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International Journal of Molecular... Jun 2024Epigenetic modulation, including histone modification, alters gene expression and controls cell fate. Histone deacetylases (HDACs) are identified as important regulators...
Epigenetic modulation, including histone modification, alters gene expression and controls cell fate. Histone deacetylases (HDACs) are identified as important regulators of dental pulp cell (DPC) mineralisation processes. Currently, there is a paucity of information regarding the nature of histone modification and HDAC expression in the dentine-pulp complex during dentinogenesis. The aim of this study was to investigate post-translational histone modulation and HDAC expression during DPC mineralisation and the expression of Class I/II HDACs during tooth development and in adult teeth. HDAC expression (isoforms -1 to -6) was analysed in mineralising primary rat DPCs using qRT-PCR and Western blot with mass spectrometry being used to analyse post-translational histone modifications. Maxillary molar teeth from postnatal and adult rats were analysed using immunohistochemical (IHC) staining for HDACs (1-6). HDAC-1, -2, and -4 protein expression increased until days 7 and 11, but decreased at days 14 and 21, while other HDAC expression increased continuously for 21 days. The Class II mineralisation-associated HDAC-4 was strongly expressed in postnatal sample odontoblasts and DPCs, but weakly in adult teeth, while other Class II HDACs (-5, -6) were relatively strongly expressed in postnatal DPCs and adult odontoblasts. Among Class I HDACs, HDAC-1 showed high expression in postnatal teeth, notably in ameloblasts and odontoblasts. HDAC-2 and -3 had extremely low expression in the rat dentine-pulp complex. Significant increases in acetylation were noted during DPC mineralisation processes, while trimethylation H3K9 and H3K27 marks decreased, and the HDAC-inhibitor suberoylanilide hydroxamic acid (SAHA) enhanced H3K27me3. These results highlight a dynamic alteration in histone acetylation during mineralisation and indicate the relevance of Class II HDAC expression in tooth development and regenerative processes.
Topics: Animals; Acetylation; Rats; Histone Deacetylases; Dentinogenesis; Dentin; Dental Pulp; Protein Processing, Post-Translational; Histones; Molar; Odontoblasts; Male
PubMed: 38928274
DOI: 10.3390/ijms25126569 -
Scientific Reports Jun 2024The aim of this study is to introduce a dental capping agent for the treatment of pulp inflammation (pulpitis). Nanohydroxyapatite with Elaeagnus angustifolia L. extract...
The aim of this study is to introduce a dental capping agent for the treatment of pulp inflammation (pulpitis). Nanohydroxyapatite with Elaeagnus angustifolia L. extract (nHAEA) loaded with metronidazole (nHAEA@MTZ) was synthesized and evaluated using a lipopolysaccharide (LPS) in vitro model of pulpitis. nHAEA was synthesized through sol-gel method and analyzed using Scanning Electron Microscopy, Transmission Electron Microscopy, and Brunauer Emmett Teller. Inflammation in human dental pulp stem cells (HDPSCs) induced by LPS. A scratch test assessed cell migration, RT PCR measured cytokines levels, and Alizarin red staining quantified odontogenesis. The nHAEA nanorods were 17-23 nm wide and 93-146 nm length, with an average pore diameter of 27/312 nm, and a surface area of 210.89 m/g. MTZ loading content with controlled release, suggesting suitability for therapeutic applications. nHAEA@MTZ did not affect the odontogenic abilities of HDPSCs more than nHAEA. However, it was observed that nHAEA@MTZ demonstrated a more pronounced anti-inflammatory effect. HDPSCs treated with nanoparticles exhibited improved migration compared to other groups. These findings demonstrated that nHAEA@MTZ could be an effective material for pulp capping and may be more effective than nHAEA in reducing inflammation and activating HDPSCs to enhance pulp repair after pulp damage.
Topics: Plant Extracts; Humans; Pulpitis; Metronidazole; Dental Pulp; Durapatite; Nanoparticles; Green Chemistry Technology; Drug Carriers; Stem Cells; Cell Movement; Cells, Cultured
PubMed: 38926433
DOI: 10.1038/s41598-024-65582-4 -
International Endodontic Journal Jun 2024Autophagy is involved in human apical periodontitis (AP). However, it is not clear whether autophagy is protective or destructive in bone loss via the receptor activator...
AIM
Autophagy is involved in human apical periodontitis (AP). However, it is not clear whether autophagy is protective or destructive in bone loss via the receptor activator of nuclear factor-κB ligand (RANKL)/RANK/osteoprotegerin (OPG) axis. This study aimed to investigate the involvement of autophagy via the RANKL/RANK/OPG axis during the development of AP in an experimental rat model.
METHODOLOGY
Twenty-four female Sprague-Dawley rats were divided into control, experimental AP (EAP) + saline, and EAP + 3-methyladenine (An autophagy inhibitor, 3-MA) groups. The control group did not receive any treatment. The EAP + saline group and the EAP + 3-MA group received intraperitoneal injections of saline and 3-MA, respectively, starting 1 week after the pulp was exposed. Specimens were collected for microcomputed tomography (micro-CT) scanning, histological processing, and immunostaining to examine the expression of light chain 3 beta (LC3B), RANK, RANKL, and OPG. Data were analysed using one-way analysis of variance (p < .05).
RESULTS
Micro-CT showed greater bone loss in the EAP + 3-MA group than in the EAP + saline group, indicated by an elevated trabecular space (Tb.Sp) (p < .05). Inflammatory cell infiltration was observed in the EAP + saline and EAP + 3-MA groups. Compared with EAP + saline group, the EAP + 3-MA group showed weaker expression of LC3B (p < .01) and OPG (p < .05), more intense expression of RANK (p < .01) and RANKL (p < .01), and a higher RANKL/OPG ratio (p < .05).
CONCLUSION
Autophagy may exert a protective effect against AP by regulating the RANKL/RANK/OPG axis, thereby inhibiting excessive bone loss.
PubMed: 38923421
DOI: 10.1111/iej.14103 -
Brazilian Dental Journal 2024This study aimed to evaluate the antimicrobial activity of calcium hypochlorite (Ca (OCl)2) and sodium hypochlorite (NaOCl) using confocal laser scanning microscopy...
This study aimed to evaluate the antimicrobial activity of calcium hypochlorite (Ca (OCl)2) and sodium hypochlorite (NaOCl) using confocal laser scanning microscopy (CLSM) and dentin organic matrix alteration by picrosirius staining and light microscopy (LM). Samples of human extracted teeth were infected with Enterococcus faecalis by centrifugation of the bacterial suspension and were treated with Ca(OCl)2 or NaOCl at 0.5%, 2.5%, and 6% for 15, 30, and 60 seconds. CLSM and viability staining were used to quantitatively analyze the proportions of dead/live bacteria in the canal lumen and border of the root canal. The data were analyzed by ANOVA and Fisher test. For LM analysis, one hundred bovine teeth were randomly divided into 10 test groups (n=10): G1- Without treatment; G2- 17% EDTA; G3- 6% NaOCl; G4- 6% NaOCl + EDTA; G5- 0.5% Ca(OCl)2; G6- 0.5% Ca(OCl)2 + EDTA; G7- 2.5% Ca(OCl)2; G8- 2.5% Ca(OCl)2 + EDTA; G9- 6% Ca(OCl)2; G10- 6% Ca(OCl)2 + EDTA. The samples were fragmented and stained with Picrosirius. Data were analyzed by Kruskal-Wallis and Dunn (P<0.05). There was a strong correlation between the results of the canal lumen and the border of the root canal (r=0.962). Both hypochlorites at a concentration of 0.5% showed less microbial reduction compared to 2.5% and 6% (P<0.05). There was less antimicrobial activity at 15 seconds compared to 30 and 60 seconds (P<0.05). Ca(OCl)2 and NaOCl showed similar results at the same concentrations (P>0.05). In conclusion, Ca(OCl)2 caused fewer alterations to the dentin organic matrix at concentrations of 0.5% and 2.5%. Ca(OCl)2 presents antimicrobial activity similar to NaOCl, and collagen damage is concentration-dependent.
Topics: Sodium Hypochlorite; Dentin; Calcium Compounds; Enterococcus faecalis; Collagen; Humans; Anti-Infective Agents; Root Canal Irrigants; Cattle; Microscopy, Confocal; Animals; Dental Pulp Cavity; In Vitro Techniques
PubMed: 38922251
DOI: 10.1590/0103-6440202405771 -
Brazilian Dental Journal 2024Studies regarding cytotoxic effects attributed to the use of adhesive bonding agents on pulp tissue are not conclusive. To point out whether these materials are safe for...
Studies regarding cytotoxic effects attributed to the use of adhesive bonding agents on pulp tissue are not conclusive. To point out whether these materials are safe for clinical use, in vivo exposure of dental pulp to adhesive bonding agents was simulated using an experimental setup in which Human Dental Pulp Stem Cells (hDPSC) are exposed to the action of two kinds of adhesives: self-etching adhesives and two-step bonding agents through a dentine barrier. Cytotoxic effects on these cells were evaluated by MTT assay protocol and fluorescence microscopy, and their results were contrasted to those obtained through Raman spectra taken on single hDPSCs. Overall, no significant cytotoxic effects were observed by combining all the techniques, and cell viability close to 90% was achieved for a dentine barrier of at least 1 mm thick. Moreover, Raman spectroscopy was able to detect structural DNA damage in some dental pulp cells when exposed to two-step bonding agents, suggesting that this technique could be considered a complementary tool with the potential to evaluate cell toxicity beyond cell viability.
Topics: Humans; Dental Pulp; Stem Cells; Spectrum Analysis, Raman; Dentin-Bonding Agents; Cell Survival; Microscopy, Fluorescence; Cells, Cultured
PubMed: 38922248
DOI: 10.1590/0103-6440202405529 -
Brazilian Oral Research 2024This review aimed to determine the prevalence of species of yellow, purple and green microbial complexes in root canals (RC) and periodontal pockets (PP) of teeth with...
This review aimed to determine the prevalence of species of yellow, purple and green microbial complexes in root canals (RC) and periodontal pockets (PP) of teeth with endodontic-periodontal lesions. For this purpose, two reviewers searched the literature up to January 2022. Studies reporting the prevalence of species of the yellow, purple and green microbial complexes in teeth diagnosed with endodontic-periodontal lesions were included. The risk of bias of the included studies was assessed using the 14 criteria from the NIH Quality Assessment Tool. Of 1,611 references identified in the initial search, only four studies were eligible and included in the qualitative analysis. The profile and prevalence rates of bacterial species in RC and PP varied among the included studies: levels of Agregatibacter actinomycetemcomitans (12% RC, 58% PP), Capnocytophaga granulosa (10% RC, 35% PP), Capnocytophaga sputigena (15-70% RC, 0-30% PP), Streptococcus mitis (30% RC, 35% PP), Streptococcus sanguinis (30% RC, 35% PP), and Veillonella parvula (70% RC, 50% PP) were identified. The high methodological heterogeneity prevented grouping and quantitative analysis of data. The risk of bias was considered 'moderate' for all studies. The included studies identified the presence of seven bacterial species belonging to the yellow, purple, and green microbial complexes in RC and PP, but with different prevalence rates. Future clinical studies are encouraged to investigate the presence and role of these species in the occurrence and development of endodontic-periodontal lesions.
Topics: Humans; Dental Pulp Cavity; Prevalence; Periodontal Pocket
PubMed: 38922208
DOI: 10.1590/1807-3107bor-2024.vol38.0048 -
Dentistry Journal Jun 2024Amelogenesis imperfecta is a hereditary disorder affecting dental enamel. Among its phenotypes, hypocalcified AI is characterized by mineral deficiency, leading to...
BACKGROUND
Amelogenesis imperfecta is a hereditary disorder affecting dental enamel. Among its phenotypes, hypocalcified AI is characterized by mineral deficiency, leading to tissue wear and, consequently, dental sensitivity. Excessive fluoride intake (through drinking water, fluoride supplements, toothpaste, or by ingesting products such as pesticides or insecticides) can lead to a condition known as dental fluorosis, which manifests as stains and teeth discoloration affecting their structure. Our recent studies have shown that extracts from Colombian native plants, and , deposit mineral ions such as phosphate and orthophosphate into the dental enamel structure; however, it is unknown whether these extracts produce toxic effects on the dental pulp.
OBJECTIVE
To assess cytotoxicity effects on human dental pulp stem cells (hDPSCs) exposed to extracts isolated from and . and, hence, their safety for clinical use.
METHODS
Raman spectroscopy, fluorescence microscopy, and flow cytometry techniques were employed. For Raman spectroscopy, hDPSCs were seeded onto nanobiochips designed to provide surface-enhanced Raman spectroscopy (SERS effect), which enhances their Raman signal by several orders of magnitude. After eight days in culture, and extracts at different concentrations (10, 50, and 100 ppm) were added. Raman measurements were performed at 0, 12, and 24 h following extract application. Fluorescence microscopy was conducted using an OLIMPUS fv1000 microscope, a live-dead assay was performed using a kit employing a BD FACS Canto TM II flow cytometer, and data analysis was determined using a FlowJo program.
RESULTS
The Raman spectroscopy results showed spectra consistent with viable cells. These findings were corroborated using fluorescence microscopy and flow cytometry techniques, confirming high cellular viability.
CONCLUSIONS
The analyzed extracts exhibited low cytotoxicity, suggesting that they could be safely applied on enamel for remineralization purposes. The use of nanobiochips for SERS effect improved the cell viability assessment.
PubMed: 38920890
DOI: 10.3390/dj12060189 -
Dentistry Journal Jun 2024Pulpal modifications taking place during prosthetic tooth preparation using worn-out burs may represent a risk for the vitality of the dental pulp. The aim of this in...
Pulpal modifications taking place during prosthetic tooth preparation using worn-out burs may represent a risk for the vitality of the dental pulp. The aim of this in vivo study was to evaluate whether the wear of diamond burs has an influence on the vascular microdynamics at the level of the dental pulp, during vertical preparation for zirconia crowns. The study was performed with a split-mouth design and included 32 vital permanent monoradicular teeth (20 maxillary and 12 mandibular), from six subjects, aged between 20 and 50 years. The teeth were randomly assigned to two study groups of 16 teeth each. For prosthetic preparation, new burs were used in the first group, and burs at their 5th use were used in the second group. Four consecutive determinations of the pulpal blood flow by Laser Doppler flowmetry (LDF-laser Doppler MoorLab instrument VMS-LDF2, Moor Instruments Ltd., Axminster, UK) were taken for each tooth included in the study: before the preparation (control values), immediately, at 24 h, and at 7 days after the prosthetic preparation. A four-way ANOVA statistical analysis was applied to analyze the effect of four considered factors (bur wear degree, time of measurement, tooth number, and tooth location) on the pulpal blood flow (PBF). A significant increase in pulpal blood flow compared to the baseline was recorded immediately after preparation ( < 0.01), at 24 h ( < 0.01), and at 7 days ( < 0.05) in both groups, but more pronounced in the case of burs at the 5th use. The blood flow was significantly higher in upper jaw teeth, irrespective of the measurement time. In conclusion, the use of worn-out diamond burs produces lasting modifications in the pulpal blood flow of teeth that undergo prosthetic crown preparation. ISRCTN registry: ISRCTN49594720.
PubMed: 38920879
DOI: 10.3390/dj12060178 -
Dentistry Journal Jun 2024(1) Background: Pulp canal obliteration (PCO) is a common condition characterized by an abnormal dentinal apposition within the canal wall, which often rises as a...
(1) Background: Pulp canal obliteration (PCO) is a common condition characterized by an abnormal dentinal apposition within the canal wall, which often rises as a consequence of dental trauma. In recent years, "guided endodontics" has offered a reliable and safer procedure for endodontic access in case of PCO. The present case report aims to introduce a new endodontic guided system with a sleeveless, open-frame titanium guide designed to reduce costs compared to traditional templates. (2) Methods: The patient is a 19-year-old female who was referred to a private clinic to treat a calcified and symptomatic tooth (3.3) with apical periodontitis. Following the first unsuccessful treatment attempt using the operating microscope, a three-dimensional cone beam computed tomography (CBCT) examination and an optical impression were performed in agreement with the patient. The Digital Imaging and Communications in Medicine (DICOM) and Standard Tessellation Language (STL) files were sent to the lab for the template packaging, and the patient was scheduled for a second appointment. The endodontic guide was accurately positioned, and shaping and filling were concluded with success. The canal was sealed with the single-cone technique and bioceramic sealer. (3) Results: The patient reported no significant post-operative symptoms. Notably, the treatment achieved total symptom resolution, as evidenced by radiographic assessments conducted 3 and 24 months post-treatment, confirming the procedure's success. (4) Conclusions: This innovative sleeveless, open-frame static titanium guide presents a promising advancement in guided endodontics for PCO treatment. The advantages include preserving healthy dental tissue, reduced chairside operating time, and cost savings compared to conventional templates. This approach holds promise for enhancing the quality and efficiency of endodontic procedures in cases of PCO. While the static guide holds promise, larger prospective studies are necessary to validate its efficacy, safety, and broader applicability in routine endodontic procedures.
PubMed: 38920867
DOI: 10.3390/dj12060166 -
Dentistry Journal May 2024Severe early childhood caries (S-ECC) is recognized as a significant chronic disease which affects the quality of life starting at very young ages and has a very rapid...
BACKGROUND
Severe early childhood caries (S-ECC) is recognized as a significant chronic disease which affects the quality of life starting at very young ages and has a very rapid evolution towards pulp complication and loss of dental tissue. Children with a high caries index DMFT are more likely to develop high levels of dental anxiety, which will influence the degree of cooperation during dental procedures. Emotions play an important role in the psychosomatic development of children, and all the factors that contribute to the modeling of these emotional states must be known and taken into consideration.
AIM
The aim of this study was to assess the association between dental anxiety in children with S-ECC and the color preferences for the components of the dental environment to reduce the levels of dental anxiety during medical visits.
MATERIAL AND METHOD
For this study, 91 children between 3 and 6 years of age diagnosed with S-ECC were selected from the Pediatric Dentistry Department of UMFST from Targu Mures and from a private dental office. The level of dental anxiety was determined by measuring the pulse rate, and a questionnaire was completed to establish the color preferences for the dental office environment and the dentist's attire. For this purpose, six different colors and their variants with three shades less intensity were chosen by using RGB (Red, Green, and Blue) identification codes for each color.
RESULT
The results showed that there was a statistically significant difference between the age of the subjects and dental anxiety levels, but there was no significant correlation between the DMFT score and dental anxiety. Also, the results showed that there was no significant difference between girls and boys when choosing the colors preferred by them for the dental office, but when comparing the colors that represented happiness, significant statistical difference was found between the girls' and boys' groups ( = 0.0039). For all the subjects, the colors associated with happiness were light yellow and pink, while the colors associated with anxiety were red and dark blue.
CONCLUSION
The data obtained showed that dental anxiety is strongly influenced by age, and an important role in inducing positive emotions is played by the dental environment if dressed in specific colors in order to reduce dental anxiety and create familiar conditions, especially for young children with S-ECC.
PubMed: 38920856
DOI: 10.3390/dj12060155