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Dental Materials : Official Publication... Jun 2024Silicon-releasing biomaterials are widely used in the field of dentistry. However, unlike bone, very little is known about the role of silicon on dental tissue formation...
OBJECTIVES
Silicon-releasing biomaterials are widely used in the field of dentistry. However, unlike bone, very little is known about the role of silicon on dental tissue formation and repair. This study investigates the influence of silicic acid on the survival, differentiation and mineralizing ability of human dental pulp stem cells (hDPSCs) in 3D pulp-like environments METHODS: Dense type I collagen hydrogels seeded with hDPSCs were cultured over 4 weeks in the presence of silicic acid at physiological (10 μM) and supraphysiological (100 μM) concentrations. Cell viability and proliferation were studied by Alamar Blue and live/dead staining. The collagen network was investigated using second harmonic generation imaging. Mineral deposition was monitored by histology and scanning electron microscopy. Gene expression of mineralization- and matrix remodeling-associated proteins was studied by qPCR.
RESULTS
Presence of silicic acid did not show any significant influence on cell survival, metabolic activity and gene expression of key mineralization-related proteins (ALP, OCN, BSP). However, it induced enhanced cell clustering and delayed expression of matrix remodeling-associated proteins (MMP13, Col I). OPN expression and mineral deposition were inhibited at 100 μM. It could be inferred that silicic acid has no direct cellular effect but rather interacts with the collagen network, leading to a modification of the cell-matrix interface.
SIGNIFICANCE
Our results offer advanced insights on the possible role of silicic acid, as released by pulp capping calcium silicates biomaterials, in reparative dentine formation. More globally, these results interrogate the possible role of Si in pulp pathophysiology.
PubMed: 38908960
DOI: 10.1016/j.dental.2024.06.021 -
JMIRx Med Jun 2024Information about the range of Hounsfield values for healthy teeth tissues could become an additional tool in assessing dental health and could be used, among other...
BACKGROUND
Information about the range of Hounsfield values for healthy teeth tissues could become an additional tool in assessing dental health and could be used, among other data, for subsequent machine learning.
OBJECTIVE
The purpose of our study was to determine dental tissue densities in Hounsfield units (HU).
METHODS
The total sample included 36 healthy children (n=21, 58% girls and n=15, 42% boys) aged 10-11 years at the time of the study. The densities of 320 teeth tissues were analyzed. Data were expressed as means and SDs. The significance was determined using the Student (1-tailed) t test. The statistical significance was set at P<.05.
RESULTS
The densities of 320 teeth tissues were analyzed: 72 (22.5%) first permanent molars, 72 (22.5%) permanent central incisors, 27 (8.4%) second primary molars, 40 (12.5%) tooth germs of second premolars, 37 (11.6%) second premolars, 9 (2.8%) second permanent molars, and 63 (19.7%) tooth germs of second permanent molars. The analysis of the data showed that tissues of healthy teeth in children have different density ranges: enamel, from mean 2954.69 (SD 223.77) HU to mean 2071.00 (SD 222.86) HU; dentin, from mean 1899.23 (SD 145.94) HU to mean 1323.10 (SD 201.67) HU; and pulp, from mean 420.29 (SD 196.47) HU to mean 183.63 (SD 97.59) HU. The tissues (enamel and dentin) of permanent central incisors in the mandible and maxilla had the highest mean densities. No gender differences concerning the density of dental tissues were reliably identified.
CONCLUSIONS
The evaluation of Hounsfield values for dental tissues can be used as an objective method for assessing their densities. If the determined densities of the enamel, dentin, and pulp of the tooth do not correspond to the range of values for healthy tooth tissues, then it may indicate a pathology.
PubMed: 38904484
DOI: 10.2196/56759 -
Photodiagnosis and Photodynamic Therapy Jun 2024This study aimed to evaluate the impact of photodynamic therapy (PDT) using two photosensitizers, methylene blue and indocyanine green, on the microtensile bond strength...
BACKGROUND
This study aimed to evaluate the impact of photodynamic therapy (PDT) using two photosensitizers, methylene blue and indocyanine green, on the microtensile bond strength of a universal adhesive to caries-affected dentin.
METHODS
The occlusal enamel of 60 third molars was cut to expose the inner one-third of the dentin. Artificial caries were induced through a pH cycling process. The samples were divided into three groups: M (Methylene blue+ diode laser), I (Indocyanine green agents+ diode laser irradiation), and control. Each group was further divided into two subgroups according to the adhesive protocol (self-etch, total-etch). After restoring with Gradia composite resin, teeth were sectioned and exposed to 5000 thermal cycles. Microtensile bond strength was measured using a universal testing machine. The data were subjected to two- and one-way ANOVA and paired comparisons were performed by the Tamhane and Tukey tests.
RESULTS
The study found significant effects of the photosensitizer, etching pattern, and their interactions on the microtensile bond strength of composite resin to caries-affected dentin (P<0.001). In the self-etching mode, PDT with indocyanine green exhibited significantly higher bond strength values compared to PDT with methylene blue (P=0.001) and the control groups (P<0.001). However, no significant differences were observed in the total-etch mode. (P=0.54).
CONCLUSIONS
The etching mode played a more significant role in the bond strength when using the universal adhesive alongside PDT with methylene blue and indocyanine green. Employing two photosensitizers in PDT during the self-etch mode significantly increased the bond strength values.
PubMed: 38897530
DOI: 10.1016/j.pdpdt.2024.104249 -
Arquivos Brasileiros de Cirurgia... 2024Bariatric surgery can cause oral health problems in individuals, such as an increase in dental caries, periodontal diseases and dental erosion, which can be avoided if... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Bariatric surgery can cause oral health problems in individuals, such as an increase in dental caries, periodontal diseases and dental erosion, which can be avoided if oral health promotion actions are implemented.
AIMS
To assess the impact of an oral health promotion program implemented among gastroplasty patients.
METHODS
This randomized clinical trial involved 208 patients undergoing gastroplasty; they were divided into two groups: Intervention Group, with participation in the Oral Health Promotion Program for Bariatric Patients, or Control Group. Assessments were carried out preoperatively, and six and 12 months postoperatively. The oral conditions assessed were: dental caries, periodontal diseases, tooth wear, dental plaque, and salivary flow. Sociodemographic information was obtained through application of structured questionnaires. For data analysis, the Chi-Square, Fisher's Exact, and Mann-Whitney tests were performed - α=5%.
RESULTS
Patients in the Intervention Group, when compared to those in the Control Group, presented: fewer changes in enamel (6M: p<0.0001; 12M: p=0.001), in dentin (6M: p<0.0001; 12M: p<0.0001), moderate tooth wear (6M=0.002; 12M=0.005), gingival bleeding (6M: p<0.0001), dental calculus (6M=0.002; 12M: p=0.03), periodontal pocket 4-5 mm (6M=0.001; 12M: p=<0.0001); greater reduction in the bacterial plaque index (6M: p<0.0001; 12M: p<0.0001), and increased salivary flow (6M: p=0.019).
CONCLUSIONS
The oral health promotion program had a positive impact on the prevention and control of the main problems to the oral health of the gastroplasty patients.
Topics: Humans; Male; Oral Health; Female; Gastroplasty; Middle Aged; Adult; Health Promotion
PubMed: 38896700
DOI: 10.1590/0102-6720202400011e1804 -
Materials (Basel, Switzerland) May 2024The purpose of the present study was to perform a preliminary analysis of the fitting of different fiber-reinforced composite (GFRC) posts to tooth root canals and...
The purpose of the present study was to perform a preliminary analysis of the fitting of different fiber-reinforced composite (GFRC) posts to tooth root canals and determine the resin cement layer thickness. The following GFRC posts were assessed: bundle posts (Rebilda GT, VOCO, Germany), sleeve system (SAP, Angelus Ind, Brazil), and accessory posts (Reforpin, Angelus, Brazil). Twenty-four freshly extracted mandibular single-rooted pre-molars were endodontically treated and divided into six groups, according to the type of GFRC post and resin cement (self-adhesive or conventional dual-cured). Then, specimens were cross-sectioned and inspected by optical microscopy regarding the cement layer thickness and presence of defects such as pores, voids, or fissures were assessed. Bundle and accessory posts revealed a regular distribution of resin cement with a lower number of voids than found with sleeve systems. The sleeve system posts showed poor fitting at the apical portion of the root canals. The type of resin cement did not affect the thickness of the interface, although both bundle and accessory posts allow a better distribution of resin cement and fibers. The present preliminary study reveals interesting insights on the fitting of bundle and accessory posts to root dentin and resin cement layer thickness in oval-shape root canals. The sleeve system posts showed adequate fitting only at the coronal portion of the canals.
PubMed: 38893784
DOI: 10.3390/ma17112520 -
International Journal of Molecular... May 2024It is remarkable how teeth maintain their healthy condition under exceptionally high levels of mechanical loading. This suggests the presence of inherent mechanical... (Review)
Review
It is remarkable how teeth maintain their healthy condition under exceptionally high levels of mechanical loading. This suggests the presence of inherent mechanical adaptation mechanisms within their structure to counter constant stress. Dentin, situated between enamel and pulp, plays a crucial role in mechanically supporting tooth function. Its intermediate stiffness and viscoelastic properties, attributed to its mineralized, nanofibrous extracellular matrix, provide flexibility, strength, and rigidity, enabling it to withstand mechanical loading without fracturing. Moreover, dentin's unique architectural features, such as odontoblast processes within dentinal tubules and spatial compartmentalization between odontoblasts in dentin and sensory neurons in pulp, contribute to a distinctive sensory perception of external stimuli while acting as a defensive barrier for the dentin-pulp complex. Since dentin's architecture governs its functions in nociception and repair in response to mechanical stimuli, understanding dentin mechanobiology is crucial for developing treatments for pain management in dentin-associated diseases and dentin-pulp regeneration. This review discusses how dentin's physical features regulate mechano-sensing, focusing on mechano-sensitive ion channels. Additionally, we explore advanced in vitro platforms that mimic dentin's physical features, providing deeper insights into fundamental mechanobiological phenomena and laying the groundwork for effective mechano-therapeutic strategies for dentinal diseases.
Topics: Dentin; Humans; Animals; Odontoblasts; Mechanotransduction, Cellular; Biomechanical Phenomena; Dental Pulp; Extracellular Matrix
PubMed: 38891829
DOI: 10.3390/ijms25115642 -
Polymers May 2024The aim of this study is to assess the micro-tensile bond strength and the mode of failure of a bioactive hybrid self-adhesive composite (Surefil one) under various...
OBJECTIVES
The aim of this study is to assess the micro-tensile bond strength and the mode of failure of a bioactive hybrid self-adhesive composite (Surefil one) under various dentin conditions.
METHODS
Thirty-two extracted human molar teeth were used to test the micro-tensile bond strength of Surefil one under different dentine conditions (no treatment, 37% phosphoric acid etching, and universal adhesive) in comparison with a resin-modified glass ionomer (RIVA). All restorations were light cure-bonded onto flat dentine and then sectioned into beams. Then, fractured specimens were observed under a light microscope to evaluate the mode of failure.
RESULTS
The Surefil one no-treatment group (NTG) exhibited the highest micro-tensile bond strength. Furthermore, there was no statistically significant difference observed between the Surefil one adhesive group (EAG) and the Surefil one acid etch group (EG). However, compared to other groups, the resin-modified glass ionomer (RIVA) produced the lowest results, which are statistically significant.
CONCLUSION
Surefil one offers superior bond strength values when compared to resin-modified glass ionomers. Furthermore, Surefil one requires no dentin condition and has more straightforward clinical steps.
PubMed: 38891504
DOI: 10.3390/polym16111558 -
Polymers May 2024We assessed the effect of non-protein thiols (NPSH), reduced glutathione (GSH) and -acetylcysteine (NAC), on resin shear bond strength (SBS) to hydrogen peroxide...
We assessed the effect of non-protein thiols (NPSH), reduced glutathione (GSH) and -acetylcysteine (NAC), on resin shear bond strength (SBS) to hydrogen peroxide (HO)-treated dentin, and their effects on the characteristics of dentin in comparison to ascorbic acid (AA) and sodium thiosulfate (STS). HO-treated dentin was conditioned with 5% AA, GSH, NAC, or STS applied for 1 or 5 min. The positive control group received HO without antioxidant application, and the first negative control group received distilled water (DW). The specimens received resin bonding immediately after treatment except for the second negative control group (delayed bonding). Microhardness, roughness, and topography were studied. The SBS values of all antioxidants were statistically greater than the positive control group ( < 0.05); however, NAC and AA applied for 1 min demonstrated the highest values, which were comparable to delayed bonding. All treatments removed the smear layer except DW, HO, and STS. The negative effect of HO on resin-dentin bonding was mitigated by the application of the antioxidants; however, their efficiencies were dependent on the antioxidant type and time of application. NAC was more effective in optimizing resin bonding to bleached dentin compared to GSH at 1 min application and STS at both application times but was comparable to AA. Negligible negative effects on the substrate's roughness and microhardness were detected. The antioxidant properties of the agent and its capacity to remove the smear layer are the processes underpinning the ability of a certain antioxidant to reverse the effect of HO on bonding.
PubMed: 38891420
DOI: 10.3390/polym16111473 -
Polymers May 2024This study investigated effects of rapid high-intensity light-curing (3 s) on increasing transdentinal temperature and cell viability.
BACKGROUND
This study investigated effects of rapid high-intensity light-curing (3 s) on increasing transdentinal temperature and cell viability.
METHODS
A total of 40 dentin discs (0.5 mm) obtained from human molars were prepared, included in artificial pulp chambers (4.5 × 5 mm), and subjected to four light-curing protocols (n = 5), with a Valo Grand light curing unit: (i) 10 s protocol with a moderate intensity of 1000 mW/cm (Valo-10 s); (ii) 3 s protocol with a high intensity of 3200 mW/cm (Valo-3 s); (iii) adhesive system + Filtek Bulk-Fill Flow bulk-fill composite resin in 10 s (FBF-10 s); (iv) adhesive system + Tetric PowerFlow bulk-fill composite resin in 3 s (TPF-3 s). Transdentinal temperature changes were recorded with a type K thermocouple. Cell viability was assessed using the MTT assay. Data were analyzed using one-way ANOVA and Tukey tests for comparison between experimental groups ( < 0.05).
RESULTS
The 3 s high-intensity light-curing protocol generated a higher temperature than the 10 s moderate-intensity standard ( < 0.001). The Valo-10 s and Valo-3 s groups demonstrated greater cell viability than the FBF-10s and TPF-3 s groups and statistical differences were observed between the Valo-3 s and FBF-10 s groups ( = 0.023) and Valo-3 s and TPF-3 s ( = 0.025), with a potential cytotoxic effect for the FBF-10 s and TPF-3 s groups.
CONCLUSIONS
The 3 s rapid high-intensity light-curing protocol of bulk-fill composite resins caused a temperature increase greater than 10 s and showed cell viability similar to and comparable to the standard protocol.
PubMed: 38891413
DOI: 10.3390/polym16111466 -
Scientific Reports Jun 2024This split-mouth blinded randomized controlled study compared the efficacy of a desensitizing agent with oxalate/resin polymer and a universal adhesive containing... (Randomized Controlled Trial)
Randomized Controlled Trial
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.
Topics: Humans; Dentin Sensitivity; Female; Male; Dentin Desensitizing Agents; Adult; Glass; Treatment Outcome; Ceramics; Dental Cements; Young Adult; Middle Aged; Porosity
PubMed: 38886498
DOI: 10.1038/s41598-024-64404-x