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Diagnostics (Basel, Switzerland) Feb 2024Periodontal disease is a site-specific disease affecting the supporting tissues of the teeth. It is useful for the clinician to have information about the prevalence and...
Periodontal disease is a site-specific disease affecting the supporting tissues of the teeth. It is useful for the clinician to have information about the prevalence and severity of alveolar bone loss (ABL) according to the site, location, and position of the teeth for a better treatment plan and expected prognosis. This study aimed to assess the prevalence and severity of ABL at mesial, distal, buccal and lingual sites of teeth in different locations, positions and sides of the dentition. The ABL of 20,620 sites of 5155 teeth in 212 patients was assessed using cone-beam computed tomography from the cemento-enamel junction to the crest of the alveolar bone. The prevalence of ABL was higher in the interproximal sites as well as anterior and mandibular teeth compared to their counterparts. Buccal sites and anterior teeth revealed higher ABL levels than the other tooth sites and posterior teeth, respectively. Furthermore, associations in the severity of ABL were observed between distal and mesial sites, buccal and lingual sites, maxillary and mandibular teeth, anterior and posterior teeth, and right and left sides. This study showed that the prevalence and severity of ABL differ from one tooth site to another and according to the tooth's location in the dentition. Higher prevalences were found in the interproximal sites, anterior teeth and mandibular teeth; higher ABL was found in buccal and distal sites, with the strongest associations between distal and mesial sites, buccal and lingual sites, and right and left sides.
PubMed: 38472979
DOI: 10.3390/diagnostics14050507 -
Australian Dental Journal Mar 2024This study compared the marginal gaps of CAD/CAM lithium disilicate (LDS) crowns constructed using a contemporary and older scanner/milling unit combination at three...
BACKGROUND
This study compared the marginal gaps of CAD/CAM lithium disilicate (LDS) crowns constructed using a contemporary and older scanner/milling unit combination at three different cement spaces.
METHODS
Twenty-four undergraduate students prepared a Columbia model lower left first molar for an LDS crown in a simulated environment. From each crown preparation, one LDS crown was constructed using an E4D scanner/E4D milling unit (E4DS/E4DM) and TRIOS 3 scanner/Sirona inLab MC X5 milling unit (TRIO/MCX5) at cement space settings of 50, 100 and 200 μm. Each LDS crown was positioned onto the original crown preparation, and then a stereomicroscope was used to make three vertical marginal gap measurements at four locations (mid-buccal, mid-lingual, mid-mesial and mid-distal). The mean marginal gap (MMG) was calculated for each crown and each individual tooth surface.
RESULTS
The MMGs of CAD/CAM LDS crowns constructed by TRIO/MCX5 were 72.31 at 50, 63.73 at 100 μm and 46.23 μm at 200 μm, which were smaller than E4DS/E4DM at each cement space.
CONCLUSIONS
Increasing the cement space decreased the MMG in both scanner/milling unit combinations. The smallest MMG was found using the newer scanner/milling unit at the 200 μm cement space. © 2024 Australian Dental Association.
PubMed: 38469907
DOI: 10.1111/adj.13014 -
American Journal of Dentistry Feb 2024To assess and compare the effects of sonic and ultrasonic instrumentation on shear bond strength (SBS) and investigate the influence of adhesive system application modes...
PURPOSE
To assess and compare the effects of sonic and ultrasonic instrumentation on shear bond strength (SBS) and investigate the influence of adhesive system application modes (etch&rinse/self-etch) on SBS.
METHODS
In this experimental study, 45 extracted sound human molars were selected. Mesial and distal surfaces of the teeth were abraded until 90 smooth enamel surfaces were obtained. Specimens were divided into two groups, with half (N= 45) conditioned in etch&rinse mode and the remaining (N= 45) in self-etch mode using Tetric N Bond Universal. Composite resin discs were produced on these surfaces by filling Teflon molds. All specimens were aged via thermocycling. Each group was further divided into three more groups (n= 15) according to the type of periodontal instrumentation (ultrasonic, sonic or none). SBS values were recorded and analyzed using two-way ANOVA. Fracture sites were examined under a stereomicroscope.
RESULTS
The type of periodontal instrumentation had no significant effect on SBS values, whether sonic, ultrasonic or their absence (P= 0.945). The type of adhesive system mode had a significant influence on the shear bond strength values. Etch&rinse groups had significantly higher shear bond strength values than self-etch groups (P< 0.001).
CLINICAL SIGNIFICANCE
This study reassures practitioners that sonic and ultrasonic instruments are safe for enamel bonding and highlights the importance of selecting adhesive techniques for optimal restorative outcomes.
Topics: Humans; Aged; Dental Cements; Dentin-Bonding Agents; Resin Cements; Dental Bonding; Ultrasonics; Composite Resins; Dental Enamel; Materials Testing; Shear Strength
PubMed: 38458979
DOI: No ID Found -
BMC Oral Health Mar 2024The preparation of the middle mesial (MM) canal of mandibular molars represents a challenge because it is often curved, narrow, and close to the root concave. The...
Micro-computed tomographic evaluation of the shaping ability of three nickel-titanium rotary systems in the middle mesial canal of mandibular first molars: an ex vivo study based on 3D printed tooth replicas.
BACKGROUND
The preparation of the middle mesial (MM) canal of mandibular molars represents a challenge because it is often curved, narrow, and close to the root concave. The purpose of this study was to evaluate the ex vivo shaping ability of 3 nickel-titanium (NiTi) rotary systems in the MM canal using 3D printed resin tooth replicas.
METHODS
A permanent mandibular first molar with a MM canal was acquired from a pool of extracted teeth and reproduced by a 3D printer. The resin tooth replicas (n = 18) were equally assigned to 3 groups for the evaluation of the shaping abilities of 3 NiTi rotary systems (OneShape [OS], Twisted Files [TF], and ProTaper Gold [PTG]) according to the manufacturer's recommendations. The tooth replicas were scanned by micro-computed tomography (micro-CT) twice before and after instrumentation of the mesiobuccal (MB), mesiolingual (ML), and MM root canals. After 3D reconstruction, the canal straightening, change of root canal volume and surface area, the mesial and distal canal wall thickness and canal transportation at the levels of 1, 2, and 3 mm below furcation were assessed. One-way variance analysis and Turkey's post hoc test were used for comparisons of the means among different groups, and paired-t test was used to compare the mesial and distal sides of the mesial roots.
RESULTS
As compared with OS and TF, the use of PTG in preparation of MM canals resulted in significantly more straightening of canal curvature (p < 0.05), greater post-instrumentation canal volume and surface area, and thinner mesial and distal remaining canal wall thickness at 1, 2 and 3 mm below furcation (all p < 0.05). Regarding the root canal transportation in the mesiodistal direction, there was no significant difference among the 3 instruments (all p > 0.05) after the preparation of the MB and ML canals. However, in the MM canal, more pronounced transportation was detected in the PTG group at 2 mm below furcation, and in the TF group at 3 mm below furcation as compared with the other 2 systems (both p < 0.05).
CONCLUSIONS
3D printed tooth replicas have the advantages of consistency and can be an ideal model to evaluate the shaping ability of different instruments in the MM canal. OS and TF files performed similarly and both are appropriate for shaping the MM canal, while PTG may cause excessive and uneven resin removal, especially near the furcation, and may lead to root fragility and procedural errors.
Topics: Humans; Dental Pulp Cavity; X-Ray Microtomography; Nickel; Titanium; Root Canal Preparation; Molar; Printing, Three-Dimensional; Equipment Design; Alloys
PubMed: 38431556
DOI: 10.1186/s12903-024-04024-z -
International Journal of Oral Science Feb 2024The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment. However,...
The utilization of optimal orthodontic force is crucial to prevent undesirable side effects and ensure efficient tooth movement during orthodontic treatment. However, the sensitivity of existing detection techniques is not sufficient, and the criteria for evaluating optimal force have not been yet established. Here, by employing 3D finite element analysis methodology, we found that the apical distal region (A-D region) of mesial roots is particularly sensitive to orthodontic force in rats. Tartrate-resistant acidic phosphatase (TRAP)-positive osteoclasts began accumulating in the A-D region under the force of 40 grams (g), leading to alveolar bone resorption and tooth movement. When the force reached 80 g, TRAP-positive osteoclasts started appearing on the root surface in the A-D region. Additionally, micro-computed tomography revealed a significant root resorption at 80 g. Notably, the A-D region was identified as a major contributor to whole root resorption. It was determined that 40 g is the minimum effective force for tooth movement with minimal side effects according to the analysis of tooth movement, inclination, and hyalinization. These findings suggest that the A-D region with its changes on the root surface is an important consideration and sensitive indicator when evaluating orthodontic forces for a rat model. Collectively, our investigations into this region would aid in offering valuable implications for preventing and minimizing root resorption during patients' orthodontic treatment.
Topics: Humans; Rats; Animals; Root Resorption; Osteoclasts; X-Ray Microtomography; Tooth Movement Techniques; Tooth Root; Molar; Alveolar Bone Loss
PubMed: 38418457
DOI: 10.1038/s41368-024-00284-1 -
Effect of repeated autoclaving on implant abutments from genesis and bredent dental implant systems.Bioinformation 2023The effect of repeated autoclaving on the implant-abutment connection of titanium abutments from Genesis and Bredent dental implant systems is of interest to dentists....
The effect of repeated autoclaving on the implant-abutment connection of titanium abutments from Genesis and Bredent dental implant systems is of interest to dentists. 40 screw-retained titanium implant abutments from Genesis and Bredent were divided into four groups of ten. Each implant was secured with an abutment using screws. Abutments were prepared for the first 30-minute autoclave cycle at 121°C. After the first autoclave cycle, the abutments were fitted onto their implant systems and examined under a scanning electron microscope (SEM). Intra-group comparison between marginal gaps of Genesis and Bredent groups at 1st autoclave and 2nd autoclave observed statistically significant differences respectively (p<0.05). Genesis group showed highest mean values for buccal and mesial sides (2.7) and lingual and distal sides (2.8) with statistically significant differences. Marginal gap and surface roughness increased with autoclaving for both Genesis and Bredent group of implant abutment systems.
PubMed: 38415044
DOI: 10.6026/973206300191419 -
American Journal of Biological... Jun 2024Dental anthropological investigations into sexual dimorphism have conventionally concentrated on evaluating the dimensions and configuration of the enamel cap of...
OBJECTIVES
Dental anthropological investigations into sexual dimorphism have conventionally concentrated on evaluating the dimensions and configuration of the enamel cap of canines. However, the morphology of the crown dentine surface can be closely linked to that of the enamel surface. This link can facilitate examination of crown morphology even when the enamel surface is slightly worn. Here, we determine if the morphology of the enamel-dentine junction (EDJ) differs within (maxillary vs. mandibular) and between a sample of male (n = 26) and female (n = 21) contemporary human permanent canines from Europe.
METHODS
The morphological data of the EDJ were gathered employing a template comprising 96 landmarks and sliding semilandmarks. Subsequently, the data underwent analysis through form space principal component analysis following Procrustes registration, utilizing standard 3D geometric morphometric techniques.
RESULTS
Significant differences in the morphology of the EDJ were observed between the sexes, particularly concerning the overall shape of the crown, the symmetry of the mesial and distal edges, and the development of the distal accessory ridge.
CONCLUSIONS
Sex differences in the morphology of the EDJ could relate in part to retention of the canine-premolar honing complex in males. Our results indicate that analyses of the permanent canine EDJ may potentially provide a novel method for estimating the sex of adult and nonadult skeletons.
Topics: Humans; Male; Female; Sex Characteristics; Cuspid; Dentin; Dental Enamel; Europe; Adult; Principal Component Analysis
PubMed: 38411322
DOI: 10.1002/ajpa.24913 -
Clinical Oral Investigations Feb 2024The aim of this study was to evaluate six files on the pericervical dentin (PCD) and the smallest dentin thickness zones (SDTZ) in mesial root canals of mandibular...
Microcomputed tomographic evaluation of 6 NiTi files on the pericervical dentin and the smallest dentin thickness zones in mesial root canals of mandibular molars: an in vitro study.
OBJECTIVE
The aim of this study was to evaluate six files on the pericervical dentin (PCD) and the smallest dentin thickness zones (SDTZ) in mesial root canals of mandibular molars.
MATERIALS AND METHODS
Sixty mandibular molars with two mesial canals and Vertucci configuration were aleatory allocated in 6 experimental groups of 10 molars and 20 root canals. Specimens were scanned before instrumentation using the SkyScan 1275 (Bruker microCT, Kontich, Belgium). Group 1 was treated with WaveOne Gold (WG), group 2 with Reciproc Blue (RB), group 3 with TRUShape (TS), group 4 with XP-endo Shaper (XP), group 5 with iRace (IR), and group 6 with TruNatomy (TN). After instrumentation, the molars were scanned again and the images recorded were reconstructed with the NRecon v.1.7 (Bruker micro-CT) and analyzed with CTAn v.1.20.8 software (Bruker micro-CT) quantifying the changes produced in the surface, volume, structure thickness, SMI, and centroids at the Pericervical Dentin area of the root canals (PCD) located from the root canal orifices at the floor of the pulp chamber to 4 mm in the apical direction, and the changes in the Smallest Dentin Thickness Zones (SDTZ) located (from the furcation to 4 mm and 7 mm in the apical direction. The data obtained were compared using Wilcoxon and ANOVA with a 5% significance level.
RESULTS
XP and TN were similar in all the parameters (P >.05) at the PCD, but TN showed significant differences from WG, RB, TS, and IR (P <.05), while XP showed significant differences from WG (P <.05) in volume, surface, and structure thickness. Regarding the changes in the SDTZ, the amount of dentin removed was similar between the groups in both canals at the middle 1/3, at the cervical 1/3 for MB canals, and in ML canals for RB, TS, XP, IR, and TN (P>.05). The action of WG was significantly different from that of XP and TN in the cervical 1/3 of the ML canal (P <.05).
CONCLUSIONS
XP and TN rotatory files with small taper and volume maintained better with minor changes at the PCD and SDTZ, while WG reciprocation file produced the largest change. All the files were maintained centered at the PCD, and their performances were safe with a minimal thickness higher 0.5 mm at the SDTZ, and without risk of perforation.
TRIAL REGISTRATION
No clinical trials were indicated in this study.
CLINICAL RELEVANCE
The choice of endodontic files is a relevant factor in the conservative performance of root canal treatments.
Topics: Dental Pulp Cavity; X-Ray Microtomography; Root Canal Preparation; Molar; Gold; Dentin
PubMed: 38388725
DOI: 10.1007/s00784-024-05493-w -
Journal of Periodontal Research Jun 2024This study aimed to evaluate the regenerative capacities of octacalcium phosphate collagen composite (OCP/Col) in one-wall intrabony defects in dogs. The background data...
OBJECTIVE
This study aimed to evaluate the regenerative capacities of octacalcium phosphate collagen composite (OCP/Col) in one-wall intrabony defects in dogs. The background data discuss the present state of the field: No study has assessed the efficacy of OCP/Col for periodontal regeneration therapy despite the fact that OCP/Col has proved to be efficient for bone regeneration.
METHODS
In six beagle dogs, the mandibular left third premolars were extracted 12 weeks before the experimental surgery. Standardized bone defects (5 mm in height and 4 mm in width) were simulated on the distal surface of the second premolars and mesially on the fourth premolars. The defect was filled with either OCP/Col (experimental group) or left empty (control group). Histological and histomorphometric characteristics were compared 8 weeks after surgery.
RESULTS
No infectious or ankylotic complications were detected at any of the tested sites. The experimental group exhibited a significantly greater volume, height, and area of newly formed bone than the control group. The former also showed a greater height of the newly formed cementum than the latter, although the results were not statistically significant. The newly formed periodontal ligaments were inserted into newly formed bone and cementum in the experimental group.
CONCLUSION
OCP/Col demonstrated high efficacy for bone and periodontal tissue regeneration that can be successfully applied for one-wall intrabony defects.
Topics: Animals; Dogs; Calcium Phosphates; Bone Regeneration; Collagen; Alveolar Bone Loss; Periodontal Ligament; Bone Substitutes; Guided Tissue Regeneration, Periodontal; Male; Mandible; Dental Cementum
PubMed: 38356157
DOI: 10.1111/jre.13245 -
The Journal of Adhesive Dentistry Jan 2024This study investigated and compared the bond strengths, microleakage, microgaps, and marginal adaptation of self-adhesive resin composites (SAC) to dentin with or...
Bond Strength, Microleakage, Microgaps, and Marginal Adaptation of Self-adhesive Resin Composites to Tooth Substrates with and without Preconditioning with Universal Adhesives.
PURPOSE
This study investigated and compared the bond strengths, microleakage, microgaps, and marginal adaptation of self-adhesive resin composites (SAC) to dentin with or without universal adhesives.
MATERIALS AND METHODS
Dentin surfaces of 75 molars were prepared for shear and microtensile bond strength testing (SBS and µTBS). Silicon molds were used to build up direct restorations using the following materials to form 5 groups: 1. Surefil One; 2. Prime&Bond active Universal Adhesive + Surefil One; 3. Vertise Flow; 4. OptiBond Universal + Vertise Flow; 5. Scotchbond Universal + Filtek Z500 (control group). Bonded specimens were thermocycled 10,000x before being tested either for SBS or µTBS using a universal testing machine at a crosshead speed of 0.5 mm/min. Direct mesial and distal class-II cavities were created on 100 sound premolars, with the gingival margin of distal cavities placed below CEJ and restored according to the five groups. After thermocycling, microleakage scores were assessed following immersion of restored premolars in 2% methylene blue dye for 24 h, while marginal gaps and adaptation percentages were investigated on epoxy resin replicas under SEM at magnifications of 2000X and 200X, respectively. Results were statistically analyzed with parametric and non-parametric tests as applicable, with a level of significance set at α = 0.05.
RESULTS
Bond strengths, microleakage scores, microgaps, and percent marginal adaptation of Surefil One and Vertise Flow were significantly (p < 0.001) inferior to the control group. Dentin preconditioning with universal adhesives significantly increased the study parameter outcomes of Surefil One and Vertise Flow, yet they were still significantly below the performance of the control group.
CONCLUSION
Conventional resin composite outperformed the SAC whether applied solely or in conjunction with their corresponding universal adhesives.
Topics: Bisphenol A-Glycidyl Methacrylate; Resin Cements; Dentin-Bonding Agents; Dental Bonding; Dental Restoration, Permanent; Dental Cements; Dentin; Composite Resins; Materials Testing
PubMed: 38329120
DOI: 10.3290/j.jad.b4949691