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Journal of Microscopy and Ultrastructure 2018Enamel is one of the most important structures of the tooth, both functionally and aesthetically. Because of the highly mineralized nature of enamel, its structure is...
INTRODUCTION
Enamel is one of the most important structures of the tooth, both functionally and aesthetically. Because of the highly mineralized nature of enamel, its structure is difficult to study under routine light microscopy. Since scanning electron microscopy (SEM) offers the possibility of studying structures under very high magnification without altering the gross specimen, it is one of the best methods to study the enamel surface.
AIMS AND OBJECTIVES
To study and compare the surface morphology and morphometry of enamel on various surfaces of permanent dentition.
MATERIALS AND METHODS
A total of 20 permanent teeth were analyzed under the SEM. In both anterior and posterior teeth, four surfaces - mesial, distal, labial, and lingual - in three thirds - cervical, middle, and incisal - were studied. In addition, the occlusal surface was also studied for the posterior teeth. The different prism morphology and prism dimensions were recorded.
RESULTS
Based on our observations, we could definitely identify striae of retzius, debris, and cracks under ×50 magnification. Three morphological patterns of prism arrangement were identified: Type 1 - shallow prisms, Type 2 - well-defined prisms, Type 3 - microporosities, on analyzing the mesial, distal, labial, lingual, and occlusal surfaces of the permanent teeth, at ×3000 magnification. The prisms were measured under ×6000 magnification and the results showed larger prisms in posterior than in anterior teeth.
CONCLUSION
The study aided us in categorizing the enamel prism structure based on morphology and morphometry in anterior and posterior teeth of the permanent dentition.
PubMed: 30221142
DOI: 10.4103/JMAU.JMAU_27_18 -
BMC Oral Health Mar 2021This study aimed to explore whether compensatory remodeling of the alveolar bone surface occurred during the buccal palatal movement of orthodontic teeth. We...
BACKGROUND
This study aimed to explore whether compensatory remodeling of the alveolar bone surface occurred during the buccal palatal movement of orthodontic teeth. We preliminarily explored whether corticotomy could activate or accelerate osteogenesis in the alveolar bone surface by measuring the expression of TGF-β1 (transforming growth factor-β1), which can facilitate the proliferation and differentiation of osteoblasts and regulate the maturity and formation of bone.
METHODS
Sixty 10-week-old male Wistar rats were selected. In the orthodontic group, 20 rats were implanted with a constriction device between the maxillary first molars under general anesthesia. In the corticotomy group, 20 rats were implanted with a constriction device, and a palatal incision was made to penetrate the cortical bone. In the control group, 20 rats underwent no experimental operation except general anesthesia. After 1, 3, 5 and 7 days, the maxillary first molars and the surrounding alveolar bone were harvested, and coronal sections containing the apical mesial buccal root were prepared and observed using tetracycline fluorescence, HE staining and immunohistochemical staining for TGF-β1. Image-Pro Plus software was used to assess the immunohistochemical results, and SPSS 22.0 statistical software was used to analyze variance and perform the LSD test.
RESULTS
The tetracycline fluorescence results showed that in the periosteum near the apical region, an obvious fluorescence signal was observed in the orthodontic group and the corticotomy group compared with the control group. In the orthodontic group and corticotomy group, HE staining showed that the morphology was similar to cube-shaped. The immunohistochemical results showed that TGF-β1 was significantly increased in the periosteum near the apical region in the orthodontic group and corticotomy group, and there were significant differences among the three groups. In addition, the expression of TGF-β1 in the periosteum in the orthodontic group and the corticotomy group gradually increased over time, reaching a peak on day 5 and slightly decreasing on day 7.
CONCLUSION
Osteogenesis occurred on the alveolar bone surface during the buccal palatal movement of orthodontic teeth, and corticotomy had a positive effect, and TGF-β1 was involved in this process.
Topics: Alveolar Process; Animals; Male; Molar; Osteogenesis; Rats; Rats, Wistar; Tooth Movement Techniques
PubMed: 33740958
DOI: 10.1186/s12903-021-01492-5 -
Journal of the Mechanical Behavior of... Apr 2023To compare the biomechanical properties of different endocrown designs on endodontically treated teeth with an extensive defect in the mesial wall using a...
OBJECTIVE
To compare the biomechanical properties of different endocrown designs on endodontically treated teeth with an extensive defect in the mesial wall using a three-dimensional finite element method (3D FEM).
METHODS
Four finite element analysis models were designed and built up based on different endocrown configurations in a mandibular molar. One model was designed as a butt joint preparation with 2 mm occlusal thickness(control), the other three models were butt joint designs with different distances between the bottom of the mesial wall preparation and the cemento-enamel junction (CEJ): 2 mm, 1 mm and 0 mm respectively. A vertical load parallel with the longitudinal axis of the tooth and an oblique load with a 45°angle to the longitudinal axis were applied to the occlusal surfaces. The maximum Von Misses (VM) stresses and stress distribution patterns were calculated and compared. Weibull risk-of-rupture analysis was used to analyze the survival probability of the restorations and tooth in the different models.
RESULTS
For the restoration, the model with a mesial wall destruction at the level of CEJ showed much higher risk of failure than other models. Overall, none of the four models showed failure. Under oblique loading, VM stress in the cement layer of the models with a mesial wall defect was higher than in the control model. In the dentin, the highest VM stresses were found in the peri-cervical dentin. Under the oblique loading, the model with the mesial wall destruction at the level of CEJ restored by endocrown showed the highest risk of failure.
CONCLUSION
Under the oblique loading, with the increase of the simulated defect in the mesial wall, the peak VM stress values in the cement layer increased accordingly. In the model with a mesial wall defect up to the level of CEJ risk of failure was highest in the cervical dentin.
Topics: Humans; Tooth, Nonvital; Molar; Finite Element Analysis; Dental Stress Analysis
PubMed: 36739827
DOI: 10.1016/j.jmbbm.2023.105691 -
Journal of Oral Biology (Northborough,... 2016An inverse relationship between dental calculus mineralization and dental caries demineralization on teeth has been noted in some studies. Dental calculus may even form...
BACKGROUND
An inverse relationship between dental calculus mineralization and dental caries demineralization on teeth has been noted in some studies. Dental calculus may even form superficial layers over existing dental caries and arrest their progression, but this phenomenon has been only rarely documented and infrequently considered in the field of Cariology. To further assess the occurrence of dental calculus arrest of dental caries, this study evaluated a large number of extracted human teeth for the presence and location of dental caries, dental calculus, and dental plaque biofilms.
MATERIALS AND METHODS
A total of 1,200 teeth were preserved in 10% buffered formal saline, and viewed while moist by a single experienced examiner using a research stereomicroscope at 15-25× magnification. Representative teeth were sectioned and photographed, and their dental plaque biofilms subjected to gram-stain examination with light microscopy at 100× magnification.
RESULTS
Dental calculus was observed on 1,140 (95%) of the extracted human teeth, and no dental carious lesions were found underlying dental calculus-covered surfaces on 1,139 of these teeth. However, dental calculus arrest of dental caries was found on one (0.54%) of 187 evaluated teeth that presented with unrestored proximal enamel caries. On the distal surface of a maxillary premolar tooth, dental calculus mineralization filled the outer surface cavitation of an incipient dental caries lesion. The dental calculus-covered carious lesion extended only slightly into enamel, and exhibited a brown pigmentation characteristic of inactive or arrested dental caries. In contrast, the tooth's mesial surface, without a superficial layer of dental calculus, had a large carious lesion going through enamel and deep into dentin.
CONCLUSIONS
These observations further document the potential protective effects of dental calculus mineralization against dental caries.
PubMed: 27446993
DOI: 10.13188/2377-987x.1000017 -
Journal of International Society of... 2021The aim of this investigation was to detect defects that may occur to Reciproc endodontic files after a single use.
OBJECTIVE
The aim of this investigation was to detect defects that may occur to Reciproc endodontic files after a single use.
MATERIALS AND METHODS
A sample of convenience of Reciproc files (VDW GmbH, Munich, Germany) that were used to prepare root canals of anterior or posterior teeth were collected. The files were divided equally into two groups: Group 1 (R25) files were used to prepare mesial root canals of 50 human permanent mandibular molars, and Group 2 (R40) included 50 files that were used to prepare permanent maxillary incisor teeth. Files were analyzed after single use by using a scanning electron microscope at X120 to detect changes in surface morphology. The data were statistically analyzed by using the χ test, and statistical significance was set at < 0.05.
RESULTS
A total of 96 Reciproc NiTi files were collected; of those, 67 (70%) were unaffected and 29 (30%) showed overall surface deformations. The types of deformation were blade disruption (22%), surface pitting (12%), and unwinding and tip deformation (1%). No microcracks were detected, and none of the studied files showed fracture. R40 was three times more likely to be deformed and showed blade disruption compared with R25 ( < 0.05).
CONCLUSIONS
Reciproc rotary NiTi files show high resistance to deformation after a single use. Blade disruption was the most frequent defect occurring in both the small and large files.
PubMed: 33688479
DOI: 10.4103/jispcd.JISPCD_412_20 -
Cureus Apr 2023Background Total treatment time in implant placement can be significantly reduced by placing immediate implants into the freshly extracted sockets. Also, immediate...
Background Total treatment time in implant placement can be significantly reduced by placing immediate implants into the freshly extracted sockets. Also, immediate implant placement can act as a guide for proper and accurate implant placement. Additionally, in immediate implant placement, the resorption of bone associated with the healing of the extraction socket is also reduced. This clinical study aimed to clinically and radiographically assess the healing of endosseous implants having different surface characteristics in nongrafted and grafted bone. Methodology In 68 subjects, 198 implants were placed, including 102 oxidized (TiUnite, Göteborg, Sweden) and 96 turned surface implants (Nobel Biocare Mark III, Göteborg) were placed. Survival was considered with clinical stability and acceptable function with no discomfort and no radiographic or clinical signs of pathology/infection. Rest cases that showed no healing and implant no osseointegration were considered failures. Clinical and radiographic examination was done by two experts after two years of loading based on bleeding on probing (BOP) mesially and distally, radiographic marginal bone levels, and probing depth (mesial and distal). Results Five implants failed in total where four implants were with the turned surface (Nobel Biocare Mark III) and one was from the oxidized surface (TiUnite). The one oxidized implant was in a 62-year-old female and was placed in the region of mandibular premolar (44) of length 13 mm and was lost within five months of placement before functional loading. Mean probing depth had a nonsignificant difference between oxidized and turned surfaces with the mean values of 1.6 ± 1.2 and 1.5 ± 1.0 mm, respectively, with = 0.5984; mean BOP in oxidized and turned surfaces was 0.3 ± 0.7 and 0.4 ± 0.6, respectively (= 0.3727). Marginal bone levels, respectively, were 2.0 ± 0.8 and 1.8 ± 0.7 mm (= 0.1231). In marginal bone levels related to implant loading, a nonsignificant difference was seen in early loading and one-stage loading with -values of 0.06 and 0.09, respectively. However, in two-stage placement, significantly higher values were seen for oxidized surfaces (2.4 ± 0.8 mm) compared to turned surfaces (1.9 ± 0.8 mm), with = 0.0004. Conclusions This study concludes that nonsignificantly higher survival rates are associated with oxidized surfaces compared to turned surfaces after two years of follow-up. Higher marginal bone levels were seen in oxidized surfaces for single implants and implants placed in two stages.
PubMed: 37139027
DOI: 10.7759/cureus.36990 -
Clinical Oral Investigations Apr 2022To evaluate re-osseointegration after electrolytic cleaning and regenerative therapy of dental implants with peri-implantitis in humans.
OBJECTIVE
To evaluate re-osseointegration after electrolytic cleaning and regenerative therapy of dental implants with peri-implantitis in humans.
MATERIAL AND METHODS
Four dental implants that developed peri-implantitis underwent electrolytic cleaning followed by regenerative therapy with guided bone regeneration. All four implants developed recurrent peri-implantitis and were therefore explanted 6 to 13 months later. Radiographic bone level, probing depth, and bleeding on probing were determined at the time of surgery, 6 months later, and before implant retrieval. The peri-implant tissues were histologically and histomorphometrically analyzed.
RESULTS
All four implants demonstrated radiographic and histological bone gain, reduced probing depth, and bleeding on probing. Radiographic bone gain was 5.8 mm mesially and 4.8 mm distally for implant #1, 3.3 mm and 2.3 mm for implant #2, 3.1 mm and 0.5 mm for implant #3, and 3.5 mm and 2.8 mm for implant #4. The histometric mean and maximum vertical bone gain for implant #1 to #4 was 1.65 mm and 2.54 mm, 3.04 mm and 3.47 mm, 0.43 mm and 1.27 mm, and 4.16 mm and 5.22 mm, respectively. The percentage of re-osseointegration for implant #1 to #4 was 21.0%, 36.9%, 5.7%, and 39.0%, respectively. In one implant, the newly formed bone was deposited directly onto calculus on the implant surface.
CONCLUSIONS
We found that (1) re-osseointegration is possible on a formerly contaminated implant surface and (2) the electrolytic cleaning process seems to be effective enough at sites with calculus residues.
CLINICAL RELEVANCE
Since re-osseointegration can be achieved by electrolytic cleaning, this decontamination technique may be considered as a future treatment concept.
Topics: Bone Regeneration; Dental Implants; Humans; Osseointegration; Peri-Implantitis
PubMed: 35244779
DOI: 10.1007/s00784-021-04345-1 -
International Journal of Clinical... Sep 2023To evaluate the thickness of the root canal dentin wall in the cervical, middle, and apical third of primary first molars.
AIM
To evaluate the thickness of the root canal dentin wall in the cervical, middle, and apical third of primary first molars.
MATERIALS AND METHODS
Cross-sectional study consisting of 30 cone-beam computed tomography (CBCT) images of primary maxillary and mandibular first molars, with crown, and root integrity. The wall dentin thickness of each canal was measured in three axial views, divided into distal (D), mesial, lingual/palatine, and buccal surfaces.
RESULTS
The smallest dentin wall thickness of the maxillary molar was located on the mesial surface of the mesiobuccal (MB) canal apical third (mean 0.55 ± 0.04 mm). The buccal and palatal (P) surfaces of the distobuccal (DB) and P canals showed the smallest dentin thickness on the cervical third (0.62 ± 0.02 mm). On the mandibular molar, we found the smallest dentin thickness on the apical third [lingual surface of the MB canal and buccal surface of the mesiolingual (ML) canal] with a mean of 0.41 ± 0.07 mm. Additionally, the dentin thickness is average of the D canal was about 0.67 ± 0.11 mm.
CONCLUSION
It is essential to understand the primary first molar's anatomy to reduce possible complications in pediatric patients from instrumentation during root canal treatments.
CLINICAL SIGNIFICANCE
Pulpectomy is among the most challenging procedures in pediatric dentistry and the knowledge of the root anatomy of primary teeth allows the professional to make better clinical decisions and reduce possible risks during root canal treatment.
HOW TO CITE THIS ARTICLE
Justiniano-Navarro C, Caballero-García S, López-Rodriguez G, Evaluating the Thickness of the Root Canal Dentin Wall in Primary First Molars using Cone-beam Computed Tomography. Int J Clin Pediatr Dent 2023;16(S-2):S122-S127.
PubMed: 38078037
DOI: 10.5005/jp-journals-10005-2660 -
Medicine and Pharmacy Reports Oct 2023The aim of this study is to quantitatively evaluate the effect of different alcoholic and non alcoholic beverages on the tooth enamel surface topography pretreated with...
A comparative evaluation of the effect of alcoholic and non alcoholic beverages on tooth enamel surface pretreated with β-tricalcium phosphate, bioactive glass and amine fluoride: an study.
BACKGROUND AND AIMS
The aim of this study is to quantitatively evaluate the effect of different alcoholic and non alcoholic beverages on the tooth enamel surface topography pretreated with various remineralizing agents using Atomic Force Microscopy.
METHODS
120 tooth specimens were prepared from 60 freshly extracted intact human premolars by sectioning from mesial to distal surfaces using low speed diamond discs and were randomly assigned to study groups and control group. Specimens of Group I, Group II and Group III were pre-treated with β-Tri calcium phosphate, bioactive glass and amine fluoride respectively for 4 minutes for 28 days, followed by storage in artificial saliva. All the specimens were evaluated for surface roughness using Atomic Force Microscopy. The specimens were then placed in alcoholic and non-alcoholic beverages for 10 minutes for 4 days and were again analyzed by Atomic Force Microscopy.Descriptive statistics was performed by using the proportional or frequency distribution of the parameters. The respondents were then grouped according to the branch of specialty if any and the data was evaluated by the one-way ANOVA with post-hoc, with p value <0.005.
RESULTS
In the present study, among the remineralizing agents tested, bioactive glass was found to be more effective than β-Tri Calcium Phosphate and Amine Fluoride. Among the demineralizing agents used in this study, the demineralization potential of Coca Cola was found to be highest, followed by wine and green tea pretreated with β-tricalcium phosphate, bioactive glass and amine fluoride.
CONCLUSIONS
The present study concluded that all the remineralizing agents tested were found to be effective in inhibiting the demineralization caused by various alcoholic and non alcoholic beverages. Among the remineralizing agents tested, bioactive glass was found to be more effective than β-tri calcium phosphate and amine fluoride.
PubMed: 37970202
DOI: 10.15386/mpr-2465 -
Brazilian Dental Journal 2022The aim of study was to evaluate periodontal conditions of upper canines and second premolars with and without proximal contact of individuals undergoing orthodontic...
The aim of study was to evaluate periodontal conditions of upper canines and second premolars with and without proximal contact of individuals undergoing orthodontic treatment associated to extractions of the upper first premolars. The study selected upper canines and premolars of individuals undergoing orthodontic treatment without extractions (30 hemiarches - control group), or with extraction of the upper first premolars and whose canines and second premolars had interproximal contact (16 hemiarches - group 1) or diastema (17 hemiarches - group 2). Clinical (plaque index, probing depth, gingival bleeding index, height of the gingival margin, clinical attachment loss and gingival clefts) and radiographic (crest height, bone height and bone-crest discrepancy) parameters of the distal surfaces of canines and mesial surfaces of premolars were evaluated. Group 1 had worse results when compared to the control group for the levels of plaque in canines and premolars and for probing depth in canines (distal and mean) and in premolars (lingual and mean), as well as increasing tendency of clinical attachment loss (lingual and mean) in premolars. Plaque level in canines in group 1 was also significantly higher than in group 2. There was no difference between group 2 and the control group. The lack of proximal contact between canines and second premolars did not significantly affect their periodontal characteristics.
Topics: Bicuspid; Dental Plaque; Dental Plaque Index; Humans; Periodontal Diseases
PubMed: 35766719
DOI: 10.1590/0103-6440202204330