Brief Narrative Review on Commercial Dental Sealants-Comparison with Respect to Their Composition and Potential Modifications

The scope of this paper is to compare different dental sealants and flow materials indicated for sealing pits and fissures considering their chemical formula. The narrative review aims to address the following questions: What is the essence of different dental sealants' activity, how does their chemical formula affect their mechanisms of caries prevention, and what makes a dental sealant efficient mean of caries prevention? Another vital issue is whether the sealants that contain fluoride, or any other additions, have potentially increased antimicrobial properties. An electronic search of the PubMed, Cochrane, Web of Science, and Scopus databases was performed. The following keywords were used: (dental sealants) AND (chemical composition). Additionally, information about composition and indications for clinical use provided by manufacturers were utilized. All of the considered materials are indicated for use both in permanent and primary dentition for sealing fissures, pits, and foramina caeca. The selection of suitable material should be made individually and adjusted to conditions of the sealing procedure and patient's needs. Cariostatic mechanisms increasing sealants' effectiveness such as fluoride release are desired in modern dentistry appreciating preventive approach. The review aims are to find crucial elements of sealants' composition which affect their cariostatic mechanisms.

Comparison of micromorphological changes in enamel using SEM analysis after conventional and erbium, chromium:yttrium, scandium, gallium, and garnet hard-tissue laser fissurotomy: An in vitro study

Background

Well articulated by John Knowles - "Everything has to evolve or else it perishes." With the paradigm shift of emphasis toward the prevention of dental caries, it has been proven that laser irradiation protects against both caries initiation and caries progression.

Aim

The aim of the study was to evaluate and compare the micromorphology of caries-free extracted premolars using a Scanning electron microscope (SEM) after fissurotomy by conventional fissurotomy bur and erbium, chromium: yttrium, scandium, gallium, and garnet (ER, CR: YSGG) hard-tissue laser.

Methodology

Sixty caries-free premolars extracted atraumatically for orthodontic treatment were included in the study. The samples were divided into two groups randomly (Group 1: fissurotomy by bur, n = 30, and Group 2: fissurotomy by hard-tissue laser, n = 30). Each sample was further divided into halves from the occlusal surface wherein one-half of the occlusal surface received fissurotomy procedure and the other half was control. Samples were analyzed by scanning electron microscopy (SEM) for micromorphological changes.

Results

Profile image of control samples revealed the disorganization of enamel surface at the junction of fissures forming a heterogeneous tissue and agglomeration of enamel with deep pit and fissure. On the contrary, the image of experimented samples (with laser fissurotomy) showed smooth enamel surface and homogeneous enamel subsurface with wider pit and fissure owing to self-cleansing ability.

Conclusion

On the grounds of the present study results, it could be concluded that the intervention of ER, CR: YSGG hard-tissue laser possesses self-cleansable pit and fissures for caries prevention and has the potential to irradicate the smear layer entirely for superior attachment of remineralizing agents.

A concise review of dental sealants in caries management

This concise review provides an update of the use of dental sealants. Dental sealants protect a tooth from caries development by providing a physical barrier to microorganism colonisation and creating a favorable environment for patients to clean. Some sealants release fluoride ions to promote remineralization. Dental sealants can be applied on pits and fissures of primary and permanent teeth to prevent and arrest early enamel caries. They are effective in caries prevention. The preventive fraction of resin sealant is up to 61% after 5 years. Dental sealants can be classified as resin, glass ionomer and hybrid (compomer or giomer) according to the material. Recent studies from 2012 to 2022 showed resin sealant has a high retention rate of up to 80% after 2 years, whereas glass ionomer sealants is 44%. Chemical etching with 37% phosphoric acid is the standard of care, whereas laser or air-abrasion cannot does not increase the sealant retention rate. Moist control is critical and studies found the use of rubber dam and cotton rolls had similar success for sealant retention. The longevity of dental sealant is also associated with clinical operative factors, including approaches of moisture control, enamel pretreatment, selection of dental adhesive, and time of acid etching.

Comparative Evaluation of Penetrative and Adaptive Properties of Unfilled and Filled Resin-Based Sealants When Placed using Conventional acid Etching, Lasing, and Fissurotomy Bur Technique of Enamel Preparation: An in vitro Scanning Electron Microscope Study

Background

There is a confusion regarding selection of unfilled or filled sealant and method of enamel preparation before sealant application. This study was carried out to compare three techniques of enamel preparation using both unfilled and filled type of sealants.

Objective

The objective of the study is to assess the penetrative and adaptive ability of filled and unfilled sealants in three techniques of enamel fissure preparations.

Materials and Methods

Total 36 extracted teeth were divided into 3 groups, each containing 12 samples. The samples of Group A were prepared by conventional acid etching with 37% phosphoric acid, and the Group B was subjected to Er: YAG lasing, while in Group C, fissurotomy followed by acid etching was done. The sealant placement was carried out using split tooth design in all the samples. Assessment of penetration and adaptation was done under scanning electron microscope using the scoring criteria adopted by Kane B et al. and Dukic W et al.

Results

Group A and Group C showed better adaptation than Group B. Statistically, no significant difference was observed in the penetration property among three techniques. Similarly, the unfilled and filled sealant showed statistically nonsignificant results for the penetration and adaptation comparison.

Conclusion

Irrespective of the sealant material selected, the conventional method of acid etching alone or in conjunction with fissurotomy bur for better retentiveness seems to be an acceptable choice of treatment modality. The study will help the clinicians to choose the sealant material and technique of enamel preparation.

The Use of Laser Energy for Etching Enamel Surfaces in Dentistry-A Scoping Review

BACKGROUND

In dental practice, different situations require etching the enamel layer. Acid etching, the present golden standard, may be replaced by other methods, such as laser etching. The main focus of our scoping review is to assess the existent literature regarding the effectiveness of different types of lasers, to identify the main aspects studied so far, and to understand where new search strategies are needed.

METHODS

The search was conducted in several databases focusing on the laser etching of human definitive enamel. We included English language articles published between January 2000 and December 2021.

RESULTS

The 34 articles reviewed showed that hard lasers, Er:YAG, Er,Cr:YAG, may represent an alternative etching method on enamel surfaces. They create a fractured, irregular surface and open dentin tubules, highly suitable for adhesion but with a lower risk of cavity formation. Nd:YAG, CO₂, and Diode lasers do not help in creating sufficient shear bond strength. There is, however, evidence suggesting that microcracks in the enamel layer may appear after thermomechanical ablation using laser energy.

CONCLUSIONS

While the use of acid etching is still successfully used for enamel conditioning, some researchers have emphasized the role played by saliva in the enamel-remineralization process a few days after the procedure. In this context, laser energy can be used, especially for bonding ceramic brackets in the case of orthodontic treatments. However, as thermomechanical ablation can generate microcracks, further research is required in order to establish clear findings concerning the use of laser energy on enamel etching.

Microleakage of pit and fissure sealings placed after enamel conditioning with phosphoric acid or with self-etching primers/adhesives

Background

It is still not fully understood what pretreatment is best for achieving maximum tightness for pit and fissure sealings (PFS).

Aim

This study investigated microleakage of PFS placed after etching with phosphoric acid or after the application of self‐etching primers/adhesives (SEPA).

Design

131 third molars were assigned to ten groups. In Hel‐P, Helioseal® was applied after phosphoric acid etching. In the other groups, SEPA were used (Dyr‐AP: Adper™ Prompt™ L‐Pop™, Dyract® Seal; Bea: BeautiSealant Primer and Paste; Hel‐Exp: Experimental primer, Helioseal®; Hel‐Cl: Clearfil™ SE Bond¹, Helioseal®). Specimens were stored in distilled water at 37°C (28 days), followed by 3500 thermocycles and staining with 5% methylene blue (M) or 5% silver nitrate (S). After methylene blue staining and sectioning, microleakage was assessed light microscopically. During silver nitrate staining, specimens were dissolved by 32% HCl and remaining PFS were evaluated under a SEM.

Results

Tightness, percentage of penetrated area, and maximum dye penetration were best for Hel‐P and Hel‐Cl (p < 0.05).

Conclusions

Phosphoric acid etching of enamel and Clearfil™ SE Bond resulted in the best sealing quality. Methylene blue staining allowed the evaluation of more criteria (fissure shape, voids, sealant penetration depth) compared to silver nitrate.

Dental Sealant Composition-Retention Assessment in Young Permanent Molars

Tooth decay in children and adolescents remains a public health problem, despite prophylaxis and preventive measures being largely available. The aim of our study was to evaluate the clinical behavior of four dental sealants, related to first permanent molar topography and patient age (when sealant was applied for the first time). We assessed, by means of visual inspection and palpation with a dental probe, a group of 200 children, enrolled corresponding to school age-grade (mean age of 7 years at baseline) and randomly divided according to the material used as dental sealant (Admira seal©, Embrace Wet Bond©, Fotoseal©, GC Fuji Triaje©) in 4 groups (n = 50). Sealant clinical evaluation was made at 6-, 12-, 18-month intervals for dental material retention assessment. At 6 months, the sealant detached the most from 3.6 molars, and the material used was Fotoseal© (27.6%). At 12 months, Fotoseal© (48.3%) and GC Fuji Triaje© (41.4%) from 3.6 molars express detachment. At 18 months, 4.6. molars sealed with Admira Seal© (25.7%) and Embrace Wet Bond© (28.6%) lost the sealant. We noticed less detachment in maxillary molars and if sealant was applied around 7 years of age. In conclusion, sealant application on first permanent molars must be encouraged and practitioners can choose between various materials available.

Lasers to prevent dental caries: a systematic review

OBJECTIVE

To assess the effectiveness of lasers (at sub-ablative parameters) in reducing caries incidence compared with traditional prophylactic interventions (TPIs) when used alone or together with other TPIs such as pits and fissures sealant or fluoride gels or varnishes.

DESIGN

A systematic review. Data sources include Medline (via PubMed), Embase, Web of Science and the Cochrane Library (December 2019).

ELIGIBILITY CRITERIA

Only randomised trials (RCTs) and controlled clinical trials (CCTs) dealing with prophylactic lasers use (vs TPI or untreated teeth) were considered as eligible. We excluded in vitro and ex vivo studies.

DATA EXTRACTION

Eligible studies were selected and data extracted independently by two reviewers. Risk of bias was assessed adopting the Cochrane Risk of Bias tool. Data on caries incidence, sealant retention, fluoride uptake, adverse events, treatment duration, patients' discomfort and cost-effectiveness ratio was extracted.

DATA ANALYSIS

Extracted data were presented narratively due to the heterogeneity of included studies.

RESULTS

Seven RCTs and two CCTs, all with an evident risk of bias, met inclusion criteria, pooling together 269 individuals and 1628 teeth. CO₂, neodymium-doped yttrium aluminium garnet, erbium-doped yttrium aluminum garnet (Er:YAG), erbium, chromium: yttrium scandium gallium garnet (Er,Cr:YSGG) and Argon lasers were used. In the permanent dentition, lasers only when used in combination with TPIs were effective in reducing caries when compared with untreated teeth (risk ratio (RR)=0.44 (0.20-0.97); Er:YAG laser) or with TPIs used alone (RR=0.39 (0.22-0.71); CO₂ laser). Moreover, Argon laser significantly improved the fluoride uptake into the enamel surfaces (ANalysis Of VAriance (ANOVA) tests: 95%, p<0.0001). Likewise, sealant retention improved when acid etching was performed on previously irradiated enamel fissures by CO₂ laser (RR=0.63 (0.38-1.04)) or Er:YAG laser (RR=0.54 (95% CI: 0.34 to 0.87)). In addition, laser resulted safe and well tolerated by patients.

CONCLUSION

Despite some positive indications, an inadequate level of evidence was found in the included studies concerning the lasers' effectiveness in preventing caries. Further studies with a higher methodological quality level are required.

Influence of Laser and Ozone Pretreatment on the Shear Bond Strength of Fissure Sealants: An In Vitro Comparative Study

Aim:

To evaluate the shear bond strength (SBS) of 3 fissure sealants used alone and with ozone and laser pretreatment.

Materials and Methods:

For the SBS test, the flattened enamel surfaces of 90 healthy third molars were randomly divided into nine groups ( n  =  10 for each groups), based on different sealants (BeautiSealant, Fuji Triage, and Grandio Seal) and pretreatment conditions (no pretreatment, pretreatment with ozone, and pretreatment with neodymium-doped yttrium aluminum garnet [Nd:YAG laser]). Ozone was applied for 30 s in caries superficial mode, and Nd:YAG laser was applied for 60 s. After the pretreatment procedures, sealants were placed inside a mold on the enamel surface. SBS was measured with a universal testing machine. Data were analyzed using analysis of variance. Tukey’s multiple comparison tests were applied to determine the difference between the groups (α  = 0.05).

Results:

The lowest SBS was observed in the Fuji triage group. Nd:YAG laser and ozone did not affect the SBS of BeautiSealant. However, significant differences were determined in the Fuji triage and Grandio Seal groups after pretreatment procedures ( P  < .05).

Conclusion:

Ozone and laser can be employed to disinfect fissures before BeautiSealant application.

The effect of the Er: YAG laser on the clinical success of hydrophilic fissure sealant: a randomized clinical trial

Purpose:

The aim of this study was to assess the effect of the Er:YAG laser on the clinical success of a hydrophilic fissure sealant over 12 months.

Subject and methods:

This study was conducted on 132 permanent first molars from 44 (19 girls and 25 boys) patients aged 7-11 years. The teeth were divided into three groups. The first group (Group A-control) of teeth were etched with phosphoric acid, the second group of teeth (Group L) were etched with an Er:YAG laser, and the third group of teeth (Group A+L) were etched with both the Er:YAG laser and phosphoric acid. Clinical evaluations were performed at baseline and at 3-, 6-, 9- and 12-month follow-up visits. The data were analyzed with Pearson chi-square tests, Cochran Q tests and Kaplan-Meier analysis.

Results:

At the end of the 12 months, total retention rates were 72.7%, 59.1%, and 65.9% in the acid group, the laser group and the laser and acid group, respectively. Although there was no statistically significant difference between group retention rates (p>0.05), the lowest retention rate was found in the laser group at the end of the 12-month follow-up period. No new caries were observed in any group during the study period.

Conclusion:

Etching with the Er:YAG laser, phosphoric acid or a combination of both methods provided similar results for the clinical success of hydrophilic based fissure sealant.

Meta-analysis of the longevity of commonly used pit and fissure sealant materials

OBJECTIVE

This systematic literature review and meta-analysis compared the clinical retention of primed or adhesively bonded sealants to that of conventional sealant materials.

METHODS

A search of the MEDLINE, EMBASE and CENTRAL databases identified 3707 abstracts published prior to 12/31/2017, of which 335 clinical publications were analysed in detail. A total of 67 studies included information about sealant retention after 24, 36, or 60 months of follow-up. A meta-analysis using a random effects model was conducted to calculate the pooled estimate of the retention rates for the five groups of sealants. Subgroup moderator analysis was performed to compare the pooled retention rate estimate (RRE) of primed sealants against those of the other groups.

RESULTS

Primed sealants had a 2-year pooled RRE of 43.2% (95% CI: 30.5-55.8), which was significantly inferior to those of auto-polymerizing (80.8%, 95% CI: 72.2-89) and light-polymerizing sealants (68.4%, 95% CI: 60.2-76.7). Fluoride-releasing and light-polymerizing sealants had the highest 3-year pooled RREs (86.4%, 95% CI: 73.4-99.3 and 83.1%, 95% CI: 75.6-90.7, respectively).

SIGNIFICANE

The results of this meta-analysis suggest that primed sealants cannot be fully recommended for clinical practice due to their moderate survival rates. Auto-polymerizing, light-polymerizing and fluoride-releasing sealants continue to be considered the reference standards for pit and fissure sealants. However, future generations and developments of primed sealant materials may change this position.

The clinical effects of laser preparation of tooth surfaces for fissure sealants placement: a systematic review and meta-analysis

Background

This systematic review aimed to assess the clinical effects of laser preparation compared to other types of chemical or mechanical preparation of tooth surfaces used in fissure sealant placement.

Methods

A systematic literature search was conducted up to January 2019, through Pubmed, Scopus, Medline/EMBASE via OVID and the Cochrane library. Only randomized clinical trials were included.

Results

Five studies were included in the systematic review and three were included in the meta-analysis. All the studies used acid-etching as a comparator to lasers. All the included studies were rated as having an overall high risk of bias introduced by performance bias. Three studies assessed the clinical effects of fissure sealants placed by acid or laser etching, one compared acid etching versus laser combined with acid etching and one investigated the influence of lasers on the objective and subjective parameters of stress during sealant application in children. The meta-analysis showed no significant difference between laser preparation and conventional acid-etching preparation at 3- (P = 0.08), 6- (P = 0.49), and 12-month (P = 0.87) follow-ups. One study reported that laser preparation as an adjunct to acid-etching enhanced the retention rate. No significant difference in the incidence of caries was reported. And no significant differences were found in heart rates, oxygen saturation or degree of the patient dental anxiety between acid-etching and laser preparation.

Conclusion

The present limited evidence suggests that lasers could be an effective pretreatment method. The retention rate was similar to that of conventional acid etching. However, the included studies had an overall high risk of bias and more rigorously designed research is needed.

Effects of Er,Cr:YSGG Laser Pulse Frequency on Microtensile Bond Strength to Enamel

Literature regarding the influence of Er,Cr:YSGG laser pulse frequency with different output power levels on adhesion properties of adhesive resin to lased enamel is limited. Therefore, the aim of the present study was to evaluate the effects of laser pulse frequency (20, 35, and 50 Hz) at two different output power settings (3 and 6 W) of Er,Cr:YSGG on the microtensile bond strength (μTBS) of adhesive resin to enamel. Crowns of 35 intact bovine incisors were embedded into self-cure acrylic resin individually, and then flat enamel surfaces were prepared with 600-grit silicon carbide papers under water cooling. Teeth were divided randomly into seven groups. Enamel surfaces were irradiated with Er,Cr:YSGG laser operated at one of six output power–pulse frequency combinations (6 W20 Hz, 6 W–35 Hz, 6 W–50 Hz, 3 W–20 Hz, 3 W–35 Hz, and 3 W–50 Hz) in groups 1-6, respectively. Bur-treated surfaces served as a control in group 7. After surface treatments and bonding procedures, composite build-ups were done in three layers up to a height of 4 mm. Next, all bonded teeth were sectioned into the resin-enamel sticks to be tested in a μTBS testing machine. The μTBS data were analyzed with univariate analysis of variance under a general linear model with the factor ‘tooth' added as a random effect to the design. Resin-enamel interfaces were evaluated with scanning electron microscopy (SEM). The μTBS to laser-irradiated enamel in group 1 (6 W–20 Hz) was significantly lower than those of bur-treated enamel (p&lt;0.05). However, group 6 (3 W–50 Hz) showed significantly higher μTBS values than did bur-treated teeth (p&lt;0.05). SEM evaluation revealed enormous morphological alterations of laser-irradiated specimens, such as extensive vertical and horizontal microcracks and gaps, with the exception of group 6. The bonding effectiveness of adhesive resin to laser-irradiated enamel was affected by the pulse frequency of the Er,Cr:YSGG laser. Although the parameters recommended by the manufacturer lowered μTBS, increasing the pulse rate may maintain optimum μTBS.

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.

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.