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International Journal of Computerized... Nov 2022To evaluate the accuracy of tridimensional (3D)-printed guide-assisted flapless cortical bone micro-osteoperforations (MOPs) in the anterior mandible on a cadaver model.
AIM
To evaluate the accuracy of tridimensional (3D)-printed guide-assisted flapless cortical bone micro-osteoperforations (MOPs) in the anterior mandible on a cadaver model.
MATERIALS AND METHODS
Five human cadaver heads with complete dentition in the anterior mandible were used in the present study. Preplanning CBCT and intraoral surface scans were obtained. After alignment, drilling sites in the interradicular areas were planned from canine to canine, and a surgical guide was printed. The drilling was performed and a postprocedure CBCT scan was obtained to assess the accuracy of the procedure in relation to the virtual planning.
RESULTS
The mean ± standard deviation (SD) mesiodistal interradicular space was 2.67 ± 0.84 mm. The mean ± SD error of the actual drilled hole compared with the planned position of the mesial drill site was 0.66 ± 0.33 mm, and to the distal drill site it was 0.56 ± 0.33 mm. There was a statistically significant difference between the number of times the teeth were hit mesially (10 out of 64 holes) and distally (none).
CONCLUSIONS
The proposed technique, limited to an ex vivo scenario, provides a valid and reliable method for mandibular MOPs using a 3D-generated surgical guide. However, the risk of damaging adjacent radicular surfaces, particularly in areas with limited mesiodistal interradicular bone, needs to be considered. Further studies should focus on using thinner drills and adding other methods to stabilize the guide. Additionally, by selecting individuals and perforation sites with more mesiodistal interradicular bone, less damage is likely. (Int J Comput Dent 2022;25(4):387-0; doi: 10.3290/j.ijcd.b2599841).
Topics: Humans; Cone-Beam Computed Tomography; Surgery, Computer-Assisted; Mandible; Printing, Three-Dimensional; Cadaver
PubMed: 35072427
DOI: 10.3290/j.ijcd.b2599841 -
Scanning 2015The study aimed to investigate the morphology and composition of the interproximal reduced enamel after exposition to saliva and casein phosphopeptide amorphous calcium...
The study aimed to investigate the morphology and composition of the interproximal reduced enamel after exposition to saliva and casein phosphopeptide amorphous calcium phosphate with sodium fluoride (CPP-ACPF). Fourteen patients undergoing an orthodontic treatment with 4 premolars extractions participated to the study. Interproximal enamel reduction (IER) was performed on mesial surfaces of 3 extractive premolars for each patient while 1 served as untreated control. Premolars were assigned to 4 groups: No-S group, sound enamel as control; S-Ex group, stripped and immediately extracted enamel; S-Sal group, stripped and exposed to saliva enamel; S-CPP group, stripped enamel treated with CPP-ACPF. Teeth were extracted at different times, depending on the group they were assigned to and sliced into mesial and distal halves. Mesial surfaces were subjected to environmental scanning electron microscopy with energy dispersive X-ray spectrometry (ESEM/EDX) and to scanning electron microscopy (SEM) analysis. ESEM/EDX investigations showed no statistically significant differences in the content of calcium and phosphate between the 4 groups. SEM observations showed no difference in the morphological appearance of stripped enamel after 30 days of exposure to saliva and CPP-ACPF. Saliva and CPP-ACPF effects on stripped enamel in vivo showed no difference after 30 days.
Topics: Bicuspid; Calcium; Caseins; Dental Enamel; Humans; Microscopy, Electron, Scanning; Phosphates; Saliva; Spectrometry, X-Ray Emission
PubMed: 25488201
DOI: 10.1002/sca.21181 -
BMC Oral Health Sep 2023This study aimed to assess the root canal morphology of primary molars using cone-beam computed tomography (CBCT).
BACKGROUND
This study aimed to assess the root canal morphology of primary molars using cone-beam computed tomography (CBCT).
METHODS
This cross-sectional study evaluated 60 maxillary and mandibular primary first and second molars on CBCT scans of patients retrieved from the archives of Hamadan School of Dentistry between 2018-2020. The teeth were evaluated regarding the number of roots and canals, canal type according to the Vertucci's classification, and root surface concavities. Data were analyzed descriptively and by independent t-test.
RESULTS
The most frequent number of canals and roots in the maxillary right and left first molars was 3 canals (60%) and 3 roots (80%). These values were 4 canals (80%) and 5 canals (50%) with 3 roots in the maxillary right and left second molars, respectively, 4 canals (100%) and 2 roots (50%), and 3 canals (60%) and 2 roots (50%) in mandibular right and left first molars, respectively, and 4 canals (92.3%) and 3 roots (61.5%) in mandibular right and left second molars. Vertucci's type IV was the most common canal type in mesial and distal canals, type I was the most common in mesiobuccal, mesiolingual, distobuccal, and distolingual, and types I and II were the most common in the palatal canal. The maximum and minimum concavities were noted in the buccal (26.7%) and mesial (8.3%) surfaces, respectively.
CONCLUSIONS
A wide variation exists in the number of roots and canals of maxillary and mandibular primary molars, which calls for further attention in treatment of such teeth.
Topics: Humans; Dental Pulp Cavity; Cross-Sectional Studies; Root Canal Therapy; Molar; Cone-Beam Computed Tomography
PubMed: 37749546
DOI: 10.1186/s12903-023-03414-z -
Magnetic Resonance Imaging 1995We demonstrate a method for quantitating changes in volume and morphology of the temporal lobe in epilepsy. The temporal lobes of 10 neurologically normal subjects and...
We demonstrate a method for quantitating changes in volume and morphology of the temporal lobe in epilepsy. The temporal lobes of 10 neurologically normal subjects and six subjects with well defined left-sided mesial temporal epilepsy were studied. From high resolution T1-weighted magnetic resonance images, the grey and white matter were manually segmented over a predetermined extent. The volumes of the grey and white matter were determined. Using the segmented images, the grey matter/CSF surface and the white matter/grey matter surface were reconstructed, allowing estimates of the surface area and calculation of indices of curvature for the two surfaces. The index of curvature was calculated for each vertex of a polygonal mesh that was fitted to the surfaces. An index of grey matter thickness (grey matter volume/white matter surface area) was also calculated. There was a significant bilateral decrease in the total volume (p < .01), grey matter volume (p < .001) and grey matter thickness index (p < .05) in epileptic subjects. In addition, there was a bilateral decrease in white matter surface area (p < .05) and a small left-sided decrease in white matter volume (p < .05) in epileptic subjects. The average distributions of indices of curvature for both surfaces differed significantly (p < .05) between normal and epileptic subjects. In the grey matter/CSF surface of normal subjects, a large peak corresponding to surface concavity was present. The amplitude of this peak was significantly lower in epileptic subjects (p < .05 for the right hemisphere; p < .001) for the left hemisphere).
Topics: Adult; Atrophy; Dominance, Cerebral; Epilepsy, Temporal Lobe; Female; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Reference Values; Temporal Lobe
PubMed: 8750319
DOI: 10.1016/0730-725x(95)02015-l -
The Open Dentistry Journal 2018Available information on the effect of orthodontic treatment on crestal alveolar bone levels measured in radiographs is contradictory. The aim of this study was to...
AIM
Available information on the effect of orthodontic treatment on crestal alveolar bone levels measured in radiographs is contradictory. The aim of this study was to compare the alveolar bone level and periodontal ligament space of banded upper first molars to untreated controls.
MATERIALS AND METHODS
This retrospective cross-sectional radiographic study investigated alveolar bone levels of upper first molars of an orthodontic test group and an untreated control group of comparable age (15-16.25 years), using existing bitewing radiographs.Eighty-six individuals were included in each group. Three parameters were measured mesially and distally on both sides of the patient as follows: I) Alveolar Bone Level (ABL): measured as the distance between the cemento-enamel junction and the alveolar crest, II) the Periodontal Ligament Space (PLS): measured as the most coronal distance between the alveolar crest and the tooth surface, and III) angle between the lines (alveolar crests mesial and distal) and (cemento-enamel junction mesial and distal).
RESULTS
The mean duration of the orthodontic treatment in the test group was 2.5 years. The periodontal ligament space was statistically significantly wider on mesial areas of right molars (mean 0.2 mm, <0.01), but there was no statistically significant difference found in the three other areas (distal part of the right molar, mesial and distal parts of the left molar). There was a statistically significant mean alveolar bone loss in the right and left mesial areas, respectively accounting for 0.3 mm (<0.001) and 0.2 mm (<0.01). No statistically significant alveolar bone loss was measured on the distal surfaces of the upper molars. The angle was wider on both sides for the test group (right <0.001 and left <0.05).
CONCLUSIONS
A significant alveolar bone loss on the mesial tooth surface of upper first molars after orthodontic treatment was found with concurrent different levelling angles in the test group. On all other sites, no statistically significant changes were found. There was some minimal statistical significant alveolar bone loss after finishing treatment in patients who had orthodontic bands placed on their maxillary 1 molars, but no clinical significance was found.
PubMed: 29760824
DOI: 10.2174/1874210601812010312 -
American Journal of Orthodontics and... Sep 2020Enameloplasty of maxillary canines is often needed for aesthetic substitution in patients with congenitally missing lateral incisors. The exact enamel thicknesses for...
INTRODUCTION
Enameloplasty of maxillary canines is often needed for aesthetic substitution in patients with congenitally missing lateral incisors. The exact enamel thicknesses for the various canine surfaces are unknown because previous studies failed to employ accurate measurement tools to report and compare detailed enamel thicknesses for each surface at various crown heights.
METHODS
Thirty-two extracted maxillary canines were collected and scanned in a microcomputed tomography scanner. The scans were imported into a custom-written MATLAB software (version 9.2; MathWorks, Natick, Mass) and the enamel thickness on the mesial, distal, labial, fossa, cingulum, and incisal edge of each tooth was computed, obtaining the mean value from slices at 0.1 mm intervals. The overall mean enamel thickness for each surface was also calculated, and these values were compared using paired t tests. Incisal wear stage and incisal enamel thickness that was measured were compared using Spearman rank correlation coefficient.
RESULTS
The mean enamel thickness was significantly thinner at the gingival level when compared with the incisal for all surfaces that were analyzed (1-tailed, P <0.001). The mean enamel coverage at the mesial was significantly thinner than the distal when measured gingival to the widest mesiodistal area. The mean enamel coverage of the cingulum was particularly thin and therefore requires extreme care in reshaping it. Incisal edge enamel thickness was highly negatively correlated with the wear stage of the scoring system that was used (1-tailed, P <0.001).
CONCLUSIONS
The enamel coverage of the maxillary canine varies depending on the tooth surface and the incisogingival measurement location.
Topics: Cuspid; Dental Enamel; Esthetics, Dental; Humans; Maxilla; Odontometry; X-Ray Microtomography
PubMed: 32653347
DOI: 10.1016/j.ajodo.2019.09.013 -
Journal of the American Dental... Apr 1987The in vivo disintegration of luting cements was determined at 6- and 12-month intervals in two test series of 20 participants each. Four cements were inserted in the...
The in vivo disintegration of luting cements was determined at 6- and 12-month intervals in two test series of 20 participants each. Four cements were inserted in the wells located in the mesial and distal surfaces of cast crowns. Glass ionomer, silicophosphate, polycarboxylate, and zinc phosphate cements prepared with recommended powder/liquid ratios are discussed, and are ranked with respect to disintegration at 6 and 12 months.
Topics: Chemical Phenomena; Chemistry, Physical; Crowns; Dental Cements; Glass Ionomer Cements; Humans; Polycarboxylate Cement; Silicate Cement; Surface Properties; Time Factors; Zinc Phosphate Cement
PubMed: 3470375
DOI: 10.14219/jada.archive.1987.0093 -
Scientific Reports Apr 2017The objective of this study was to determine the effects of teeth bleaching on the tensile bond strength of metal brackets bonded with light-curing adhesive system to...
The objective of this study was to determine the effects of teeth bleaching on the tensile bond strength of metal brackets bonded with light-curing adhesive system to the human enamel. 40 recently extracted human permanent molars were used for the study. The mesial buccal surface of each tooth was used as a control group and the distal buccal surface was used as an experimental group. Control group surfaces were not submitted to bleaching, while experimental group surfaces were bleached with in-office bleaching material containing 35% hydrogen peroxide. 30 days after the bleaching, identical premolar metal brackets were bonded to each surface using light-curing adhesive. Both groups were submitted to a tension test, using a universal machine. The tensile bond strength of brackets bonded to the bleached enamel was 15% lower than that of brackets bonded to the unbleached enamel. After debonding, more adhesive was left on the bracket base in experimental group than in the control group. The conclusion of this study was that bleaching with an in-office bleaching material containing 35% hydrogen peroxide reduced the tensile bond strength of orthodontic bracket adhesive to the enamel surface.
Topics: Humans; Hydrogen Peroxide; Metals; Orthodontic Brackets; Tensile Strength; Tooth Bleaching; Tooth Bleaching Agents
PubMed: 28400596
DOI: 10.1038/s41598-017-00843-z -
Journal of Oral Science Oct 2021To evaluate the influence of the restorative material and matrix system on proximal contact tightness and morphological characteristics of class II restorations in...
PURPOSE
To evaluate the influence of the restorative material and matrix system on proximal contact tightness and morphological characteristics of class II restorations in primary molars.
METHODS
Occluso-mesial cavities in second primary artificial molars were randomly restored using different materials (Filtek Z500 or Filtek Bulk Fill composites or high-viscosity glass ionomer cement Ketac Universal) and different matrix system (Tofflemire, AutoMatrix, matrix band with ring, contoured sectional matrix) (n = 12). Proximal contact tightness was measured using a custom-made device in an Instron 3345, and proximal surface morphology and marginal adaptation were scored after digital scanning. Two-way ANOVA, Tukey and Fischer's exact tests were performed (P < 0.05).
RESULTS
Proximal contact tightness values were significantly influenced by the restorative material (P < 0.05), the matrix system (P < 0.001), and their interaction (P < 0.01). Both resin composites showed statistically differences in proximal shape according to the matrix used to restore and exhibited overhanging margins. Ketac Universal restorations showed similar morphology and gaps on the margins regardless of the matrix system.
CONCLUSIONS
Overall, both composite restorations achieved tighter proximal contact than those restored with the high-viscosity glass ionomer cement. None of the matrix systems tested provided a convex seamless proximal morphology.
Topics: Dental Materials; Glass Ionomer Cements; Molar; Tooth, Deciduous; Viscosity
PubMed: 34511588
DOI: 10.2334/josnusd.21-0264 -
Journal of Clinical Periodontology Mar 2004A variety of techniques are employed for planing and scaling of the superficial root surfaces, of which hand and ultrasonic instrumentations have been preferentially... (Clinical Trial)
Clinical Trial Comparative Study Randomized Controlled Trial
BACKGROUND/AIMS
A variety of techniques are employed for planing and scaling of the superficial root surfaces, of which hand and ultrasonic instrumentations have been preferentially used in routine periodontics clinics. This study was undertaken to compare the effectiveness of ultrasonic scalers and hand curettes in facilitating fibroblast attachment to the scaled root surfaces.
MATERIALS AND METHODS
Sixteen patients with periodontally involved teeth and nine subjects without periodontal diseases (control subjects) were selected. Two single-rooted teeth were extracted from each subject. Mesial and distal surfaces of teeth were selected in treated and untreated groups, respectively. The mesial surface of each tooth was randomly chosen to be treated either by hand curettes or ultrasonic instrumentation. The degree of cell attachment on the root surfaces of treated and untreated groups from control subjects and patients was then determined by the use of a gingival fibroblast line established and employed at early passages. The attachment and proliferation of gingival fibroblasts on the root surfaces were evaluated using neutral red assay and scanning electron microscopy (SEM).
RESULTS
Fibroblast survival and proliferation on the surfaces of untreated periodontally involved roots were found to be significantly lower compared with control untreated surfaces (p<0.0001) or treated surfaces from patients (p<0.0001). No significant difference, however, was observed between root surfaces treated either by hand curettes or ultrasonic scalers.
CONCLUSION
These results indicate the beneficial effectiveness of both techniques in root treatment and planing.
Topics: Adult; Aged; Cell Adhesion; Cell Division; Cell Line; Cell Survival; Dental Scaling; Equipment Design; Female; Fibroblasts; Gingiva; Humans; Male; Microscopy, Electron, Scanning; Middle Aged; Root Planing; Subgingival Curettage; Tooth Root; Ultrasonic Therapy
PubMed: 15016018
DOI: 10.1111/j.0303-6979.2004.00458.x