Accurate transfer of soft tissue morphology with interim prosthesis to definitive cast.

With conventional fixed dental prostheses, the interim restoration is a valuable diagnostic tool in the evaluation of esthetics and function. To achieve predictable definitive esthetic results, information about the subgingival and the supragingival contour of a properly designed restoration should be communicated to the dental laboratory technician. The technique described enables the accurate transfer of the soft tissue morphology developed with an interim prosthesis to the definitive cast. This modified definitive cast allows the dental laboratory technician to fabricate a restoration with an emergence profile identical to that of the interim prosthesis.

Garre's osteomyelitis of the mandible managed by nonsurgical re-endodontic treatment.

Chronic osteomyelitis with proliferative periostitis, known as Garre's osteomyelitis, is a type of osteomyelitis characterized by a distinctive gross thickening of the periosteum of bones. Peripheral reactive bone formation can be caused by mild irritation or infection. Garre's osteomyelitis is usually diagnosed in children and young adults, and the mandible is more affected than the maxilla. The following is a case report of a 12-year-old female patient with Garre's osteomyelitis of the mandible due to an infection of a root canal-treated tooth. Without surgical intervention, the patient's symptoms were relieved through nonsurgical root canal re-treatment with long-term calcium hydroxide placement. A cone-beam computed tomography image obtained 6 months after treatment completion displayed complete healing of the periapical lesion and resolution of the peripheral reactive buccal bone. Due to the clinical features of Garre's osteomyelitis, which is characterized by thickening of the periosteum, it can be mistaken for other diseases such as fibrous dysplasia. It is important to correctly diagnose Garre's osteomyelitis based on its distinctive clinical features to avoid unnecessary surgical intervention, and it can lead to minimally invasive treatment options.

Desensitizing efficacy of a universal dentin adhesive containing mesoporous bioactive glass on dentin hypersensitivity: a randomized clinical trial with a split-mouth model.

This split-mouth blinded randomized controlled study compared the efficacy of a desensitizing agent with oxalate/resin polymer and a universal adhesive containing mesoporous bioactive glass (MBG) for dentin hypersensitivity (DH) relief, using Schiff sensitivity score (SSS) and visual analog scale (VAS). Split quadrants containing teeth with DH were treated with either MS Coat ONE or Hi-Bond Universal with MBG as the functional additive. Assessments at baseline, immediately post-application, and at 1- and 2-week follow-ups used standardized stimulus protocols (air, cold, and acid). The SSS difference was the primary outcome, while the VAS difference was the secondary outcome. A mixed linear effect model performed statistical analysis. Immediate DH reduction occurred in response to air stimuli, with a significant decrease in Group HB than in Group MS (p = 0.0178). Cold stimulus reduction exhibited a gradual cumulative effect, with consistently greater reductions in Group HB than in Group MS (p ≤ 0.0377). Both groups effectively managed acidic stimuli, with no significant differences (p > 0.05). The VAS scores decreased gradually over the follow-up period (p < 0.0001). This study highlights the differential efficacy of treatments for various DH triggers and recommends specific approaches based on different stimulus types. The universal adhesive containing MBG demonstrated DH relief potential, promising efficacy identical to or superior to that of a dedicated desensitizing agent. Further research exploring the long-term efficacy and underlying mechanisms is warranted. The universal adhesive containing MBG can be adopted as an in-office desensitizing agent for DH relief. The desensitizing efficacy of universal adhesive matches or surpasses dedicated agents for air and cold stimuli.

Management of complicated crown-root fractures using intentional replantation: two case reports.

The management of complicated crown-root fractures is a challenge. Intentional replantation with 180° rotation may be a useful procedure to overcome this problem. In Case 1, a 23-year-old woman with complicated crown-root fractured teeth #11, #21, and #22 was referred for treatment. All fractured teeth were extracted, rotated 180°, and replanted in a slightly extruded position. After 3 months, root canal treatment was completed and the final restorations fabricated. At the 18-month follow up, the patient was asymptomatic, the tooth was functional, and no root resorption was observed radiographically. At the 90-month follow up, slight cervical root resorption of tooth #11 was noted. In Case 2, a 27-year-old woman with a crown-root fractured tooth #21 was referred for treatment. Despite immediate repositioning of the coronal fragment and a 2-week stabilization with a wire splint, the coronal fragment remained separated from the apical tooth segment. The apical segment was extracted, rotated 180°, and replanted in a slightly extruded position. After 1 and 4 weeks, the root canal treatment was completed and the final restoration fabricated, respectively. At the 24-month follow up, the patient was asymptomatic and apical healing was completed.

A randomized clinical trial for comparing the efficacy of desensitizing toothpastes on the relief of dentin hypersensitivity.

The 4-week double-blind clinical trial to manage dentin hypersensitivity (DH) using different desensitizing toothpastes was conducted. 53 participants with DH were enrolled in this trial. The participants were randomized into 3 groups: Group N; no active ingredient-containing toothpaste (Pleasia fluoride-free), Group SC; a toothpaste containing strontium chloride (Sensodyne Original), and Group TP; a toothpaste containing tricalcium phosphate (Vussen S). They were instructed to brush their teeth manually for 3 min, 3 times per day for 4 weeks with the allocated toothpastes, and were assessed at baseline (0), 2, and 4 weeks, respectively. Schiff sensitivity score was recorded to 3 different stimuli (air-blast, cold, and acid) at each assessment. Overall DH was also assessed using a visual analog scale (VAS). The longer participants used the toothpastes, the greater reduction in DH in all groups to the three stimuli. Group TP demonstrated significant reduction of DH compared to group N for air-blast and cold stimuli. Group TP showed significantly lower VAS than group N and SC. Tricalcium phosphate containing toothpaste used in this trial was most useful to reduce DH. It can be one of the treatment options that alleviate DH.

Antioxidants, like coenzyme Q10, selenite, and curcumin, inhibited osteoclast differentiation by suppressing reactive oxygen species generation.

Coenzyme Q10 (CoQ10), selenium, and curcumin are known to be powerful antioxidants. Osteoclasts are capable of resorbing mineralized bone and excessive bone resorption by osteoclasts causes bone loss-related diseases. During osteoclast differentiation, the reactive oxygen species (ROS) acts as a secondary messenger on signal pathways. In this study, we investigated whether antioxidants can inhibit RANKL-induced osteoclastogenesis through suppression of ROS generation and compared the relative inhibitory activities of CoQ10, sodium selenite, and curcumin on osteoclast differentiation. We found that antioxidants markedly inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells in both bone marrow-derived monocytes (BMMs) and RAW 264.7 cells. Antioxidants scavenged intracellular ROS generation within osteoclast precursors during RANKL-stimulated osteoclastogenesis. These also acted to significantly suppress the gene expression of NFATc1, TRAP, and osteoclast-associated immunoglobulin-like receptor (OSCAR), which are genetic markers of osteoclast differentiation in a dose-dependent manner. These antioxidants also suppressed ROS-induced IκBα signaling pathways for osteoclastogenesis. Specially, curcumin displayed the highest inhibitory effect on osteoclast differentiation when concentrations were held constant. Together, CoQ10, selenite, and curcumin act as inhibitors of RANKL-induced NFATc1 which is a downstream event of NF-κB signal pathway through suppression of ROS generation, thereby suggesting their potential usefulness for the treatment of bone disease associated with excessive bone resorption.

Effect of Dentin Desensitizer Containing Novel Bioactive Glass on the Permeability of Dentin.

The objective of this study was to evaluate the effect of novel bioactive glass (BAG)-containing desensitizers on the permeability of dentin. Experimental dentin desensitizers containing 3 wt% BAG with or without acidic functional monomers (10-MDP or 4-META) were prepared. A commercial desensitizer, Seal & Protect (SNP), was used as a control. To evaluate the permeability of dentin, real-time dentinal fluid flow (DFF) rates were measured at four different time points (demineralized, immediately after desensitizer application, after two weeks in simulated body fluid (SBF), and post-ultrasonication). The DFF reduction rate (ΔDFF) was also calculated. The surface changes were analyzed using field emission scanning electron microscopy (FE-SEM). Raman spectroscopy was performed to analyze chemical changes on the dentin surface. The ΔDFF of the desensitizers containing BAG, BAG with 10-MDP, and BAG with 4-META significantly increased after two weeks of SBF storage and post-ultrasonication compared to the SNP at each time point (p < 0.05). Multiple precipitates were observed on the surfaces of the three BAG-containing desensitizers. Raman spectroscopy revealed hydroxyapatite (HAp) peaks on the dentin surfaces treated with the three BAG-containing desensitizers. Novel BAG-containing dentin desensitizers can reduce the DFF rate about 70.84 to 77.09% in the aspect of reduction of DFF through the HAp precipitations after two weeks of SBF storage.

Effect of heparin and alendronate coating on titanium surfaces on inhibition of osteoclast and enhancement of osteoblast function.

The failure of orthopedic and dental implants has been attributed mainly to loosening of the implant from host bone, which may be due to weak bonding of the implant material to bone tissue. Titanium (Ti) is used in the field of orthopedic and dental implants because of its excellent biocompatibility and outstanding mechanical properties. Therefore, in the field of materials science and tissue engineering, there has been extensive research to immobilize bioactive molecules on the surface of implant materials in order to provide the implants with improved adhesion to the host bone tissue. In this study, chemically active functional groups were introduced on the surface of Ti by a grafting reaction with heparin and then the Ti was functionalized by immobilizing alendronate onto the heparin-grafted surface. In the MC3T3-E1 cell osteogenic differentiation study, the alendronate-immobilized Ti substrates significantly enhanced alkaline phosphatase activity (ALP) and calcium content. Additionally, nuclear factor kappa B ligand (RANKL)-induced osteoclast differentiation of RAW264.7 cells was inhibited with the alendronate-immobilized Ti as confirmed by TRAP analysis. Real time PCR analysis showed that mRNA expressions of osteocalcin and osteopontin, which are markers for osteogenesis, were upregulated in MC3T3-E1 cells cultured on alendronate-immobilized Ti. The mRNA expressions of TRAP and Cathepsin K, markers for osteoclastogenesis, in RAW264.7 cells cultured on alendronate-immobilized Ti were down-regulated. Our study suggests that alendronate-immobilized Ti may be a bioactive implant with dual functions to enhance osteoblast differentiation and to inhibit osteoclast differentiation simultaneously.

Effect of Bioactive Glass-Containing Light-Curing Varnish on Enamel Remineralization.

This study aimed to evaluate the effect of novel experimental light-curing bioactive glass (BAG)-containing varnish on enamel remineralization. An experimental light-curing, BAG-containing varnish and two commercial varnishes (Nupro White Varnish; Dentsply International, York, PA, USA and Tooth Mousse; GC Corporation, Tokyo, Japan) were used. Microhardness tests (n = 3), field emission scanning electron microscopy (FE-SEM) coupled with energy dispersive X-ray spectroscopy (EDS) (n = 5), and X-ray diffraction (XRD) analysis (n = 5) were performed to compare the remineralization effect of three varnishes with and without ultrasonication. The data of microhardness test were analyzed using one-way ANOVA and Tukey's post hoc comparison (P < 0.05). Microhardness of demineralized enamel increased after the application of three varnishes (P < 0.05). The experimental BAG-containing varnish showed the highest microhardness among the three varnishes (P < 0.05). Ultrasonication decreased microhardness of Tooth Mousse and BAG-containing varnish groups (P < 0.05). FE-SEM and XRD revealed precipitates of hydroxyapatite (HAP) or fluorapatite (FAP) crystals of three varnishes. The novel experimental BAG-containing varnish may be a promising clinical strategy for the remineralization of early carious lesions or demineralized enamel surfaces.

Effect of bioactive glass addition on the physical properties of mineral trioxide aggregate.

BACKGROUND: The addition of bioactive glass (BG), a highly bioactive material with remineralization potential, might improve the drawback of weakening property of mineral trioxide aggregates (MTA) when it encounters with body fluid. This study aims to evaluate the effect of BG addition on physical properties of MTA. METHODS: ProRoot (MTA), and MTA with various concentrations of BG (1, 2, 5 and 10% BG/MTA) were prepared. Simulated body fluid (SBF) was used to investigate the effect of the storage solution on dentin remineralization. Prepared specimens were examined as following; the push-out bond strength to dentin, compressive strength, setting time solubility and X-ray diffraction (XRD) analysis. RESULTS: The 2% BG/MTA showed higher push-out bond strengths than control group after 7 days of SBF storage. The 2% BG/MTA exhibited the highest compressive strength. Setting times were reduced in the 1 and 2% BG/MTA groups, and solubility of all experimental groups were clinically acceptable. In all groups, precipitates were observed in dentinal tubules via SEM. XRD showed the increased hydroxyapatite peaks in the 2, 5 and 10% BG/MTA groups. CONCLUSION: It was verified that the BG-added MTA increased dentin push-out bond strength and compressive strength under SBF storage. The addition of BG did not negatively affect the MTA maturation reaction; it increased the amount of hydroxyapatite during SBF maturation.

Effects of bioactive glass incorporation into glass ionomer cement on demineralized dentin.

The effects of the incorporation of sodium-free bioactive glass into glass ionomer cement (GIC) on the demineralized dentin are studied. Four experimental groups with various amounts of BAG in GIC were considered: BG0 group: 0 wt% (control); BG5 group: 5 wt%; BG10 group: 10 wt%; BG20 group: 20 wt%. The GIC surface and GIC-approximated demineralized dentin surfaces were evaluated using field emission scanning electron microscopy (FE-SEM). X-ray diffraction (XRD) analysis was performed to evaluate the chemical changes in the GIC-approximated dentin surface. In addition, a shear bond strength test was performed to evaluate the effects of BAG incorporation on the bond strength of GIC. FE-SEM analysis indicated that BAG-incorporated GICs formed distinct precipitates on their surface. Precipitates were also formed on the GIC-approximated demineralized dentin surface. It was more obvious when the amount of BAG increased. In the XRD analysis, fluorapatitie (FAP) peaks were detected in the BG5, BG10, and BG20 groups. There was no significant difference in the shear bond strength among all experimental groups. BAG-incorporated GIC precipitated FAP crystals underlying demineralized dentin surface without affecting bond strength. This study suggests the possibility of BAG as a beneficial additive in GIC.

Effect of Novel Bioactive Glass-Containing Dentin Adhesive on the Permeability of Demineralized Dentin.

This study aimed to evaluate the effect of a novel bioactive glass (BAG)-containing dentin adhesive on the permeability of demineralized dentin. Bioactive glass (85% SiO2, 15% CaO) was fabricated using the sol-gel process, and two experimental dentin adhesives were prepared with 3 wt% silica (silica-containing dentin adhesive; SCA) or BAG (BAG-containing dentin adhesive; BCA). Micro-tensile bond strength (µTBS) test, fracture mode analysis, field-emission scanning electron microscopy (FE-SEM) analysis of adhesive and demineralized dentin, real-time dentinal fluid flow (DFF) rate measurement, and Raman confocal microscopy were performed to compare SCA and BCA. There was no difference in µTBS between the SCA and BCA (p > 0.05). Multiple precipitates were evident on the surface of the BCA, and partial occlusion of dentinal tubules was observed in FE-SEM of BCA-approximated dentin. The DFF rate was reduced by 50.10% after BCA approximation and increased by 6.54% after SCA approximation. Raman confocal spectroscopy revealed an increased intensity of the hydroxyapatite (HA) peak on the dentin surface after BCA application. The novel BAG-containing dentin adhesive showed the potential of both reducing dentin permeability and dentin remineralization.

Bleaching toothpaste with two different concentrations of hydrogen peroxide: A randomized double-blinded clinical trial.

OBJECTIVES: This randomized double-blinded clinical trial evaluated the bleaching efficacy and incidence of contact hypersensitivity of three kinds of bleaching toothpaste. METHODS: Forty-nine participants above A2 shade on the maxillary central incisor (#11) and canine (#13) were randomized into three groups: TW group (n = 15), 0.75 % HP-containing toothpaste (Toothwhole white); VL group (n = 15), 0.75 % HP-containing toothpaste (Vussen 7); and VH group (n = 17), 2.8 % of HP-containing toothpaste (Vussen 28). Participants were instructed to manually brush their teeth for 3 min, 3 times per day for 12 weeks. They were followed-up after 4 and 12 weeks. Shade measurements were performed using a spectrophotometer (SP), and data were calculated with CIELab (ΔEab*) and CIEDE2000 (ΔE00) formula. Additionally, visual inspection (VI) using the Vitapan classical shade guide was also performed, and the correlation between the two measurements was analyzed by comparing the CIELab (ΔEab*) values. The incidence of contact hypersensitivity at each follow-up was recorded. A mixed-effect model was performed to assess shade changes and chi-square tests for the incidence of contact hypersensitivity, respectively. RESULTS: At 12 week follow-up, all groups showed ΔEab* above 3.46, and ΔE00 above 2.25 for tooth #11. For tooth #13, the ΔEab* and ΔE00 of VH and TW groups only were above those thresholds. Shade change varied according to toothpaste and follow-up points. SP and VI showed a moderate positive correlation for L*, a*, and b*, respectively (P < 0.05). Contact hypersensitivity was not significantly different among the groups (P > 0.05). CONCLUSIONS: Bleaching toothpaste with higher HP yields a better shade change than other toothpaste after 12 weeks. CLINICAL SIGNIFICANCE: The use of bleaching toothpaste with a higher HP concentration results in a better shade improvement.

Effect of elastin-like polypeptide incorporation on the adhesion maturation of mineral trioxide aggregates.

The aim of this study was to investigate the effects of the incorporation of elastin-like polypeptide (ELP) on the adhesion maturation of mineral trioxide aggregates (MTA). Two types of ELPs (V125 and V125E8) were genetically synthesized. V125 consisted of 125 repeating pentapeptides (Val-Pro-Gly-Xaa-Gly) and V125E8 was functionalized with octaglutamic acid in the C-terminus of V125; both were diluted to 10 wt% in solution. Three 1.5 mm diameter holes in dentin discs were filled with MTA mixed with either a solution of ELP or deionized water. Push-out bond strength tests were performed following storage in simulated body fluid (SBF) for 1, 2, 4, and 8 weeks (n = 12). The interface between dentin and MTA was observed via scanning electron microscopy (SEM). The maturation of MTA was evaluated with a stereoscopic microscope and SEM. The incorporation of a specific ELP (V125E8) significantly increased the bond strength of MTA to dentin with regard to every maturation period (p < 0.05). The bond strength of MTA also significantly increased with a longer maturation time irrespective of ELP incorporation (p < 0.05). V125E8-incorporated MTA exhibited a more intimate interface with dentin compared to the other groups. More spindle-shaped crystal structures and thicker crystals were observed in all MTA mixtures as the storage duration increased even though V125E8 exhibited fewer crystal structures on the surface. Within the limitations of this study, the incorporation of V125E8 increased the adhesive properties of MTA and the maturation of MTA occurred regardless of ELP incorporation.

In Vitro Characterization of Dental Pulp Stem Cells Cultured in Two Microsphere-Forming Culture Plates.

Various three-dimensional (3D) culture methods have been introduced to overcome the limitations of in vitro culture and mimic in vivo conditions. This study aimed to evaluate two microsphere-forming culture methods and a monolayer culture method. We evaluated cell morphology, viability, osteo-, adipo-, and chondrogenic differentiation potential of dental pulp stem cells (DPSCs) cultured in 3D culture plates: ultra-low attachment (ULA) and U-bottomed StemFit 3D (SF) plates, and a two-dimensional (2D) monolayer plate. RNA sequencing (RNA-seq) revealed differentially expressed gene (DEG) profiles of the DPSCs. In contrast to an increasing pattern in the 2D group, cell viability in 3D groups (ULA and SF) showed a decreasing pattern; however, high multilineage differentiation was observed in both the 3D groups. RNA-seq showed significantly overexpressed gene ontology categories including angiogenesis, cell migration, differentiation, and proliferation in the 3D groups. Hierarchical clustering analysis revealed a similar DEG regulation pattern between the 3D groups; however, a comparatively different DEG was observed between the 2D and 3D groups. Taken together, this study shows that DPSCs cultured in microsphere-forming plates present superior multilineage differentiation capacities and demonstrate higher DEG expression in regeneration-related gene categories compared to that in DPSCs cultured in a conventional monolayer plate.

Effect of various agitation methods on adhesive layer formation of HEMA-free universal dentin adhesive.

This study evaluates the effects of various agitation methods on the adhesive layer formation of a new HEMA-free universal dentin adhesive. The µTBS of the universal adhesive, G-Premio BOND in the self-etch mode was evaluated using three agitation methods [passive agitation (PA), active agitation (AA), ultrasonic agitation (UA)], with and without aging treatment. Two-way analysis of variance revealed that aging treatment was not a statistically significant factor. Tukey's HSD test showed significant differences based on the application method, UA>AA>PA. TEM images of the PA group revealed multiple water blisters in the adhesive layers; AA and UA groups presented significantly less or no blisters within the adhesive layers; thus, AA and UA groups exhibited better bonding performance for the HEMA-free universal adhesive. It is assumed that the entrap ped blisters can be reduced with the active application of dentin adhesive, and thus improving the bonding performance.

Effect of bioactive glass-containing resin composite on dentin remineralization.

OBJECTIVES: The purpose of this study was to evaluate the effect of bioactive glass (BAG)-containing composite on dentin remineralization. METHODS: Sixty-six dentin disks with 3 mm thickness were prepared from thirty-three bovine incisors. The following six experimental groups were prepared according to type of composite (control and experimental) and storage solutions (simulated body fluid [SBF] and phosphate-buffered saline [PBS]): 1 (undemineralized); 2 (demineralized); 3 (demineralized with control composite in SBF); 4 (demineralized with control composite in PBS); 5 (demineralized with experimental composite in SBF); and 6 (demineralized with experimental composite in PBS). BAG65S (65% Si, 31% Ca, and 4% P) was prepared via the sol-gel method. The control composite was made with a 50:50 Bis-GMA:TEGDMA resin matrix, 57 wt% strontium glass, and 15 wt% aerosol silica. The experimental composite had the same resin and filler, but with 15 wt% BAG65S replacing the aerosol silica. For groups 3-6, composite disks (20 × 10 × 2 mm) were prepared and approximated to the dentin disks and stored in PBS or SBF for 2 weeks. Micro-hardness test, attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR) and field-emission scanning electron microscopy (FE-SEM) was investigated. RESULTS: The BAG-containing composite significantly increased the micro-hardness of the adjacent demineralized dentin. ATR-FTIR revealed calcium phosphate peaks on the surface of the groups which used BAG-containing composite. FE-SEM revealed surface deposits partially occluding the dentin surface. No significant difference was found between SBF and PBS storage. CLINICAL SIGNIFICANCE: Bioactive glass is a potentially useful material for remineralization of tooth structure. When incorporated into a resin composite, it may aid in remineralizing the adjacent demineralized dentin, thus preventing further destruction of the tooth. CONCLUSION: BAG-containing composites placed in close proximity can partially remineralize adjacent demineralized dentin.

Virtual Simulation of Autotransplantation Using 3-dimensional Printing Prototyping Model and Computer-assisted Design Program.

This case report describes an innovative virtual simulation method using a computer-aided rapid prototyping (CARP) model and a computer-aided design (CAD) program for autotransplantation of an immature third molar.A compromised left mandibular second molar (#18) was extracted and replaced by autotransplantation using an immature left mandibular third molar (#17). In order to minimize the surgical time and injury to the donor tooth, a virtual 3-dimensional (3D) rehearsal surgery was planned. Cone-beam computed tomographic images were taken to fabricate the 3D printing CARP model of the donor tooth and tentative extraction socket. Subsequently, both CARP models were scanned with an intraoral scanner (CEREC Omnicam; Dentsply Sirona, Bensheim, Germany) followed by superimposition and virtual simulation of osteotomy preparation of the recipient alveolus using the CAD analysis program. During the surgery, the extraction socket was precisely prepared according to the predetermined location and dimensions via virtual simulation rehearsal surgery using CAD analysis. The donor tooth was atraumatically transplanted into the prepared socket. The follow-up examination revealed that the root developed with a normal periodontal ligament and lamina dura.Virtual simulation using a 3D printing CARP model and a CAD program could be clinically useful in autotransplantation of an immature third molar by ensuring an atraumatic and predictable surgery.

Effect of zinc on the collagen degradation in acid-etched dentin.

BACKGROUND/PURPOSE: Matrix metalloproteinases (MMPs) play a crucial role in the pathogenesis of dental caries, collapse of adhesive interface, and chemical erosion of teeth. The objective of this study was to investigate the inhibitory effect of zinc on collagen degradation. MATERIALS AND METHODS: Human dentin was ground and demineralized by citric acid (pH 2.0). The demineralized ground dentin was incubated in six different media: artificial saliva (AS); 5 mg/ml doxycycline in AS; 3.33, 6.82, 13.63, and 27.26 mg/ml of zinc chloride (Zn) in AS. Each group was divided into two subgroups, and active MMP-2 was incorporated into one subgroup. Specimens were incubated for 24 h, 1 week, and 2 weeks. Collagen degradation product was assessed using ELISA. The results were analyzed using repeated measured ANOVA and Duncan's post hoc analysis (α = 0.05). RESULTS: The amount of collagen degradation was the lowest in Doxy group. Zn groups showed a significant inhibitory effect in collagen degradation for all concentrations (P < 0.05). In subgroups without exogenous MMP-2, zinc-mediated inhibition increased in a concentration-dependent manner with increasing zinc concentration. The amount of collagen degradation product slightly increased with increased incubation time from 24 h to 2 weeks. However, in subgroups with exogenous MMP, the inhibitory effect of zinc on collagen degradation did not depend on zinc concentration. CONCLUSION: All Zn groups for the four concentrations tested exhibited statistically significant inhibitory effect on collagen degradation.

Multi-functional nano-adhesive releasing therapeutic ions for MMP-deactivation and remineralization.

Restoration of hard tissue in conjunction with adhesive is a globally challenging issue in medicine and dentistry. Common clinical therapies involving application of adhesive and substitute material for functional or anatomical recovery are still suboptimal. Biomaterials with bioactivity and inhibitory effects of enzyme-mediated adhesive degradation can render a solution to this. Here, we designed a novel copper-doped bioactive glass nanoparticles (CuBGn) to offer multifunction: metalloproteinases (MMP) deactivation and remineralization and incorporated the CuBGn in resin-dentin adhesive systems, which showed most common failure of MMP mediated adhesive degradation among hard tissue adhesives, to evaluate proposed therapeutic effects. A sol-gel derived bioactive glass nanoparticles doping 10 wt% of Cu (Cu-BGn) for releasing Cu ions, which were well-known MMP deactivator, were successfully created and included in light-curing dental adhesive (DA), a filler-free co-monomer resin blend, at different concentrations (up to 2 wt%). These therapeutic adhesives (CuBGn-DA) showed enhanced (a)cellular bioactivity, cytocompatibility, microtensile bond strength and MMP deactivation-ability. In conclusion, the incorporation of Cu ions releasing nano-bioactive glass demonstrated multifunctional properties at the resin-dentin interface; MMP deactivation and remineralization, representing a suitable strategy to extend the longevity of adhesive-hard tissue (i.e. resin-dentin) interfaces.