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Journal of Functional Biomaterials May 2024The aim of this study was to evaluate the effect of different irrigating solutions as well as their combination and activation modes on root canal dentin microhardness.... (Review)
Review
The aim of this study was to evaluate the effect of different irrigating solutions as well as their combination and activation modes on root canal dentin microhardness. The protocol was registered in PROSPERO and PRISMA guidelines were followed. The structured question was as follows: "Which type of irrigating solution used in endodontic treatment causes more change in dentin microhardness?" The literature was screened via PubMed, Google Scholar, Scopus, and Science Direct. The last search was carried out in February 2023 with English language restriction. Two reviewers independently performed screening and evaluation of articles. A total of 470 articles were retrieved from all the databases, whereas only 114 articles were selected for full-text analysis. After applying eligibility criteria, 44 studies were evaluated and included in this review. The results showed that with increased contact time with irrigants, dentin microhardness decreases. Increased contact time with sodium hypochlorite (NaOCl) was associated with more reduction in dentin microhardness compared with other irrigants. Other irrigants, with the exception of distilled water, including EDTA, citric acid, herbal irrigants, glycolic acid, phytic acid, etc., in this study significantly decreased dentin microhardness. The maximum reduction in dentin microhardness was seen with 2.5% NaOCl after 15 min of contact time. The use of irrigating solutions alters the chemical composition of dentin, thereby decreasing its microhardness, which affects the clinical performance of endodontically treated teeth.
PubMed: 38786643
DOI: 10.3390/jfb15050132 -
Revista Cientifica Odontologica... 2023Identify the histological characteristics of bovine dentin using histological technique by decalcification with Masson's Trichrome staining.
OBJECTIVES
Identify the histological characteristics of bovine dentin using histological technique by decalcification with Masson's Trichrome staining.
MATERIALS AND METHODS
This was an observational and descriptive study using units of analysis. Bovine teeth were used, which were subjected to a decalcification technique and Masson's trichrome staining. Microscopic observation and registration of the structures was carried out.
RESULTS
In the microscopic observation of the teeth subjected to decalcification, dentin, predentin and the structural organization of the tubular and peritubular dentin were observed. The odontoblasts arranged in a palisade with the odontoblastic process included within the dentinal tubule and the periprocedural space. The presence of interglobular dentin is not observed in areas of coronary dentin. The histomorphological pattern corresponding to dentin-predentin-pulp is arranged in a similar way to human teeth.
CONCLUSIONS
Bovine dentin constitutes an ideal substrate for in vitro research work with dental biomaterials, since it presents histological characteristics similar to bovine teeth; the absence of interglobular dentin would not represent a significant difference according to what was observed in this study.
PubMed: 38312466
DOI: 10.21142/2523-2754-1104-2023-176 -
Archives of Oral Biology Sep 2023Variation in enamel and dentine mineral concentration and total effective density can be reliably collected using Micro-CT scans. Both variables are suggested to reflect...
OBJECTIVE
Variation in enamel and dentine mineral concentration and total effective density can be reliably collected using Micro-CT scans. Both variables are suggested to reflect mechanical properties such as hardness and elastic modulus in dental tissues, meaning Micro-CT methods allow relative composition and mechanical properties to be collected non-destructively.
DESIGN
16 lower molars from 16 Catarrhine primates were Micro-CT scanned alongside hydroxyapatite phantoms using standardized settings and methods to calculate mineral concentration and total effective density. Mineral concentration, total effective density and thickness of dentine and enamel were calculated for four cusps, representing each 'corner' of the tooth and four lateral crown positions (i.e., mesial, buccal, lingual and distal).
RESULTS
The results show mean mineral concentration and total effective density values were higher in areas of thicker enamel, while the opposite was observed for dentine. Buccal positions had significantly higher mineral concentration and total effective density values than lingual areas. Cuspal positions had higher mean values than lateral enamel, for both dentine (mineral concentration cuspal: 1.26 g/cm; lateral: 1.20 g/cm) and enamel (mineral concentration cuspal: 2.31 g/cm; lateral: 2.25 g/cm). Mesial enamel had significantly lower values than other locations.
CONCLUSIONS
These common patterns across Catarrhine taxa may be linked to functional adaptations related to optimization of mastication and tooth protection. Variation in mineral concentration and total effective density may also be associated with wear and fracture patterns, and can be used as baseline information to investigate the effect of diet, pathological changes and aging on teeth through time.
Topics: Animals; Dentin; Dental Enamel; Molar; Tooth; Primates
PubMed: 37385050
DOI: 10.1016/j.archoralbio.2023.105752 -
Scientific Reports Nov 2023The present study aimed to investigate the possible use of a non-instrumentation technique including blue light irradiation for root canal cleaning. Extracted human...
The present study aimed to investigate the possible use of a non-instrumentation technique including blue light irradiation for root canal cleaning. Extracted human single rooted teeth were selected. Nine different groups included distilled water, NaOCl, intra-canal heated NaOCl, and NaOCl + EDTA irrigation after either instrumentation or non-instrumentation, and a laser application group following non-instrumentation technique. The chemical assessment of the root canal dentine was evaluated using energy dispersive spectroscopy (EDS) and Fourier transform infrared (FT-IR) spectroscopy. Surface microstructural analyses were performed by using scanning electron microscopy (SEM). The antimicrobial efficacy of different preparation techniques was evaluated using microbial tests. Light application didn't change the calcium/phosphorus, carbonate/phosphate and amide I/phosphate ratios of the root canal dentin. The root canal dentin preserved its original chemistry and microstructure after light application. The instrumentation decreased the carbonate/phosphate and amide I/phosphate ratios of the root canal dentin regardless of the irrigation solution or technique (p < 0.05). The application of light could not provide antibacterial efficacy to match the NaOCl irrigation. The NaOCl irrigation both in the non-instrumentation and instrumentation groups significantly reduced the number of bacteria (p < 0.05). The use of minimally invasive root canal preparation techniques where the root canal is not instrumented and is disinfected by light followed by obturation with a hydraulic cement sealer reduced the microbial load and preserved the dentin thus may be an attractive treatment option for management of vital teeth needing root canal therapy.
Topics: Humans; Spectroscopy, Fourier Transform Infrared; Dentin; Root Canal Therapy; Phosphates; Carbonates; Amides; Root Canal Irrigants; Edetic Acid; Sodium Hypochlorite; Microscopy, Electron, Scanning
PubMed: 37990070
DOI: 10.1038/s41598-023-47682-9 -
The Journal of Prosthetic Dentistry Nov 2023Layered composite resins may adequately mask discolored substrates. However, whether color changes that occur over time affect masking ability is unclear.
STATEMENT OF PROBLEM
Layered composite resins may adequately mask discolored substrates. However, whether color changes that occur over time affect masking ability is unclear.
PURPOSE
The purpose of this in vitro study was to investigate the effect of layering and water aging on the masking ability of 2 composite resins.
MATERIAL AND METHODS
Disk specimens (1.5 mm-thick and shade A1) from Charisma Diamond (CD) and Filtek Z350XT (Z350) were made according to the composite resin shade combination used in the layering strategies: bilayer for CD (enamel/dentin) and for Z350 (enamel/body and enamel/dentin) and trilayer for Z350 (enamel/body/dentin) (n=5). Color measurements were obtained with a spectrophotometer over an A3.5 ceramic substrate, and the whiteness index for dentistry (WI) was calculated. The specimens were aged in water at 37 °C and evaluated at different times: 24 hours, 1 week, 1 month, 2 months, 6 months, 12 months, 18 months, and 24 months. CIEDE2000 color differences (ΔE) and WI differences (ΔWI) were calculated and interpreted by 50:50% color and whiteness perceptibility and acceptability thresholds. Changes among strategies and aging times were analyzed using the Kruskal-Wallis test (α=.05). Contrasts were made using the Mann-Whitney U test with Bonferroni correction (α=.001).
RESULTS
ΔE decreased from 24 hours to 2 months of aging. From 2 months onwards, ΔE increased for all layering strategies and times, without significant changes in lightness for CD (P>.004). Overall, for the CD restorative system, an increase in ΔWI was observed after 1 month of aging (P<.001), while for the Z350 restorative system, ΔWI decreased after aging (P<.001), except for the Z350 bilayer strategy (enamel + dentin) at 1 week and 2 months (P>.004). For all layering strategies and aging times, color differences were higher than the 50:50% perceptibility threshold for ΔE and, after 6 months, higher than the 50:50% acceptability threshold for ΔE and the 50:50% whiteness acceptability threshold.
CONCLUSIONS
The ability of the tested composite resins to mask a discolored substrate was affected by the layering approach applied and by prolonged water aging.
Topics: Color; Composite Resins; Ceramics; Spectrophotometry; Materials Testing
PubMed: 37730467
DOI: 10.1016/j.prosdent.2023.08.031 -
International Journal of Dentistry 2023This study aimed to evaluate Nd:YAG laser, calcium phosphate, and adhesive system effect as different pretreatments in different protocols on dentin permeability (DP)...
This study aimed to evaluate Nd:YAG laser, calcium phosphate, and adhesive system effect as different pretreatments in different protocols on dentin permeability (DP) and bond strength (BS). Fifty human dentin discs were used (4 mm in diameter and 1,5 mm in height). Specimens were divided into five groups ( = 10): (A): adhesive system (control); (AL): adhesive system + Nd:YAG laser; (LAL): Nd:YAG laser + adhesive system + Nd:YAG laser; (PAL): calcium phosphate-based dentin desensitizer TeethMate + adhesive system + Nd:YAG laser; and group (PLAL): Nd:YAG laser + calcium phosphate-based dentin desensitizer + adhesive system + Nd:YAG laser. All materials were used according to the manufacturers' instructions. The specimens were submitted to artificial aging (5,000 thermal cycles and 12 × 10 mechanical cycles) then a bond test was performed. DP was measured using the split chamber model. Data were submitted to one-way analysis of variance (ANOVA), paired -test, RM ANOVA, and Tukey test ( < 0.05). All treatments were effective in DP reduction. For BS, the groups PAL and PLAL had improved BS with a statistically significant difference of the control group (A). Nd:Yag laser irradiation and calcium phosphate-based desensitizing agents significantly reduced DP, and the association between them could improve the BS on resin-human dentin interface.
PubMed: 37435112
DOI: 10.1155/2023/2182651 -
Dental Materials Journal Aug 2023This study evaluated the effect of tricalcium phosphate-containing fluoride varnish on the prevention of root caries using an in-air micro-proton induced X-ray/gamma-ray...
This study evaluated the effect of tricalcium phosphate-containing fluoride varnish on the prevention of root caries using an in-air micro-proton induced X-ray/gamma-ray emission system and microcomputed tomography. Either fluoride varnish (FV) or tricalcium phosphate-containing fluoride varnish (WV) was applied to root dentin, whereas dentin without varnish were considered controls. After immersion in saline, dentin sections were prepared, and concentration of fluoride ion was measured. These specimens were demineralized, and the mineral loss was measured. Caries inhibition in sound and demineralized dentin was observed in both FV and WV groups compared to the control group. Significantly low mineral loss was found especially in the demineralized dentin, which is probably due to the combination effect of calcium and fluoride ions at a concentration range of 100,000 ppm, as supplied by the varnish. The use of calcium-containing fluoride varnish, especially in demineralized dentin, is effective in arresting initial dentin caries.
Topics: Humans; Fluorides; Dental Caries; Cariostatic Agents; Fluorides, Topical; Calcium; X-Ray Microtomography; Minerals; Dentin; Sodium Fluoride
PubMed: 37271539
DOI: 10.4012/dmj.2022-252 -
Journal of Dentistry Sep 2023To evaluate the influence of two glutaraldehyde-based desensitizers (L: GLUMA Desensitizer, Heraeus Kulzer and G: GLUMA Desensitizer PowerGel) prior to the adhesive...
OBJECTIVES
To evaluate the influence of two glutaraldehyde-based desensitizers (L: GLUMA Desensitizer, Heraeus Kulzer and G: GLUMA Desensitizer PowerGel) prior to the adhesive procedures on microtensile bond strength (µTBS) to dentin and endogenous enzymatic activity.
METHODS
Noncarious human third molars (N = 48) were cut to expose middle coronal dentin. Six experimental groups were formed according to the dentin pre-treatment (L or G) and the universal adhesives (IBU - iBond universal, Kulzer or AU - Adhese Universal, Ivoclar Vivadent) used in the self-etch mode (n = 8): 1) L/IBU; 2) G/IBU; 3) IBU; 4) L/AU; 5) G/AU; 6) AU. Specimens were cut into sticks and stressed until failure after 24 h (T) or 1 yr of aging (T). Additional 4 teeth were used for in situ zymography evaluation and data were statistically analyzed (α = 0.05).
RESULTS
Dentin pre-treatment, adhesive and aging statistically influenced bond strength and enzymatic activity (P<0.001). AU demonstrated higher bond strength values than IBU (P<0.001). The L resulted in higher bond strength compared to the G and control groups (P<0.001). aging statistically influenced bonding performance, especially when no dentin pre-treatment was performed (P<0.001). In situ zymography revealed that at baseline the control groups exhibited lower interfacial fluorescence compared to the experimental groups, irrespective of the adhesive used (P<0,001). However, after 1 yr of artificial storage, no differences were found among the groups (P>0.05).
CONCLUSIONS
Glutharldeadeyde-based products increased bond strength and determined a stabilization of the adhesive interface over time apparently not related to the MMPs inhibition.
CLINICAL SIGNIFICANCE
The results of this in vitro study suggest that the application of glutaraldehyde-based desensitizers prior to the adhesive procedures when associated with universal adhesives could result in increased bond strength and stabilization of the adhesive interface over time.
Topics: Humans; Dental Cements; Glutaral; Dentin-Bonding Agents; Dental Bonding; Resin Cements; Materials Testing; Tensile Strength; Adhesives
PubMed: 37524197
DOI: 10.1016/j.jdent.2023.104643 -
Contemporary Clinical Dentistry 2023Disinfection and dentin conditioning promote a favorable scenario for regenerative endodontic treatment. Clinical reports have confirmed periapical normality with high...
BACKGROUND
Disinfection and dentin conditioning promote a favorable scenario for regenerative endodontic treatment. Clinical reports have confirmed periapical normality with high variability in disinfection protocols; nevertheless, the nature of neoformed tissue varied between them. Thus, this study aimed to present the impact of disinfection protocols on the clinical, histological, and molecular outcomes of regenerative endodontics procedures in permanent teeth with incomplete root formation.
MATERIALS AND METHODS
Eighteen teeth with incomplete root formation which required endodontic regenerative treatment were treated with different disinfection and conditioning agents and followed under clinical control. One case was evaluated under histological and immunohistochemical analyses.
RESULTS
Clinical outcomes revealed periapical repair in 17/18 cases. Histological and immunohistochemical analyses confirmed the neoformation of the dentinal matrix and its mineralization.
CONCLUSIONS
Chemical conditioning could impact the outcome of regenerative endodontic procedures. The histological and immunohistochemical analysis showed the nature of the newly formed tissue that correlates with the clinical outcome.
PubMed: 38075542
DOI: 10.4103/ccd.ccd_44_23 -
Biomedicines Nov 2023In dentistry, various animal models are used to evaluate adhesive systems, dental caries and periodontal diseases. Metalloproteinases (MMPs) are enzymes that degrade...
In dentistry, various animal models are used to evaluate adhesive systems, dental caries and periodontal diseases. Metalloproteinases (MMPs) are enzymes that degrade collagen in the dentin matrix and are categorized in over 20 different classes. Collagenases and gelatinases are intrinsic constituents of the human dentin organic matrix fibrillar network and are the most abundant MMPs in this tissue. Understanding such enzymes' action on dentin is important in the development of approaches that could reduce dentin degradation and provide restorative procedures with extended longevity. This in silico study is based on dentistry's most used animal models and intends to search for the most suitable, evolutionarily close to . We were able to retrieve 176,077 mammalian MMP sequences from the UniProt database. These sequences were manually curated through a three-step process. After such, the remaining 3178 sequences were aligned in a multifasta file and phylogenetically reconstructed using the maximum likelihood method. Our study inferred that the animal models most evolutionarily related to were (MMP-1 and MMP-8), (MMP-13), (MMP-2) and (MMP-9). Further research will be needed for the biological validation of our findings.
PubMed: 38002041
DOI: 10.3390/biomedicines11113042