Effect of bromelain enzyme for dentin deproteinization on bond strength of adhesive system

Effect of natural agents on the bond strength to eroded dentin

OBJECTIVE

This study evaluated the effect of bromelain and propolis extract on the bond strength (BS) of a universal adhesive system to eroded dentin.

MATERIALS AND METHODS

Sixty human molars with exposed dentin were halved, with one half protected by composite resin and the other subjected to erosive treatment followed by remineralization. After the erosive treatment, the composite resin was removed, and the teeth were randomly assigned to three groups (n = 20): Adhesive-Control System; Br-10%; Pr-16%. Following the treatments, composite resin blocks were built on the dentin surfaces and sticks of 0.9 mm2 were obtained and stored in distilled water at 37°C for 24 h and 6 months. After these periods, the sticks underwent bond strength testing and the data were analyzed using 2-way ANOVA, Bonferroni test, p < 0.05. Fracture patterns were observed using light microscope and scanning electron microscopy.

RESULTS

Irrespective of the substrate and aging duration, propolis demonstrated higher BS (p < 0.05) compared to the other treatments. Eroded dentin exhibited greater removal of the smear layer and dentinal tubules with a larger diameter than sound dentin, especially when treated with bromelain, resulting in the formation of resin tags.

CONCLUSIONS

Propolis consistently promoted the highest bond strength, irrespective of aging or substrate. Eroded dentin treated with propolis, or bromelain exhibited a higher prevalence of non-adhesive fractures and resin tag formation.

CLINICAL SIGNIFICANCE

Propolis shows promise for enhancing the longevity of adhesive restorations in eroded dentin due to its ability to promote high bond strength.

Effect of the use of bromelain associated with bioactive glass-ceramic on dentin/adhesive interface

OBJECTIVES

To evaluate the effect of bromelain associated with Biosilicate on the bond strength (BS) of a universal adhesive system to sound (SD) and caries-affected dentin (CAD), and on the proteolytic activity.

MATERIALS AND METHODS

Cavities were prepared in 360 molars, half submitted to cariogenic challenge. Teeth were separated into groups (n=20): Control-No treatment; CHX-0.12% chlorhexidine; NaOCl-5% sodium hypochlorite; Br5%-5% bromelain; Br10%-10% bromelain; Bio-10% Biosilicate; NaOClBio-NaOCl+Bio; Br5%Bio-Br5%+Bio; Br10%Bio-Br10%+Bio. Following treatments, the adhesive system was applied, and cavities were restored. Samples were sectioned into sticks and stored at 37 °C for 24 h, 6 months, and 1 year. Microtensile BS (2-way ANOVA, Bonferroni's test, α=0.05), fracture patterns (SEM), and adhesive interfaces (TEM) were evaluated. Bacterial collagenase assay and in situ zymography were performed.

RESULTS

In CAD, Br10% presented higher BS (p=0.0208) than Br5%Bio. Br5% presented higher BS (p=0.0033) after 6 months than after 24 h; and association of treatments, higher BS (p<0.05) after aging than after 24 h. Mixed fractures were the most prevalent. Association of treatments promoted a more uniform hybrid layer with embedded Bio particles. Experimental groups presented lower (p<0.0001) relative fluorescence units than Control. Bromelain, associated or not with Bio, showed collagenolytic degradation.

CONCLUSIONS

Bromelain associated with Biosilicate did not affect the BS to SD. In CAD, Br5%Bio decreased immediate BS but had no long-term influence. This association decreased the proteolytic activity.

CLINICAL RELEVANCE

Bromelain and Biosilicate may enhance the longevity of adhesive restorations by inhibiting endogenous proteases.

Evaluation of the microleakage of class V composite restoration after cavity treatment with Erbium, CO2 lasers, Papain, and Bromelain enzymes

OBJECTVES

Different surface preparation and treatment methods may have dissimilar effects on the microleakage of composite resin. This study was conducted to determine the deproteinizing effect of 10% bromelain enzyme, 10% papain enzyme, CO2 , and erbium-YAG laser in regard to decrease in the microleakage of composite restorations.

MATERIALS AND METHODS

Thirty teeth were selected and 60 class V cavities were prepared on the lingual and buccal sides. They were divided into six groups (n = 10): Group 1, phosphoric acid gel; Group 2, bromelain enzyme 10%; Group 3, papain enzyme 10%; Group 4, mixed papain and bromelain enzymes 10%; Group 5, CO2 laser; and Group 6, erbium-YAG laser. They were stored in basic fuchsine and dye penetration was evaluated. Kruskal-Wallis and Mann-Whitney tests were used for statistical analysis, p < 0.05 RESULTS: In both occlusal and gingival margins, comparison of microleakage between groups 1, 2, 3, 4, and 5 showed no significant differences (p = 1) and group 6 had a significant difference with other groups (p ˂ 0.001).

CONCLUSIONS

Microleakage of composite resin in the dentin surface was not affected significantly using either bromelain or papain 10% enzymes or erbium laser. However, CO2 laser had a negative effect on the enamel and dentin margins and increased the microleakage. Erbium laser showed a better effect than enzymes on microleakage.

Effect of limonene associated with bioactive glass-ceramic on dentin/adhesive interface

This study evaluated the effect of pretreatment with limonene and/or biosilicate on the bond strength of a universal adhesive system in self-etch mode to dentin. Occlusal cavities were prepared in 80 human molars and the teeth were randomly allocated to one of four groups (n = 20), according to the pretreatment regimens applied before the adhesive. The pretreatments were (i) Control, no pretreatment, (ii) LIM, 0.5% limonene; (iii) Bio, 10% biosilicate; and (iv) LIMBio, LIM + Bio. After adhesive application and restoration, the specimens were sectioned into sticks, separated, and stored in distilled water at 37°C for 24 h or 6 months. Microtensile bond strength test was carried out and measurements were compared across pretreatment groups and storage times. Fracture patterns and adhesive interfaces were observed. Loss of dry mass was calculated (n = 10). There was no statistically significant difference in the bond strength between the groups and the most prevalent fracture pattern was the non-adhesive. LIM and LIMBio resulted in more open dentinal tubules. LIM and Bio, whether separate or combined, showed particles of those substances, which decreased in size and number after 6 months. All groups lost mass weight after treatment, with no statistically significant differences between them. Limonene and biosilicate pretreatment did not affect the bond strength to dentin of the universal adhesive system, but resulted in more non-adhesive fractures, even after 6 months.

Effect of nonthermal atmospheric plasma on bond strength of composite resin using total-etch and self-etch adhesive systems

Aim

The aim of this study was to assess the impact of nonthermal atmospheric plasma (NTAP) on the bond strength of composite resin following plasma application at different steps of dentin bonding in total-etch and self-etch adhesive systems.

Materials and Methods

Ninety extracted third molars were taken, and the occlusal surfaces were removed until the exposure of the dentin. Samples were distributed into two main groups: Group T: total-etch adhesive system and Group S: self-etch adhesive system. Groups are further subdivided (n = 10) based on plasma application at different steps of dentin bonding. T1: surface etching with 37% phosphoric acid and bonding agent application. T2: plasma application and bonding agent application. T3: plasma application, etching, and bonding agent application. T4: etching, plasma application, and bonding agent application. T5: etching, plasma application, bonding agent application, and again plasma application. S1: self-etch bonding agent application. S2: plasma application and bonding agent application. S3: Bonding agent application and plasma application. S4: plasma application, bonding agent application, and again plasma application. For all the samples, composite resin buildup was done, and shear bond strength (SBS) was measured. The contact angle was measured at different steps of dental adhesive systems.

Statistical Analysis

Two-way analysis of variance and the post hoc Tukey's test were used for analysis, regarding P < 0.05 as statistically significant.

Results

Among all groups of total-etch and self-etch adhesives, Group T4 (48.81 Mpa) and Group S2 (36.59 Mpa), respectively, have demonstrated significantly greater bond strength values than the corresponding control groups.

Conclusion

NTAP enhanced the composite resin's SBS when plasma treatment was done before bonding agent application and significantly reduced the contact angles of the distilled water.

Comparison of Different Dentin Deproteinizing Agents on Bond Strength and Microleakage of Universal Adhesive to Dentin

Aim:

To evaluate the effects of papain (Brix 3000), bromelain, sodium hypochlorite (NaOCl), and chlorine dioxide (ClO2) application to the deep dentin surface on shear bond strength (SBS), microleakage, and dentin surface properties.

Materials and Methods:

Deep dentin surface ( n = 100) for evaluating SBS, class V preparation at the buccal surface for testing microleakage ( n = 100), and deep dentin slices ( n = 20) for evaluating surface properties were conducted on the 220 molar teeth. Four different deproteinizing agents (Brix 3000, 40% bromelain, 5.25% NaOCl (Chloraxid), and 0.12% ClO2) were applied to the dentin, and then the universal adhesive was used in self-etch (SE) and etch&rinse (E&R). Deproteinizing agents were not applied to the control group. All of the samples were subjected to 5000 cycles of thermal aging at 5ºC–55ºC. SBS (MPa) was tested by a universal testing machine. The microleakage of resin composite bonded with different adhesive modes was evaluated under a stereomicroscope. The changes in the surface morphology were examined with scanning electron microscopy (SEM) and attenuated total reflection – fourier transform infrared spectroscopy (ATR-FTIR).

Results:

ClO2 exhibited the highest bond strength among deproteinizing agents. Compared to the SE mode, E&R mode significantly showed higher bond strength ( p < .05). In gingival margin, bromelain SE exhibited the highest marginal leakage, while Brix 3000 SE had the lowest mean microleakage score.

Conclusion:

Deproteinizing with ClO2 was effective in improving the SBS of universal adhesive in the E&R mode to deep dentin. Deproteinization with bromelain before universal adhesive in SE mode showed more microleakage on both the occlusal and gingival surfaces.

Effect of Er:YAG, Co2 lasers, papain, and bromelain enzymes dentin treatment on shear bond strength of composite resin

OBJECTIVE

Effective bond strength of composite resin restoration leads to its durability, so evaluation of dentin surface treatment with enzymes and laser for higher bond strength is an important factor.

MATERIALS AND METHODS

Sixty human molar teeth were cut at a depth of 2 mm of occlusal part and divided into six groups (n = 10). G1: etched with 37% phosphoric, G2 and G3: 10% papain or bromelain enzymes were used on the dentinal surface, G4: 10% papain and bromelain enzyme mixture were used for. Then, the specimens were washed with distilled water. In G5 and G6: Er:YAG or Co2 lasers were used on the dentin surface. An adhesive system was applied and then nanohybrid composite was placed in teflon mold and light cured. Samples were subjected to a shear bond strength (SBS) test by universal testing machines. Statistical analysis was performed, using one-way analysis of variance and Tukey HSD tests (p < .05).

RESULTS

The mean SBS in G1 was significantly higher in comparison with the other groups (p < .0001). On the other hand, a comparison of mean SBS between groups 2, 3, 4, and 5 shows no significant differences (p = .221). The mean SBS in group 6 (Co2 laser) was significantly lower in comparison with the other groups (p < .0001).

CONCLUSION

Results showed that SBS of composite resin to dentin was not significantly affected, using either bromelain or papain 10% enzymes or erbium laser. Co2 laser had a negative effect on dentin and decreased the SBS. Phosphoric acid has the best result.

Bromelain: A Potent Phytomedicine

The commercially available protein-digesting enzyme bromelain is derived from the pineapple fruit or stem. Bromelain from fruit and stems are produced in different ways and has varied enzyme compositions. “Bromelain” often refers to the "stem bromelain". Bromelain is a combination of several thiol endopeptidases and others including various protease inhibitors, glucosidase, cellulase, phosphatase, peroxidase, and escharase. Studies conducted in both the lab and on animals show that bromelain has a variety of fibrinolytic, anti-edematous, antithrombotic, and anti-inflammatory effects. The body can absorb bromelain to a significant extent without it ceasing its proteolytic activity or having any negative side effects. Numerous therapeutic advantages of bromelain include wound debridement, improved drug absorption, and the management of sinusitis, bronchitis, angina pectoris, surgical trauma, and thrombophlebitis. Additionally, it treats numerous cardiovascular conditions, diarrhoea, and osteoarthritis. Bromelain also encourages apoptotic cell death and exhibits some anti-cancerous properties. This review compiles the crucial traits, medical and dental uses of bromelain as well as its potential mechanism of action.

Collagen-depletion strategies in dentin as alternatives to the hybrid layer concept and their effect on bond strength: a systematic review

Strategies aiming to improve the longevity of resin-dentin adhesive interface developed so far have only been able to retard the problem. Different approaches are thus needed. The objective of this review was to determine whether the use of collagen-depletion strategies after acid-etching procedures may improve the bond strength of resin-based materials to dentin. A systematic review was planned following 2021 PRISMA statement guidelines, with a search strategy performed in five electronic databases: PubMed/Medline, Scopus, EMBASE, SciELO and IADR Abstract Archive (last search: 17/01/2022). Inclusion criteria encompassed studies which evaluated a collagen-depletion strategy in acid-etched human dentin and tensile/shear bond strength tests. Risk of bias assessment was carried out by two reviewers, working independently on an adapted five-domain risk of bias (RoB) checklist for laboratory studies. Results were synthesized qualitatively, as a meta-analysis was not possible due to limited number of studies and their RoB. A total of eight studies were eligible for inclusion in the systematic review after inclusion/exclusion criteria application. Out of these, two evaluated the effect of using NaOCl followed by an antioxidant, and the remaining six evaluated different enzymatic treatments (bromelain, chondroitinase ABC, papain, and trypsin). None of the studies reported a decrease of bond strength when a collagen-depletion strategy was used, in comparison to traditional hybrid layers (control). All enzymatic treatment studies which respected the inclusion criteria improved the bond strength to dentin. Some specific collagen-depletion strategies seem to play a favorable role in improving immediate bond strengths to dentin. Further research with sound methodology is required to consolidate these findings, since limitations in RoB and a low number of studies were found. The assessment of further proteolytic agents and long-term outcomes is also required.

Comparison the Effect of Bromelain Enzyme, Phosphoric Acid, and Polyacrylic Acid Treatment on Microleakage of Composite and Glass Ionomer Restorations

Statement of the Problem

Resin modified glass-ionomer cement (RMGIC) shows low microleakage values. Bromelain enzyme is a deproteinizing agent with an anti-inflammatory effect in human body.Efective cavity treatment is an important factor in reduction of microleakage.

Purpose

The aim of this study was to determine the effectiveness of the deproteinizing aspect of 10% bromelain enzyme on the microleakage of RMGIC and composite restorations.

Materials and Method

In this experimental study, 40 non-carious extracted human molar teeth were categorized in eight experimental groups (n=5). Standard class V cavities were prepared on the buccal and lingual surfaces of the teeth (n=10). The specimen were classified as Group 1, in which 20% polyacrylic acid (PAA) was applied on the teeth then treated with 10% bromelain enzyme; Group 2: 10% bromelain enzyme was applied; Group 3: 10% bromelain enzyme was applied and then treated with polyacrylic acid; Group 4: 20% polyacrylic acid was applied. Groups1 to 4 were restored with RMGIC (Fuji II LC, GC, Japan). Group 5: etched by 37% phosphoric acid and then treated by 10% bromelain; Group 6: 10% bromelain enzyme was applied without etching; Group 7: teeth were deproteinized with 10% bromelain enzyme and then etched with 37% phosphoric acid; and Group 8: cavities were etched with 37% phosphoric acid. In the groups 5 to 8, Adper single bond (3M, ESPE, USA) and filled with composite resin Z350 (3M, ESPE, USA). After thermocycling, the teeth were sectioned. Microleakage scores were measured using stereomicroscope (40×). Kruskal-Wallis and Mann-Whitney tests were used for data analysis. (p< 0.05).

Results

Statistical analysis did not show any significant difference in occlusal and gingival margin microleakage in glass ionomer groups (1-4) (occlusal p= 0.218, gingival p= 0.192). Kruskal-Wallis revealed significant difference in occlusal and gingival margin microleakage of Groups 5 to 8 (occlusal p= 0.006 and gingival p= 0.00). Group 5 demonstrated the lowest occlusal microleakage (occlusal mean=0.00).

Conclusion

Applying bromelain or polyacrylic acid did not affect the microleakage of glass ionomer filling. Due to the antinflamatory effects of bromelain, we suggest using it instead of PAA. Pretreatment of 10% bromelain enzyme after phosphoric acid significantly decreased microleakage in the occlusal and gingival margin of composite filling.

Effect of nonthermal atmospheric plasma, grape seed extract, and bromelain on immediate bonding of composite to bleached and microabraded surfaces

Background:

Tooth whitening procedures such as bleaching and microabrasion alters the enamel surface and thus reduce the composites’ bond strength. Hence, various surface treatments were introduced to overcome this problem.

Aim:

To assess the effect of nonthermal atmospheric plasma (NTAP), grape seed extract (GSE) and bromelain on the shear bond strength (SBS) of the composite after bleaching and microabrasion.

Materials and Methods:

Eighty extracted maxillary anterior teeth were distributed into two groups. Group 1: bleaching and Group 2: Microabrasion and further subdivided into four subgroups (n = 10) based on the form of surface treatment employed. Group A: no surface treatment, Group B: bromelain, Group C: GSE, Group D: NTAP. Composite resin was bonded to the labial surface and placed in artificial saliva for 24 h. SBS testing was done for all the samples.

Statistical Analysis:

Analysis was performed using two-way analysis of variance and post hoc Tukey's test with P < 0.05 considered statistically significant.

Results:

Group 1D revealed the highest bond strength (35.4 Mpa) and Group 1A showed the least bond strength values (15.7 Mpa). Among the bleaching groups, significant difference was observed between all the subgroups except Group 1A and 1B (P = 0.972). In microabrasion group, significant difference was observed between Group 2A and 2D (P = 0.0001), Group 2B and 2D (P = 0.0010), and Group 2C and 2D (P = 0.0001).

Conclusions:

Following bleaching, NTAP application and GSE significantly improved the SBS of composite resin. Application of NTAP to microabraded surfaces increased the bond strength of composite resin.

Evaluation of the Effects of Bromelain and Papain Enzymes on Shear Bond Strength of Composite Resin to Enamel

Aim

This study aimed to evaluate the effects of 6% bromelain and 10% papain enzymes on shear bond strength (SBS) of composite resin to enamel compared to conventional 37% phosphoric acid etching.

Materials and Methods

50 human maxillary premolar teeth were randomly divided into 5 groups (G1–G5/n = 10). In G1 and G2, after etching enamel with 37% phosphoric acid for 15 seconds and washing the surface, 10% papain and 6% bromelain enzymes were used, respectively. In G3 and G4, 6% bromelain or 10% papain enzymes were applied on enamel. In G5, the enamel surface was etched with 37% phosphoric acid for 15 seconds. A two-step etch-and-rinse adhesive system (Adper Single Bond 2) was applied. A nanohybrid composite (Z350) was placed using Teflon molds. All the samples were then subjected to the SBS test using a universal testing machine. Data analysis was performed using a one-way ANOVA test followed by the Tukey test. p values less than 0.05 were considered significant.

Results

Comparison of the mean SBS between G1, G2, and G5 shows no significant differences (p > 0.05); however, they had higher mean SBS compared with G3 and G4 (p < 0.0001).

Conclusions

The shear bond strength of composite to enamel was not affected significantly using either 6% bromelain or 10% papain enzymes after 37% phosphoric acid application. Moreover, 6% bromelain and 10% papain enzymes were not as effective as 37% phosphoric acid alone.

Effect of Cavity Disinfectants on Dentin Bond Strength and Clinical Success of Composite Restorations-A Systematic Review of In Vitro, In Situ and Clinical Studies

Cavity disinfection becomes an important step before a dental restorative procedure. The disinfection can be obtained cleaning the dental cavity with antimicrobial agents before the use of adhesive systems. The aim of this study was to conduct a systematic review on the effect of different cavity disinfectants on restorations’ adhesion and clinical success. A search was carried out through the Cochrane Library, PubMed, and Web of Science. In vitro and in situ studies reporting results on dentin bond strength tests, and clinical studies published until August 2020, in English, Spanish and Portuguese were included. The methodological quality assessment of the clinical studies was carried out using the Revised Cochrane risk-of-bias tool. Chlorhexidine could preserve adhesion to dentin. EDTA and ethanol had positive results that should be further confirmed. Given the significant lack of scientific evidence, the use of lasers, fluoridated agents, sodium hypochlorite, or other products as cavity disinfectants should be avoided. Chlorhexidine is a safe option for cavity disinfection with adequate preservation of adhesion to dentin. Moreover, future researches should be focused on the efficacy of these disinfectants against cariogenic bacteria and their best application methods.

Comparison of Different Dentin Deproteinizing Agents on the Shear Bond Strength of Resin-bonded Dentin

Aim

To assess and analyze the resin-bonded dentin in terms of shear bond strength after using deproteinizing agents 5% sodium hypochlorite, 10% sodium hypochlorite, and bromelain.

Materials and methods

Overall 140 permanent and intact human premolars were split into four groups, three experimental groups and one control group. In all four groups, the occlusal surface of the teeth was wet ground to expose superficial dentin. In group I, teeth were etched and deproteinized with 5% sodium hypochlorite. In group II, teeth were etched and deproteinized with 10% sodium hypochlorite. In group III, teeth were etched and bromelain was used to deproteinize. In group IV, teeth were etched and no deproteinization was being performed and simultaneous fulfillment of the resin composite and later inserted into the plastic tube and polymerized with light. Samples were stored at 37°C for 24 hours and the later samples were transferred to the universal testing machines to shear bond strength analysis at a speed of 0.5 mm/minute.

Results

The outcome of the bond strength was significantly influenced by the application of bromelain enzymes. A remarkable difference was observed between the shear bond strength of sodium hypochlorite (5 and 10%) and in the bromelain enzyme-treated group. Group III showed better results than group I and group II.

Conclusion

This study concluded that bromelain shear has the maximum value for shear bond strength. Bond strength improved because of removal of unsupported collagen fiber with bromelain enzyme after acid etching.

Clinical significance

Natural pineapple enzyme, i.e., bromelain improves bond strength by removal of unsupported collagen fiber. Hence, it is completely safe to use.

How to cite this article

Khan R, Sharma N, Garg Y, et al. Comparison of Different Dentin Deproteinizing Agents on the Shear Bond Strength of Resin-bonded Dentin. Int J Clin Pediatr Dent 2020;13(S-1):S69–S77.

Microtensile Bond Strength of Composite Resin Following the Use of Bromelain and Papain as Deproteinizing Agents on Etched Dentin: An In Vitro Study

Aim and objectives

The aim of this study was to evaluate and compare the deproteinizing effect of sodium hypochlorite, bromelain, and papain on microtensile bond strength of composite resin to etched dentin.

Materials and methods

Eighty freshly extracted permanent molars were wet grounded into a flat surface using a diamond disk to expose the superficial dentinal surface. Teeth were etched with 37% phosphoric acid for 15 seconds and rinsed with water and blot dried. Teeth were divided into four groups (n = 20) based on the method of dentin deproteinization. Group I: only etching; group II: deproteinized with 5.25% sodium hypochlorite for 1 minute; group III: deproteinized with 8% bromelain enzyme for 1 minute; and group IV: deproteinized with 8% papain enzyme for 1 minute. All the samples were washed off with distilled water to remove deproteinizing agents. Sample surfaces were blot dried and bonding of the dentin surface was performed and restored with light cure bulk fill composite. Samples were stored in distilled water (37°C/24 hours) and thermocycled. Then, the teeth were longitudinally sectioned and individually fixed to a sectioning block using acrylic resin. The block was mounted on hard tissue microtome and sectioned to get one to three slabs of 1 mm thick sections. The beam was then attached to a custom-made jig using screws subjected to the Instron universal testing machine. A tensile load was applied at a crosshead speed of 0.5 mm/minute until the beam fractured.

Results

Higher mean bond strength was recorded in group IV followed by group III, group II, and group I, respectively. Group III presented a statistically significant highest mean score compared to other study groups with group I and group II (p < 0.001), followed by group IV having significantly higher mean score compared to group I and group II (p < 0.001) and finally a significant difference was observed between group II and group I (p < 0.001). However, the mean microtensile bond strength score did not differ significantly between group III and group IV (p = 0.20).

Conclusion

Within the limitations of this present in vitro study, the following conclusions were drawn. The microtensile bond strength of dentine tested in various deproteinizing agents is as follows: 8% bromelain > 8% papain > 5.25% NaOCl > control group. Naturally occurring deproteinizing agents, such as bromelain and papain, used in this study have resulted in greater bond strength values when compared to that of traditionally used chemical agent such as NaOCl.

How to cite this article

Khatib MS, Devarasanahalli SV, Aswathanarayana RM, et al. Microtensile Bond Strength of Composite Resin Following the Use of Bromelain and Papain as Deproteinizing Agents on Etched Dentin: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(1):43–47.

Comparing the Efficacy of Three Minimally Invasive Techniques on Demineralized Dentin in Primary Teeth and Evaluating Its Residual Dentin and Microhardness Levels: An In Vitro Study

Aim

This study aims to compare the caries removal efficacy of three minimally invasive techniques and to analyze qualitatively under stereomicroscopy and quantitatively using Vickers hardness test.

Materials and methods

Thirty non-carious anterior primary teeth were selected and subjected to demineralization and the same was confirmed using RadioVisioGraphy (RVG). Samples were divided into three groups: Bromelain gel, smart bur, and atraumatic restorative technique (ART). Caries removal was carried out for a time period of 2 minutes. The remaining demineralized dentin was measured using stereomicroscopy. Random dentin blocks were prepared and a microhardness test was conducted.

Statistical analysis

Data were subjected to statistical analysis by one-way analysis of variance (ANOVA) test.

Results

Stereomicroscopic analysis revealed bromelain gel and smart burs to be superior to ART. Bromelain gel was found to have comparable microhardness levels as healthy dentin. Statistically significant (p < 0.001) results were obtained.

Conclusion

In terms of caries removal and microhardness, bromelain gel was highly efficient when compared to other groups.

Clinical significance

Fear and anxiety of children and parents about conventional drills led to the emerging trends of minimally invasive restorative dentistry. This research indicated the use of bromelain gel and smart bur in the process of caries removal and that bromelain was more efficient when compared to other groups.

How to cite this article

Abinaya R, Nagar P, Urs Pallavi, et al. Comparing the Efficacy of Three Minimally Invasive Techniques on Demineralized Dentin in Primary Teeth and Evaluating Its Residual Dentin and Microhardness Levels: An In Vitro Study. Int J Clin Pediatr Dent 2020;13(6):585–589.

Three-Year Effects of Deproteinization on the In Vitro Durability of Resin/Dentin-Eroded Interfaces

Objective:

To evaluate the effect of sodium hypochlorite on the immediate and three-year bonding properties of a resin-eroded dentin interface produced by one of two adhesive strategies.

Methods and Materials:

Forty-eight molars were randomly assigned to six experimental groups, according to the combination of the adhesive strategy (etch-and-rinse and self-etch) and the dentin surface (control groups without erosion, eroded dentin surface [ED], and eroded dentin surface + NaOCl 5.2% [ED + NaOCl]). After completing restoration, specimens were stored in water (37°C) for 24 hours and then sectioned into resin–dentin beams (0.8 mm2) to be tested under tension (0.5 mm/min) immediately thereafter or after three years of water storage. To assess nanoleakage (NL), specimens were immersed in silver nitrate solution and examined by scanning electron microscopy at both time points. The dentin-etching pattern was examined under a scanning electron microscope. Data were subjected to appropriate statistical analysis (α=0.05)

Results:

In both strategies, a more pronounced and significant reduction of the microtensile bond strength (μTBS) values was observed for the ED groups (p=0.0001) after three years. However, in the ED + NaOCl group, μTBS values were maintained after three years of water storage. Furthermore, application of NaOCl to eroded dentin significantly reduced the immediate NL values and also preserved these values after three years of water storage for both adhesive strategies (p&gt;0.05). When considering the ED group, a superficial removal of the smear layer and enlarged lumen tubules in comparison to control were present. However, for ED + NaOCl, there was a total removal of the smear layer and significant numbers of collagen fibrils were exposed.

Conclusion:

The use of NaOCl may maintain the long-term stability of a resin-eroded dentin interface formed by etch-and-rinse and self-etch adhesives.

Recent Advances in Adhesive Bonding - The Role of Biomolecules, Nanocompounds, and Bonding Strategies in Enhancing Resin Bonding to Dental Substrates

PURPOSE OF REVIEW

To present an overview on the main agents (i.e., biomolecules and nanocompounds) and/or strategies currently available to amplify or stabilize resin-dentin bonding.

RECENT FINDINGS

According to studies retrieved for full text reading (2014-2017), there are currently six major strategies available to overcome resin-dentin bond degradation: (i) use of collagen crosslinking agents, which may form stable covalent bonds with collagen fibrils, thus strengthening the hybrid layer; (ii) use of antioxidants, which may allow further polymerization reactions over time; (iii) use of protease inhibitors, which may inhibit or inactivate metalloproteinases; (iv) modification of the bonding procedure, which may be performed by using the ethanol wet-bonding technique or by applying an additional adhesive (hydrophobic) coating, thereby strengthening the hybrid layer; (v) laser treatment of the substrate prior to bonding, which may cause specific topographic changes in the surface of dental substrates, increasing bonding efficacy; and (vi) reinforcement of the resin matrix with inorganic fillers and/or remineralizing agents, which may positively enhance physico-mechanical properties of the hybrid layer.

SUMMARY

With the present review, we contributed to the better understanding of adhesion concepts and mechanisms of resin-dentin bond degradation, showing the current prospects available to solve that problematic. Also, adhesively-bonded restorations may be benefited by the use of some biomolecules, nanocompounds or alternative bonding strategies in order to minimize bond strength degradation.