pattern analyzed under Scanning Electron Microscope (SEM).

RESULTS

Mean bond strengths were Group I - 47.17 ± 1.61 MPa (type I etching pattern); Group II - 32.56 ± 1.64 MPa, Group III - 29.10 ± 1.34 MPa, Group IV - 23.32 ± 1.53 MPa (type III etching pattern); Group V - 24.43 MPa ± 1.55 (type II etching pattern).

CONCLUSIONS

Different adhesive systems yielded significantly different SBSs. Acid etching significantly increased the adhesion in laser treated enamel. No differences in SBS values were obtained between AdheSE(®) and ExciTE(®) without condition with PA. FuturaBond(®) NR and Xeno(®) V showed similar SBS, which was lower in comparison to the others adhesives. No correlation between enamel surface morphology and SBS values was observed, except when PA was used.

Evaluation of the effect of enamel preparation on retention rate of fissure sealant

Background:

Prevention from caries is a principle in dentistry and fissure sealant therapy is being used as a preventive method success of sealants is directly depending on their retention.

Aim:

The Aim of the present study is to evaluate effects of enamel preparation on sealant retention.

Settings and Design:

Clinical trial.

Materials and Methods:

About 57 children aged 6-8 year old took part in this study. 200 first molar teeth of these children has been randomly separated into two groups: A case group (Mechanically preparation of enamel) and a control group (conventional method, without preparation). After applying fissure sealants children were followed up 6 months later.

Statistical Analysis Used:

Mann- U- Whitney Test was used.

Results:

Complete retention after 6 month follow up was 86.7% in case group and 82.8% in control group. No significant difference was seen between the groups after 6 month follow up. (P = 0.508).

Conclusion:

Although statistical evaluation didn't show significant difference, but sealant retention was more after preparation technique.

Assessment and comparison of microleakage of a fluoride-releasing sealant after acid etching and Er: YAG laser treatment - An in vitro study

Aim:

The aim of the present study was to estimate and compare the microleakage of a pit and fissure sealant after etching and Er:YAG laser treatment.

Materials and Methods:

Twenty non-carious premolars extracted for orthodontic reasons were equally divided into two groups. Samples in Group- I were treated with 37% phosphoric acid. Samples in Group II were irradiated with Er: YAG laser at 400 mJ at 4 Hz. Sealant was placed and light cured. Then, the samples were subjected to thermocycling. The samples were then immersed in 1% methylene blue. The samples were sectioned and examined under stereomicroscope at ×10 magnification.

Results:

Acid etched samples showed significantly less microleakage when compared to laser etching and it was statistically significant (P<0.01).

Removal of organic debris with Er:YAG laser irradiation and microleakage of fissures sealants in vitro

The current study was conducted to improve fissure sealing by pre-treatment with Er:YAG laser irradiation in order to remove organic debris. The surface morphology, surface roughness of fissure cavities, and the degree of microleakage after laser treatment were compared with those after bristle brush treatment in vitro. Sixty extracted human teeth were used in this study. The teeth were randomly divided into two groups of 30 each. Artificial fissures were prepared in all teeth into which artificial organic debris was placed. The debris in 30 teeth of one group was removed by means of Er:YAG laser system and the remaining 30 teeth were cleaned using a bristle brush with prophylaxis paste. Surface morphology and surface roughness of were analyzed in ten samples from each group by color laser three-dimensional (3D) microscopy and by scanning electron microscopic examination. The remaining samples were then filled with sealant and subjected to a microleakage test under thermocycling. Statistical analysis was performed using the Mann-Whitney U test; a value of p < 0.05 was considered significant. Morphologically, most of the debris was removed by Er:YAG laser treatment, whereas some fissures were not cleaned by bristle brush. However, microleakage test of both laser and etched brush methods showed similar results. Laser technique might facilitate good adaptation of resin sealant to enamel, because of an increase in surface roughness and favorable surface characteristics.

In vitro comparison of microleakage of two materials used as pit and fissure sealants

Background and aims

Marginal seal of the material is extremely important in fissure sealant therapy. The aim of this study was to investigate microleakage of flowable composite resins and conventional fissure sealants with or without dentin bonding agent.

Materials and methods

The occlusal surface of 60 intact extracted human premolars, divided into four groups, were cleaned with pumice/slurry, etched with 37% phosphoric acid for 15 seconds, rinsed and dried. Groups were treated differ-ently: Excite bonding agent followed by Helioseal F fissure sealant in group1; Helioseal F alone in group 2; Excite bonding agent followed by Tetric Flow in group 3; and Tetric Flow alone in group 4. Light-curing was done after each application. After thermocycling, the whole surface of each specimen was coated with nail varnish except for one millimeter around the fissure sealant. The teeth were immersed in 2% basic fuchsin for 24 hours and then sectioned buccolingually. The sections were analyzed for leakage under a stereomicroscope. Data was analyzed by Kruskal-Wallis and Mann-Whitney tests at asignificance level of P < 0.05.

Results

There were no statistically significant differencesbetween the study groups in terms of the mean microleakage scores (P > 0.05), except for groups 2 and 4 (P = 0.002) and groups 3 and 4 (P = 0.033).

Conclusion

Use of a flowable composite with bonding agent is a good alternative for sealing pits and fissures; however, further in vitro and in vivo studies are necessary.

Tensile bond strength of sealants following Er:YAG laser etching compared to acid etching in permanent teeth

The aim of this in vitro study was to assess the effect of Er:YAG laser surface treatment on the tensile bond strength of a sealant in permanent teeth. A total of 30 sound third molars were selected and embedded in cold-cure acrylic resin. The enamel surfaces were flattened by a grinding. The teeth were randomly divided into three groups and pretreated as follows: (1) 37% phosphoric acid; (2) Er:YAG laser (1.5 ml/min water spray, 100 mJ energy output, 10 Hz frequency, focal distance 17 mm); (3) Er:YAG laser + 37% phosphoric acid. The treated surfaces were isolated by double adhesive Sellotape and after insertion of a split Teflon matrix at an isolated site, sealant was applied. The specimens were thermocycled and stored at 37°C in distilled water for 72 h, then subjected to a tensile bond strength test (50 kgf at 0.5 mm/min). The mean tensile bond strengths (± SD, in megapascals) were: 18.51 ± 5.68 in group 1, 8.06 ± 2.69 in group 2, and 17.33 ± 5.04 in group 3. Data were submitted to analysis of variance and the Tukey test. No significant difference were found between groups 1 (37% phosphoric acid) and group 3 (Er:YAG laser + 37% phosphoric acid) but treatment with the Er:YAG laser alone (group 2) resulted in significantly lower tensile bond strength than seen in the other groups. In this setting, the Er:YAG laser prepared the enamel surface for sealing but did not eliminate the need for acid etching before sealant application.