Dentin Biomodification Research Articles

Influence of Natural Dentin Biomodification Agent on Push-Out Bond Strength and Nanoleakage of Self-Adhesive Resin Cement Luting of Glass-Fiber Posts.

To evaluate the plant-derived compound lignin (LIG) as a pretreatment of intraradicular dentin in combination with EDTA on push-out bond strength (PBS) and nanoleakage of the glass fiber posts (GFPs) cemented using adhesive resin cement. Twenty-eight human incisor roots were prepared for GFP cementation and divided based on dentin pretreatment: (1) CONTROL: no pretreatment, (2) EDTA: 17% EDTA for 3 min, (3) EDTA-LIG: 17% EDTA and 2% lignin for 3 min, (4) EDTA-PAC: 17% EDTA and 2% lignin for 3 min. The GFPs were cemented using the self-adhesive resin cement Multilink Speed. The roots (n = 7) were sectioned into 1 mm-thick discs and subjected to PBS testing after 1 week or 6 months. Nanoleakage was analyzed by SEM. Statistical analysis was performed using two-factor ANOVA and Tukey's test (p < 0.05). Higher PBS was identified for the CONTROL group (p < 0.001). After 6 months, the EDTA-LIG maintained the bond strength with a predominance of mixed failures, while the EDTA-PAC, EDTA, and CONTROL groups showed reduction of bond strength, with a predominance of adhesive failures along with severe silver infiltration in the interface. LIG associated with EDTA as a pretreatment for intraradicular dentin shows significant potential for attaining stable bond strength and interfacial integrity of self-adhesive resin cement to intraradicular dentin.

An in vitro assessment of the influence of dentinal pretreatment with chlorhexidine, nonthermal atmospheric plasma, chitosan, and proanthocyanidins on shear bond strength to composite.

Dentin biomodification has been emphasized as a means of improving the bond between composite resin and tooth surface, consequently enhancing its longevity. To evaluate the shear bond strength (SBS) of dentin after pretreatment with 2% chlorhexidine (CHX), 2% chitosan, nonthermal atmospheric plasma (NTAP), proanthocyanidins (5% pine bark ((PB) and 5% bromelain). The study was designed as an in vitro investigation. Sixty extracted mandibular molars (n = 60) were gathered for this in vitro research. The teeth were decoronated to expose the dentinal surface. All samples have been etched with 37% phosphoric acid and then pretreated with respective dentin biomodifiers. Group I (control): No pretreatment was done, Group II: 2% CHX, Group III: NTAP, Group IV: 5% PB, Group V: 2% chitosan, Group VI: 5% bromelain. Specimens were evaluated for the SBS test, which was done under the instron universal machine at a speed of 1 mm/min after a bonding agent and composite build-up were applied. While Group I had the lowest SBS (10.391.59Mpa), Group V had the highest SBS (30.111.53 Mpa). Pretreatment of the dentin enhanced the SBS of dentin to composite. When utilized after etching, dentin biomodification increased all experimental group's bond strength in contrast to the control. The highest SBS values were recorded with 2% chitosan, followed by NTAP.

Effects on dentin nanomechanical properties, cell viability and dentin wettability of a novel plant-derived biomodification monomer

ObjectivesTo evaluate the effects of dentin biomodification agents (Proanthocyanidin (PAC), Cardol (CD) and Cardol-methacrylate (CDMA) on dentin hydrophilicity by contact angle measurement, viability of dental pulp stem cells (DPSCs) and nanomechanical properties of the hybrid layer (HL). MethodsCDMA monomer was synthesized from cardol through methacrylic acid esterification. Human extracted third molars were used for all experiments. For nanomechanical tests, specimens were divided in four groups according to the primer solutions (CD, CDMA, PAC and control) were applied before adhesive and composite coating. Nanomechanical properties of the HL were analyzed by nanoindentation test using a Berkovich probe in a nanoindenter. Wettability test was performed on dentin surfaces after 1 min biomodification and measured by contact angle analysis. Cytotoxicity was assessed by a MTT assay with DPSCs after 48 and 72 h. Data were analyzed with Student's t test or Two-way ANOVA and Tukey HSD test (p < 0.05). ResultsCD and CDMA solutions achieved greater hydrophobicity and increased the water-surface contact angles when compared to PAC and control groups (p < 0.05). PAC group showed a greater reduction of elastic modulus in nanoindentation experiments when compared to CD and CDMA groups (p < 0.05) after 4 months of aging. CD inhibited cell proliferation compared to all further materials (p < 0.05), whilst CDMA and PAC indicated no cell cytotoxicity to human DPSCs. SignificanceCardol-methacrylate provided significantly higher hydrophobicity to dentin and demonstrated remarkable potential as collagen crosslinking, attaining the lowest decrease of HL’s mechanical properties. Furthermore, such monomer did not affect pulp cytotoxicity, thereby highlighting promising feasibility for clinical applications.

Chemical Transformation of B- to A-type Proanthocyanidins and 3D Structural Implications.

In nature, proanthocyanidins (PACs) with A-type linkages are relatively rare, likely due to biosynthetic constraints in the formation of additional ether bonds to be introduced into the more common B-type precursors. However, A-type linkages confer greater structural rigidity on PACs than do B-type linkages. Prior investigations into the structure-activity relationships (SAR) describing how plant-derived PACs with B- and complex AB-type linkages affect their capacity for dentin biomodification indicate that a higher ratio of double linkages leads to a greater interaction with dentin type I collagen. Thus, A-type PACs emerge as particularly intriguing candidates for interventional functional biomaterials. This study employed a free-radical-mediated oxidation using DPPH to transform trimeric and tetrameric B-type PACs, 2 and 4, respectively, into their exclusively A-type linked analogues, 3 and 5, respectively. The structures and absolute configurations of the semisynthetic products, including the new all-A-type tetramer 5, were determined by comprehensive spectroscopic analysis. Additionally, molecular modeling investigated the conformational characteristics of all trimers and tetramers, 1-5. Our findings suggest that the specific interflavan linkages significantly impact the flexibility and low-energy conformations of the connected monomeric units, which conversely can affect the bioactive conformations relevant for dentin biomodification.

Biomodification of eroded and abraded dentin with epigallocatechin-3-gallate (EGCG)

This study aimed to evaluate in vitro the effects of epigallocatechin-3-gallate (EGCG) as a biomodifier of eroded and abraded dentin. Forty dentin specimens were obtained from the buccal surface of bovine teeth. The specimens were randomly distributed in 4 groups according to dentin substrate: sound or eroded/abraded and dentin biomodification: with 0.5% EGCG and no biomodification (control group). Specimens were subdivided according to aging time: 24 h and 3 months for the analysis of microtensile bond strength (n = 10), morphology of the adhesive interface by SEM (n = 3) and dentin micropermeability by fluorescence microscope (n = 8). Statistical analysis was performed using SPSS system version 20.0 with a significance level of 5%. The results revealed that the control group with eroded-abraded dentin exhibited the lowest bond strength values at 24 h and 3 months. However, the application of 0.5% EGCG as a biomodifier significantly increased bond strength on both sound and eroded-abraded substrates. After 3 months, all groups exhibited an adhesive interface with a more intense fluorescence in the adhesive layer, indicating an increase in porosity at the interface. In conclusion, the EGCG application as a biomodifier enhanced bond strength on both sound and eroded-abraded dentin substrates, however, adhesive interfaces are more regular when restorations are performed on sound dentin, regardless of the biomodification with EGCG.

Effect of Delayed Endodontic Sealing with Dentin Biomodification on Fracture Resistance of Endodontically Treated Teeth

Aim: Endodontically treated teeth display altered tooth structure pertaining to various chemical irrigants and intracanal medicaments. To prevent the compromised adhesive bond, dentin biomodification is indicated. This study was designed to evaluate the influence of dentin biomodification on the fracture resistance of root canal-treated teeth following Delayed Endodontic Sealing (DES). Materials and Methods: In 50 maxillary central incisors, Class III cavities along with access cavities were prepared. The samples were randomly divided into five groups. Group 1: Intact teeth ( N = 10), Group 2: Immediate Endodontic Sealing (IES) ( N = 10); Group 3: DES after irrigation with 3% NaOCl ( N = 10); Group 4: DES with 2% chlorhexidine (CHX) as a biomodifier ( N = 10) and Group 5: DES with 5% grape seed extract (GSE) as a biomodifier ( N = 10). In Group 2 samples, composite restorations were done prior to irrigation with 3% sodium hypochlorite (NaOCl). Group 3 samples received root canal irrigation with 3% NaOCl for 1 min, etch and rinse procedure and composite restorations. In Groups 4 and 5, dentin biomodification was done prior to composite restorations. Teeth were subjected to fracture resistance tests. Statistical analysis was carried out employing analysis of variance (ANOVA) and Tukey’s post hoc tests ( p &lt; .05). Results: IES group demonstrated the highest fracture resistance, with a significant difference statistically ( p &lt; .05) when compared with the DES groups. DES modified with GSE resulted in significantly superior fracture resistance compared to DES only, but no statistical difference was present between the CHX and grape seed-treated DES groups. Conclusion: DES with the use of dentin biomodifiers such as 5% GSE and 2% CHX increased the fracture resistance of root canal-treated teeth compared to DES only.

Effect of Dentin Biomodification on Resin Dentin Bond Strength

Effect of Dentin Biomodification on Resin Dentin Bond Strength

Effect of novel biomodification strategies on bonding to pulp chamber dentin - An In Vitro study.

Adhesion to dentin remains a tough challenge due to its heterogeneous composition, complex histologic structure and high tubular content, warranting the need to investigate methods to improve the bond strength of the commonly used access restorative materials to pulp chamber dentin. To evaluate the effect of dentin biomodification using 6.5% grape seed extract and a 980 nm diode LASER on the shear bond strength of resin-based bonded restoration to pulp chamber dentin. Access cavities were prepared in 42 extracted human maxillary premolars, which were then sectioned in a buccolingual direction. The samples were serially immersed in 5.25% NaOCl for 40 minutes and 17% EDTA for 3 minutes and allocated into three groups: the control group, the group pre-treated with 6.5% grape seed extract (GSE) and the group pre-treated with a 980 nm diode light amplification by stimulated emission of radiation (LASER). All the samples were restored with resin composites and subjected to shear bond strength testing using a universal testing machine. Statistical analysis was done using SPSS version 23 software. The mean shear bond strength was highest in the group pre-treated with GSE, followed by that pre-treated with diode LASER and finally in the control group. Dentin biomodification using both chemical and physical agents such as grape seed extract and diode LASER was shown to improve the shear bond strength of resin composite endodontic access restorations to the pulp chamber dentin.

The effect of kaempferol on the dentin bonding stability through matrix metalloproteinases inhibition and collagen crosslink in dentin biomodification

Background/purposeNaturally derived collagen crosslinkers with matrix metalloproteinases (MMPs) inhibitory activity for dentin bonding have been previously studied. One of these crosslinkers is flavonoids. The purpose of this study was to investigate whether dentin pretreatment with kaempferol (KEM), one of the flavonoids, enhances dentin bond stability and nanoleakage at the dentin-resin interface through MMPs inhibition and collagen crosslinking. Materials and methodsThe experimental KEM-containing solution was used to pretreat demineralized dentin prior to the application of a universal adhesive. KEM is a natural flavonoid and those which did not take the experimental solution served as the control group (CON). Microtensile bond strength (μTBS) and nanoleakage tests were conducted before and after the thermocycling to evaluate the influence of KEM on dentin bond strength. The MMPs inhibition activity of KEM was analyzed via MMPs zymography using a confocal microscopy. Fourier-transform infrared (FTIR) spectroscopy was used to demonstrate that KEM inhibits MMPs and enhances collagen crosslinking. ResultsThe μTBS values of KEM group exhibited a higher bond strength after thermocycling. At the resin-dentin interface, the KEM group did not exhibit any signs of nanoleakage after thermocycling. Furthermore, MMPs zymography confirmed that there was a relatively low activity of MMPs in the presence of KEM. In FTIR analysis, the PO4 peak representing the cross-link between dentin and collagen was significantly higher in the KEM group. ConclusionOur findings suggest that pretreatment with KEM enhances the dentin bonding stability at the resin-dentin interface by acting as a collagen crosslinker and MMPs inhibitor.

Seco B-Type Oligomers from Pinus massoniana Expand the Procyanidin Chemical Space and Exhibit Dental Bioactivity.

Investigation of a pine bark extract for bioactive proanthocyanidin oligomers resulted in the isolation of structurally related dimeric seco B-type procyanidin derivatives, 1-5. This includes scalemic mixtures of gambiriin A1 (1a) and A2 (2a) and their newly described optical antipodes, ent-gambiriin A1 (1b) and ent-gambiriin A2 (2b), respectively, as well as a racemic mixture of the newly described (ent-)gambiriin A5 (3a/3b). Furthermore, the study now fully characterizes the previously reported optically pure dimers gambiriin B1 (4) and gambirflavan D1 (5), and characterized the novel seco B-type procyanidin trimer, 6 (gambirifuran C1). Thermal conversion of catechin in aqueous solution provided further evidence for the structures of 1-6 and led to the purification of semisynthetic 1a and 2a as well as additional dimers 7-10. Elucidating the structures of the natural dimers, 1-5, from comprehensive NMR and ECD data and synthetic evidence provided crucial reference points for establishing the structure of the seco B-type procyanidin trimer, 6. Serving as assigned building blocks, data from the dimers supported the 3D structural assignment of 6 based on NMR substituent chemical shift differences (s.c.s., syn. ΔδC) and component-based empirical ECD calculations. Within the newly characterized series of PAC-related molecules, 5 exhibited high dentin biomodification potential. In addition, considering the nomenclature issues and plausible biosynthetic pathways of this group of compounds led to a consolidated nomenclature of all currently known seco B-type procyanidins. These findings, thereby, expand the chemical space of bioactive catechin oligomers, which have promise as agents for the natural enhancement of dental biomaterials. Finally, the current knowledge of the chemical space of seco B-type procyanidin derivatives was compiled to the level of absolute configuration.

Effect of dentin biomodification using natural collagen cross-linkers on the durability of the resin-dentin bond and demineralized dentin stiffness

ObjectiveThe purpose of this study was to evaluate the effect of using natural cross-linkers as sumac and curcumin on the durability of the resin-dentin bond and stiffness of demineralized dentin matrix. MethodsThirty sound molars were divided into 5 groups: Control (CO), Grape Seed extract (GSE), Cacao seed extract (CSE), Sumac extract (SE) and Curcumin extract (CE). The teeth had their coronal dentin exposed, etched, and pre-treated for 1 min with the extracts. Teeth were then bonded using Single-Bond II adhesive and 4 mm composite was built up on dentin surface. Teeth were sectioned into 1 × 1 × 8mm beams and their micro-tensile bond strength (μTBS) was tested after 24 h and 6 months of water storage.For stiffness testing, 15 teeth were sectioned to obtain dentin beams (1 × 1 × 6.5 mm), the beams were demineralized in 10% phosphoric acid then rinsed and divided into 5 groups. Beams were then immersed in their respective extract solution for 1 min after which they were subjected to a 3- point loading test using a universal testing machine to calculate their modulus of elasticity. ResultsAfter 24 h, no significant difference in μTBS was shown between all groups. After 6 Months, GSE, CE, and SE showed significantly higher μTBS compared to CO (p ≥ 0.05). For the modulus of elasticity; only GSE showed a significantly higher modulus compared to other groups. Clinical relevanceThe application of grape seed extract, curcumin and sumac extract as dentin pre-treatments appear to be a promising approach to enhance the durability of the resin-dentin bond in a clinically relevant application time.

Development of Proanthocyanidin-Loaded Mesoporous Silica Nanoparticles for Improving Dental Adhesion.

Dentin biomodification is a promising approach to enhance dental tissue biomechanics and biostability for restorative and reparative therapies. One of the most active dentin tissue biomodifiers is proanthocyanidin (PAC)-rich natural extracts, which are used in the dental bonding procedure in combination with resin-based adhesives (RBAs). This study aimed to investigate the use of mesoporous silica nanoparticles (MSNs) for the sustained delivery of PACs for dentin biomodification as a novel drug-delivery system for dental applications. The effects of the incorporation of MSN functionalized with 3-aminopropyltriethoxysilane (APTES) and loaded with PAC into an experimental RBA were assessed by characterizing the material mechanical properties. In addition, the immediate and long-term bonding performance of an experimental resin-based primer (RBP) containing MSN-APTES loaded with PAC was also evaluated. For that, different formulations of RBA and RBP were prepared containing 20% w/v MSN-APTES loaded with PAC before or after functionalization (MSN-PAC-APTES and MSN-APTES-PAC, respectively). The incorporation of MSN-APTES-PAC did not negatively impact the degree of conversion or the overall mechanical properties of the RBA. However, adding MSN-PAC-APTES resulted in inferior mechanical properties of the experimental RBA. In the adhesion studies, APTES-functionalized MSN was successfully added to an experimental RBP for drug-delivery purposes without compromising the bond strength to the dentin or the failure mode. Interestingly, the sequence of surface functionalization with APTES resulted in differences in the bonding performance, with better long-term results for RBP containing MSN loaded with PAC after functionalization.

B-type Proanthocyanidins with Dentin Biomodification Activity from Cocoa (Theobroma cacao).

To enable translational studies, a scalable preparative isolation scheme was developed for underivatized cocoa (Theobroma cacao) proanthocyanidins (PACs), affording six all-B-type oligomeric PACs, including a new tetramer 4. Their structures, including absolute configuration, were unambiguously established by comprehensive spectroscopic and chemical methods. Evaluation of the PACs' dentin biomodification properties employed dynamic mechanical and infrared spectroscopic analyses in dentin bioassay models. PAC treatment enhanced the biomechanical strength of dentin by 5- to 15-fold compared to untreated dentin. Among the PAC agents, the pentamer, cinnamtannin A3 (6), led to the highest complex modulus value of 131 MPa, whereas the "branched" tetramer, 4, showed the lowest, yet still significant bioactivity. This study of specifically singly linked medium-length oligomeric PACs indicates that the linkage site is paramount in determining the potency of these PACs as dentin biomodifiers.

Phosphoric acid containing proanthocyanidin enhances bond stability of resin/dentin interface.

Proanthocyanidin (PA) is a promising dentin biomodifier due to its ability to stabilize collagen fibrils against degradation by matrix metalloproteinases (MMPs); however, the most effective protocol to incorporate PA into bonding procedures is still unclear. This study evaluated the effect of dentin biomodification with a PA acid etchant on MMP activity, adhesive interface morphology and resin-dentin microtensile bond strength. Sound extracted human molars were flattened to expose dentin and acid-etched for 15 s according to the groups: EXP - experimental phosphoric acid; EXP+PA - experimental phosphoric acid 10% PA; TE - total-etching system; SE - self-etching system. Samples were restored with composite resin and stored in distilled water (37ºC). MMP activity and interface morphology were analyzed after 24 h by in situ zymography (n=6) and scanning electron microscopy (n=3), respectively. The resin-dentin microtensile bond strength (μTBS) was evaluated after 24 h and 6 months storage (n=6). Significantly higher MMP activity was detected in etched dentin compared with untreated dentin (p<0.05), but no difference among acid groups was found. Resin tags and microtags, indicative of proper adhesive system penetration in dentinal tubules and microtubules, were observed along the hybrid layer in all groups. There was no difference in μTBS between 24 h and 6 months for EXP+PA; moreover, it showed higher long-term μTBS compared with TE and EXP (p<0.05). The results suggest that 15 s of biomodification was not sufficient to significantly reduce MMP activity; nonetheless, EXP+PA was still able to improve resin-dentin bond stability compared with total- and self-etching commercial systems.

The influence of dimethyl sulfoxide on resin–dentin bonding: A systematic review

This article aims to systematically review published literature about the influence of dimethyl sulfoxide (DMSO) on resin–dentin bonding. Online databases (Medline (PubMed), Embase, Web of Science, and the Cochrane Library) were searched on this topic. Gray literature was searched using Google Scholar. Published works until December 2020 were collected, and pertinent articles were selected in accordance with the eligibility criteria. Quality assessment was conducted via the modified Consolidated Standards of Reporting Trials (CONSORT) checklist and the modified Cochrane risk of bias tool. Thirty-eight studies were identified, twelve of which satisfied the eligibility criteria were included in this review. Micro tensile bond strength (MTBS) was set as the main outcome. Secondary outcomes include nanoleakage evaluation, the effect of DMSO on dentin collagen fibrils, and protease inhibition. Several studies proved the promotion of DMSO on long-term dentin bond strength of etch-and-rinse adhesives. However, evidence about its effect on bond strength of self-etch adhesives was insufficient. Different concentrations of DMSO solution also cause diverse impact on dentin bonds. Based on the included studies, DMSO considerably affects resin–dentin bonds by dissociating demineralized dentin matrix, inhibiting matrix metalloproteinases (MMPs), and enhancing penetration of resin monomers. The influence of DMSO on dentin bonding may offer inspirations for dental clinical practice to optimize resin–dentin bonds. • DMSO is beneficial for improving the long-term dentin bond strength of etch-and-rinse adhesives. • The influence of DMSO on self-etch adhesives remains controversial and needs more validation. • DMSO can dissociate demineralized dentin matrix, inhibit matrix metalloproteinases, and enhance resin monomer penetration. • DMSO may enlighten the concept of “wet bonding” technique from surface moisture to bio-modification of dentin. • DMSO offers inspiration for dental clinical practice to optimize resin–dentin bonds.

Dentin Biomodification with Flavonoids and Calcium Phosphate Ion Clusters to Improve Dentin Bonding Stability.

The purpose of this study was to evaluate the effects of flavonoids and calcium phosphate ion clusters (CPIC) on dentin bonding stability. Seven experimental solutions were synthesized using icaritin (ICT), fisetin (FIS), silibinin (SIB), CPIC, and combinations of one of three flavonoids and CPIC (ICT + C, FIS + C, SIB + C). The experimental solutions were applied to demineralized dentin prior to the application of a universal adhesive. A group without any experimental solution served as a control. Dentin specimens pretreated with the experimental solutions were assayed using Fourier transform infrared (FTIR) spectroscopy. The microtensile bond strength (µTBS) and nanoleakage were evaluated at 24 h and after 10,000 thermocycles. FIS and ICT + C showed significantly higher µTBS than the control group at 24 h. CPIC, ICT + C, FIS + C, and SIB + C showed significantly higher µTBS than the control group after thermocycling. After thermocycling, silver infiltration into the hybrid layer and interfacial gaps was more noticeable in the control group than in the other groups. The FTIR spectra revealed the formation of apatitic minerals in the demineralized dentin in the flavonoid and CPIC combination groups. The pretreatment of demineralized dentin with flavonoids and CPIC improved dentin bonding stability. The flavonoid and CPIC combinations preserved dentin bond strength.

Proanthocyanidin Tetramers and Pentamers from Cinnamomum verum Bark and Their Dentin Biomodification Bioactivities.

To enable the further exploration of structure-activity relationships (SARs) of proanthocyanidins (PACs) with dentin biomodification abilities, Cinnamomum verum was selected for scaled-up purification of mixed A-/B-type, medium-size PAC oligomers. Sequential purification by centrifugal partition chromatography (CPC), Sephadex LH-20, and semiprep HPLC chromatography yielded four underivatized tetrameric (5-8) and two pentameric (9-10) PACs. Their unambiguous structural characterization involved extensive spectral and chemical degradation approaches to show that epicatechin units are connected by plant-specific combinations of doubly linked A- and singly linked B-type interflavanyl bonds. The biomechanical properties (via dynamic mechanical analysis) and physicochemical structure (via infrared spectroscopy) were assessed to evaluate the biomodification potency of PAC-treated collagen in a preclinical dentin model. This study revealed that (4→8) versus (4→6) bonds in PAC interflavan linkages have limited influence on biomechanical outcomes of dentin. By exhibiting a 25-fold increase in the complex modulus of treated dentin compared to control, aesculitannin E (5) was found to be the most potent PAC known to date for enhancing the mechanical properties of dentin in this preclinical model.

Is dentin biomodification with collagen cross-linking agents effective for improving dentin adhesion? A systematic review and meta-analysis.

ObjectivesThe aim of this investigation was to evaluate the effectiveness of collagen cross-linking agents (CCLAs) used in combination with the adhesive technique in restorative procedures.Materials and MethodsIn this systematic review, the authors followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. An electronic search was performed using PubMed, Scopus, Web of Science, Cochrane Library, LILACS, and DOSS, up to October 2020. The gray literature was also researched. Only randomized clinical trials were selected.ResultsThe selection process yielded 3 studies from the 838 retrieved. The addition of CCLAs in the retention of restorations increased the number of events. The postoperative sensitivity scores and marginal adaptation scores showed no significant difference between the CCLA and control groups, and the marginal pigmentation scores showed a significant increase in the CCLA group. There were no caries events in any group throughout the evaluation period.ConclusionsThis systematic review showed that there is no clinical efficacy to justify the use of CCLAs in the protocols performed.

Longevity of bonded composite restorations after dentin biomodification with neolignans obtained from Nectandra leucantha

Objective: This in vitro study evaluated the effect of neolignan-containing solutions on dentin biomodificationpreviously applied to the bonding procedure in adhesive restorations. Material and Methods: Neolignans,dehydrodieugenol B–CP1 and dehydrodieugenol B methyl ether–CP2, were isolated from Nectandra leucanthaand two aqueous solutions containing 0.13% neolignans, 0.2% propylene glycol and 3.0% ethanol were prepared.Bovine teeth were ground flat to obtain 2-mm thick specimens which received resin composite restorations(N=10). The neolignan solutions were applied before the bonding procedure (60 s). Experimental groups were:control, untreated group, 0.12% chlorhexidine gel, 0.13% CP1 solution, and 0.13% CP2 solution. A push-outbond strength test was conducted (0.5 mm/min). Bovine tooth sections (0.5×1.7×7.0 mm) were also obtained toassess the modulus of elasticity and mass change after treatment (N=15). A three-point bending test evaluated theelastic modulus of fully demineralized dentine beams after immersion in the solutions. The data were statisticallyanalyzed (a = 0.05). Results: The bond strength of the restorations to dentin was significantly improved by thetreatment with neolignan-containing solutions, irrespective of the evaluation time (p&lt;0.05). After 6 months, asignificant reduction in the bond strength was observed in the groups treated with the solutions (p&gt;0.05), butthe means were significantly higher than the control groups (p&lt;0.05). The elastic modulus of demineralizeddentin was significantly improved after the treatment with the solutions (p&lt;0.05). All groups lost mass weight.Conclusion: The solutions improved the in vitro longevity of bonded restorations, possibly due to the dentinbiomodification effect of the neolignans. KEYWORDSDental restorations; Permanent; Dentin; Collagen type I; Plants medicinal; Lignans.

Effect of Dentin Biomodification Using Natural Collagen Cross-Linkers on the Durability of the Resin-Dentin Bond and Demineralized Dentin Stiffness

Effect of Dentin Biomodification Using Natural Collagen Cross-Linkers on the Durability of the Resin-Dentin Bond and Demineralized Dentin Stiffness