Effect of Tannic Acid Application on Durability of Bond of Etch and Rinse Adhesive Resins

Aim: To determine the effect of different concentrations and application times of tannic acid on bond strength to dentin. Materials and Methods: Occlusal surfaces of 180 human molars were randomly divided into two groups of immediate shear bond strength evaluation and evaluation after 2 months of storage in collagenase solution. Each group was divided into 10 subgroups according to the solutions applied: no additional treatment (control), chlorhexidine 2% (Positive control), tannic acid 20% (30s, 1 min, 3min, 5min) and Tannic acid 30% (30s, 1 min, 3 min, 5 min). Failure mode were assessed using a stereo-microscope. The data were statistically analyzed by One-way ANONA and Tukey’s post hoc test. Results: There was no significant difference in immediate bond strength among experimental groups. However, after 2 months storage in collagenase solution, a significant difference was found among the groups.  Bond strengths of CHX and 20% TA applied for 3 minute were significantly higher than the control group. Conclusion: Use of tannic acid and chlorhexidine has no negative effect on immediate shear bond strength. However, their application significantly prevents compromised bond strength caused by storage in collagenase solution

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

Rigid Rod Polymer Fillers in Acrylic Denture and Dental Adhesive Resin Systems

Polymeric materials have been used in dental applications for decades. Adhesion of polymeric materials to each other and to the tooth substrate is essential to their successful use. The aim of this series of studies was two-folded. First, to improve adhesion of poly(paraphenylene) based rigid rod polymer (RRP) to other dental polymers, and secondly, to evaluate the usability of a new dentin primer system based on RRP fillers. Poly(paraphenylene) based RRP would be a tempting material for dental applications because of its good mechanical properties. To be used in dental applications, reliable adhesion between RRP and other dental polymers is required. In this series of studies, the adhesion of RRP to denture base polymer and the mechanical properties of RRP-denture base polymer-material combination were evaluated. Also adhesion of BisGMA-TEGDMA-resin to RRP was determined. Different surface treatments were tested to improve the adhesion of BisGMA-TEGDMA-resin to RRP. Results were based on three-point bending testing, Vickers surface hardness test and scanning electron microscope analysis (SEM), which showed that no reliable adhesion between RRP and denture base polymer was formed. Addition of RRP filler to denture base polymer increased surface hardness and flexural modulus but flexural strength decreased. Results from the shear bond strength test and SEM revealed that adhesion between resin and RRP was possible to improve by surface treatment with dichloromethane (DCM) based primer and a new kind of adhesive surface can be designed. The current dentin bonding agents have good immediate bond strength, but in long term the bond strength may decrease due to the detrimental effect of water and perhaps by matrix metalloproteinases. This leads to problems in longevity of restorations. Current bonding agents use organic monomers. In this series of studies, RRP filled dentin primer was tested in order to decrease the water sorption of the monomer system of the primers. The properties of new dentin primer system were evaluated in vitro by comparing it to commercial etch and rinse adhesive system. The results from the contact angle measurements and SEM showed that experimental primer with RRP reinforcement provided similar resin infiltration to dentin collagen and formed the resin-dentin interface as the control primer. Microtensile bond strength test and SEM revealed that in short term water storing, RRP increased bond strength and primer with BMEP-monomer (bis[2-(methacryloyloxy)-ethyl]phosphate) and high solvent concentration provided comparable bonding properties to the commercial control primers. In long term water storing, the high solvent-monomer concentration of the experimental primers decreased bond strength. However, in low solvent-monomer concentration groups, the long-term water storing did not decrease the bond strength despite the existence of hydrophilic monomers which were used in the system. These studies demonstrated that new dentin primer system reached the mechanical properties of current traditional etch and rinse adhesive system in short time water storing. Improved properties can be achieved by further modifications of the monomer system. Studies of the adhesion of RRP to other polymers suggest that adhesion between RRP and other dental polymers is possible to obtain by certain surface treatments.Rigid rod polymeeri fillerit akryylisissä pohjalevypolymeereissä ja hammaslääketieteen adhesiiviresiini systeemeissä Polymeerejä on käytetty hammaslääketieteessä vuosikymmeniä. Polymeerien kiinnittyminen toisiin polymeereihin ja hampaaseen on välttämätöntä niiden kliiniselle käytölle. Tällä väitöskirjatyöllä oli kaksi tavoitetta. Ensinnä kehittää menetelmiä poly(paraphenyleeni)-pohjaisen rigid rod -polymeerin (RRP) kiinnittämiseksi muihin hammaslääketieteessä käytettyihin polymeereihin ja toiseksi arvioida uudentyyppisen RRP-vahvistetun dentiiniprimerin ominaisuuksia hammaspaikka-aineen kiinnittämiseksi hampaaseen. Poly(paraphenyleeni)-pohjainen RRP on houkutteleva materiaali hammaslääketieteelliseen käyttöön hyvien mekaanisten ominaisuuksien vuoksi. Jotta RRP:ä voitaisiin hyödyntää kliinisessä käytössä, olisi löydettävä keino kiinnittää RRP muihin hammaslääketieteen polymeereihin. Väitöskirjatyön tutkimuksissa arvioitiin RRP:n kiinnittymistä proteesin pohjalevypolymeeriin ja samalla tutkittiin RRP-pohjalevypolymeeri-materiaaliyhdistelmän mekaanisia ominaisuuksia. Niin ikään tutkittiin BisGMA-TEGDMA-resiinin kiinnittymistä RRP:in. Tutkimuksissa arvioitiin myös erilaisten pintakäsittelymenetelmien vaikutusta resiinin ja RRP:n väliseen sidokseen. Kolmipistetaivutuskokeista, pintakovuustesteistä ja pyyhkäisyelektronimikroskooppianalyysista saadut tulokset osoittivat, että RRP ei kiinnity luotettavasti proteesin pohjalevypolymeeriin. RRP-täyteaineen lisääminen kasvatti taivutusmoduulia ja pintakovuutta, mutta laski taivutuslujuutta. Tulokset sidoslujuustesteistä ja elektronimikroskooppianalyysistä osoittivat, että sidos resiinin ja RRP:n välille on mahdollista saavuttaa. Dikloorimetaani-pohjainen primeri paransi sidoslujuutta ja muodosti uudenlaisen sidospinnan RRP:n pinnalle. Nykyisillä dentiinisidosaineilla on saatavissa hyvä välitön sidoslujuus hampaan ja paikka-aineen välille, mutta pitempiaikainen sidoslujuus heikkenee veden imeytymisen ja mahdollisesti matriksimetalloproteinaasien toiminnan myötä. Tämä aiheuttaa ongelmia kliinisessä työssä. Nykyiset dentiinisidosaineet sisältävät orgaanisia monomeereja. Tämän väitöskirjatyön tavoitteena oli yrittää kehittää RRP-vahvistettu dentiiniprimeri, joka vähentäisi vedenimeytymisen haitallisia vaikutuksia. Kokeellisen primerin ominaisuuksia verrattiin kaupalliseen “etch-and-rinse” sidosaineeseen. Tulokset kontaktikulmamittauksista ja elektronimikroskooppianalyysistä osoittivat, että kokeellinen primeri edesauttaa adhesiivin tunkeutumista dentiinin kollageeniverkostoon kaupallisen primerin tavoin. Mikrovetolujuustesti ja elektronimikroskooppianalyysi paljastivat, että lyhyessä vesisäilytyksessä RRP nosti sidoslujuutta ja hydrofiilinen korkean liuotinpitoisuuden omaava primeri tarjosi samanlaiset mekaaniset ominaisuudet kuin kaupallinen kontrolli materiaali. Pitkässä vesisäilytyksessä korkea liuotinpitoisuus laski kuitenkin sidoslujuutta, kun taas pienen liuotinpitoisuuden omaava primeri säilytti mekaaniset ominaisuutensa käytetyistä hydrofiilisistä monomeereistä huolimatta. Väitöskirjatyön tutkimukset osoittivat, että kokeellisella primerilla saavutettiin lyhyessä vesisäilytyksessä samat ominaisuudet kuin kaupallisella kontrolliprimerilla. Kokeellisen primerin ominaisuuksia voitaneen edelleen parantaa modifioimalla monomeerikoostumusta. Lisäksi tutkimukset osoittivat, että RRP voidaan kiinnittää muihin hammaslääketieteen polymeereihin pintakäsittelymenetelmien avulla.Siirretty Doriast

Effect of Chlorhexidine and Green Tea Extract Application on The Microtensile Bond Strength and Durability of Etch-and-Rinse Adhesives.

Introduction: Despite improvements in dentin bonding, the bond will be demolished over time and decreased by water and matrix metalloproteinase (MMP). This study aimed to evaluate the effects of the combination of different methods of MMP inhibition and detect the possible synergic effect on strength and bond durability. Methods: Thirty human third molar teeth without any cracks or decay were used in this study. The occlusal surface of teeth were removed, and dentine surfaces were flattened with silicon carbide plates. After preparing for restoration, teeth were divided into 4 groups, including 1- the control group, 2- the chlorhexidine (CHX) 2% group, 3- the green tea (GT) extract 15%+rinse+CHX 2% in 30 sec, and 4- GT extract15%+rinse+CHX 2% in 60 sec for the application time of GT. Composite samples were divided into two groups, and microtensile bond strength was evaluated immediately and 3 months after storage in water. The fracture type of samples was then evaluated using a stereomicroscope. Results: The immediate bond strength had no significant difference in experimental groups. The mean bond strength for GT+CHX in 30 and 60 sec after a 3-month storage had a significant difference with the 3-month storage control group, however, not significant with the immediate control group. Conclusion: The use of GT extract with CHX led to bond durability after a 3-month storage. Further studies are required for investing the in vivo effect of this combination

An in vitro study of the microleakage of a compomer (polyacid modified resin composite) bonded to enamel and dentine with different bonding systems and the effect of saliva contamination there of.

Magister Scientiae Dentium - MSc(Dent)Restorative systems classified as polyacid modified composite resins, or compomers, have appeared on the market. An example of this is Dyract AP. Dyract AP must be used with the Prime & Bond NT bonding system. Prime & Bond NT can be applied without any form of prior etching, or it can be applied after application of Non Rinse Conditioner, or it can be applied after etching with 36% phosphoric acid. The purpose of the study was to determine the qualitative microleakage of Dyract AP and its bonding systems, as well as the influence of saliva contamination there of. Freshly extracted, non-carious, human premolars were randomly divided into 8 groups of 18 teeth each. Apiseetomies coated with Polivar varnish and restored with amalgam were performed on all teeth. Class V type cavities of 3 mm diameter and 1,5 mm depth were prepared on the CEJ junction on the buccal side of all teeth. Dyract AP restorations were placed using the bonding procedures indicated: Group 1: P&B NT (Prime & Bond NT); group 2: acid (36% phosphoric acid) + P&B NT; group 3: NRC (Non Rinse Conditioner) + P&B NT; group 4: P&B NT + Saliva; group 5: acid + Saliva + P&B NT; group 6: acid + P&B NT + Saliva; group 7: NRC + Saliva + P&B NT; group 8: NRC + P&B NT + Saliva. Restorations were finished with Sof-Lex discs. After 24 hours storage in distilled water the teeth were removed and coated with two layers of nail varnish, except for 1 mm around the restorations. The teeth were then thermocycled in a 0.5% basic fuchsin solution for 500 complete cycles between 8°C and 50°C, with a dwell time of 15 seconds

Effect of Collagen Crosslinkers on Dentin Bond Strength of Adhesive Systems: A Systematic Review and Meta-Analysis

This study aimed to identify the role of crosslinking agents in the resin-dentin bond strength (BS) when used as modifiers in adhesives or pretreatments to the dentin surface through a systematic review and meta-analysis. This paper was conducted according to the directions of the PRISMA 2020 statement. The research question of this review was: "Would the use of crosslinkers agents improve the BS of resin-based materials to dentin?" The literature search was conducted in the following databases: Embase, PubMed, Scielo, Scopus, and Web of Science. Manuscripts that reported the effect on the BS after the use of crosslinking agents were included. The meta-analyses were performed using Review Manager v5.4.1. The comparisons were performed by comparing the standardized mean difference between the BS values obtained using the crosslinker agent or the control group. The subgroup comparisons were performed based on the adhesive strategy used (total-etch or self-etch). The immediate and long-term data were analyzed separately. A total of 50 articles were included in the qualitative analysis, while 45 articles were considered for the quantitative analysis. The meta-analysis suggested that pretreatment with epigallocatechin-3-gallate (EGCG), carbodiimide, ethylenediaminetetraacetic acid (EDTA), glutaraldehyde, and riboflavin crosslinking agents improved the long-term BS of resin composites to dentin (p ≤ 0.02). On the other hand, the use of proanthocyanidins as a pretreatment improved both the immediate and long-term BS values (p ≤ 0.02). When incorporated within the adhesive formulation, only glutaraldehyde, riboflavin, and EGCG improved the long-term BS to dentin. It could be concluded that the application of different crosslinking agents such as carbodiimide, EDTA, glutaraldehyde, riboflavin, and EGCG improved the long-term BS of adhesive systems to dentin. This effect was observed when these crosslinkers were used as a separate step and when incorporated within the formulation of the adhesive system

Bonding Strength to Teeth with Amelogenesis Imperfecta

Background Amelogenesis Imperfecta (AI) is an inherited dental condition of enamel, which can cause increased tooth sensitivity, difficulties maintaining oral hygiene, rapid tooth loss or enamel fractures, as well as defects in enamel thickness, colour, and shape. All these factors may impair aesthetic appearance and masticatory ability, requiring dental treatment for a lifetime which may affect their overall quality of life. Aim: 1. To assess the burden of care for children with AI attending the Paediatric Dental Department at the Eastman Dental Hospital (EDH). 2. To review the available scientific evidence on the adhesive interface between AI affected teeth and restorative materials. 3. To analyze different AI classifications quoted in the literature, to determine the consistency and standardization of reporting on AI classifications. Material and method: A service evaluation of AI patients being treated in the department from 2002- 2019. Two systematic searches were conducted using search terms in both electronic and hand search journals. Results: The burden and impact of care audit showed the average number of appointments per year was 5, (SD=2.5). The average distance travelled to the hospital was 33.7 miles (SD =30 miles) and the treatment provided included: • Extractions - majority in hypoplastic group (78%, n=10). • Composite restorations - hypoplastic (66%, n=18), mixed (16%, n=4). • Indirect coronal restorations – hypoplastic (67%, n=17), mixed (12%, n=3). • Bleaching and microabrasion - most performed in hypomature group (56%, n= 8 and 67%, n=5 respectively). • More failed composite restorations occurred in hypocalcified (25%, n=4) and mixed type (23%, n=40) with debonding being the most common reason. In the systematic review of bonding strength to AI affected teeth, studies showed a lower bonding strength of AI affected teeth in comparison to sound teeth. The bonding strength of composite was not significantly different when using self-etch compared with etch and rinse adhesives and deproteinization with sodium hypochlorite had no effect on shear bond strength, but chlorine dioxide and sodium fluoride showed better values in enhancing bonding strength. In the review of classification of AI papers did not use or cite a classification (n=12, 36%) and 43% only described the phenotype with no information regarding the basic genetic information if known. Those results are elaborated in each chapter in detail. Conclusion: The service evaluation provides data on the burden of care for children with AI. The high number of appointments, treatment needs, and miles travelled illustrate the scope of complications that can occur and stress the need for comprehensive management of this condition. Lower bonding strength values and durability of restorations to AI affected teeth requires further laboratory studies. There are variations and inconsistencies of classification used for studies published from 2015

Antibacterial and Bonding Properties of Universal Adhesive Dental Polymers Doped with Pyrogallol

This study investigated the antibacterial activity, bond strength to dentin (SBS), and ultra-morphology of the polymer–dentin interface of experimental adhesive systems doped with pyrogallol (PY), which is a ubiquitous phenolic moiety that is present in flavonoids and polyphenols. A universal adhesive containing 4-META and 10-MDP was used in this study. PY behaves as an antioxidant and anti-cancerogenic agent and it was incorporated into the adhesive at different concentrations (0.5 and 1 wt.%). The antibacterial activity and SBS were analyzed and the results were statistically analyzed. The ultra-morphology of the polymer–dentin interface was assessed using scanning electron microscopy (SEM). At 24 h, a lower antibacterial activity was observed for the control adhesive compared to those with 0.5% and 1% PY. No difference was seen in SBS between the three groups at 24 h. After 6 months, the SBS of the 0.5% PY adhesive was significantly lower than the other tested adhesives. The specimens created with 1% PY adhesive presented a higher bond strength at six months compared with that found at 24 h. No morphological differences were found at the polymer–dentin interfaces of the tested adhesives. Pyrogallol may be incorporated into modern universal adhesive systems to preserve the polymer–dentin bonding interface and confer a certain degree of antibacterial activity.</jats:p

Nanotechnology in dentistry: prevention, diagnosis, and therapy

Ensanya Ali Abou Neel,1&ndash;3 Laurent Bozec,3 Roman A Perez,4,5 Hae-Won Kim,4&ndash;6 Jonathan C Knowles3,5 1Division of Biomaterials, Operative Dentistry Department, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia; 2Biomaterials Department, Faculty of Dentistry, Tanta University, Tanta, Egypt; 3UCL Eastman Dental Institute, Biomaterials and Tissue Engineering, London, UK; 4Institute of Tissue Regenerative Engineering (ITREN), 5Department of Nanobiomedical Science and BK21 Plus NBM Global Research Center for Regenerative Medicine, 6Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan, Republic of Korea Abstract: Nanotechnology has rapidly expanded into all areas of science; it offers significant alternative ways to solve scientific and medical questions and problems. In dentistry, nanotechnology has been exploited in the development of restorative materials with some significant success. This review discusses nanointerfaces that could compromise the longevity of dental restorations, and how nanotechnolgy has been employed to modify them for providing long-term successful restorations. It also focuses on some challenging areas in dentistry, eg, oral biofilm and cancers, and how nanotechnology overcomes these challenges. The recent advances in nanodentistry and innovations in oral health-related diagnostic, preventive, and therapeutic methods required to maintain and obtain perfect oral health, have been discussed. The recent advances in nanotechnology could hold promise in bringing a paradigm shift in dental field. Although there are numerous complex therapies being developed to treat many diseases, their clinical use requires careful consideration of the expense of synthesis and implementation. Keywords: nanotechnology, nanointerfaces, biofilm-related oral diseases, tissue engineering, drug delivery, toxicit