A new concept in hybridization: Bromelain enzyme for deproteinizing dentin before application of adhesive system

Caries affected Dentin biomodification using Bromelain, Riboflavin photosensitizer via UVA, and Chitosan Nanoparticles on shear bond strength and microleakage scores: A SEM evaluation

AIMS

Assessment of the impact of different dentin bio-modifiers i.e., Bromelain, Riboflavin photosensitizer (RFP/Ultraviolet-A), and Chitosan nanoparticles (CHNPs) on the shear bond strength (SBS) and microleakage of composite bonded to acid etched carious affected dentin (CAD).

MATERIALS AND METHODS

Sixty-four human molars in which carious lesions extend till the middle third of the dentin were included. The infected dentin was removed and CAD was exposed. All specimens were categorized into four groups based on the application of dentin bio-modifier (n = 16) Group 1 (No dentin modifier), Group 2 (Bromelain), Group 3 (RFP/UVA), and Group 4 (CHNPs). Dental adhesive application and composite buildup were performed. A dye penetration test was used to assess marginal leakage. Resin CAD interface assessment was performed using SEM. For SBS and failure pattern analysis, a universal testing machine and stereomicroscope were used respectively. One-way ANOVA followed by Bonferroni's posthoc test was employed to analyze the differences among various groups (p≤0.05) RESULTS: The lowest microleakage (13.27 ± 0.10) and highest SBS (11.64 ± 0.16 MPa) were observed in Group 2 (Bromelain). However, the maximum values of marginal leakage (37.21 ± 0.21) and minimum SBS (7.34 ± 0.07 MPa) were detected in Group 1 samples. The length of resin tags in the Group 2 specimens (Bromelain) was found to be the highest (102.11 ± 5.12 μm). However, Group 1 (No modifier) exhibited the lowest resin tag length (50.45 ± 2.37 μm).

CONCLUSION

Caries-affected dentin modified with Bromelain resulted in satisfactory SBS with minimal microleakage scores. Chitosan nanoparticles and RFP/Ultraviolet-A also presented better outcomes in terms of microleakage and SBS than the control.

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.

Bromelain-based endodontic irrigant: preparation, properties, and biocompatibility: An in-vitro study

The aim of the study was to determine the properties, efficacy and biocompatibility of combining bromelain enzyme, chlorohexidine and EDTA (BCE) to create a novel endodontic irrigant. Fourier transform infrared spectrometry was performed to confirm the stability of the BCE and direct contact inhibition test was performed to determine antibacterial action. Baseline pH and surface tension of irrigants was compared with determine stability. Subcutaneous injection to dorsal skin of rabbits was graded for presence of inflammation, oedema, granulation and fibrosis. BCE caused less overall irritation, less oedematous and was earlier to heal than 2.5% NaOCl. The pH stability of BCE was also superior to 2.5% NaOCl. A one-way ANOVA test was performed for the direct contact inhibition and microleakage test. A significant difference was determined (p ≤ 0.05) between BCE and 2.5% NaOCl for antibacterial action. BCE irrigant is effective in preparing dentinal surfaces for root canal without adverse effects and promising longevity.

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.

Anti-Inflammatory and Mineralization Effects of Bromelain on Lipopolysaccharide-Induced Inflammation of Human Dental Pulp Cells

Background and Objectives: Bromelain is a mixture of protease obtained from pineapple fruits or stems. Even though the biological mechanism of action of bromelain has not been completely understood, it is well known that bromelain possesses anticancer, anti-inflammatory and immunomodulatory effects. This study investigated the anti-inflammatory effects of bromelain on lipopolysaccharide (LPS)-induced human dental pulp cells (hDPCs). Materials and Methods: Cell viability after bromelain treatment was measured using WST-1 assay. We exposed hDPCs to 5 µg/mL of LPS with 2.5 or 5 µg/mL of bromelain. We performed reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay to detect interleukin-1β, interleukin-6, and interleukin-8 levels. Western blots were used to detect intercellular adhesion molecules-1 (ICAM-1) and vascular cell adhesion molecules-1 (VCAM-1) levels. Immunofluorescence staining and Western blots were used to determine bromelain’s anti-inflammatory mechanism. We also performed alkaline phosphatase and Alizarin red staining to verify mineralization nodule formation. Results: Bromelain at 2.5, 5, 10, or 20 µg/mL did not affect the viability of hDPCs significantly. LPS increased interleukin-1β, interleukin-6, interleukin-8, ICAM-1 and VCAM-1 expression in hDPCs. Bromelain significantly decreased interleukin-1β, interleukin-6, interleukin-8, ICAM-1, and VCAM-1 levels in hDPCs, which were stimulated by LPS. Bromelain treatment significantly reduced p65 phosphorylation in the cytoplasm and the nucleus. It also significantly decreased phosphorylation levels of extracellular signal-related kinases (ERK) and p38 mitogen-activated protein kinases (p38). Bromelain also promoted ALP activity and mineralized nodule formation. Conclusions: Bromelain inhibits the expression of inflammatory cytokines in LPS-stimulated hDPCs. The inhibitory effect of bromelain on inflammatory mediators is related to decreased NF-κB and the MAPK pathway. Therefore, bromelain might have the potential to be used for regenerative endodontics, including vital pulp therapy.

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.

Effect of bromelain enzyme on the microleakage of composite resin restorations after external tooth bleaching: An in vitro study

Aims:

The aim of this study is to evaluate in vitro the effect of application of bromelain enzyme on the microleakage of composite resin restorations after external tooth bleaching using spectrophotometric evaluation.

Subjects and Methods:

Buccal Class V cavities were prepared on the surface of fifty intact premolars, which were randomly divided into five groups. All cavities were filled with composite resin.

Group I: Teeth were not bleached but restored (n = 10). External bleaching with 35% hydrogen peroxide was carried out for the rest of the specimens

Group II: Cavities were restored immediately after bleaching (n = 10)

Group III: Cavities were restored after a delay of 3 weeks (n = 10)

Group IV: Cavities were treated with sodium ascorbate after bleaching and then restored (n = 10)

Group V: Cavities were treated with bromelain enzyme solution after bleaching and then restored (n = 10). Microleakage was assessed by the dye extraction method using a spectrophotometer.

Statistical Analysis Used:

The data were analyzed statistically by comparison of mean microleakage and post hoc test using SPSS 2.0 software.

Results:

Group I displayed the least amount of microleakage, whereas Group II showed the greatest amount of microleakage (P < 0.05). Groups III, IV, and V showed a significantly lower amount of microleakage compared to Group II (P < 0.05). There was no statistically significant difference between Groups IV and V.

Conclusions:

Microleakage increased significantly after external bleaching with 35% hydrogen peroxide, and decreased when the bleached teeth were treated with antioxidants. Ten percent bromelain enzyme was effective in decreasing microleakage; however, its efficacy was similar to 10% sodium ascorbate.

Collagenolytic Enzymes and their Applications in Biomedicine

Nowadays, enzymatic therapy is a very promising line of treatment for many different diseases. There is a group of disorders and conditions, caused by fibrotic and scar processes and associated with the excessive accumulation of collagen that needs to be catabolized to normalize the connective tissue content. The human body normally synthesizes special extracellular enzymes, matrix metalloproteases (MMPs) by itself. These enzymes can cleave components of extracellular matrix (ECM) and different types of collagen and thus maintain the balance of the connective tissue components. MMPs are multifunctional enzymes and are involved in a variety of organism processes. However, under pathological conditions, the function of MMPs is not sufficient, and these enzymes fail to deal with disease. Thus, medical intervention is required. Enzymatic therapy is a very effective way of treating such collagen-associated conditions. It involves the application of exogenous collagenolytic enzymes that catabolize excessive collagen at the affected site and lead to the successful elimination of disease. Such collagenolytic enzymes are synthesized by many organisms: bacteria, animals (especially marine organisms), plants and fungi. The most studied and commercially available are collagenases from Clostridium histolyticum and from the pancreas of the crab Paralithodes camtschatica, due to their ability to effectively hydrolyse human collagen without affecting other tissues, and their wide pH ranges of collagenolytic activity. In the present review, we summarize not only the data concerning existing collagenase-based medications and their applications in different collagen-related diseases and conditions, but we also propose collagenases from different sources for their potential application in enzymatic therapy.

Trends and Prospects of Plant Proteases in Therapeutics

The main function of proteases in any living organism is the cleavage of proteins resulting in the degradation of damaged, misfolded and potentially harmful proteins and therefore providing the cell with amino acids essential for the synthesis of new proteins. Besides this main function, proteases may play an important role as signal molecules and participate in numerous protein cascades to maintain the vital processes of an organism. Plant proteases are no exception to this rule. Moreover, in contrast to humanencoded enzymes, many plant proteases possess exceptional features such as higher stability, unique substrate specificity and a wide pH range for enzymatic activity. These valuable features make plant-derived proteolytic enzymes suitable for many biomedical applications, and furthermore, the plants can serve as factories for protein production. Plant proteases are already applied in the treatment of several pathological conditions in the human organism. Some of the enzymes possess antitumour, antibacterial and antifungal activity. The collagenolytic activity of plant proteases determines important medical applications such as the healing of wounds and burn debridement. Plant proteases may affect blood coagulation processes and can be applied in the treatment of digestive disorders. The present review summarizes recent advances and possible applications for plant proteases in biomedicine, and proposes further development of plant-derived proteolytic enzymes in the biotechnology and pharmaceutical industries.

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

Aims:

To assess the deproteinizing effect of bromelain enzyme and compare it with 5% sodium hypochlorite (NaOCl) on shear bond strength before application of the adhesive system.

Materials and Methods:

A total of 30 extracted human premolars were divided into three groups, each one consisted of 10 teeth. The occlusal surface was wet ground to expose superficial dentin. In Group 1, teeth were etched; in Group 2, teeth were etched and deproteinized with bromelain enzyme; in Group 3, teeth were etched and deproteinized with 5% NaOCl. Upon completion of the adhesive procedures, resin composite was inserted into the plastic tube and light-polymerized. All specimens were stored at 37°C in water for 24 h, and the specimens were transferred to the universal testing machine, and then subjected to shear bond strength analysis at a crosshead speed of 1.0 mm/min.

Statistical Analysis Used:

Data were statistically analyzed using one-way analysis of variance and unpaired t-test at a significance level of 0.05. The statistical analysis was performed using SPSS version 12.0.1 for Windows (SPSS Inc., Chicago, IL, USA).

Results:

The bond strength results were significantly influenced by the application of bromelain enzyme. Statistically significant differences were not demonstrated in control group and NaOCl-treated group. The highest bond strength was seen in bromelain enzyme-treated group.

Conclusions:

Within the limitations of the present study, it was concluded that removal of unsupported collagen fiber with bromelain enzyme after acid etching results in improved bond strength.