Chemical and morphological analysis of dentin irradiated by different high-power lasers: a systematic review.

PURPOSE: This systematic review provides an overview of the main chemical and morphological alterations generated on dentin by different high-power lasers' irradiation. METHODS: The review was registered in PROSPERO (CRD42023394164) and PRISMA guidelines were followed. The search strategy was conducted on MEDLINE (PubMed), Embase (Elsevier), and Web of Science (Clarivate) databases. The eligibility criteria were established according to the PICOS strategy, focusing on in vitro and ex vivo studies that assessed the chemical and morphological changes in dentin using five high-power lasers: Nd:YAG (1064 nm), Er:YAG (2940 nm), Er, Cr:YSGG (2780 nm), diode (980 nm), and CO2 (10,600 nm). Publication range was from 2010 to 2022. Data was summarized in tables and risk of bias was assessed by QUIN tool. RESULTS: The search resulted in 2255 matches and 57 studies composed the sample. The methods most used to assess the outcomes were scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and Raman. The studies presented "medium" and "low" risk of bias. The laser prevalently identified was the Er:YAG laser, associated with dentin ablation, absence of smear layer, and exposed tubules. The Nd:YAG laser generated vitreous surface and thermal damage, such as carbonization and cracks. The other lasers caused an irregular surface and no adverse thermal effects. Regarding the chemical structure, only the Er,Cr:YSGG laser caused collagen matrix reduction. The effects found were more intense with higher dosimetry. CONCLUSION: Evidence available indicates that the irradiation of dentin with high-power lasers are related to morphological outcomes favorable to adhesive restorative procedures, with minimal changes in collagen matrix and mineral content. However, those observations should be carried carefully by clinicians and more clinical trials regarding the association of high-power laser irradiation and restorative procedure longevity are needed.

Use of Immediate Obturator Prosthesis as a Rehabilitation Option in Cases of Squamous Cell Carcinoma.

ABSTRACT: Maxillary defects caused by surgical resection generate abnormal communication between the nasal and oral cavities, hindering proper eating and phonetics, and causing aesthetic damage. Prosthetic intervention is necessary to rehabilitate these patients, in order to block communication and allow correct speech and swallowing functions. This article reports the manufacture of an immediate palatal obturator prosthesis after hemimaxillectomy due to the surgical removal of an intraoral squamous cell carcinoma, which guaranteed better conditions for postoperative recovery, as well as better adaptation to the definitive prosthesis and the use of the prosthetic apparatus.

Morphological characteristics of non-carious cervical lesions. A systematic review.

OBJECTIVES: This systematic review assessed the morphological characteristics of non-carious cervical lesions (NCCL), among clinical and ex-vivo studies assessed by observational and imaging methods. DESIGN: The search strategy was conducted on four online databases (MEDLINE, Embase, Scopus and Web of Science) and grey literature (Google Scholar and OpenGrey). The study selection was performed by three reviewers from March to September (2023). The eligibility criteria were established according to the PICO strategy and included NCCL, morphological characteristics and clinical and ex-vivo study designs. The data extraction considered general data that identifies the study, evaluation method, parameter to assess the outcome and the main results for each study. The risk of bias was evaluated using Joanna Briggs Institute critical appraisal tool, and a personalized tool. RESULTS: The search resulted in 252 studies. A total of 14 studies were included. Prevalence of NCCLs ranged from 3.5 %to 77.78 % with a higher presence in premolars. Common characteristics were wear facets, occluded tubules or cracks, occlusal stress, scratch marks, dimples and craters, structure loss, and dentin sclerosis, which appear more often on buccal surface and were generally classified as wedge-shaped, saucer-shaped. Etiological hypothesis was mainly related to multifactorial factors. In most of the studies, the risk of bias was classified as high. CONCLUSIONS: The morphological characteristics of NCCL showed a wide range of descriptions regarding appearance, prevalence, lesion-related measures, and macro and microscopic descriptions.

Influence of Initial Root Canal Treatment on Intratubular Penetrability and Bond Strength of Nonsurgical Retreatment: An InVitro Study.

INTRODUCTION: To assess the effect of combinations of two different endodontic sealers used in initial and endodontic retreatment on the bond strength of the secondary obturation and the penetrability of the sealers. METHODS: Forty-eight mandibular premolars were used, receiving standardized endodontic access and biomechanical preparation. Twenty-four teeth received AH Plus sealer (AHP) in primary obturation and the others received Bio-C Sealer (BCS). Retreatment protocol was performed with an R50 instrument. The samples were further subdivided into four groups (n = 12) based on the combination of primary/secondary obturation sealers: AHP/AHP; AHP/BCS; BCS/AHP; and BCS/BCS. Four samples from each subgroup received the addition of fluorophores to the sealer for penetrability analysis using laser scanning confocal fluorescence microscopy. The root portion on the 8 push-out samples was sectioned into 6 slices of 1.0 mm. Bond strength (BS) was assessed using a universal testing machine until displacement of the filling mass. Failure pattern was evaluated under a stereomicroscope (20× magnification). BS data were analyzed using two-way analysis of variance followed by Tukey's test (P < .05), and the association between the failure pattern and BS value was assessed using the chi-square test (P < .05). Penetrability was qualitatively evaluated. RESULTS: The highest BS values were observed in the AHP/AHP (4.54 ± 1.5 MPa) and BCS/AHP (5.00 ± 1.0 MPa) groups (P < .05), with a higher percentage of adhesive failures to the filling material for all groups. Laser scanning confocal fluorescence microscopy images indicated greater penetrability of AHP compared to BCS, both in initial treatment and retreatment. CONCLUSION: AHP sealer exhibited higher BS and greater penetrability compared to BCS sealer.

Correction: The investigation of WNT6 and WNT10A single nucleotide polymorphisms as potential biomarkers for dental pulp calcification in orthodontic patients.

[This corrects the article DOI: 10.1371/journal.pone.0288782.].

A Fluorescence-based Method to Reaccess Root Canals in Endodontically Treated Teeth: A Micro-Computed Tomography Tridimensional Assessment.

INTRODUCTION: The aim of this study was to evaluate the volume of dentin removal and the volume of remnants of restorative material after the removal of an esthetic restorative coronal set and cervical barrier in endodontically treated mandibular molars with the aid of different magnification methods using 3-dimensional (3D) micro-computed tomographic (micro-CT) morphometric analysis. METHODS: A sample of 30 mandibular first molars (N = 30) was used. All teeth were endodontically treated, and the specimens were initially scanned using micro-CT imaging and reconstructed. The molars were filled by a single-cone technique, and immediately the material at the initial 2-mm cervical level was removed. Cervical barriers were confected using ionomer glass cement with fluorescein 0.1%, filling the 2 mm at the cervical level of the canals and an additional 2 mm as the base. The coronal restoration set was performed using esthetic resin composites. A simulated tooth aging process was performed with 20,000 thermocycling cycles. The sample was distributed into the following 3 groups (n = 10) for the removal of the restoration set and cervical barrier with diamond burs based on the magnification aid: no magnification aid (naked eye), operative microscope aid, and REVEAL device (Design for Vision Inc, Bohemia, NY) aid. After removal, the final 3D micro-CT scanning and reconstruction were conducted with the same parameters as the initial scanning, and superposition of the final and initial scanning was performed. Morphometric analysis was conducted using CTAn software (Bruker microCT, Kontich, Belgium) to assess the volume of remnant restorative material (mm³), the volume of dentin removal (mm³), and the direction and site of dentin removal. Data were analyzed using 1-Way analysis of variance (P < .05). RESULTS: The REVEAL group showed better results regarding the volume of remnant material (3.17 ± 1.65) and the percentage of dentin removal (2.56 ± 1.34). The microscope group showed no statistical difference compared with the REVEAL group regarding dentin removal (3.30 ± 1.48) and was statistically similar to the naked eye group in the volume of remnant material (9.63 ± 4.33). The naked eye group showed the worst results for the volume of remnant material (7.60 ± 2.68) and the percentage of dentin removal (6.60 ± 3.70). CONCLUSIONS: The use of fluorescence associated with magnification was the method that presented the best results, with lower percentages of dentin removal and smaller volumes of remaining restorative material. This is an innovative technology in endodontics that shows potential to overcome the challenge of reaccessing root canals in the context of endodontic retreatment.

The investigation of WNT6 and WNT10A single nucleotide polymorphisms as potential biomarkers for dental pulp calcification in orthodontic patients.

The aim of this study is to evaluate if single nucleotide polymorphisms (SNPs) in WNT6 and WNT10A are associated with the risk of dental pulp calcification in orthodontic patients. This cross-sectional study followed the "Strengthening the Reporting of Genetic Association Studies" (STREGA) guidelines. Panoramic radiographs (pre- and post-orthodontic treatment) and genomic DNA from 132 orthodontic patients were studied. Dental pulp calcification (pulp stones and/or pulp space narrowing) was recorded in upper and lower first molars. The SNPs in WNT6 and WNT10A (rs7349332, rs3806557, rs10177996, and rs6754599) were assessed through genotyping analysis using DNA extracted from buccal epithelial cells. The association between pulp calcification and SNPs were analyzed using allelic and genotypic distributions and haplotype frequencies (p<0.05). Prevalence of dental pulp calcification was 42.4% in the 490 studied molars. In the genotypic analysis, the SNPs in WNT10A showed a statistically significant value for molar calcification (p = 0.027 for rs1017799), upper molar calcification (p = 0.040 for rs1017799) (recessive model), and molar calcification (p = 0.046 for rs3806557) (recessive model). In the allelic distribution, the allele C of the SNP rs10177996 in WNT10A was associated with molar calcifications (p = 0.042) and with upper first molar calcification (p = 0.035). Nine combinations of haplotypes showed statistically significant value (p<0.05). The findings of this study indicates that SNPs in WNT10A and WNT6 are associated with dental pulp calcification in molars after orthodontic treatment and may be considered as biomarkers for dental pulp calcification.

Geographic Information Systems (GIS) to Assess Dental Caries, Overweight and Obesity in Schoolchildren in the City of Alfenas, Brazil.

Childhood-related obesity and overweight are increasing concerns for the health and well-being of children. Dental caries (decay) is the most prevalent oral disease during childhood, and several studies have suggested that nutritional status and dental caries are associated in children. Therefore, this study aimed to determine the geographic distribution of childhood overweight/obesity and dental caries in a medium-sized Brazilian city. This cross-sectional study was conducted with 269 children of both genders enrolled in four public schools in the city of Alfenas. The children were clinically examined to assess cavitated dental caries and nutritional status (overweight and obesity). In addition, the GIS was used for the geospatial clustering analyses. A heat map was created by the Kemel method to estimate the concentration of the outcomes. The cavitated dental caries and overweight/obesity were also pointed out by dots on the map. However, of the 269 children, 118 were boys (43.87%) and 151 were girls (56.13%). One hundred fifty-seven children (58.4%) were classified as having "non-cavitated caries," while 112 (41.6%) were classified as having "cavitied caries." In the nutritional status assessment, 204 children (75.84%) were classified as "eutrophic," while 65 children (24.16%) were classified as "overweight/obesity," A geographical correlation of dental caries with overweight/obesity may exist in the northeast and southwest areas. In conclusion, a geographical concordance between the dental caries and the occurrence of overweight/obesity among the schoolchildren from Alfenas may exist in some areas. Future studies are necessary.

Endodontical treatment of periapical tooth injury with photodynamic therapy: Case report.

This article describes the use of Photodynamic Therapy (PDT) during the endodontic treatment of teeth with periapical lesion. Patients presented tooth 35 with diagnostic hypotheses of Periapical Cyst or Granuloma. The Crown-Down preparation was performed with the HyFlex CM system. In case I it was not possible to reach the working length, in case II the foraminal debridement was performed at the actual tooth length. In the final irrigation, the E1 - Irrisonic ultrasonic insert was used, promoting sequentially agitation of NaOCl 2.5%, EDTA 17% and NaOCl 2.5%. Then, PDT was applied with 0.005% methylene blue dye. Calcium Hydroxide with Parammonochlorophenol was used and after 15 days, the final irrigation protocol and PDT were performed again. After 90 days of case I and 1 year of case II, the total lesion regression was observed in both cases. It is concluded that the proposed treatment improved the microbial disinfection favoring the regression of the periapical alterations providing satisfactory clinical and radiographic results.

Comparação de dois métodos de rugoscopia palatina na identificação humana / Comparison of two methods of palatal rugoscopy in human identification

A Odontologia Legal é cada vez mais requisitada para a obtenção de dados que permitam a identificação humana. Entre muitas ferramentas, a análise das rugas palatinas se destaca como um meio eficaz para a identificação, contudo são necessários estudos que permitam estabelecer padrões de análise que levem a um maior sucesso no processo. Assim, esse estudo teve por objetivo averiguar se há diferença entre a execução da rugoscopia por comparação visual ou por meio de um software. Para isso, foi utilizada uma amostra de 30 indivíduos (n=30), os quais foram submetidos à realização de fotografias intraorais do palato, à obtenção de modelo de gesso do arco alveolar superior com delineamento e ressalte das rugas em cada modelo com grafite, além da tomada de uma fotografia de cada modelo com as rugas demarcadas. Duas análises foram realizadas, sendo a primeira comparação de fotos de modelo de gesso com fotos intraorais via software por sobreposição, e a segunda entre modelos de gesso com fotografias intraorais por análise visual. Com quatro avaliadores em cada análise, registrou-se o resultado obtido de compatibilidade entre modelo-foto, ou foto-foto. Na análise estatística dos dados obtidos, foram aplicados os testes t student (P=0,053) e Kruskal-Wallis (P=0,990), que demonstraram não existir diferença significativa entre os resultados obtidos pelas diferentes análises, e nem variância estatisticamente significativa entre os grupos. Desse modo, pode-se dizer que um software pode ser usado simultaneamente com análise visual

The Forensic Dentistry is being increasingly requested for obtaining data that allows human identification. Among many of its tools, the analysis of the palatal rugae stands out as an effective device for the identification, but more studies are needed to allow an establishment of standards that increases the success rate. So, this study had the main goal to ascertain if there is a difference between choosing the execution of the rugoscopy by visual comparison or by software. This way, it started from a sample of 30 individuals (n=30), in which all of them had their palates photographed, a plaster model from the upper arch with the rugae highlighted with graphite obtained, and finally a photograph of each plaster model made. Two analyses have been done, being the first one a comparison of the photographs of the models and the intraoral ones, on a software by overlapping them, and the second was a comparison between the plaster models and the intraoral photographs, visually. With four evaluators in each analysis, the results from the compatibility among model-photo and photo-photo were registered. In the statistical analysis of this results, the t student t (P=0,053) and the Kruskal-Wallis (P=0,990) tests were performed, and they demonstrated the non-existence of significant difference between the results of the two analysis, nor variance statistically significant between the groups. Being so, it can be said that the software could be simultaneously used with a visual analysis