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

Evaluation of the marginal integrity of various pit and fissure sealants

PURPOSE

To evaluate the marginal integrity of various pit and fissure sealants subjected to different application methods.

METHODS

A total of 253 non-carious human third molars extracted and randomly divided into two groups according to the preparation method employed: invasive or non-invasive. Eight fissure sealant materials were tested: nano-filled flowable composite (Filtek Ultimate Flow), nanohybrid flowable composite (GrandioSo Flow), micro-hybrid flowable composite (Majesty Flow), resin-based unfilled fissure sealant (ClinPro Sealant), resin-based filled fissure sealant (Fissurit FX), resin-based highly filled fissure sealant (GrandioSeal), giomer-based fissure sealant (BeautiSealant), and glass ionomer-based fissure sealant (Fuji Triage). Samples were subjected to two-year cyclic thermo-mechanical and brushing simulations. Two observers quantitatively evaluated the restoration margins and classified them as either "permanent restoration edge", or if a gap larger than 250 μm was evident, "gapping at the restoration edge". The extent of the gap was recorded as a percentage relative to the total length of the restoration edge.

RESULTS

The baseline marginal adaptation had no significant effect on the marginal adaptation (P > 0.05). However, the preparation method and type of fissure sealant material had a significant impact on the marginal adaptation (P < 0.05).

CONCLUSION

On the basis of quantitative analysis, the highest marginal integrity was observed for flowable composites, whereas the lowest was observed for glass ionomer-based fissure sealant.

Retention rate of resin sealants in dental enamel with structural alterations: a systematic review

Resin sealants have been used preventively and therapeutically in tooth enamel. The latter can present different conditions in its structure. In this sense, adhesive retention in enamel has ample evidence of its effectiveness, but not in enamel with structural alterations. In this way, it is relevant to know the adhesive retention of these materials and how they behave over time in enamel with variations in its composition. To determine the retention rate of resin sealants in tooth enamel with structural alterations. The study is part of a systematic review following the PRISMA protocol. Articles published between 2010 and 2020 on the retentive behavior of resin sealants in dental with structural alterations were examined. The electronic search was carried out in Web of Science, Scopus, PubMed and Medline. Those articles that used resin sealants in dental enamel with structural alterations were incorporated in clinical trials. Results: Eight articles were found. These were stratified according to the application surface; (i) carious surface, (ii) surface with fluorosis and (iii) surface with hypomineralization of the molar incisor. It was evidenced that the retention rate of resin sealants on decayed enamel is 80% on average, in enamel with dental fluorosis 67.5% and enamel with hypomineralization of the molar incisor 72% 2 years after their application. The retentive behavior of resin sealants on enamel with structural alterations is adequate for the three application surfaces. However, further studies are required regarding dental fluorosis and molar incisor hypomineralization. The most significant evidence on the retention rate was found on various surfaces.

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.

Does etching time affect the in vitro performance of a sealant material?

This in vitro study evaluated the shear bond strength (SBS), failure mode and microleakage of fissure sealing materials in relation to different etching times on aprismatic and prismatic enamel. Ninety-six healthy human third molars were randomly allocated to the following groups: 1) prismatic or aprismatic enamel; 2) etching: 15, 30, 45, 60 s. After 5,000-fold thermocycling SBS, failure mode and microleakage were measured. Statistical evaluation included Mann-Whitney-U-test and linear regression analysis. In the aprismatic enamel group, an increasing etching time resulted in higher SBS. The linear regression model revealed that 60 s of etching time led to a significant increase in SBS. Microleakage was found to be low in all test groups. This study indicated that 60 s of etching time showed to a significantly better SBS. When considering the small differences of SBS, failure modes and microleakage between 30 and 60 s etching time, 30 s acid etching seems to also be justifiable.

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.