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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 -
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 -
NeuroImage. Clinical 2016Despite the common assumption that genetic generalized epilepsies are characterized by a macroscopically normal brain on magnetic resonance imaging, subtle structural...
Despite the common assumption that genetic generalized epilepsies are characterized by a macroscopically normal brain on magnetic resonance imaging, subtle structural brain alterations have been detected by advanced neuroimaging techniques in Childhood Absence Epilepsy syndrome. We applied quantitative structural MRI analysis to a group of adolescents and adults with Juvenile Absence Epilepsy (JAE) in order to investigate micro-structural brain changes using different brain measures. We examined grey matter volumes, cortical thickness, surface areas, and subcortical volumes in 24 patients with JAE compared to 24 healthy controls; whole-brain voxel-based morphometry (VBM) and Freesurfer analyses were used. When compared to healthy controls, patients revealed both grey matter volume and surface area reduction in bilateral frontal regions, anterior cingulate, and right mesial-temporal lobe. Correlation analysis with disease duration showed that longer disease was correlated with reduced surface area in right pre- and post-central gyrus. A possible effect of valproate treatment on brain structures was excluded. Our results indicate that subtle structural brain changes are detectable in JAE and are mainly located in anterior nodes of regions known to be crucial for awareness, attention and memory.
Topics: Adolescent; Adult; Analysis of Variance; Anticonvulsants; Brain; Brain Mapping; Epilepsy, Absence; Female; Functional Laterality; Humans; Image Processing, Computer-Assisted; Magnetic Resonance Imaging; Male; Middle Aged; Valproic Acid; Young Adult
PubMed: 27551668
DOI: 10.1016/j.nicl.2016.07.007 -
Medicina Oral, Patologia Oral Y Cirugia... Jul 2022A study is made of the findings of high-magnification rigid endoscopy at the root end surface following apicoectomy of teeth subjected to periapical surgery.
BACKGROUND
A study is made of the findings of high-magnification rigid endoscopy at the root end surface following apicoectomy of teeth subjected to periapical surgery.
MATERIAL AND METHODS
A cross-sectional study was made of patients subjected to periapical surgery at the Unit of Oral Surgery and Implantology (University of Valencia, Valencia, Spain) between 2011 and 2019. Following apicoectomy, the root end surfaces were inspected, with the evaluation of untreated canals, isthmuses, craze lines, crack lines, opaque dentin and gaps. Likewise, an analysis was made of the association between patient age and the tooth type and restoration and the presence of craze lines, cracks, opaque dentin and gaps.
RESULTS
The final sample consisted of 168 patients subjected to periapical surgery, with 177 operated teeth and 206 roots. Untreated canals were observed in 14 roots (6.8%). Isthmuses were identified in 74 roots (35.9%), particularly in the mesial root of the lower first molar (94.1%). In turn, craze lines were identified in 8.3% of the roots, cracks in 3.9%, and gaps in 53.4%. The prevalence of opaque dentin was 78.3%, with a greater presence in posterior teeth (90.3% in premolars and 86.2% in molars) than in anterior teeth (50.6%) (p<0.001). Patient age and tooth restoration showed no correlation to the studied parameters.
CONCLUSIONS
Craze lines and crack lines were observed in less than 10% of the roots, though opaque dentin was identified in 73% of the roots, particularly in posterior teeth, and gaps were found in over half of the canals.
Topics: Apicoectomy; Cross-Sectional Studies; Dental Pulp Cavity; Humans; Molar; Tooth Root
PubMed: 35660728
DOI: 10.4317/medoral.25311 -
The Bulletin of Tokyo Dental College Mar 2020Many types of interdental instrument, such as dental floss and interdental brushes, can be purchased easily and sell in large numbers. Many studies have compared the...
Many types of interdental instrument, such as dental floss and interdental brushes, can be purchased easily and sell in large numbers. Many studies have compared the effects of such instruments. Few studies have investigated their relationship with regions of residual plaque, however. The purpose of this study was to compare rates of plaque removal from the mesial and distal surfaces of the bilateral maxillary and mandibular premolars and molars among 3 types of interdental instrument: finger-winding-dental floss, holder-type dental floss, and an interdental brush. Prior to the experiment, the artificial teeth in a jaw model were removed for application of artificial plaque. The teeth were then replaced and the model attached to a phantom. An operator brushed the teeth in a posture close to that adopted in actual tooth brushing with each type of instrument, after which the plaque removal rate was compared among them. The rate of plaque removal using finger-winding floss was the highest, although this type of instrument is less easy to hold than the others. The rate with a handle-equipped interdental instrument showed a decrease in some regions, although it is easy to hold. The results of this study suggest that the type of interdental instrument used should differ depending on the region to be cleaned.
Topics: Dental Devices, Home Care; Dental Plaque; Dental Plaque Index; Humans; Molar; Toothbrushing
PubMed: 32074586
DOI: 10.2209/tdcpublication.2019-0005 -
Brazilian Oral Research 2020The present study aimed to evaluate the performance of cone beam computed tomography (CBCT) and digital periapical radiographs (PR) in diagnosing external root...
The present study aimed to evaluate the performance of cone beam computed tomography (CBCT) and digital periapical radiographs (PR) in diagnosing external root resorption (ERR) in human permanent teeth replanted after traumatic avulsion. The samples comprised 39 permanent maxillary incisors replanted after traumatic avulsion. Digital PR and CBCT images were taken from each tooth and independently examined by 2 calibrated examiners to assess the ERR activity regarding type and extension. The degrees of agreement between both imaging examinations were determined by the mean global agreement index using SPSS software. The two imaging examinations diverged greatly in the diagnosis of the type of ERR since CBCT identified more cases as inflammatory ERR and PR as replacement ERR. A discordance level of 69.2% was observed between the two methods in the diagnosis of the type of ERR when CBCT for mesial and distal (MD) surfaces was considered and 61.5% when CBCT for mesial, distal, buccal and lingual (MD/BL) was considered. Likewise, CBCT and PR differed regarding the ERR index. PR examinations classified most cases as moderate or severe (69.2%), while CBCT examinations classified more cases as mild either in the MD surfaces analysis (41.4%) or in the analysis of the MD-BL surfaces (51.3%). In conclusion, the present results highlight a discrepancy between CBCT and digital PR performance in the diagnosis of different types and extent of ERR in replanted teeth.
Topics: Cone-Beam Computed Tomography; Dentition, Permanent; Humans; Incisor; Maxilla; Root Resorption
PubMed: 32696909
DOI: 10.1590/1807-3107bor-2020.vol34.0067 -
International Journal of Implant... Jul 2020The aim of the present retrospective study was to evaluate clinical and radiological outcomes, in terms of implant survival rate, marginal bone loss, and...
PURPOSE
The aim of the present retrospective study was to evaluate clinical and radiological outcomes, in terms of implant survival rate, marginal bone loss, and peri-implantitis incidence, of a titanium implants with an innovative laser-treated surface.
MATERIALS AND METHODS
A total of 502 dental implants were inserted in four dental practices (Udine, Arezzo, Frascati, Roma) between 2008 and 2013. All inserted implants had laser-modified surface characterized by a series of 20-μm-diameter holes (7-10 μm deep) every 10 μm (Synthegra®, Geass srl, Italy). The minimum follow-up period was set at 1 year after the final restoration. Radiographs were taken after implant insertion (T0), at time of loading (T1), and during the follow-up period (last recall, T2). Marginal bone loss and peri-implant disease incidence were recorded.
RESULTS
A total of 502 implants with a maximum follow-up period of 6 years were monitored. The mean differential between T0 and T2 was 0.05 ± 1.08 mm at the mesial aspect and 0.08 ± 1.11 mm at the distal with a mean follow-up period of 35.76 ± 18.05 months. After being in function for 1 to 6 years, implants reported varying behavior: 8.8% of sites did not show any radiographic changes and 38.5% of sites showed bone resorption. The bone appeared to have been growing coronally in 50.7% of the sites measured.
CONCLUSION
Implants showed a maintenance of marginal bone levels over time, and in many cases, it seems that laser-modified implant surface could promote a bone growth. The low peri-implant disease incidence recorded could be attributed to the laser titanium surface features that seem to prevent bacterial colonization. Future randomized and controlled studies are needed to confirm the results of the present multi-centrical retrospective analysis.
PubMed: 32719900
DOI: 10.1186/s40729-020-00230-w -
Beijing Da Xue Xue Bao. Yi Xue Ban =... Dec 2020To provide the basis for the clinical development of ultrasonic shoulder preparation by comparing the roughness and three-dimensional topography of shoulder surface...
OBJECTIVE
To provide the basis for the clinical development of ultrasonic shoulder preparation by comparing the roughness and three-dimensional topography of shoulder surface between ultrasonic instruments and conventional rotary instruments, to make preliminary suggestions for clinical use of ultrasonic instruments.
METHODS
(1) Four areas of buccal and palatal surfaces of six extracted human premolars were prepared with different grit size of rotary instruments. Polyether was used to take impression of the shoulder area, 3-D topography measurement laser microscope (3-D TMLM) was used to scan the impressions and compare the shoulder surface roughness of the four areas. (2) Six extracted human premolars were prepared, mesial half of the shoulder was finished with traditional rotary instruments and distal half with ultrasonic instruments. Polyether was used to take impression of the shoulder area, 3-D TMLM was used to scan the impressions and compare the shoulder surface roughness and 3-D topography, and the shoulder surface morphology was observed by surgical microscope (×25 magnification). (3) Twenty extracted human maxillary symmetrical homonymous anterior teeth were poured into die stone using artificial gingiva, ultrasonic instruments group and rotary instruments group were divided randomly. After preparing the teeth and taking the shoulder impression with polyether in dental simulate on the training system, the surface roughness of the shoulder impression in mesial, middle and distal areas was scanned and compared. The data were analyzed using SPSS 25.0 software package.
RESULTS
(1) There was no significant difference in Ra and Rz values between the abutment shoulder and impression shoulder in different areas. (2) The surface roughness of the shoulder impression prepared by ultrasonic instruments [Ra:(6.59±2.33) μm, Rz:(34.69±7.29) μm] was significantly smaller than that of the rotary instruments [Ra:(21.79±4.89) μm, Rz:(91.69±14.82) μm] ( < 0.05). The morphology of the shoulder prepared by ultrasonic instruments was clear and continuous under microscope observation. (3) The surface roughness of each area of the shoulder prepared by ultrasonic instruments was significantly lower than that of the rotary instruments ( < 0.001); there was no significant difference of the surface roughness (Ra) in each area of the shoulder impression after ultrasonic instrument preparation, while the shoulder impression roughness in the mesial and distal areas was significantly higher than that in the middle area ( < 0.001) after rotary instrument preparation.
CONCLUSION
Compared with the rotary instruments, the ultrasonic instruments can obtain a smoother shoulder surface, especially can significantly improve the shoulder preparation effect near the proximal surface.
Topics: Bicuspid; Humans; Microscopy, Electron, Scanning; Shoulder; Surface Properties; Ultrasonics
PubMed: 33550341
DOI: 10.19723/j.issn.1671-167X.2021.01.014 -
Materials (Basel, Switzerland) Jan 2021We aimed to analyze the morpho-geometric changes of the root canal system created by two rotary systems (TF Adaptive and BioRace) using micro-CT technology. Two concepts...
We aimed to analyze the morpho-geometric changes of the root canal system created by two rotary systems (TF Adaptive and BioRace) using micro-CT technology. Two concepts of rotary file system kinematics, continuous rotation and adaptive kinematics, were used in root canal preparation. Twenty mandibular molars (n = 20) were selected with the following criteria: the teeth have mesial roots with a single and continuous isthmus connecting the mesiobuccal and mesiolingual canals (Vertucci's Type I configuration) and distal roots with independent canals. Teeth were scanned at a resolution of 14 μm. Canals were divided equally into two groups and then enlarged sequentially using the BioRace system and TF Adaptive system according to manufacturer protocol. Co-registered images, before and after preparation, were evaluated for morphometric measurements of canal surface area, volume, structure model index, thickness, straightening, and un-instrumented surface area. Before and after preparation, data were statistically analyzed using a paired sample -test. After preparation, data were analyzed using an unpaired sample test. The preparation by both systems significantly changed canal surface area, volume, structure model index, and thickness in both systems. There were no significant differences between instrument types with respect to these parameters ( > 0.05). TF Adaptive was associated with less straightening (8% compared with 17% for BioRace in the mesial canal, > 0.05). Both instrumentation systems produced canal preparations with adequate geometrical changes. BioRace straightened the mesial canals more than TF Adaptive.
PubMed: 33499266
DOI: 10.3390/ma14030531 -
NeuroImage. Clinical 2020Previous imaging studies in patients with refractory temporal lobe epilepsy (TLE) have examined the spatial distribution of changes in imaging parameters such as...
PURPOSE
Previous imaging studies in patients with refractory temporal lobe epilepsy (TLE) have examined the spatial distribution of changes in imaging parameters such as diffusion tensor imaging (DTI) metrics and cortical thickness. Multi-compartment models offer greater specificity with parameters more directly related to known changes in TLE such as altered neuronal density and myelination. We studied the spatial distribution of conventional and novel metrics including neurite density derived from NODDI (Neurite Orientation Dispersion and Density Imaging) and myelin water fraction (MWF) derived from mcDESPOT (Multi-Compartment Driven Equilibrium Single Pulse Observation of T1/T2)] to infer the underlying neurobiology of changes in conventional metrics.
METHODS
20 patients with TLE and 20 matched controls underwent magnetic resonance imaging including a volumetric T1-weighted sequence, multi-shell diffusion from which DTI and NODDI metrics were derived and a protocol suitable for mcDESPOT fitting. Models of the grey matter-white matter and grey matter-CSF surfaces were automatically generated from the T1-weighted MRI. Conventional diffusion and novel metrics of neurite density and MWF were sampled from intracortical grey matter and subcortical white matter surfaces and cortical thickness was measured.
RESULTS
In intracortical grey matter, diffusivity was increased in the ipsilateral temporal and frontopolar cortices with more restricted areas of reduced neurite density. Diffusivity increases were largely related to reductions in neurite density, and to a lesser extent CSF partial volume effects, but not MWF. In subcortical white matter, widespread bilateral reductions in fractional anisotropy and increases in radial diffusivity were seen. These were primarily related to reduced neurite density, with an additional relationship to reduced MWF in the temporal pole and anterolateral temporal neocortex. Changes were greater with increasing epilepsy duration. Bilaterally reduced cortical thickness in the mesial temporal lobe and centroparietal cortices was unrelated to neurite density and MWF.
CONCLUSIONS
Diffusivity changes in grey and white matter are primarily related to reduced neurite density with an additional relationship to reduced MWF in the temporal pole. Neurite density may represent a more sensitive and specific biomarker of progressive neuronal damage in refractory TLE that deserves further study.
Topics: Adult; Brain; Diffusion Tensor Imaging; Epilepsy, Temporal Lobe; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Myelin Sheath; Neurites; Neuroimaging; Young Adult
PubMed: 32146320
DOI: 10.1016/j.nicl.2020.102231