Effect Of Deproteinization Research Articles

Sodium p-Toluenesulfinate Enhances the Bonding Durability of Universal Adhesives on Deproteinized Eroded Dentin.

The effects of deproteinization using sodium hypochlorite (NaOCl) and the subsequent application of an antioxidant (sodium p-toluenesulfinate, STS) onto the bonding durability of universal adhesives on eroded dentin were investigated. Untreated sound dentin served as the control, whereas eroded dentin, which had been prepared by pH-cycling in 1% citric acid and a remineralization solution, was either untreated, deproteinized with a 10% NaOCl gel or deproteinized with the 10% NaOCl gel and subsequently treated with an STS-containing agent. The dentin surfaces were bonded using a universal adhesive (Clearfil Universal Bond Quick, Scotchbond Universal or G-Premio Bond), and the micro-tensile bond strength (µTBS) test was performed after 24 h or 10,000 thermal cycles. The µTBS data were statistically analyzed using a three-way ANOVA and Tukey’s HSD post hoc tests. The lowest µTBS was measured on untreated eroded dentin (p < 0.001). Deproteinization of eroded dentin resulted in µTBS similar to untreated sound dentin (p > 0.05), but the highest µTBS was obtained if deproteinization was followed by the application of STS. Thermocycling significantly decreased µTBS in all groups (p < 0.001), except for STS-treated deproteinized eroded dentin (p > 0.05). This indicated that deproteinization, followed by the application of STS, could enhance the bonding durability of universal adhesives on eroded dentin.

Effects of deproteinization on rheological properties of polysaccharides from Rosa acicularis ‘Lu He’ and Rosa acicularis Lindl fruits

Polysaccharides from the fruits of Rosa acicularis are one of the main functional components with superior biological activities and physicochemical properties. Rosa acicularis 'Lu He' is a new variety derived from the wild type Rosa acicularis Lindl. A comparative study was performed on the chemical composition and rheological properties of polysaccharides of rosehip from Rosa acicularis 'Lu He' (RLHP) and Rosa acicularis Lindl (RLDP) before and after deproteinization. The polysaccharide extracts, regardless of deproteinization, were acidic heteropolysaccharides composed of 48.3–51.6% carbohydrate and 29.2–43.2% uronic acid on dry weight basis and small amounts of protein (1.8–6.2%) and polyphenol (2.1–6.3%). Steady shear and frequency scanning measurements were used to evaluate the changes in concentration, temperature, pH and salts on the apparent viscosity and dynamic viscoelasticity of polysaccharide of rosehip solutions. The results showed that the apparent viscosity of RLHP was higher than that of RLDP at the same concentrations (2–6%), while apparent viscosity of RLHP and RLDP increased by 7.2% and 20.5% after deproteinization, respectively. Solutions of polysaccharide of rosehip exhibited shear-thinning behaviors, and higher concentrations caused more significant pseudoplastic effects. The solution properties changed from pseudoplasticity to plasticity when the initial apparent viscosity was below 7.5 mPa s. Thixotropy of polysaccharides of rosehips was stronger after protein removal; moreover, the polysaccharides before deproteinization (RLHP-1, RLDP-1) exhibited better gel properties than the deproteinized polysaccharides (RLHP-2, RLDP-2). This rheological property information will help proper product design to ensure the stability of food products enhanced with polysaccharides from rosehips.

A green and efficient deproteination method for polysaccharide from Meretrix meretrix Linnaeus by copper ion chelating aerogel adsorption

Abstract Polysaccharides (PMM) from Meretrix meretrix Linnaeus exhibit a variety of biological activities; however, conventional purification methods are costly, time consuming and introducing toxic agents. This paper aimed to develop a green and efficient method for the deproteinization of PMM by copper ion chelating aerogel (CCA) adsorption. First, CCA was successfully prepared by copper ion chelating composite aerogel (CA). Then, CCA adsorption was applied to remove protein mixed in PMM. The optimal parameter conditions of this deproteinization method were screened, using the deproteinization rate (Dr%), polysaccharide recovery rate (Rr%) and selectivity coefficient (Kc) as evaluation indicators, by single factor experiment. The optimal conditions were obtained as follows: CCA dose of 1.4%, pH value of 5.0 and adsorption temperature of 30 °C. Under these conditions, equivalent Dr% (93.31 ± 1.33%), higher Rr% (93.34 ± 1.08%) and Kc (14.01 ± 0.46) were achieved compared with the latest reported deproteinization report. Finally, the effect of deproteinization between CCA adsorption and Sevag method, which is the most classical deproteinization method, were compared to verify the practicability of CCA adsorption. As a result, CCA adsorption not only showed much higher Rr% as well as Kc, but also would not cause any reagent contamination and environment pressure. In conclusion, CCA adsorption would be a green and highly efficient method with great potential in large-scale environmentally sustainable deproteinization of polysaccharides in the future.

The effects of deproteinization and primer treatment on microtensile bond strength of self-adhesive resin cement to dentin

본 연구의 목적은 탈단백(deproteinization)이나 추가적인 프라이머의 처리가 상아질과 자가접착형 레진 시멘트 사이의 미세인장결합강도에 미치는 영향을 평가하기 위함이다. 총 40개의 사람 제 3 대구치를 선별하여 아크릴 레진에 매몰한 후 교합면의 상아질을 노출시켰다. 표면을 600번 실리콘 카바이드 연마지로 연마하여 도말층을 형성한 후 노출된 상아질에 다음과 같이 처리하였다: 아무런 처리하지 않은 대조군; 탈단백제(5% 차아염소산나트륨) 처리; 프라이머(G-CEM ONE Adhesive enhancing primer, GC) 도포; 탈단백제 처리 후 프라이머 도포. 복합레진(Filtek Z250, 3M ESPE)을 지름 10 mm, 높이 4 mm의 원통형 플라스틱 주형에 2 mm씩 적층 충전 및 광중합한 후 표면 처리된 상아질에 자가접착형 레진 시멘트(G-CEM ONE, GC)를 적용하고 광중합하여 접착시킨다. 그 후 37℃ 증류수에 24시간 보관하고 단면이 1 mm2인 막대기 형태로 절단하여 미세인장결합강도를 측정하였다. 각 결과값은 one-way analysis of variance와 Tukey’s honestly significant difference test로 분석하였다. 실험 결과 상아질에 표면 처리를 한 그룹이 대조군에 비해 유의하게 높은 미세인장결합강도를 보였다(p0.05). 상아질에 프라이머를 단독 처리한 그룹에서 가장 높은 미세인장결합강도가 관찰되었다(p0.05). 탈단백제 처리나 탈단백제 처리 후 프라이머를 처리한 그룹은 그 다음으로 유의하게 높은 미세인장결합강도를 나타냈으며(p0.05) 두 그룹 사이에 유의한 차이는 관찰되지 않았다(p0.05). 결론적으로, 본 연구에 사용한 자가접착형 레진 시멘트는 상아질에 탈단백제나 특정 프라이머를 함께 사용하는 경우 접착력이 향상될 수 있으나 두 제제를 병용하는 것은 추천되지 않는다.

Evaluation of deproteinization on clinical success and longevity of pit and fissure sealants on erupting permanent first molars – An In vivo study

Objective: Higher protein content in the maturing enamel could hamper adequate etching for sealant application. Removing the organic content could improve its adhesion due surface alterations in the enamel. To enhance retention of sealants, higher protein content in immature permanent molar enamel could be deproteinized with sodium hypochlorite. Hence, the purpose of the study was to evaluate the effect of deproteinization with 5% sodium hypochlorite before and after acid etching on the longevity of pit and fissure sealants. Methodology: One hundred and five immature first permanent molar in 35 children aged 6–9 years were included. In Group A, a protocol of etching, bonding and sealant application was followed. In Group B and Group C, deproteinization was done after and before etching, respectively, followed by bonding and sealant application. Groups were examined at 3, 6, and 9 months for sealant retention using Simonsen's criteria. Results: Intergroup comparison for retained sealants across all three groups over 9 months revealed that retention is more in Group A, followed by Group B and least in Group C. Conclusion: Deproteinization does not have an added advantage in the retention of pit and fissure sealant over routine acid etching method. Deproteinization after etching is better compared to deproteinization before etching.

Effect of deproteinization on the shear bond strength of metallic orthodontic bracket bonded to enamel surface using self-etching primer

Effect of deproteinization on the shear bond strength of metallic orthodontic bracket bonded to enamel surface using self-etching primer

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

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. 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>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. 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.

Deproteinization of Fluorosed Enamel with Sodium Hypochlorite Enhances the Shear Bond Strength of Orthodontic Brackets: An In vitro Study.

Context:Improving bonding strength to fluorosed teeh.Aims:To determine the effect of deproteinization using 5.25% sodium hypochlorite (NaOCl) prior to acid etching on shear bond strength of orthodontic brackets bonded to fluorosed teeth.Settings and Design:In vitro experimental study.Methods and Material:Forty freshly extracted human mandibular first premolars with TFI 4 were selected and divided into two groups of 20 each. In Group I the teeth were acid etched with 37% phosphoric acid and bonded with composite. In Group II the teeth were deproteinized with 5.25% NaOCl prior to acid etching with 37% phosphoric acid and were bonded with composite. Samples were then subjected to shear bond test by Instron Universal Testing machine. The sample from each group were selected for the SEM study (prior to bonding) to analyze the etching patterns achieved.Statistical Analysis Used:Data was checked for normality by Shapiro Wilk Test, to compare the two groups unpaired t test was used. P value was predetermined at ≤ 0.05.Results:The S BS of Group II (11.75 ± 2.83 MPa) was higher than Group I (7.44 ± 2.43 MPa) and the difference was statistically significant (P = 0.000). On SEM the etching pattern was more of type 1 and 2 in Group II.Conclusions:Deproteinization using 5.25% NaOCl prior to acid etching significantly increases the shear bond strength of brackets bonded to fluorosed teeth and can be used as a convenient and effective option in orthodontic bonding to fluorosed teeth.

A Clinical Evaluation of Deproteinization and Different Cavity Designs on Resin Restoration Performance in MIH-Affected Molars: Two-Year Results.

The aim of this study was to evaluate the clinical effects of deproteinization of the hypomineralized enamel and different cavity designs on the performance of the composite resin restorations(CRRs) placed into the cavities of MIH (molar incisor hypomineralization)-affected molars. 95 MIH-affected permanent first molars (PFMs) and 31 caries but not MIH-affected PFMs (126 teeth in total) were included in the study. The MIH-affected molars were divided into three groups. In Group I, all hypomineralized tissue was removed until healthy enamel was reached. In Group II, carious and cheesy hypomineralized tissue was removed until a reasonable resistance was detected in the hypomineralized tissue. In Group III, cavities designed as Group II, differently from this group deproteinization of the left hypomineralized tissue was performed prior to the placement of CRRs. Group IV served as the control group consisting of unaffected carious PFMs. Restorations were evaluated according to modified USPHS criteria for 24 months. The retention rates were 93.7% for Group I, 80.7% for Group II, 93.5% for Group III and 100% for Group IV. The success rate for the restorations in Group II proved significantly lower (p<0.05) than that of the other three groups. No significant difference in success rates was observed between Group I, Group III and Group IV (p>0.05) at the end of 24 months. Failure of the restorations was predominant in the group that the hypomineralized tissue was left surrounding the cavities. Deproteinization of the hypomineralized enamel was found to enhance the retention rates of CRRs.

Effects of Processing Treatments on the Antioxidant Properties of Polysaccharide from Cordyceps militaris

Abstract: The effects of deproteinization and drying methods on the antioxidant activities and physiochemical properties of C. militaris polysaccharide were evaluated. The results showed that the IC50 of crude polysaccharide (CMP)was similar with that of deproteined polysaccharide by sevag (CMP-D-S), but significant higher (p &lt; 0.05)than that of deprotiened polysaccharie by enzyme (CMP-D-E)on DPPH· scavenging. The IC50 of CMP was significant higher (p &lt; 0.05)than that of CMP-D-S and CMP-D-E on OH· scavenging. Deproteinization by sevag or enzymatic method could not improve the antioxidant activity of C. militaris polysaccharide. However, drying methods influenced the antioxidant activities of C. militaris polysaccharide. Polysaccharide dried by freeze drying (CMP-F)showed respectively 55.47 % and 61.99 % higher OH· scavenging capacity on IC50 than that dried by hot air drying (CMP-H)and spray drying (CMP-S). The IC50 of CMP-F was 56.23 % higher than that of CMP-S, but similar with that of CMP-H on ABTS· scavenging. The reducing power of CMP-F was respectively 20.10 % and 27.25 % higher than that of CMP-H and CMP-S at 6 mg/mL. Spectroscopy analysis showed the dried CMPs were similar in IR and UV absorption. However, the monosaccharide ratio of CMP was changed by drying techniques. Morphological analysis showed that CMP-F consisted mainly of fluffy powder with rough and porous surface, CMP-S was spherical particle with smooth surface, and CMP-H was pyknotic and similar to anomalistic stones. Freeze drying was a recommendable method for antioxidant polysaccharide preparation from C. militaris.

Deproteinization stabilises dentin bonding of self-adhesive resin cements after thermocycling

This study examined the effect of deproteinization on the microtensile dentin bond strength (µTBS) and nanoleakage (NL) of conventional and self-adhesive resin cements after 24h or after 20,000 thermocycles. Occlusal dentin of thirty-two human molars were distributed into four groups according to the type of cement used: conventional or self-adhesive; and the strategy of luting: RelyX ARC/Single Bond 2 (RAc) following the manufacturer׳s instructions (control), RelyX ARC/Single Bond 2 (RAd) applied after dentin deproteinization; RelyX U200 (RUc) following the manufacturer´s instructions (control); RelyX U200 (RUd) applied after dentin deproteinization. The specimens were cut into non-trimmed dentin–composite sticks and the half sticks of each group were subdivided into two subgroups: 24h water storage and after 20,000 thermal cycles, before microtensile bond test. For NL, 5 bonded sticks from each subgroup were prepared and analyzed under SEM. Three-way ANOVA showed that the dentin deproteinization increased the µTBS of both cements, although the RAd group showed a decrease on the µTBS after thermocycling. Chi-square test showed significant loss of specimens by premature failure for the groups after thermocycling, except for the RUd group. The dentin deproteinization improved the initial µTBS and decreases the NL of both cements tested, but, after thermocycling, this technique is only effective for RelyX U200.

Consequences of enamel preparation with sodium hypochlorite, polyacrylic and phosphoric acids for the bonding of brackets with resin-modified glass ionomer cements

The aim of this study was to evaluate the effects of deproteinization with 5.25% sodium hypochlorite (NaOCl) prior to enamel conditioning with 10% polyacrylic acid (PAA) and 35% phosphoric acid (PA) on the bond strength (BS) of brackets bonded with resin-modified glass ionomer cement (RMGIC). One hundred human premolars extracted for orthodontic reasons were divided into 5 groups (n = 20 in each group): G1 (control), enamel conditioning with PA, application of adhesive and bonding of brackets with TransbondTM XT composite resin (3M/Unitek, Monrovia, CA, USA); G2, enamel conditioning with PAA and bonding with RMGIC (Fuji OrthoTM LC, GC America, Alsip, IL, USA); G3, NaOCl-treated enamel, conditioning with PAA and bonding with RMGIC; G4, enamel conditioning with PA and bonding with RMGIC; and G5, NaOCl-treated enamel, conditioning with PA and bonding with RMGIC. Once the brackets were bonded, the teeth were stored in distilled water for 24 hours at room temperature and pressure until being subjected to shear stress in a Universal Mechanical Testing Machine (EMIC® DL 500, São José dos Pinhais, PR, Brazil). The BS value was higher in G1 (17.08 ± 6.39) than in any of the experimental groups (p < 0.05). No statistically significant differences were noted between groups using RMGIC (p > 0.05), except between G3 (9.86 ± 2.90) and G5 (5.00 ± 2.49). No statistically significant differences were noted between the mean Adhesive Remnant Index values among the evaluated groups (p > 0.05). Conclusion: The use of NaOCl combined with PAA increased the BS of brackets bonded with RMGIC. The deproteinization of the group treated with PA reduced the shear bond strength of the brackets.

Dentin deproteinization effect on bond strength of self-adhesive resin cements

This study examined the effect of deproteinization on the bond strength between self-adhesive resin cements and dentin surfaces that were untreated (control), acid-etched, or acid-etched and subjected to a post-etch deproteinization treatment. Cylinders of RelyX Unicem or BisCem (n = 6) cement were build-up on the dentin surfaces and tested to determine shear strength. The results were analyzed using two-way ANOVA and Tukey's test (5%). While neither dentin pretreatment improved the bond strength for RelyX Unicem, deproteinization treatments resulted in greater bond strength in BisCem specimens while acid etching alone did not improve the performance of the material.

Effects of Deproteinization and Derivatization in Serum Preparation on Serum Metabolome Based on Gas Chromatography-Mass Spectrometry

The effects of different deproteinization and derivatization methods in serum sample preparation on metabolome were compared by gas chromatography-mass spectrometry.The relative standard derivations(RSD) of peak area and information content of profile were calculated.The principal components analysis(PCA),qualitative and quantitative analysis of serum samples and quality control samples(QC) were done.The RSD of QC and serum samples was less than 10%.The result of information content and PCA showed that these serum preparation methods were stable and reliable.The PCA result of profile produced by four preparation methods showed that the differences existed in serum metabolome when the samples were deproteinized and derivatizated by different reagents in preparation procedures.The influence of derivatization reagents on serum metabolome was great than that of deproteinization reagents.The information content of samples derivatizated by N-methyl-N-(trimethylsilyl) trifluoroacetamide(MSTFA)(8.9) was higher than that of samples derivatizated by BSTFA(8.7).Forty-four metabolites were obtained by qualitative analysis.Five metabolites were unique to samples derivatizated by MSTFA,and six metabolites were unique to samples derivatizated by N,O-Bis(trimethylsilyl) trifluoroacetamide(BSTFA).We proposed that when polar amino acids and short-chain fatty acids were concerned,BSTFA was recommended as derivatization reagent,and when nonpolar amino acids and long-chain fatty acids were concerned,MSTFA was recommended as derivatization reagent.

In vitro evaluation of the effect of deproteinization on the marginal leakage of resin restorations using three bonding agents

In vitro evaluation of the effect of deproteinization on the marginal leakage of resin restorations using three bonding agents

Effect of deproteinization on degree of oxidation of ozonated starch

Effects of deproteinization on the degree of oxidation of ozonated starch (corn, sago, and tapioca) were investigated. Starch in dry powder form was exposed to ozone for 10 min at different ozone generation times (OGTs: 1, 3, 5, 10 min), and then native starches (NS) and deproteinized starches (DPS) were analyzed for protein content. Deproteinization caused a significant reduction in protein content for corn (∼21%) and sago (∼16%) starches relative to NS. Carbonyl and carboxyl contents increased significantly in all ozonated deproteinized starches (ODPS) with increasing OGT. Carbonyl and carboxyl contents of ODPS ranged from 0.03 to 0.13% and 0.14 to 0.28%, respectively. The carboxyl content for all ODPS was significantly higher than that of ozonated native starches (ONS). A Rapid Visco Analyser was used to analyze pasting properties of all starches. Deproteinization increased the pasting viscosities of corn and sago starches compared to their native forms. Generally, pasting viscosity of all ODPS decreased drastically as OGT increased. At the highest oxidation level (10 min OGT), all ODPS exhibited the lowest pasting viscosities compared to their ozonated native form, except for peak viscosity, breakdown viscosity, and setback viscosity for ozonated deproteinized corn starch. In conclusion, deproteinization as a pretreatment prior to starch ozonation successfully increased the degree of oxidation in the three types of starch studied. However, the extent of starch oxidation varied among the different starches, possibly due to differences in rates of degradation on amorphous and crystalline lamellae and in rates of oxidation of carbonyl and carboxyl groups.

Effect of deproteinization and tubular occlusion on microtensile bond strength and marginal microleakage of resin composite restorations

Dentin adhesion procedure presents limitations, especially regarding to lifetime stability of formed hybrid layer. Alternative procedures have been studied in order to improve adhesion to dentin. Objective: The aim of this study was to evaluate in vitro the influence of deproteinization or dentin tubular occlusion, as well as the combination of both techniques, on microtensile bond strength μTBS) and marginal microleakage of composite resin restorations. Material and Methods: Extracted erupted human third molars were randomly divided into 4 groups. Dentin surfaces were treated with one of the following procedures: (A) 35% phosphoric acid gel (PA) + adhesive system (AS); (B) PA + 10% NaOCl + AS; (C) PA + oxalate + AS and (D) PA + oxalate + 10% NaOCl + AS. Bond strength data were analyzed statistically by two-way ANOVA and Tukey's test. The microleakage scores were analyzed using Kruskal-Wallis and Mann-Whitney non-parametric tests. Significance level was set at 0.05 for all analyses. Results: μTBS data presented statistically lower values for groups D and B, ranking data as A>C>B>D. The use of oxalic acid resulted in microleakage reduction along the tooth/restoration interface, being significant when used alone. On the other hand, the use of 10% NaOCl alone or in combination with oxalic acid, resulted in increased microleakage. Conclusions: Dentin deproteinization with 10% NaOCl or in combination with oxalate significantly compromised both the adhesive bond strength and the microleakage at interface. Tubular occlusion prior to adhesive system application seems to be a useful technique to reduce marginal microleakage.

Dentine deproteinization and microleakage around gingival third resin restorations

Objectives:A significant factor in achieving satisfactory adhesion of restorative resins to dentine substrate is the method by which the dentine surface is treated before an adhesive is applied. The aim of this study was to evaluate the effect of deproteinization on microleakage around gingival third resin restorations.Materials and Methods:Standardised Class V preparations were made on randomly selected intact upper and lower human molars. These were treated in one of five ways (no treatment, enamel etch only, total etch, total etch followed by deproteinization, and deproteinization only) and then adhesively bonded using either an acetone or ethanol based bonding system. The samples were first immersed in 2% methylene blue dye and then 35% nitric acid, for 72 hours each. The solutions were filtered and centrifuged, and the supernatant was used to determine absorbance in a spectrophotometer at 670 nm. The results were recorded as a measure of transmission of light of the test solutions.Results:The results were subjected to multiple comparisons amongst groups, using anova. There was a statistically significant difference between all treatment groups for the two different bonding systems used. The experimental groups, total etch alone and total etch followed by deproteinization showed statistically significant differences, as compared to all other groups. However, although the total etch group showed a decrease in microleakage, when compared to the total etch followed by deproteinization group, this was not statistically significant.Conclusion:Within the limitations of this study, collagen removal may be important to reduce microleakage whilst using acetone based adhesive systems and it may not influence the amount of microleakage for ethanol or water based adhesive systems.

Effect of deproteinization on composite bond strength in hypocalcified amelogenesis imperfecta

The aim of this study was to evaluate the effect of the treatment of sodium hypochlorite (NaOCl) after acid conditioning of the enamel and dentin of the primary teeth affected with hypocalcified amelogenesis imperfecta (HCAI) on the shear bond strength of the composite material. Primary teeth from a 12-year-old girl affected with HCAI and primary teeth collected from apparently healthy children were used. A total of four groups, experimental and control with and without NaOCl treatment were specified. In the control group conventional composite procedure was performed and in the treatment group 5% NaOCl was applied after acid conditioning and then the procedure continued as in the control group. In teeth affected with HCAI, enamel shear bond strengths were significantly enhanced in the treatment group compared with the conventional procedure. Deproteinization could be attributed as effective in enhancing the enamel bonding in HCAI teeth and could be used to overcome the high failure rates of adhesive restorations in HCAI cases.

Electrochemical Preparation of Chitin Materials

Electrochemical processes for preparation of various chitin materials are examined. Physicochemical and biochemical properties of the products are studied, particularly the effect of deproteinization and degreasing of chitin materials on their sorption and other characteristics.