Dentin Blocks Research Articles

Preventing dentin erosion with silver diamine fluoride and salivary pellicle: an in vitro study

ObjectivesTo investigate the preventive and discoloring effects of a single and two weekly applications of 38% silver diamine fluoride (SDF) against dentin erosion.Materials and methods180 dentin blocks were divided into four groups. Group 1 (SDF2) received two weekly applications of 38% SDF. Group 2 (SDF1) received a single application of 38% SDF. Group 3 (SNF) received a daily application of stannous chloride/amine fluoride/sodium fluoride (standard of care for dental erosion). Group 4 (DW) received a daily application of deionized water. The treated blocks were subjected to a 14-day erosive challenge. Crystal characteristics, elemental composition, surface morphology, percentage of surface microhardness loss (%SMHL), surface loss, and color change (ΔE) were investigated using X-ray diffraction (XRD), energy-dispersive spectrometry (EDS), scanning electron microscopy (SEM), hardness testing, profilometry, and digital spectrophotometry, respectively.ResultsXRD and EDS showed dentin surfaces had silver compounds in SDF2 and SDF1, and stannous chloride in SNF. SEM revealed less dentin demineralization with tubular occlusion in SDF2, SDF1, and SNF, but severe demineralization in DW. The %SMHL of SDF2, SDF1, SNF, and DW were 10.8 ± 2.1, 15.7 ± 2.1, 17.9 ± 2.1, and 28.7 ± 2.0 (SDF2 < SDF1 < SNF < DW, p < 0.05). Surface loss (µm) of SDF2, SDF1, SNF, and DW were 5.0 ± 0.6, 6.0 ± 0.6, 6.0 ± 0.7, and 9.0 ± 0.5 (SDF2 < SDF1 = SNF < DW, p < 0.001). ΔE of SDF2, SDF1, SNF, and DW were 26.0 ± 3.4, 12.1 ± 3.8, 6.9 ± 3.5, and 3.9 ± 3.6 (SDF2 > SDF1 > SNF = DW, p < 0.001).Conclusion38% SDF with two weekly applications provided better preventive effects against dentin erosion, but it might discolor dentin.Clinical relevanceThe increased 38% SDF application showed a better anti-erosive potential against dentin erosion. However, SDF caused black staining on the dentin.

Evaluation of Augmentated Ridge Using Autogenous Dentin Block Graft

Evaluation of Augmentated Ridge Using Autogenous Dentin Block Graft

Efficacy of silver diamine fluoride (SDF) in arresting dentin caries against inter-kingdom biofilms of Streptococcus mutans and Candida albicans.

To compare, in vitro, the efficacy of three proprietary silver diamine fluoride (SDF) products in mitigating progression of dentinal caries induced by an inter-kingdom, dual-species, bacterial-yeast biofilm. Human dentin blocks were demineralized to create artificial caries lesions and randomized into three SDF test groups: Saforide, Topamine, T-SDF, and an aqueous control (n = 26 per group). After application of foregoing SDF variants, the blocks were incubated with Streptococcus mutans and Candida albicans for 24 h for biofilm development, and subsequently subjected to a microbe-induced, pH-cycling process for 7 days, to mimic the oral eco-system. The biofilm cell viability and surface topography were assessed by colony-forming units (CFUs) and scanning electron microscopy respectively. The lesion depth and mineral density were evaluated by micro-computer tomography. SDF precipitate and matrix-to-mineral ratio were evaluated by X-ray diffraction and Fourier transform infrared spectroscopy, respectively. Standard, accepted methodology was used for all these evaluations and procedures. After pH cycling, the SDF groups demonstrated comparable inhibition of the biofilm relative to the control. the log CFU of S. mutans for Saforide, Topamine, T-SDF, and control were 6.69±0.73, 6.48±0.56, 6.63±0.66, and 8.01±0.45, respectively. For C. albicans, the log CFU were 4.86±0.44, 4.72±0.53, 4.92±0.29, and 5.60±0.27, respectively. The log CFU of S. mutans and C. albicans in the SDF groups were significantly lower than the control group (p<0.001). Further, the lesion depth decreased by approximately 14.79±7.00% in the SDF groups, while it increased by 11.07±8.61% in the control (p<0.001), and the mineral density increased by 16.36±4.58% in the SDF group, as opposed to a 5.59±2.64% reduction in the control (p<0.001) implying their caries mitigating effect. These findings were corroborated by SEM images of the lesions. SDF significantly mitigated dentin caries due to an assault by a polymicrobial plaque biofilm whilst arresting mineral loss and lesion growth. There was no difference in the caries-arresting efficacy of the compared SDF variants.

Developing a novel antibacterial copper tetraamine fluoride

ObjectiveTo develop a novel and biocompatible copper tetraamine fluoride (CTF) with antibacterial and nondiscolouring properties. MethodThis study used copper fluoride and ammonia solution to develop CTF solution. The CTF was characterized by X-ray photoelectron spectroscopy (XPS). Cytotoxicity was evaluated by stem cells from human exfoliated deciduous teeth (SHED) and human gingival fibroblasts (HGF-1). The fluoride concentration was determined using ion-selective electrode. The alkalinity was measured by a pH electrode. The human dentine blocks were treated with CTF and then incubated with Streptococcus mutans to evaluate the antimicrobial and discolouring effects. The silver diamine fluoride (SDF) was employed as the positive control, and water was the negative control. The colony-forming units (CFUs) and confocal laser scanning microscopy (CLSM) were used to examine the kinetics and viability of the biofilm. The discolouring property on dentine was assessed by spectrophotometry. One-way analysis of variance with the Bonferroni post hoc test was performed to assess and compare the data. ResultsXPS confirmed synthesis of CTF solution. The half-maximal inhibitory concentration of CTF on SHED and HGF-1 was 195±16 ppm and 137±11 ppm. The fluoride concentration was 121,000±5,000 ppm. The pH value was 9. Log10 CFU of the CTF, SDF and water group were 5.0 ± 0.2, 4.9 ± 0.1 and 7.4 ± 0.1 (p < 0.001, CTF, SDF<Water). CLSM showed that the dead-to-live ratio of the CTF, SDF and water group were 0.8 ± 0.2, 0.8 ± 0.2, and 0.3 ± 0.1 (p < 0.001, CTF, SDF>Water). Spectrophotometry showed that the ΔE of the CTF, SDF and water group were 5 ± 2, 6 ± 3 and 45±2 (p < 0.001, CTF, Water<SDF). ConclusionThis study developed an alkaline 58% CTF solution, which is biocompatible, antibacterial and non-discolouring. Clinical significanceIf CTF is successfully translated into clinical care, CTF can be a simple and affordable anti-caries agent for clinicians to prevent dental caries.

Do in vitro and in situ erosive challenges alter the bonding performance of universal adhesives?

ObjectiveTo evaluate microtensile bond strengths (μTBS), nanoleakage (NL), and degree of conversion (DC) of two universal adhesives, using etch-and-rinse (ER) or self-etch (SE) strategies on eroded dentin submitted to in vitro and in situ erosive challenges. MethodsDentin blocks were prepared from 120 human molars and categorized based on dentin condition (sound, in vitro eroded, and in situ eroded), adhesive system (Scotchbond Universal [SBU] and Zip bond Universal [ZIP]), and adhesive strategy (ER and SE). In the in situ erosive challenge, 20 volunteers wore acrylic resin palatal devices with dentin blocks, immersing them in cola soft drink for 90 s, six times daily for 15 days. The same erosive protocol was used in vitro, followed by rinsing and remineralization. Sound dentin blocks served as controls. Afterward, all dentin blocks were restored with composite resin and sectioned into resin-dentin bonded sticks for μTBS, NL, and DC assessments. Data were analyzed using three-way ANOVA and Tukey's test (α = 0.05). ResultsSound dentin exhibited the highest μTBS and DC values and the lowest NL values, while in situ eroded dentin showed the lowest μTBS and DC values and the highest NL values (p = 0.000001). While some differences in the μTBS values were observed between universal adhesives when evaluated on sound dentin (p = 0.0001), no significant differences between adhesives were observed when tested on in vitro and in situ eroded dentin. Regarding NL and DC, no significant differences were found between SBU and ZIP, as well as among adhesive strategies (p > 0.05). ConclusionErosion in dentin, especially under in situ conditions, presents significant challenges to the adhesion of restorative materials. The choice of an effective adhesive system is crucial, as dentin eroded in situ showed lower adhesion strength and greater nanoleakage. These results highlight the need for specific clinical strategies to improve the durability and effectiveness of restorations.

Effects of proanthocyanidin-functionalized hydroxyapatite nanoparticles on dentin bonding

ObjectivesTo evaluate the effect of proanthocyanidin-functionalized hydroxyapatite nanoparticles (nHAp_PA) used as pretreatment at different concentrations on the microtensile bond strength (µTBS) and endogenous enzymatic activity (MMPs) on pH-cycled dentin after 24 h and 6 months of artificial aging.Materials and methodsFifty human sound dentin blocks were randomly assigned to 5 groups (n = 10): (i) negative control (no treatment); (ii) positive control (pH-cycling); (iii) pH-cycling + 2% nHAp_PA for 60s; (iv) pH-cycling + 6.5% nHAp_PA for 60s; (v) pH-cycling + 15% nHAp_PA for 60s. A self-etch adhesive was used for bonding procedures before resin composite build-ups. Specimens were tested with the µTBS test after 24 h and 6 months of laboratory storage. The proteolytic activity in each group was evaluated with gelatin zymography and in situ zymography. Data were statistically analyzed (p < 0.05).ResultsAt 24 h, the µTBS of the experimental groups were significantly higher than the controls (p ≤ 0.001), and no differences were observed between different concentrations (p > 0.05). Artificial aging significantly decreased bond strength in all groups (p ≤ 0.008); however, nHAp_PA 2% still yielded higher bonding values than controls (p ≤ 0.007). The groups pretreated with nHAp_PA exhibited lower MMP-9 and MMP-2 activities compared to the positive control group and almost the same enzymatic activity as the negative control group. In situ zymography showed that after 6 months of aging, nHAp_PA 2% and nHAp_PA 6,5% decreased enzymatic activity as well as the negative control.ConclusionsDentin pretreatment with nHAp_PA increased the bonding performance of a self-etch adhesive and decreased MMP-2 and MMP-9 activities after 6 months.

Assessment of Autogenous Tooth Dentin Graft with Allogenic Bone Graft in the Preservation of Alveolar Ridge: A Clinicoradiographic Study

Abstract Background: Alveolar ridge is dynamic in nature. Preservation of residual alveolar ridge is always desirable. Bone grafts and platelet concentrates can be used for socket preservation. Maintenance of bone volume is essential and various ridge augmentation techniques are used for desirable functional and esthetic outcomes. Aim: Evaluation and comparison of the efficacy of autogenous dentin block versus allograft block in preserving alveolar ridge dimension with 6-month follow-up. Materials and Methods: Twenty subjects indicated for tooth extraction were randomly divided into three groups. In Group I, autogenous dentin graft with platelet-rich fibrin (PRF) membrane was used as socket filling material, Group II: allogenic bone graft with PRF membrane, or Group III: control group (socket left ungrafted). Clinical and radiographic examinations were done using periodontal probe and cone-beam computed tomography. Results: On intragroup comparison of socket size, the mean for Group I was found to be 33.270 mm2 at baseline and 25.358 mm after 12 months for Group II was found to be 53.250 mm2 at baseline and socket fill was 41.875 mm2 at 12 months. Group III was found to be 43.483 mm2 at baseline, and socket fill was 15.063 mm2 at 12 months. On intergroup comparison, the values were found to be statistically nonsignificant both at baseline (12 months postoperatively. The crestal bone loss was 0.975 for Group I, 1.075 for Group II, and 2.925 mm for Group III. Crestal bone loss was seen highest in Group III and lowest for Group I. The mean percentage of socket fill was found to be 80.01% for Group I, 76.13% for Group II, and 34.03% for Group I. Conclusion: A significant amount of radiographic socket fill was appreciated over 12 months in all the three groups. The percentage of socket fill in Group I was 80.01% and in Group II was 76.13% and the difference between them was statistically nonsignificant. Statistically significant socket fill was seen for both Group 1 and Group 2.

Analysis of dentin wear and biological properties promoted by experimental inoffice desensitizing materials

BackgroundThis study aimed to evaluate dentin wear and biological performance of desensitizing materials.MethodsSeventy bovine root dentin blocks were sectioned. Half of the surface of each specimen was untreated (control) and the other half was immersed in EDTA and treated with the following desensitizing materials: placebo varnish (PLA), fluoride varnish (FLU), sodium fluoride (NaF) varnish + sodium trimetaphosphate (TMP), universal adhesive (SBU), S-PRG varnish (SPRG), biosilicate (BIOS), and amelotin solution (AMTN). After application, the specimens were submitted to an erosive-abrasive challenge and the wear analyzed by optical profilometer. Serial dilutions of extracts obtained from the culture medium containing discs impregnated with those desensitizers were applied on fibroblasts and odontoblasts-like cells cultures. Cytotoxicity and production of total protein (TP) by colorimetric assays were determined after 24 h. Data were statistically analyzed using Kruskal-Wallis, Dunn’s, One-way ANOVA and Tukey tests (p ≤ 0.05).ResultsNo dentin wear was observed only for SBU. The lowest dentin wear was observed for AMTN and TMP. Cell viability was significantly reduced after treatment with undiluted extracts of PLA, FLU, TMP and SBU in fibroblasts and TMP and SBU in odontoblast-like cells. SPRG, BIOS and AMTN were cytocompatible at all dilutions tested. Considering TP results, no statistical difference was observed among the groups and high levels for TP were observed after TMP and FLU treatments.ConclusionsUniversal adhesive system may protect dentin with opened tubules from wear after challenge. Extracts of adhesive and fluoride varnishes presented cytotoxic mainly on fibroblasts. The enamel protein may be a future alternative to treat dentin with opened tubules because it may cause low wear under erosive-abrasive challenge with low cytotoxic effects.

Theaflavin -3,3'-digallate/ethanol: a novel cross-linker for stabilizing dentin collagen.

To study the ability of theaflavin-3,3'-digallate (TF3)/ethanol solution to crosslink demineralized dentin collagen, resist collagenase digestion, and explore the potential mechanism. Fully demineralized dentin blocks were prepared using human third molars that were caries-free. Then, these blocks were randomly allocated into 14 separate groups (n = 6), namely, control, ethanol, 5% glutaraldehyde (GA), 12.5, 25, 50, and 100mg/ml TF3/ethanol solution groups. Each group was further divided into two subgroups based on crosslinking time: 30 and 60s. The efficacy and mechanism of TF3's interaction with dentin type I collagen were predicted through molecular docking. The cross-linking, anti-enzymatic degradation, and biomechanical properties were studied by weight loss, hydroxyproline release, scanning/transmission electron microscopy (SEM/TEM), in situ zymography, surface hardness, thermogravimetric analysis, and swelling ratio. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy were utilized to explore its mechanisms. Statistical analysis was performed using one and two-way analysis of variance and Tukey's test. TF3/ethanol solution could effectively crosslink demineralized dentin collagen and improve its resistance to collagenase digestion and biomechanical properties (p < 0.05), showing concentration and time dependence. The effect of 25 and 50mg/ml TF3/ethanol solution was similar to that of 5% GA, whereas the 100mg/mL TF3/ethanol solution exhibited better performance (p < 0.05). TF3 and dentin type I collagen are mainly cross-linked by hydrogen bonds, and there may be covalent and hydrophobic interactions. TF3 has the capability to efficiently cross-link demineralized dentin collagen, enhancing its resistance to collagenase enzymatic hydrolysis and biomechanical properties within clinically acceptable timeframes (30s/60s). Additionally, it exhibits promise in enhancing the longevity of dentin adhesion.

Application of autogenous dentinal block to increase alveolar bone volume: a clinical case

Introduction. Materials based on extracted teeth in various studies have been radiographically and histologically proven to be effective in osteoplastic operations. These materials can be used in the form of crushed dentin matrix, a fragment of the tooth’s root and an autogenous dentin block. The purpose of this clinical case was to evaluate the effectiveness of using an autogenous dentin block to increase the alveolar process of the jaws in the preimplantation period.Description of a clinical case. Patient F., 30 years old, applied to the clinic of the Clinical Center of Maxillofacial, Plastic Surgery and Dentistry Russian University of Medicine with a complaint of a missing tooth in the frontal region of the lower jaw. At the time of treatment, the patient was already undergoing orthodontic treatment in another medical institution in Moscow. The patient underwent a clinical and radiological examination together with a prosthodontst. A diagnosis of «partial secondary adentia», «atrophy of the alveolar ridge in the frontal part of the lower jaw» and «dystopia of teeth 1.8, 2.8, 3.8, 4.8» was established. A comprehensive treatment plan has been drawn up. At the first stage, the patient underwent extraction of teeth 1.8, 2.8, 3.8, 4.8 for orthodontic indications with simultaneous bone grafting of the alveolar ridge in the area of the missing tooth 3.1. At the second stage, the patient underwent a trephine biopsy in the area of augmentation and installation of a dental implant in the area of missing tooth 3.1. The third stage was rational prosthodontic treatment on a dental implant in the department of prosthodontics.Results. The present study showed that autogenous dentinal block can serve as an alternative material for alveolar ridge augmentation.

Effect of different intracanal medicaments combined with chitosan nanoparticles on microhardness and fracture resistance of root dentin – An in vitro study

Abstract Introduction: Chitosan nanoparticles (CSN) are widely used for endodontic disinfection; however, their combination with other intracanal medicaments is least studied; therefore, this study aims to evaluate the effect of various intracanal medicaments incorporated with 0.2% CSN on root dentin microhardness and fracture resistance. Materials and Methods: Fifty extracted human single-rooted premolars were cleaned, decoronated, and standardized to 13 mm root length. After access opening and working length determination, specimens were instrumented with ProTaper rotary files till apical size F3 and alternatively irrigated with 5 ml of 2.5% sodium hypochlorite and normal saline (NS). Final irrigation was done with 5 ml of 1% phytic acid. The specimens were allocated randomly into five groups (n = 10), followed by placement of intracanal medicament for 1 week as follows. Group 1 – 0.2% CSN, Group 2 – Calcium hydroxide (Ca[OH] 2) + 0.2% CSN, Group 3 – Triple antibiotic paste (TAP) + 0.2% CSN, Group 4 – Propolis + 0.2% CSN, and Group 5 – Chlorhexidine gluconate (CHX) + 0.2% CSN. The specimens were then rinsed with NS and 3 mm coronal portion of each specimen was horizontally sectioned to create dentin blocks that were further split vertically and tested for Vickers microhardness (n = 10). The remaining root segment of each specimen was then vertically embedded in an acrylic block and evaluated for fracture resistance (n = 10) under a universal testing machine. The data acquired were statistically assessed using one-way ANOVA and posthoc Tukey tests (P &lt; 0.05). Results: Propolis incorporated with 0.2% CSN showed the highest microhardness and fracture resistance values followed by CHX + 0.2% CSN, TAP + 0.2% CSN, Ca(OH)2 + 0.2% CSN, and least in 0.2% CSN alone. Conclusion: Intracanal medicaments incorporated with 0.2% CSN exhibited a synergetic effect on microhardness and fracture resistance of endodontically treated teeth; however, propolis with 0.2% CSN exhibited higher microhardness and fracture resistance of root dentin.

Antibacterial efficacy of silver nanoparticles, sodium hypochlorite, chlorhexidine, and hypochlorous acid on dentinal surfaces infected with Enterococcus faecalis.

The purpose of this study was to evaluate the antibacterial effect of silver nanoparticles (AgNPs) against Enterococcus faecalis and compare it with different irrigation solutions. This study was performed using 64 dentin blocks. E. faecalis suspension was dispensed to each sample and incubated under anaerobic conditions at 37°C throughout 21 days. After the inoculation period, the following solutions were added to each group and kept for 5 min: Group 1, 5.25% sodium hypochlorite (NaOCl); Group 2, 2.5% NaOCl; Group 3, 1% NaOCl; Group 4, 2% chlorhexidine (CHX); Group 5, 200 ppm hypochlorous acid (HOCl); and Group 6, AgNPs. The samples of positive control were treated with sterile saline. Biofilm viability assay was performed using the LIVE/DEAD BacLight Bacterial Viability Kit. Samples were examined using confocal laser scanning microscopy, respectively. There was no significant difference between the 5.25% NaOCl, 2.5% NaOCl, and 1%NaOCl groups (p > .05). However, these groups showed statistically higher antibacterial activity than the 2% CHX, 200 ppm HOCl, and AgNP groups. Also, 2% CHX showed greater percentage of dead cells compared with the AgNP and HOCl groups. While AgNPs group showed lower dead cell rate than all NaOCl groups and 2% CHX, it caused higher dead cells than 200 ppm HOCl group. The 200 ppm HOCl group showed the lowest percentage of dead cells (p < .05) Although the antibacterial effect of AgNPs is not as high as NaOCl and CHX, it has considerable bactericidal activity against E. faecalis and can be improved by further studies. RESEARCH HIGHLIGHTS: New antimicrobial approaches for root canal irrigation. Antimicrobial effect of silver nanoparticles against E. faecalis. Elimination of the biofilm layer for the success of endodontic treatment.

Preventive dental erosion with silver diamine fluoride: An in vitro study

ObjectivesTo evaluate the erosion preventive effect of 38 % silver diamine fluoride (SDF) solution in enamel and dentin of human permanent teeth. MethodsNinety enamel and ninety dentin blocks were prepared from permanent molars and allocated into three groups. Gp-SDF received a one-off application of 38 % SDF solution. Gp-SNF received a one-off application of a solution containing 800 ppm stannous chloride and 500 ppm fluoride. Gp-DW received a one-off application of deionized water. The blocks were submitted to acid challenge at pH 3.2, 2 min, 5 times/day for 7 days. All blocks were immersed in human saliva between cycles for one hour. The crystal characteristics, percentage of surface microhardness loss (%SMHL), surface loss, and elemental analysis and surface morphology were examined by X-ray diffraction (XRD), microhardness test, non-contact profilometry, and energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM), respectively. Data of%SMHL and surface loss were analyzed by one-way ANOVA. ResultsXRD spectra revealed that fluorapatite and silver compounds formed in Gp-SDF, while fluorapatite and stannous compounds formed in Gp-SNF. Gp-DW presented only hydroxyapatite. The median (interquartile range) of%SMHL in Gp-SDF, Gp-SNF and Gp-DW were 27.86(3.66), 43.41(2.45), and 46.40(3.54) in enamel (p< 0.001), and 14.21(1.57), 27.99(1.95), and 33.18(1.73) in dentin, respectively (p < 0.001). The mean (standard deviation, μm) of surface loss of Gp-SDF, Gp-SNF, and Gp-DW were 2.81(0.59), 4.28(0.67), and 4.63(0.64) in enamel (p < 0.001) and 4.13(0.69), 6.04(0.61), and 7.72(0.66) in dentin, respectively (p < 0.001). SEM images exhibited less enamel corruption and more dentinal tubular occlusion in Gp-SDF compared to Gp-SNF and Gp-DW. EDS analysis showed silver was detected in Gp-SDF while stannous was detected in the dentin block of Gp-SNF. Conclusion38 % SDF yielded superior results in protecting enamel and dentin blocks from dental erosion compared to SNF and DW. Clinical significanceTopical application of 38 % SDF is effective in preventing dental erosion in human enamel and dentin.

Marginal Leakage in Interfaces Formed by Bovine Dentin and Adhesive Cements Applied with Different Bonding Techniques

Objectives: The aim of this in vitro study was to evaluate the marginal microleakage in interfaces formed by bovine dentin and adhesive cements applied with different bonding techniques. Materials and Methods: Thirty bovine teeth dentin blocks measuring 5 mm x 5 mm x 1 mm were made with one side completely in dentin substract (20 mm2). The dentin blocks were randomly divided into three groups according to the cementation technique used: CTS+RX (conventional 3-step adhesive + dual-activation resin cement), SBS+RX (single-bottle self-etching adhesive + dual-activation resin cement), and SAC (self-adhesive cement). A photopolymerizable composite resin block with the same dimensions was fixed on the dentin block according to the instructions for each adhesive technique. The dentin-composite resin blocks made with each adhesive technique were separated into subgroups (n = 5) for 7 days (control) and for 6 months of water storage. After each period, the blocks were individually immersed in test tubes containing neutral methylene blue dye for 2 hours. The samples were washed, dried, and evaluated with a stereoscopic magnifying glass, and the amount of infiltrated pigment was analyzed using spectrophotometry (Beckman DU 65). The data were submitted to two-way ANOVA and Tukey’s test (5%). Results: Microleakage level for the conventional 3-step or self-etching technique remained similar for 7 days (18 ± 25 and 43 ± 45 μm, respectively) or 6 months (42 ± 55 and 52 ± 87 μm, respectively). The self-adhesive technique showed higher microleakage levels for 7-day (263 ± 98 μm) and 6-month periods (441 ± 226 μm) compared to other adhesive techniques. There was a statistically significant difference between evaluation times only for the self-adhesive technique. Conclusions: Higher microleakage levels by storage in water occurred with the self-adhesive technique in both evaluation periods. Clinical Relevance: The different microleakage levels promoted at the dentin-composite resin interface should be considered in adhesive clinical procedures in relation to long-term use.

Low-fluoride gels supplemented with nano-sized sodium trimetaphosphate reduce dentin erosive wear in vitro

ObjectiveThe study assessed the effect of low-fluoride gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMP) on dentin erosive wear in vitro. DesignBovine dentin blocks (n = 154) were selected by surface microhardness and randomly allocated into seven groups (n = 22/group), according to the gels: Placebo; 4500 ppm F (4500F); 9000 ppm F (9000F); 5% TMP microparticulate plus 4500F (5TMPm+4500F); 2.5% TMP nanoparticulate plus 4500 F (2.5TMPn+4500F); 5% TMP nanoparticulate plus 4500F (5TMPn+4500F); and 12,300 ppm F acid gel (APF). All blocks were treated only once for 60 s and cyclically eroded (ERO, citric acid, 4 × 90 s/day) or eroded and brushed (4 × 15 s/day, five strokes/s, ERO+ABR) over five days (each subgroup n = 11). Dentin wear and integrated hardness loss in depth (ΔKHN) were determined, and the data were submitted to two-way ANOVA, followed by Tukey’s test, and Spearman’s correlation (p < 0.05). ResultsFor ERO, all gels containing 4500F supplemented with TMP significantly reduced dentin wear compared with their counterpart without TMP, reaching values similar to 9000F. For ERO+ABR, 5TMPn+ 4500F gel led to significantly lower wear than all its counterparts, reaching values similar to 9000F and APF. As for ΔKHN, all gels containing TMP promoted superior protective effects compared with 4500F, reaching values similar to 9000F and APF under both challenges. A positive correlation between dentin wear and mineral content in depth was verified. ConclusionsGels containing 4500F supplemented with TMP significantly reduced dentin erosive wear compared with pure 4500F, with additional benefit from the use of nanoparticles.

Comparative Evaluation of Residual Antibacterial Substantivity of Chlorhexidine, MTAD and Chitosan Against Enterococcus Faecalis in Human Root Dentin - An In vitro Study.

Complex anatomy of the root canal system results in incomplete debridement with mechanical instrumentation, leaving some areas or root canal walls untouched. There comes the significance of endodontic irrigants with residual antibacterial substantivity which prolongs the post-antibiotic effect, thereby improving the success and predictability of endodontic treatment. To comparatively evaluate the residual antibacterial substantivity of 2% chlorhexidine, Biopure MTAD and 2% chitosan against Enterococcus faecalis at intervals of 1, 14 and 28 days. Seventy-five therapeutically extracted permanent single rooted mandibular premolars teeth were selected. Dentin blocks of 4 mm thickness were prepared and enlarged to 1.6 mm. The autoclaved blocks were inoculated with 24-hour colonies of pure cultures of E. faecalis for 14 days. After the contamination period, canals of each dentin block were irrigated with 5 ml of sterile saline and dried with sterile paper points. A total of 75 dentin blocks were randomly divided into five groups as follows: Group A (21 specimens): 2% chlorhexidine, Group B (21 specimens): Biopure MTAD, Group C (21 specimens): 2% chitosan, Group D (6 specimens): positive control (infected dentin tubes) and Group E (six specimens): negative control (sterile dentin tubes). Then, the lumens of dentin blocks were irrigated with the respective irrigants for 10 mins and were dried using sterile paper points. The specimens were then incubated at 37°C for 28 days to maintain humidity. At experimental intervals of 1, 14 and 28 days, dentin shavings were removed from the canals of respective groups by circumferential filing with sterile no. 35 Hedstrom files. The powdered dentin samples obtained with each dentin block were observed for colony forming units (CFUs) using a Digital Colony counter and were expressed as CFUs/mL. All the irrigants in the study showed a significant decrease in CFUs from day 1 to day 28 indicating that they have residual antibacterial substantivity against E. faecalis. Group B (Biopure MTAD) showed significantly least mean CFUs compared to Group A (2% CHX) and Group C (2% chitosan) against E. faecalis at B1(day 1), B2(day 14) and B3(day 28). Group A (2% CHX) showed significantly higher mean CFUs than Group C (2% chitosan) at A1(day 1). Group C (2% chitosan) showed significantly higher mean CFUs compared to Group A (2% CHX) at C2(day 14) and C3 (day 28). MTAD showed statistically higher residual antibacterial substantivity against E. faecalis at experimental periods of 1, 14 and 28 days. The residual antibacterial effect of 2% chitosan was better compared to 2% CHX at day 1. The residual antimicrobial substantivity of 2% CHX was higher compared to 2% chitosan at intervals of 14 and 28 days.

Effect of Casearia sylvestrison the obliteration of dentinal tubules and the control of dental sensitivity

The present study evaluated the efficacy of the mineralizing action of Casearia sylvestris ethanolic extract on bovine dentin blocks in its pure form and in dental paste, through scanning electron microscopy. The dentin blocks were immersed in artificial saliva and incubated at 37°C for 7 days. Subsequently, six groups were treated with different test substances and analysed qualitatively and quantitatively at 30 and 60 days. The tests used were Kruskal-Wallis and Dunn's. Shapiro-Wilk and ANOVA. The qualitative analysis at 30 days showed a difference between the groups treated with ethanolic extract and toothpaste. Quantitatively, at 30 days, treatment with ethanolic extract of Casearia showed a greater number of open dentinal tubules. At 60 days, the difference persisted only for the blocks treated with toothpaste. The results obtained indicated that there is a positive relationship between the use of Casearia sylvestris and obliteration of dentinal tubules.

In Vitro Risk Assessment of Dental Acid Erosion Caused by Long-Term Exposure to Oral Liquid Bandages.

Oral mucosa inflammation can cause severe pain and interfere with eating, reducing quality of life. However, few options for self-care are available. An oral liquid bandage forms a protective film over the affected area. We aimed to assess the acid erosion risk when a newly developed oral liquid bandage (ORAPLA) is accidentally deposited on teeth and to examine the relative acid erosion risk at multiple time points of the maximum recommended duration of continuous use. ORAPLA was applied to both enamel and dentin blocks from 45 bovine anterior mandibular teeth, and an acid challenge was performed in a simulated oral cavity with artificial saliva, with one exposure cycle lasting 6 h. The enamel showed substantial defects and a decrease in Vickers hardness after nine cycles, with no change in surface roughness. Dentin showed an increase in parenchymal defects and surface roughness and a trend toward decreased Vickers hardness with increasing exposure time. We found no significant acid corrosion in enamel after up to nine times the upper limit of normal use time or in dentin after up to six times the upper limit. We conclude that the acid erosion risk due to accidental attachment to teeth is low, and in the human oral cavity with salivary buffering and remineralization, likely even lower.

The effect of the enzymes trypsin and DNase I on the antimicrobial efficiency of root canal irrigation solutions.

The purpose of this study was to evaluate the antibacterial efficacy of using 2.5% NaOCl, 2% chlorhexidine (CHX), Irritrol, and chitosan-coated silver nanoparticles (AgCNPs) alone or in combination with deoxyribonuclease I (DNase I) and trypsin pre-enzyme applications in dentin samples contaminated with Enterococcus faecalis (E. faecalis) by CLSM. 144 dentin blocks with confirmed E. faecalis biofilm formation were divided randomly according to the irrigation protocol (n = 12): NaOCl, CHX, Irritrol, AgCNPs, trypsin before NaOCl, CHX, Irritrol, AgCNPs, and DNase I before NaOCl, CHX, Irritrol, AgCNPs. Dentin blocks were stained with the Live/Dead BacLight Bacterial Viability Kit and viewed with CLSM after irrigation applications. The percentage of dead and viable bacteria was calculated using ImageJ software on CLSM images. At a significance level of p < 0.05, the obtained data were analyzed using one-way Anova and post-hoc Tukey tests. In comparison with NaOCl, CHX had a higher percentage of dead bacteria, both when no pre-enzyme was applied and when DNase I was applied as a pre-enzyme (p < 0.05). There was no difference in the percentage of dead bacteria between the irrigation solutions when trypsin was applied as a pre-enzyme (p > 0.05). AgCNPs showed a higher percentage of dead bacteria when trypsin was applied as a pre-enzyme compared to other irrigation solutions (p < 0.05), while the pre-enzyme application did not affect the percentage of dead bacteria in NaOCl, CHX, and Irritrol (p > 0.05). No irrigation protocol tested was able to eliminate the E. faecalis biofilm. While the application of trypsin as a pre-enzyme improved the antimicrobial effect of AgCNPs, it did not make any difference over other irrigation solutions.

Evaluation of the antimicrobial efficacy of different nonsteroidal anti-inflammatory drugs alone or in combination with calcium hydroxide intracanal medicament: an in vitro study.

This study explored the antimicrobial effects of ketoprofen, piroxicam, and celecoxib alone or combined with calcium hydroxide (CH) against two strains of Enterococcus faecalis (E. faecalis) and assessed the influence of such combinations on the pH of CH. Minimum inhibitory concentrations (MICs) of the three tested NSAIDs were determined. Tested pastes were placed into wells punched in seeded agar plates and the bacterial inhibition zones were measured. Antibiofilm activity was assessed against 3 weeks of biofilm induced in bovine dentine blocks. The pH of the pastes was measured at four-time intervals. MIC values were 3.12, 25, and 25mg/ml for ketoprofen, piroxicam, and celecoxib, respectively, and were similar for both bacterial strains except for celecoxib, which showed 8% growth at the highest tested concentration against vancomycin-resistant E. faecalis. Ketoprofen had the largest mean inhibition zone that was comparable to CH. None of the six tested pastes exhibited antibiofilm activity of a significant level in comparison to CH. A noticeable increase in the antibiofilm activity was found when 20% NSAIDs were added to CH while maintaining an alkaline pH. Ketoprofen was found to be the most effective among the tested NSAIDs. Although its effect was comparable to CH, adding ketoprofen at a ratio of 20% resulted in 50% higher antimicrobial action than CH alone. Accordingly, incorporating NSAIDs in inter-appointment dressing has the potential to utilize their anti-inflammatory, local analgesic, and antibacterial actions, which overcome the limitations of CH and improve the outcome of root canal treatment.