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Volumetric resorption of the alveolar ridge often occurs in both horizontal and vertical directions following tooth extraction. There is a specific lack of evidence for alveolar ridge reconstruction at molar and premolar sites with severe bone resorption. This randomized controlled trial used 3D and linear analyses to evaluate volumetric changes of the alveolar bone following alveolar ridge reconstruction (ARR) at molar and premolar sites with severe bone resorption as compared to unassisted socket healing before implant placement. A total of 31 patients (15 men, 16 women) with > 50% hard tissue loss in one or more socket walls were recruited and randomized into either a test group (postextraction ARR using deproteinized bovine bone mineral with 10% collagen [DBBM-C] and platelet-rich fibrin [PRF] with a resorbable collagen membrane) or a control group (natural healing after extraction). The clinical, linear, and volumetric implant-related and patient-reported outcomes were analyzed after 4 months of healing. Linear bone assessments revealed significantly greater ridge width gains in the test group (25% in the mesial, midfacial, and distal aspects) and less reduction of vertical bone ridge than in the control group (P < .05). Further, volumetric bone remodeling was significantly higher in the test group (35.1% ± 34.9% for ARR, 14.2% ± 12.8% for control; P < .05). Patient-reported discomfort and keratinized mucosal changes were comparable between groups. ARR with a combination of DBBM-C, PRF, and a resorbable membrane at posterior sites with a severe socket wall deficiency (> 50% bone loss) is a safe and more capable therapeutic method when compared to natural healing and unassisted sockets. Collectively, the present analyses demonstrate that ARR represents an efficient method to maintain and augment crestal bone at posterior extraction sites with severe bone defects when assessed after 4 months of healing. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate inlay and onlay marginal adapta2on of two different ceramic materials using two intracoronal prepara2on designs. Materials and Methods: An examina2on of the marginal adap2on of two materials--lithium disilicate (LD; IPS e.max CAD) and polymer infiltrated ceramic network material (PICN; Vita Enamic)--and two prepara2on designs, where D1 represents MOD inlay prepara2on with no cusp reduc2on and for D2, in addi2on to the basic MOD prepara2on, the buccal cusps (func2onal cusps) were reduced by 1.5 mm. Four sub-groups (LD-D1, LD-D2, PICN-D1, PICN-D2) were conducted. In total, 40 (n = 40) mandibular molars were used. A stereomicroscope was used to assess the marginal gap before, aWer cementa2on and aWer thermocycling. Values were calculated for the mean, median, SD, minimum, maximum, and 95% CI. Pairwise comparisons using Tukey post-hoc test were performed following an ANOVA significance of P = .05. Results: The results revealed that lithium disilicate showed sta2s2cally significantly higher mean gap distance than PICN material (61 µm to 99 µm). Pairwise comparisons showed that D2 design has sta2s2cally significant higher mean gap values than D1. Conclusions: Both LD and PICN material provided marginal adapta2on within clinical accepted range. PICN material restora2ons provided beer fit than lithium disilicate restora2ons. Cusp coverage has a greater marginal gap compared to conven2onal prepara2on. [ABSTRACT FROM AUTHOR]

Purpose: To determine the change in the sagittal and vertical position of mini-implants placed in the maxilla during distal movement of the entire maxillary dentition. Materials and Methods: Overall, 28 mini-implants (1 placed on each side in 14 patients) were evaluated in healthy patients aged 15 to 25 years old. CBCTs were taken immediately after leveling and aligning prior to distalization (T1) and after 6 months (T2) to evaluate the distal movement of the maxillary teeth and position of the mini-implants. The vertical and sagittal angulation of each mini-implant was measured at T1 and T2. The linear distance between the mini-implant and the alveolar crest, the maxillary sinus, the maxillary second premolar, and the maxillary first permanent molar were measured. The change in angulation and the linear displacement of the mini-implant were evaluated in the vertical and sagittal plane. Wilcoxon signed rank test was performed to determine if there was a statistically significant change in the position of the mini-implant. Results: Vertically, there was a significant change in the linear distance between the mini-implant and the alveolar crest on the right side (P ≤ .006) as well as the mini-implant and the maxillary sinus on the left side (P ≤ .003). Sagittally, there was a statistically significant rotation of the mini-implant occlusally (left side P ≤ .004 and right side P≤ .002). The head and tip of the mini-implant were displaced toward the maxillary second premolar and away from the maxillary first permanent molar, respectively. There was a significant relative displacement of the mini-implant anteriorly away from the maxillary first permanent molar (left side P ≤ .026 and right side P ≤ .041) and closer to the maxillary second premolar (left side: P ≤.011 and right side: P≤ .002). Conclusions: There was a statistically and clinically significant rotation of the mini-implant in the vertical and sagittal direction during distal movement of the entire maxillary arch. The linear displacement of the mini-implant was more pronounced in the sagittal direction than the vertical direction. [ABSTRACT FROM AUTHOR]

Objective: An altered sensation during endodontic treatment can occur due to the extrusion of endodontic materials. This study aims to discuss intentional replantation to address paresthesia resulting from an endodontic file penetrating the inferior alveolar nerve canal and provide a protocol for managing nerve injuries in such incidents. Case presentation: A 12-year-old girl developed paresthesia when an endodontic file separated and was inadvertently pushed through the apical foramen into the inferior alveolar nerve canal during root canal treatment of the mandibular left first molar. A CBCT scan revealed the file penetrating the canal towards the inferior border of the mandible. After considering the treatment options, intentional replantation was deemed suitable. The tooth was atraumatically extracted and preserved in sterile saline. The surgeon then carefully cleaned and irrigated the socket. The radiographic assessment confirmed successful file removal from the socket. The root ends were resected, and retrograde preparation and obturation were conducted using ultrasonic tips and mineral trioxide aggregate. The tooth was then replanted into the socket. Successful replantation was confirmed by tooth stability and an audible click. The patient was prescribed antibiotics and steroids. After completion of the endodontic treatment, a stainless steel crown was cemented. The successful intentional replantation procedure resulted in rapid improvement in the patient's condition. The normal sensation had been restored, indicating nerve recovery. At the 15-month follow-up, periapical bone healing and the eruption of the adjacent second molar were observed, affirming the treatment protocol's overall success. Conclusion: Prompt intervention and immediate intentional replantation facilitated direct inspection of the separated file within the socket. Collaboration between an oral maxillofacial surgeon and an endodontist ensures expedited and targeted treatment, leading to favorable outcomes. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the dimensional accuracy of implant impressions obtained using five different tray types and two techniques. Materials and Methods: A partially dentate maxillary Kennedy Class II model was created as a reference model through 3D printing. Then, implant analogs 4.3 mm in diameter were placed at the first premolar, first molar, and second molar sites. Five types of trays were used to create impressions: (1) metal stock trays, (2) plastic stock trays, (3) custom trays fabricated using liquid crystal display (LCD), (4) custom trays fabricated using fused deposition modeling (FDM), and (5) custom trays fabricated using urethane dimethacrylate (UDMA) resin. Open and closed tray techniques were also compared. In total, 150 impressions were obtained. The reference model and impressions were scanned using a laboratory scanner. Additionally, the positional and angular deviations of implants with different tray types and techniques were evaluated using the superimposition method. Results: There was no statistically significant difference (P > .05) between the impression accuracy with the different tray types and impression techniques. The angular deviations with plastic and UDMA trays were greater than those with metal, FDM, and LCD trays. Angular deviation at the second molar was greater when using closed plastic trays compared to open plastic trays. The highest and lowest positional deviations were observed at the first molar implant with an open plastic tray impression (mean ± SD of 62.46 ± 28.54 mm) and a closed LCD tray impression (36.59 ± 29.93 mm). The greatest angular deviation was observed with an open FDM tray impression at the first premolar implant (0.067 ± 0.024 degree), and the lowest angular deviation was observed with a closed metal stock tray impression at the second molar implant (0.039 ± 0.025 degree). Statistical differences were detected using the Mann-Whitney U test for paired groups and the Kruskal-Wallis test for groups with more than three comparisons (P > .05). Conclusions: Plastic and metal stock trays or conventional and 3D-printed custom trays can be used to obtain implant impressions for maxillary partially edentulous arches with similar dimensional accuracy. The five tray types and two techniques may be safely used to obtain impressions of partially edentulous maxillary arches with three implants. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the effect of restora0on design on fracture resistance and stress distribu0on of veneered and monolithic three-unit zirconia fixed par0al dentures (FDPs) using finite element analysis (FEA). Materials and Methods: Iden0cal epoxy resin replicas of mandibular second premolars and second molars (to serve as abutments for the three-unit bridges) were divided into four groups (n = 10): monolithic zirconia (MZ) restora0ons; conven0onal layering veneering technique (ZL); heat pressed-on technique (ZP); or CAD/CAM lithium-disilicate glass-ceramics (CAD-on). Specimens were subjected to compressive cyclic loading on the mesio-buccal cusp of the pon0c (load range 50 to 600 N; aqueous environment; 500,000 cycles) in a universal tes0ng machine. Data were sta0s0cally analyzed at 5% significance level with Fisher exact test and Kaplan-Meier survival analysis. 3D models were constructed in accordance with experimental groups. The stress distribu0on in each model was analyzed and evaluated according to the loca0on and magnitude of the maximum principal stresses (MPSs) using ANSYS so\ware. Results: Specimens from ZL and ZP groups failed at different stages of the 500,000 cycles fa0gue, while CAD-on and MZ restora0ons survived the fa0gue test. Sta0s0cally, there was a significant difference between the groups (P < .001). The MPS were located under the mesial connector in both monolithic and bilayered three-unit zirconia FDPs. These stresses were found to be higher in monolithic geometries compared to bilayered zirconia FDPs. Conclusions: Monolithic threeunit zirconia and CAD-on zirconia frameworks resulted in superior fracture resistance. Restora0on design significantly affected the stress distribu0on of three-unit zirconia FDPs. [ABSTRACT FROM AUTHOR]

Objective: The evidence base for the use of space maintainers is relatively sparce despite being used for decades after the premature loss of primary molars. This study aims to increase the dental evidence base via investigating retrospectively the success rates of prefabricated fixed and removable space maintainers inserted from 2019 to 2021 and followed up until February 2023 at a specialized university clinic and to identify reasons for any reported minor and major failure. The authors hypothesized that there is no significant difference in failure rates between fixed and removable space maintainers inserted after the premature loss of a single primary molar per quadrant. Method and materials: Patients' digital records were searched yielding 645 space maintainers. After the application of inclusion criteria, 157 (67%) fixed prefabricated space maintainers in 112 children and 77 (33%) removable space maintainers in 61 children were analyzed for an average of 18.4 ± 9.5 months. Results: Kaplan-Meier survival analysis with Mantel-Cox statistics showed an overall cumulative survival time of 31.6 months (SE = 1.15, 95% CI = 29.4 to 33.9). Major failure occurred significantly more in removable maintainers (n = 40/67, 59.7%), mostly due to loss of the appliance, compared to fixed space maintainers (n = 27/67, 40.3%; P < .001). The present study indicates that space maintainers were mainly placed in young children with high caries experience, where treatment was mostly possible using advanced behavior management. Conclusions: Fixed space maintainers had a significantly lower failure rate than their removable counterpart. However, both require continual repairs, preservation, or even replacement till the eruption of the permanent tooth. [ABSTRACT FROM AUTHOR]

Purpose: To compare the volumetric loss of clinical crown structure in commonly encountered clinical situations for monolithic ceramic crowns, occlusal overlays, and partial-coverage onlays. Materials and Methods: Typodont teeth made with preexisting mesio-occlusodistal (MOD) preparations for mandibular first molars and maxillary first premolars were prepared with three different preparations: a full-contour monolithic zirconia crown, a lithium disilicate occlusal overlay, and mesio-occlusodistobuccal/mesio-occlusodistolingual (MODB/MODL) lithium disilicate onlays for premolars and molars. 3D-metrologic software was used to evaluate the volumetric loss of clinical crown structure for each preparation type. Subsequently, the mesiolingual cusps of mandibular molars and buccal cusps of maxillary premolars were excluded for a separate analysis to simulate patient presentation with an existing restoration and sheared-off cusp. Results: Full-coverage monolithic zirconia crowns removed 45.37 to 219.53 mm³ of the remaining clinical tooth structure, depending on the clinical scenario and tooth position, while lithium disilicate overlays removed 27.48 to 105.13 mm³ and MODB/MODL lithium disilicate onlays removed 5.48 to 47.45 mm³. In each scenario tested, MODB/MODL onlays removed significantly less clinical crown structure than overlays (P < .001); both MODB/MODL onlays and overlays removed significantly less structure than full-coverage crowns (P < .001). Conclusions: Monolithic zirconia crown restorations require significantly more removal of remaining tooth structure than lithium disilicate occlusal overlays and partial-coverage onlays for commonly occurring clinical situations requiring indirect restorations. [ABSTRACT FROM AUTHOR]

Autotransplantation has been proven as a viable method of reconstructing missing teeth. While preparing the recipient site, the bone reduction location depends largely on the surgeon's experience. Inappropriate overpreparation can cause biologic and esthetic complications, such as buccal or lingual bone resorption. This paper provides an innovative method to aid clinicians in precisely preparing a recipient site with the assistance of medical image-processing software and a real-time navigation system. This case report presents the autotransplantation of a mandibular molar using this technique with good short-term (6 months) clinical outcomes, including radiographic bone fill, normal probing pocket depth, physiologic tooth mobility, acceptable gingival level, and satisfactory restoration. [ABSTRACT FROM AUTHOR]

Purpose: To compare the marginal and internal fit of monolithic zirconia (MZ) 3-unit fixed dental prostheses (FDPs) fabricated using two CAD/CAM workflows: full-chairside (FCH) and lab (LAB). Materials and Methods: The right maxillary first premolar and first molar were prepared for MZ 3-unit FDPs on a typodont. CEREC Primescan digiOzed the typodont model 15 Omes. A total of 30 FDPs was fabricated using two processes: FCH (n = 15) and LAB (n = 15). FCH and LAB FDPs were designed using CEREC SW 4.5.1 and Exocad and milled using CEREC MC X and Zirkonzhan 600/V3, respecOvely. A fast-sintering protocol was used in both groups. A dual-scan technique was used to assess the cement space at the occlusal surface (OC), axial wall (AX), and margin (MA). StaOsOcal analysis of the results was performed using univariate ANOVA with Scheffè post hoc test (a = .05). Results: Measurements in the FCH and LAB groups were within the clinically acceptable marginal and internal fit. The fit of FCH FDPs at MA, AX, and OC was 77.50 ± 29.99 μm, 99.67 ± 21.58 μm, and 150.03 ± 30.78 μm, respecOvely. The fit of LAB FDPs at MA, AX, and OC was 100.27 ±27.06 μm, 116.53 ±17.90 μm, and 142.30 ±19.00 μm, respecOvely. The difference between the two groups was not staOsOcally significant. Conclusions: MZ 3-unit FDPs fabricated using FCH have clinically acceptable marginal and internal fit. This result verifies the ability of FCH workflow to fabricate MZ mulOunit FDPs in a single visit. [ABSTRACT FROM AUTHOR]

Purpose: To review experimental peri-implantitis studies using rat models and summarize different peri-implantitis induction techniques and evaluate their effectiveness. Materials and Methods: Electronic searches were conducted by two independent examiners to address the following issues. Meta-analyses explored the marginal bone loss (MBL) of four types of peri-implantitis induction methods in rats. The detailed induction tactics--such as the implant design, implant size, surgical process, time cost, induction methods, and endpoint measurements--were summarized. Results: Of the 18 included studies, 38.9% of the studies placed implants at the maxillary first molar, and 44.4% placed them at the alveolar ridge region anterior to the maxillary first molar. As for the induction method, the numbers of published studies on ligature methods, bacterial inoculation, and bacterial lipopolysaccharide inoculation were equally high among all selected studies. The total implant survival rate at the end was 160 out of 213 implants (75.11%). Eight studies with high pooled heterogeneity (I2 = 98, P < .01) in the meta-analysis reported an overall MBL (µ-CT) of 0.47 mm (95% CI = 0.14 to 0.81). A subgroup analysis estimated an MBL of 0.31 mm (95% CI = 0.12 to 0.50) for bacterial inoculation and 0.66 mm (95% CI = 0.07 to 1.26) for the ligature method. Histopathologic analysis revealed that peri-implantitis in rats was similar to peri-implantitis lesions in humans. Conclusions: Implant placement at the maxillary first molar with bacterial inoculation and the silk ligature method to build peri-implantitis rat models is reliable to use for research on peri-implantitis. [ABSTRACT FROM AUTHOR]

The Custom Alveolar Ridge Splitting (CARS) technique was recently reported as a less-invasive treatment option for augmentation of the maxillary anterior area in cases where alveolar width deficiency exists due to bone resorption and remodeling. This technique creates an intraosseous defect to improve success when horizontal ridge augmentation is attempted. The purpose of the present case report was to demonstrate implant placement in an atrophic posterior mandibular site using the CARS technique. This technique was used in the mandibular right second premolar area, followed by placement of a single implant. The restored implant showed stable soft and hard tissue outcomes at 6 months postloading. [ABSTRACT FROM AUTHOR]

Purpose: To assess the impact of fatigue loading on the internal and marginal fit of CAD/CAM-fabricated endocrowns for restoring endodontically treated molars using different machinable blocks. Materials and Methods: A total of 72 mandibular first molars were prepared using a standardized method and were divided into four groups (n = 18), each restored with a different CAD/CAM material: group V = polymerinfiltrated ceramic (Vita Enamic); group K = partially stabilized tetragonal zirconia (Katana); group E = lithium disilicate ceramic (IPS e.max CAD; and group B = polyetheretherketone (BioHPP). Endocrowns were subjected to thermomechanical fatigue loading. Internal and marginal adaptation of the endocrowns were examined at 66 points using the sectioning technique and a stereomicroscope. Data were analyzed using one-way ANOVA and Tukey post hoc test (a = .05). Results: Statistical tests showed that adhesive cementation resulted in significantly increased marginal and internal gap values in all regions in all four tested groups (P < .001). After thermomechanical fatigue loading, all regions in groups B and K showed a statistically significant difference, while no significant differences were found in the regions in group V (P > .05). In group E, the marginal (F = 71.00) and pulpal (F = 28.065) regions showed statistically significant differences (P < .001). Conclusion: Polymer-infiltrated ceramics showed the lowest gap even after thermomechanical fatigue loading and may therefore provide enhanced clinical survival of the restored tooth, favoring the use of this material for fabricating endocrown restorations. [ABSTRACT FROM AUTHOR]

Objectives: Treatment of carious primary molars is always indicated, especially on young children; however, there are no clear guidelines that precisely explain the best treatment approach for Class II carious molars with marginal breakdown (International Caries Detection and Assessment System [IC-DAS] 5). The objective of this prospective observational clinical study was to assess the efficacy of three restorative techniques in treating ICDAS 5 Class II lesions in primary molars: compomerfillings (CF), preformed metal crowns (PMC), and pulpotomy and conventional preformed metal crowns (PMC+P). The secondary goal was to evaluate the impact of some cofactors on the course of treatment. Method and materials: Overall, 92 children (female, n = 50, 54.3%; male, n = 42, 45.7%) aged 2 to 9 years old (mean age = 5.9 ± 1.9 years) with 166 treated teeth were included. The average number of decayed, missing, or filled teeth (d3mft) of the whole sample was 8.0 ± 3.4. The distribution of the sample according to type of treatment was CF = 53 (31.9%), PMC = 64 (38.6%), and PMC+P = 49 (29.5%). Paired ttest, nonparametric Friedman ANOVA test, and decision tree analysis were used as the basis for the statistics. Results: After 12 months, data from 75.8% (72/95) treated patients, corresponding to 62.0% (103/166) of the treated teeth (CF = 42/53, 79.2%; PMC = 38/64,59.4%; PMC+P = 23/49,46.9%) were available for analysis. The mean patients age was 6.8 ± 1.8years; 32 (47.1%) boys and 36 (52.9%) girls. The mean d3mft of the remaining sample was 7.8±3.35. PMC and PMC+P arms showed the highest success rates (> 91%) as compared to the CF arm, which showed the lowest success rates (61.9%), with 9/42 teeth of the CF group (21.4%) presenting with minor failures, and 7/42 teeth (16.7%) with major failures (P< .0001). Conclusion: Accordingtothe decision tree analysis, PMC and PMC+P had a success rate of 99%, whereas CF had a success rate of only 69%. Some cofactors (treatment decision, Approximal Plaque Index, and tooth number) had a higher impact on the decision tree analysis than others (age, dmfs, and dmft values), especially when the treatment selection was CF. In future studies it is necessary to examine the impact of other cofactors on the outcomes of conventional fillings using a larger sample size. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the fracture strength of endodontically treated molars filled with different composite resins with vs without fiber reinforcement. Materials and Methods: A total of 60 intact mandibular molars were selected and endodontically treated. A standardized mesio-occlusal-distal cavity was prepared with cervical margins 1 mm above the cementoenamel junction and oral and buccal walls with 1.5-mm thickness. Universal adhesive was used in all specimens in etch-and-rinse mode. Specimens were divided into four groups (n = 15 each) according to restoration technique: group CSM = adhesive overlay with hybrid ceramic; group EXP = direct restoration with short fiber-reinforced composite; group ESU = direct restoration with nanohybrid composite; and group EST = direct restoration with nanohybrid composite reinforced with horizontal bidirectional glass fibers placed over the pulpal chamber floor. After 7 days of storage in water, samples were loaded until fracture using a universal testing machine. The maximum breaking loads were recorded in Newtons, and statistical analysis was then conducted with two-way ANOVA and post hoc Tukey test. Fragments were analyzed using scanning electron microscopy. Results: Mean fracture resistance values were: CSM = 1,428.91 ± 316.90 N; EXP = 1,874.57 ± 299.47 N; ESU = 1,557.44 ± 355.65 N; and EST = 1,870.27 ± 145.11 N. The CSM and EXP groups showed the highest strength values when compared to the other groups. The variable fiber insertion did not significantly alter the fracture resistance. The origin of the fracture was always located on the occlusal surface, mainly in the major contact loading area. Conclusion: The use of fiber-reinforced composite showed great improvement in fracture resistance, similar to a cuspal coverage restoration. However, only short fiber-reinforced composites showed a favorable fracture pattern. [ABSTRACT FROM AUTHOR]

Background: The surgical treatment for mandibular repositioning using a bilateral sagittal split osteotomy (BSSO) favours the development of techniques that result in adequate repair and stability. In Puricelli's mandibular sagittal split osteotomy (PMSSO) proposal, the vertical lateral cut osteotomy is located in the interradicular space between the lower first molar and second premolar. Objectives: This in silico study aimed to investigate the mechanical stability of PMSSO and compare it with the classical Obwegeser–Dal Pont technique for mandibular advancement. Materials and methods: A computational geometric model of the mandible was created in a virtual environment using computer-aided design (CAD) software. After reproducing the advancements, two test groups were developed: GTOD10, Obwegeser–Dal Pont osteotomy, and GTP10, Puricelli osteotomy, both simulating a 10-mm mandibular advancement, allowing for measuring the area of overlap between bone segments. With the geometric changes promoted by the osteotomy, boundary conditions of displacement and force were applied to a CAD software based on finite element analysis (FEA), allowing for quantitative and comparative analysis of the stress and vertical displacement of the mandible, mechanical measurements that may be associated with strength and stiffness. Results: A 17.48% higher stress was observed in the GTP10 group than in GTOD10. However, the region of highest stress in GTP10 was found in a part of the bone that was still intact and far from the area of fragility caused by lateral vertical osteotomy. In contrast, in GTOD10, the region with high stress was in a less resistant bone region. The GTP10 group showed a 28.73% lower displacement than GTOD10. The area of overlap between the proximal and distal segments of the mandible was 33.13% larger in the GTP10 than in the GTOD10 group. Conclusion: The PMSSO method, performed in large mandibular advancements, keeps the point of highest stress away from the mandibular fragility zone. Considering the same amount of advancement, it also promotes less displacement and larger areas of bone overlap. Clinical relevance: The results suggest that PMSSO, applied in large mandibular advancement, presents greater postoperative stability. [ABSTRACT FROM AUTHOR]

Background: There are differences in the research results regarding which edge design of occlusal veneers can achieve the best long-term success rate as a relatively new fixed prosthesis restoration method. Further research is needed. The three-dimensional finite element method was used to conduct stress analysis on occlusal veneers of maxillary first permanent molars with different thicknesses and margin preparation designs. The aim of this study was to provide mechanical research evidence and a reference for exploring standardized clinical protocols for the design of occlusal veneer restorations of maxillary first molars. Method: A 3Shape (Intraoral Scanner) was used to scan the maxillary first molar teeth in vitro, after which 3D printing was carried out. Three different edge designs were applied to identical teeth: straight-beveled finishing line(SFL), chamfer finishing line(CFL), and standard cuspal inclination(SCI). Preparation was carried out with a thickness of 0.5 mm. Using the surface deformation feature, the occlusal veneer was thickened to 0.5 mm and 1.0 mm, and periodontal ligaments were added. They were then placed into the upper and lower jaws and dental arches. Finite element analysis was performed after applying bite force dispersion to the loading area on the mandible following dynamic contact. Results: (1) As the thickness increased, the maximum Von Mises stress in the occlusal veneers SFL and CFL also increased, while the SCI exhibited the opposite trend. (2). The trend of the maximum Von Mises stress in the adhesive layer decrease gradually with increasing thickness of the occlusal veneer. The stresses of the SFL and CFL is concentrated primarily at the edge position below the functional cusp, resulting in relatively low adhesive stress. However, in the SCI group, the maximum stress at the edge of the adhesive layer exceeds the maximum shear strength of commonly used adhesives. Conclusions: Under the experimental conditions, the mechanical properties of the maximum Von Mises stress in the SFL, CFL, and SCI occlusal veneers meet clinical needs. Incorporating the minimally invasive concept of tooth preservation, a thickness of 1.0 mm are optimal for glass ceramic occlusal veneers on maxillary first molars. Highlights: This experiment combined finite element analysis with traditional mechanical experiments and prepared models with identical shapes using 3D printing. This approach avoided experimental errors caused by variations in the shape of natural teeth among individuals, uneven bonding agent thickness, and different design morphologies of the occlusal surface. Additionally, the roughness of the prepared surface more closely resembled the true roughness encountered in clinical settings. By incorporating periodontal ligament (PDL) hyperelastic materials into jaw dentition, a more realistic nonlinear analysis of periodontal ligament deformation was conducted. Dynamic contact results, which differed from the static loading stresses typically used in finite element analyses, were obtained by applying biting forces and simulating the movement of biting. Daily chewing is not merely a collision between highly elastic model materials and restorations or teeth, as in extraoral experiments. Instead, it simulates the mechanical properties of the daily foods of primates, using materials that closely match these properties. [ABSTRACT FROM AUTHOR]

Introduction: Sufficient information is not available regarding the comparative accuracy of digital and conventional impression techniques at different depths for the fabrication of endocrown restorations. Thus, this study aimed to compare the marginal (M) and internal (I) adaptation of endocrowns at different depths fabricated by the digital and conventional impression techniques. Materials and Methods: In this in vitro study, two endodontically treated molar teeth with 2‐ and 4‐mm cavity depths were used for the fabrication of endocrowns. Conventional and digital impressions were made from each tooth 17 times. A total of 68 zirconia endocrowns were fabricated and seated, and their I and M adaptation was assessed by the silicone replica technique. Data were statistically analyzed. Results: The M and I gaps at 2‐ and 4‐mm cavity depths were significantly smaller in the digital, than the conventional, impression technique (p < 0.05). Increasing the cavity depth significantly increased the M and I gaps only in the digital technique (p < 0.05). The largest gap in all groups was noted in the pulpal (P) region (p < 0.05). The smallest gap was found in the M and cervical (C) regions in the conventional groups with 2‐ and 4‐mm cavity depths, and the digital group with 4 mm cavity depth, and in the M region in the digital group with 2 mm cavity depth (p < 0.05). Conclusion: Unlike the conventional impression technique, the M and I adaptation decreased by an increase in cavity depth in the digital technique; nonetheless, the digital impression technique still showed higher M and I adaptation than the conventional technique. [ABSTRACT FROM AUTHOR]

To evaluate the dimensional accuracy of occlusal veneers printed using a novel direct ink writing (DIW) system and a clinically approved dental composite. A novel three-dimensional printer was developed based on the extrusion-based DIW principle. The printer, constructed primarily with open-source hardware, was calibrated to print with a flowable resin composite (Beautifil Flow Plus). The feasibility of this technology was assessed through an evaluation of the dimensional accuracy of 20 printed occlusal veneers using a laboratory confocal scanner. The precision was determined by pairwise superimposition of the 20 prints, resulting in a set of 190 deviation maps used to evaluate between-sample variations. Without material waste or residuals, the DIW system can print a solid occlusal veneer of a maxillary molar within a 20-minute timeframe. Across all the sampled surface points, the overall unsigned dimensional deviation was 30.1 ± 20.2 µm (mean ± standard deviation), with a median of 24.4 µm (interquartile range of 22.5 µm) and a root mean square value of 36.3 µm. The pairwise superimposition procedure revealed a mean between-sample dimensional deviation of 26.7 ± 4.5 µm (mean ± standard deviation; n = 190 pairs), indicating adequate precision. Visualization of the deviation together with the nonextrusion movements highlights the correlation between high-deviation regions and material stringing. This study underscores the potential of using the proposed DIW system to create indirect restorations utilizing clinically approved flowable resin composites. Future optimization holds promise for enhancing the printing accuracy and increasing the printing speed. • An experimental 3D printer was constructed based on the direct ink writing principle. • The printer produced indirect restorations using clinically approved composites. • Remarkable dimensional accuracy was achieved through proper tuning. • This approach enables clean on-demand production with excellent affordability. [ABSTRACT FROM AUTHOR]

Background: First permanent molars (FPM) are highly susceptible to decay before the age of 15. When they are severely affected, the decision between conservation and extraction arises, particularly considering the potential for the second permanent molar (SPM) to replace the FPM. This cohort study aimed to evaluate clinical practices regarding FPM pulp necrosis treatment in children aged eight to twelve in two hospital departments in the Paris region. A second objective was to evaluate the one-year outcomes of the two therapies. Methods: A retrospective analysis was conducted using computerized billing software to identify patients aged eight to twelve who underwent either extraction or root canal treatment (RCT). Data collected included sex, age, arch involved, number of decayed surfaces, presence of Molar Incisor Hypomineralization (MIH), presence of infection, and treatment type. Results: A total of 66 patients were included, representing 61 extracted teeth and 23 RCT. Three main decision criteria were identified: presence of MIH (p < 0.005), extent of decay (p < 0.05), and SPM Nolla's stage. A total of 48% of the patients were seen at one year. A total of 16 of the 32 extractions and five of the nine RCTs had favorable evolution (p = 1). Conclusions: The question of whether to perform RCT or extraction of necrotic FPM in children aged eight to twelve is difficult to assess. It appears that five criteria need to be considered before the decision: possibility of long-term sealed coronal reconstruction, SPM Nolla's stage, follow-up possibilities, arch concerned, and presence of third permanent molar. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the influence of multiplanar reconstruction thickness on the detection of peri‐implant bone defects with a standalone zirconia implant and compare it to when another implant is in the vicinity using cone‐beam computed tomography (CBCT). Materials and Methods: Five dry human mandibles were used to create twenty implant sites in the second premolar and first molar regions. The OP300 Maxio was used to acquire CBCT images (90 kVp, 6.3 mA, 5 × 5 cm FOV, and 0.125 mm3 voxel size) before and after creating 3 mm peri‐implant bone defects in the buccal aspect of the premolar region. Half of the scans featured a single zirconia implant in the premolar region, while the others had two implants in the premolar and molar regions. Three reconstruction thicknesses (0.125 mm, 1 mm, and 2 mm) were considered for the multiplanar reconstruction analyses. Five oral and maxillofacial radiologists assessed the detection of peri‐implant bone defects using a 5‐point scale. Diagnostic parameters were calculated and compared using Two‐way ANOVA (α =.05). Results: The studied factors showed no significant influence on the diagnosis of peri‐implant bone defects (p >.05). Diagnostic performance was notably higher with a single implant, especially with a 2‐mm reconstruction thickness (AUC = 0.88, sensitivity = 0.68, specificity = 0.94). Although the differences were not statistically significant, the results were more modest when two implants were present (AUC = 0.80, sensitivity = 0.58, specificity = 0.82). Conclusions: The presence of an adjacent zirconia implant and variations in reconstruction thickness did not influence the detection of 3 mm buccal peri‐implant bone defects on CBCT images. [ABSTRACT FROM AUTHOR]

(1) Background: This study aimed to compare the shaping abilities of modern minimally invasive endodontic systems using natural teeth and 3D-printed resin replicas. These replicas offer a standardized approach for studying root canal preparation while eliminating the variability and scarcity of natural teeth. (2) Methods: Eleven mandibular molars with Vertucci class IV anatomy and their 3D-printed replicas (n = 132 canals) were scanned using micro-CT before and after preparation with six rotary systems. Shaping abilities were assessed by comparing volume, surface area, and unprepared areas between natural teeth and their 3D replicas, focusing on the apical third. Statistical analysis included the Shapiro–Wilk test to assess data normality and ANOVA and t-tests to compare different endodontic systems. (3) Results: Both qualitative and quantitative analyses revealed high similarity between natural teeth and 3D replicas. No significant differences in volume or surface area were found except in the apical third, where 3D replicas showed slightly larger increases in volume. (4) Conclusions: 3D resin replicas closely mimic natural teeth and provide a practical tool for assessing the shaping abilities of endodontic systems. This study demonstrates that 3D-printed models are suitable for endodontic research, offering a standardized and accessible alternative to natural teeth. [ABSTRACT FROM AUTHOR]

Mineral metabolism is critical for proper development of hard tissues of the skeleton and dentition. The dentoalveolar complex includes the following 4 mineralized tissues: enamel, dentin, cementum, and alveolar bone. Developmental processes of these tissues are affected by inherited disorders that disrupt phosphate and pyrophosphate homeostasis, although manifestations are distinct from those in the skeleton. The authors discuss original data from experiments and comparative analyses and review articles describing effects of inherited phosphate and pyrophosphate disorders on dental tissues. A particular emphasis is placed on how new therapeutic approaches for these conditions may affect oral health and dental treatments of affected patients. Disorders of phosphate and pyrophosphate metabolism can lead to reduced mineralization (hypomineralization) or inappropriate (ectopic) calcification of soft tissues. Disruptions in phosphate levels in X-linked hypophosphatemia and hyperphosphatemic familial tumoral calcinosis and disruptions in pyrophosphate levels in hypophosphatasia and generalized arterial calcification of infancy contribute to dental mineralization defects. Traditionally, there have been few options to ameliorate dental health problems arising from these conditions. New antibody and enzyme replacement therapies bring possibilities to improve oral health in affected patients. Research over the past 2 decades has exponentially expanded the understanding of mineral metabolism, and has led to novel treatments for mineralization disorders. Newly implemented and emerging therapeutic strategies affect the dentoalveolar complex and interact with aspects of oral health care that must be considered for dental treatment, clinical trial design, and coordination of multidisciplinary care teams. [ABSTRACT FROM AUTHOR]

Pursuing a proficient age estimation methodology introducing novel radiographic methods remains an ongoing and demanding aspect of forensic and medicolegal research. In 2017, Roberts GJ et al. (J Forensic Sci 62(2):351-4, 2017) described a new radiographic method, i.e., root canal width (RCW) patterns to assign a subject to above 18-year-age threshold. Since then, few researchers have investigated the validity of this radiographic method in other populations. The present study aimed to test the usefulness of these RCW patterns in predicting 18 years in a sample of South Indian juveniles and sub-adults aged between 16 and 23. Descriptive analysis revealed that pattern-A was initially observed at a minimum age of 16.08 and 16.22 years in males and females. Pattern-B at 16.31 years in males and 16.22 years in females, while pattern-C was initially recorded at 18.73 years in males and 19.01 years in females, respectively. In summary, if an individual, regardless of sex, exhibits a fully-formed (apex closed) mandibular first, second, and third molars and concurrently displays RCW-C, there is a strong likelihood that the person has exceeded the legally relevant age of 18 years. However, due to higher rate of technically unacceptable errors (adults wrongly identified as individuals below 18 years), reliance on this method alone should be restricted, and it is advisable to combine it with other methods. [ABSTRACT FROM AUTHOR]

Age estimation in forensic odontology is mainly based on the development of permanent teeth. To register the developmental status of an examined tooth, staging techniques were developed. However, due to inappropriate calibration, uncertainties during stage allocation, and lack of experience, non-uniformity in stage allocation exists between expert observers. As a consequence, related age estimation results are inconsistent. An automated staging technique applicable to all tooth types can overcome this drawback. This study aimed to establish an integrated automated technique to stage the development of all mandibular tooth types and to compare their staging performances. Calibrated observers staged FDI teeth 31, 33, 34, 37 and 38 according to a ten-stage modified Demirjian staging technique. According to a standardised bounding box around each examined tooth, the retrospectively collected panoramic radiographs were cropped using Photoshop CC 2021® software (Adobe®, version 23.0). A gold standard set of 1639 radiographs were selected (n31 = 259, n33 = 282, n34 = 308, n37 = 390, n38 = 400) and input into a convolutional neural network (CNN) trained for optimal staging accuracy. The performance evaluation of the network was conducted in a five-fold cross-validation scheme. In each fold, the entire dataset was split into a training and a test set in a non-overlapping fashion between the folds (i.e., 80% and 20% of the dataset, respectively). Staging performances were calculated per tooth type and overall (accuracy, mean absolute difference, linearly weighted Cohen's Kappa and intra-class correlation coefficient). Overall, these metrics equalled 0.53, 0.71, 0.71, and 0.89, respectively. All staging performance indices were best for 37 and worst for 31. The highest number of misclassified stages were associated to adjacent stages. Most misclassifications were observed in all available stages of 31. Our findings suggest that the developmental status of mandibular molars can be taken into account in an automated approach for age estimation, while taking incisors into account may hinder age estimation. [ABSTRACT FROM AUTHOR]

Dental age assessment based on evaluating dental mineralization status is one of the most common methods used in forensic practice. The aim of this study is to enhance the accuracy of age diagnostics and provide reference data from the Syrian population for forensic application. After several selection steps, a total of 280 orthopantomograms (OPGs) from 140 males and 140 females from the Syrian population divided into 14 age groups between 12 and 25 years were analysed. Based on Demirjian's classification system, the mineralization stages of third molars (18, 28, 38 and 48) as well as lower second molars (37 and 47) were evaluated. Statistical investigations and evaluations were carried out to estimate the marginal probabilities of the subjects having attained ages 14 and 18 by generalized estimating equation models. Our results show that no significant differences can be revealed in the mineralization status with respect to jaw side and sex. In the Syrian population, third molars showing mineralization stage G provide evidence of reaching the age of 14 years with the highest standard of proof ("beyond reasonable doubt"). A completed mineralization in lower second molars (stage H) provides very high marginal probabilities (more than 90%) of the subjects having attained age 14 years. Nevertheless, this cannot exclude an age under 14 years. For the age threshold of 18 years, third molars showing incomplete root development (G dental stage or lower) are associated with a low probability (less than 40%) of the subject having reached 18 years of age. A person's probability of having attained 18 years of age is very high (82– 95%) when the roots of third molars are fully developed (stage H). Nevertheless, third molars at stage H do not conclusively exclude an age under 18 years. [ABSTRACT FROM AUTHOR]

This study explores the reliability of four established legal age threshold estimation approaches in a Croatian sample. We applied Haavikko stages, Demirjian stages, Olze's third molar eruption stages, and second and third molar maturity indices measurement in 593 orthopantomograms of Croatian children and adolescents aged 11.00–20.99 years old. The left mandibular second and third molar were assessed. Logistic regression analysis was conducted to test the significance of predictive variables. Logistic Receiver operating characteristic (ROC) curves were performed to evaluate the classification ability of variables for estimating 14- and 16-year-old thresholds. The areas under the ROC curve (AUC), accuracy (Acc), sensitivity (Se), specificity (Sp), Positive Likelihood Ratio (LR +), Negative Likelihood Ratio (LR-), and Bayes post-test probability (Bayes PTP) were calculated to evaluate classification performance. Results suggest that the combination of I2M&I3M is the best classifier for the 14-year-old threshold (AUC = 0.879); for males alone, I2M is an even better classifier (AUC = 0.881). The highest Acc 80.1% (95%CI, 75.9%-83.9%), Bayes PTP 86.5% (95%CI, 82.8%-89.7%) and Sp 88.9% (95%CI, 83.0%-93.3%) were by I3M < 0.81 & I2M < 0.03 in total samples; the highest Acc 86.1% (80.6%- 90.6%), Bayes PTP 87.2% (95%CI, 81.7%- 91.4%) and Sp 87.8% (95%CI, 78.2%- 94.3%) were by I2M < 0.01 in males, Acc of Haavikko Ac and Demirjian H stage in second molar is very close with slightly lower Bayes PTP and Sp. I3M is a good classifier for 16-year-old threshold (AUC = 0.889). The cut-off value I3M < 0.34 can be used to classify the 16-year-old threshold with Acc of 80.6% (95%CI, 77.2%-83.7%), Sp of 83.4% (95%CI, 79.0%-87.3%), and 81.7% (95%CI, 78.4%-84.8%) Bayes PTP. In conclusion, to classify the 14-year-old threshold, a pair of cut-off values I3M < 0.81 & I2M < 0.03 can be used in Croatian females; I2M < 0.01, Demirjian H stage, Haavikko Ac stage in second molar, and the pair I3M < 0.81 & I2M < 0.03 can all be used in Croatian males. I3M < 0.34 can classify the 16-year-old threshold in Croatian populations. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the fracture behavior of human molars with extensive MOD restorations using short‐fiber‐reinforced resin composite of varying viscosities. Materials and Methods: Human molars were randomly divided into seven groups (n = 12): intact teeth (control); restoration using conventional high‐viscosity resin composite without (Filtek Z350XT, 3M) or with fibers (everX Posterior, GC); conventional low‐viscosity resin composite without (Filtek Supreme Flowable, 3M) or with fibers (everX Flow Dentin Shade, GC); bulk‐fill low‐viscosity resin composite (Filtek Bulk Fill Flow, 3M) or with fibers (everX Flow Bulk Shade, GC). Restorations were performed on extensive MOD preparations, following the manufacturers' recommendations for each material. Specimens underwent fracture strength testing (N) and fracture pattern (%) categorized as repairable, possibly repairable, or non‐repairable. Results were analyzed using a generalized linear model (N) and Fisher's exact test (%), with α = 0.05. Results: Restorations performed with high‐viscosity materials showed fracture strength values similar to the control and higher than those of restorations using low‐viscosity resin composites (p < 0.0001), except for the bulk‐fill low‐viscosity resin composite with fibers (p > 0.05). Teeth restored using low‐viscosity resin composite with fibers showed a higher % of repairable and possibly repairable fractures than the control (p = 0.0091). Conclusions: The viscosity of materials mediated the fracture strength, with restorations using high‐viscosity resin composites promoting values similar to the intact tooth; however, the presence of fibers influenced the fracture pattern. Clinical Significance: Teeth with MOD cavities restored with high‐viscosity resin composites showed similar fracture strength to intact teeth. Fiber‐reinforced low‐viscosity resin composite for the base of restoration resulted in a more repairable/possibly repairable fracture pattern. [ABSTRACT FROM AUTHOR]

Background: Long-term durability of a restoration relies on the marginal integrity and its ability to withstand the occlusal forces. Fiber-reinforced composites (FRCs) exhibited superior properties in terms of fracture toughness, flexural strength, and wear resistance. Aim: The aim of this study was to assess and compare marginal adaptation and microtensile bond strength (µTBS) of posterior FRCs comparing with a condensable composite. Materials and Methods: Standardized mesio- and disto-occlusal cavities were prepared on 60 maxillary molars with 3.5 mm pulpal floor depth, 3 mm buccolingual width, and 1.5 mm axial depth. The mesial cavities were restored with everX Posterior and Build-It FRCs, while distal cavities of all teeth were restored with Alert composite and were thermomechanically aged. Half of the specimens from each group (n = 15) were evaluated for marginal adaptation under scanning electron microscope (SEM), and the other half were sectioned for μTBS testing with Instron testing machine. Bond failure mode was examined under SEM. Results: Marginal microgaps were significantly high for the Alert group than FRC groups. Gingival surface showed more gaps. Mean µTBS values were significantly high for FRCs. Cohesive failures are more among FRCs, and adhesive failures are more in condensable composite. Conclusion: The short FRCs showed superior marginal adaptation and better bond strength than condensable composite. [ABSTRACT FROM AUTHOR]

Background: Because of controversial results from clinical studies comparing different dental local anesthesia methods in children, the primary objective of this randomized, split‐mouth, crossover, controlled trial was to compare pain intensity during local anaesthesia (LA) performed with a computer‐controlled LA delivery system (C‐CLADS) versus a conventional syringe (CONV). Secondary objectives included comparisons during dental treatment. Methods: Participants (4–8 years) with tooth pair requiring similar treatment were recruited from five French hospitals. The right primary molar, which was treated at the first visit, was randomly allocated to one of the anaesthesia groups (either intraosseous with C‐CLADS or infiltration with CONV), whereas the contralateral molar (treated at the second visit) was assigned to the other group. Pain intensity and behaviour outcomes, assessed with the Faces Pain and Venham revised scales, respectively, were compared between groups using Proc mixed. Stratified analyses were performed on dentition and location. Results: Among 107 participants, the analysis revealed reduced pain perception during LA in the C‐CLADS group compared with the CONV group (−0.72, 95% CI: −1.43, −0.006), but not during dental treatment. Stratified analyses showed that this effect was observed only in primary dentition (p =.006) and mandibular molars (p =.005). Behavioural issues were fewer in the C‐CLADS group than in the CONV group (p =.05) only during injection. Conclusion: C‐CLADS emerged as the preferable system in primary dentition. [ABSTRACT FROM AUTHOR]

Background: Children with dental caries are treated with stainless steel metal crowns (SSC), but the aesthetics and precision still need to be improved. Currently, both 3D‐printed resin crowns (PRC) and computer‐aided design/computer‐aided manufacture (CAD/CAM) resin crowns (CRC) meet the clinical requirements for crown applications in terms of strength, production time, cost, and aesthetics. Aim: This study replaced SSC with customized resin crowns by 3D printing and CAD/CAM. Design: In this study, PRC, CRC, and SSC were used for incisor and molar restorations, and 60 crowns were made with 10 for each group. The fabrication efficiency, surface characteristics, marginal fit, and stability of the two different crowns were evaluated. Results: PRC and CRC show superior color and surface characteristics, though production times are longer (5.3–12.4 times and 3.3–9.1 times, respectively) than for SSC (p <.05). They, however, can be completed within 80 min. Edge gaps for PRC and CRC are significantly lower (13.0–19.2 times and 13.0–13.7 times) than for SSC (p <.05). All materials exhibit good stability. Conclusion: The 3D‐PRCs and CAD/CAM resin crowns may replace SSCs as a potential choice for clinical child caries. [ABSTRACT FROM AUTHOR]

Background: Paediatric‐preformed zirconia crowns have been associated with several issues, primarily their inability to be crimped and the need for extensive tooth preparation. Additionally, the capacity to adjust the size, shape, and fit of these crowns is very limited. Aim: To evaluate and compare the fracture strength of four different types of dental crowns intended for paediatric patients. Design: The fracture resistance of four types of paediatric crowns was evaluated using the universal testing machine; freshly extracted primary molars received one of the following: preformed zirconia crowns, custom‐made computer‐aided design and computer‐aided manufacturing (CAD–CAM) zirconia crowns, custom‐made CAD–CAM ceramic crowns, and custom‐made CAD–CAM hybrid composite crowns. Data were statistically compared using the Kruskal–Wallis test followed by the Bonferroni test, and the level of significance was set at 5%. Results: Results showed that there was a statistically significant difference among the four groups (p <.001). The highest value of fracture force was observed for the milled zirconia crown and the lowest for the prefabricated zirconia. Conclusion: The implementation of the CAD–CAM digital crown fabrication technique has the potential to address issues associated with preformed crowns in paediatric patients, particularly in terms of fracture resistance. [ABSTRACT FROM AUTHOR]

Aim: The aim of the presented case report was to report a rare complication of Inferior Alveolar Nerve Block (IANB) in a 5‐year‐and‐4‐month‐old child and to discuss the possible complications. Materials and Methods: Five years and four months old Egyptian male child presented in paediatric dentistry practice complaining of pain in the lower right primary molars that kept him awake all night. Examination revealed decayed lower right primary first and second molars and the treatment plan was designed to include a pulpectomy procedure for tooth 85 and a pulpotomy procedure for tooth 84. Administration of 1 mL of arctician 4% with 1:100,000 epinephrine anaesthetic solution using the inferior alveolar nerve block technique was done uneventfully. Then, the dental procedure was done as usual. The next morning, the child presented to the dental practice with a non‐painful change in colour in the lower part of the child's right cheek, with small scanty blisters. Results: The possible causes of such a complication and the proper management are discussed in this article with a confirmation of the superficial skin necrosis as the most possible cause. Conclusion: Although proper awareness of the anatomical structures of the orofacial region along with meticulous administration technique of local anaesthesia is mandatory for the everyday dental practice, the dentist may face possible, sometimes rare complications of local anaesthesia and he should be able to manage them probably. [ABSTRACT FROM AUTHOR]

Objective: Given the significant role of retention in the long‐term success of implant‐supported prostheses, this study aimed to compare the retentive strength of three‐unit implant‐supported frameworks manufactured using the conventional, subtractive milling, and 3D printing methods. Materials and Methods: In this in vitro study, two fixture analogs were placed in the mandibular right first premolar and first molar region of a Dentiform model, and two prefabricated abutments were secured in the fixture analogs. A total of 27 three‐unit frameworks were fabricated utilizing wax patterns prepared through conventional, milling, and 3D printing techniques (n = 9 per group). The frameworks were cemented with zinc oxide eugenol and subjected to thermocycling. The retentive strength of each specimen was evaluated through a pull‐out test conducted with a universal testing machine. The data were analysed using one‐way ANOVA and Tukey's post hoc test (p < 0.05). Results: The three groups were found to be significantly different (p = 0.01). While the 3D printing and milling groups were not significantly different (p = 0.99), they yielded significantly higher retentive strength compare to the conventional group (p = 0.02 for 3D printing and p = 0.03 for milling group). Conclusion: The utilization of 3D printing and milling technique for wax pattern preparation significantly increased the retention of the implant‐supported framework, with no statistically significant difference between the two methods. [ABSTRACT FROM AUTHOR]

Background: Continuously growing teeth are an important innovation in mammalian evolution, yet genetic regulation of continuous growth by stem cells remains incompletely understood. Dental stem cells responsible for tooth crown growth are lost at the onset of tooth root formation. Genetic signaling that initiates this loss is difficult to study with the ever-growing incisor and rooted molars of mice, the most common mammalian dental model species, because signals for root formation overlap with signals that pattern tooth size and shape (i.e., cusp patterns). Bank and prairie voles (Cricetidae, Rodentia, Glires) have evolved rooted and unrooted molars while retaining similar size and shape, providing alternative models for studying roots. Results: We assembled a de novo genome of Myodes glareolus, a vole with high-crowned, rooted molars, and performed genomic and transcriptomic analyses in a broad phylogenetic context of Glires (rodents and lagomorphs) to assess differential selection and evolution in tooth forming genes. Bulk transcriptomics comparisons of embryonic molar development between bank voles and mice demonstrated overall conservation of gene expression levels, with species-specific differences corresponding to the accelerated and more extensive patterning of the vole molar. We leverage convergent evolution of unrooted molars across the clade to examine changes that may underlie the evolution of unrooted molars. We identified 15 dental genes with changing synteny relationships and six dental genes undergoing positive selection across Glires, two of which were undergoing positive selection in species with unrooted molars, Dspp and Aqp1. Decreased expression of both genes in prairie voles with unrooted molars compared to bank voles supports the presence of positive selection and may underlie differences in root formation. Conclusions: Our results support ongoing evolution of dental genes across Glires and identify candidate genes for mechanistic studies of root formation. Comparative research using the bank vole as a model species can reveal the complex evolutionary background of convergent evolution for ever-growing molars. [ABSTRACT FROM AUTHOR]

The palatal anchorage device (PAD) is commonly used in fixed appliance for anchorage, but the biomechanics of PAD in patients treated with clear aligners(CAs)remains poorly understood, especially in its elastic mode and force magnitude. This study aimed to assess the biomechanical effects of using PAD for retraction during clear aligner treatment (CAT) with the extraction of two maxillary first premolars. Four finite element models were created: (1) Incisors retraction (IR) with active contraction of the clear aligner only; (2) IR with PAD using different forces (50,75,100 g) or not; (3) PAD without IR (forces of 50,75,100 g), and (4) Different elastic directions (D1, D2, D3) from aligner to PAD without IR. IR caused lingual tipping and extrusion of the central incisors, as well as mesial and buccal tipping of the first molar. PAD during IR provided strong anchorage for the first molar, with elastics slightly increasing the lingual tipping and extrusion of the central incisors. Elastics applied to the U-shaped arch led to central incisor intrusion and reduced lingual retraction. The highest stress was observed on the mesial attachment of the canine. PAD effectively reinforced posterior anchorage in CAT, while anterior positioning facilitated anterior teeth intrusion. The biomechanical importance of the canine's mesial attachments in maxillary teeth treatment planning was highlighted. [ABSTRACT FROM AUTHOR]

Aim Methodology Results Conclusions To assess Spanish dentists' management preferences for deep caries removal and exposed pulps in permanent teeth.A web‐based open and anonymous survey was distributed by social media and a specific website for this project amongst dentists practicing in Spain. The questionnaire comprised 40 questions, divided into five sections: (1) demographic data and professional activity; (2) carious tissue removal; (3) decision‐making regarding pulp exposure; (4) direct pulp capping and (5) pulpotomy procedures in permanent teeth. Results were descriptively analysed. Logistic regression (95% CI) analyses and X2 tests were carried out.A total of 538 responses were received. Half the respondents (53.7%) preferred to perform complete caries excavation for shallow and moderate carious dentin lesions, and selective excavation to firm dentin for deep lesions (57.8%). Selective removal to soft dentin and stepwise removal were much less indicated (15.4% and 10.9%, respectively). Exposed pulps in asymptomatic teeth were treated by direct pulp capping (over 80%), decreasing in the presence of reversible pulpitis symptoms (57.1%). If irreversible pulpitis was diagnosed, a pulpectomy would be performed by 53.5% and 89.9% of the respondents in, respectively, immature and mature teeth. Pulpotomy was performed routinely only by 26.4% of the clinicians. Patients' attitudes and priorities were the most relevant criteria when performing direct pulp capping and pulpotomy, together with the history of pain and the presence of bleeding. Regarding the clinical procedure, dry cotton was preferred to obtain haemostasis and Biodentine was the material of election.Caries removal preferences and management of pulp exposure by dentists practicing in Spain deviated from vital pulp treatment guidelines, mainly regarding indications and case selection. Pulp exposure was managed by direct pulp capping in asymptomatic cases, whilst immature permanent molars favoured the indication of pulpotomy when pulpitis was diagnosed. Most clinicians used hydraulic calcium silicate cement, specifically Biodentine, to perform vital pulp treatments. Postgraduate formation and continuing education in caries lesions management and vital pulp treatments were consistently related to more conservative and updated decisions. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective Méthodology Résults Conclusion Prosthetic restorations require functional occlusal planes to ensure therapeutic success. The purpose of the present study was to develop a new Broadrick flag support for a semi‐adjustable articulator and to investigate the effectiveness of occlusal planes drawn using the Broadrick flag method by inexperienced practitioners in complex situations such as skeletal class II relationships associated with edentulous areas.The Broadrick flag support was designed and manufactured by the additive technique and was adapted to the Quick Master articulator. The QR code of the manufacturing file of the Broadrick flag support is accessible to any practitioner. Thirty‐seven third‐year students (inexperienced practitioners) were randomised into two groups for drawing occlusal planes on two models either with or without the Broadrick flag method. A prosthodontic professor (experienced practitioner) drew occlusal planes on the models to serve as references. Each model was analysed using a standardised method to measure the distances between the occlusal planes drawn by experienced and inexperienced practitioners.Only the distance measured for the right second molar of the first model with the Broadrick flag method was significantly shorter than those measured without using this method (p < 0.05, Wilcoxon test). Visual observations showed that only the second molar drawings of the inexperienced practitioners were above the drawings of the experienced practitioner.The Broadrick flag method helped inexperienced practitioners to draw occlusal planes of models in complex skeletal class II relationships associated with edentulous areas with natural teeth located both anterior and posterior to them. [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to assess the prevalence and configuration of C‐shaped canal morphology in maxillary molars in an Iranian population residing in Kermanshah Province of Iran using cone‐beam computed tomography (CBCT). Materials and Methods: This cross‐sectional study was conducted on 2290 CBCT scans of 804 maxillary first molars, 1049 maxillary second molars, and 437 maxillary third molars. The Maxillary Upper‐C Classification System was used for the detection of C‐shaped canal morphology, and the classification by Jo et al. was used for assessment of the configuration of C‐shaped canals. Data were analyzed by the Chi‐square test (α = 0.05). Results: The prevalence of C‐shaped canals in the maxillary first, second, and third molars was 1%, 7%, and 9%, respectively. Type III other types (B‐P) was the most frequent configuration followed by type I subtype C (MB‐DB). The prevalence of C‐shaped canal morphology was not significantly different among different age groups (p > 0.05); however, its prevalence in females was almost twice that in males (p < 0.05). The prevalence of C‐shaped canals was not significantly different in the right and left quadrants (p = 0.099). The most frequent configuration was type I subtype B (DB‐P) in males, and type III other types (B‐P) in females (p = 0.364). Conclusion: The prevalence of C‐shaped canals in maxillary first, second, and third molars was 1%, 7%, and 9%, respectively. C‐shaped canals were more common in females, and type III other types (B‐P) was the most frequent configuration in our study population. [ABSTRACT FROM AUTHOR]

Objectives: This study evaluated maxillary growth and dental arch relationships at 5 and 10 years of age in patients with unilateral cleft lip and palate (UCLP) who underwent early cleft lip and palate surgery. Methods: 28 patients with UCLP who underwent cleft lip surgery in neonatal age and cleft palate surgery at average age of 7 months without orthodontic treatment (intervention group) were measured for intercanine and intermolar distances and for dental arch length. These measurements were compared with those of 30 healthy participants in a control group. Dental arch relationships in the intervention group were evaluated by 5-YO index at 5 years and the GOSLON Yardstick score at 10 years of patients' age. Results: Patients in the intervention group had significantly shorter mean intercanine distance and arch length than control patients at both 5 and 10 years of age (p<.001 for all). There were no significant differences in intermolar distance at both 5 (p =.945) and 10 years (p =.105) of patients' age. The average 5YO index increased from 2.46 to an average GOSLON 10-year score of 2.89 in intervention group. Conclusion: Intercanine distance and dental arch length of patients with UCLP are significantly reduced at 5 and 10 years after early cleft lip and palate surgeries compared to the healthy population. Dental arch relationships at 5 and 10 years of patients with UCLP show comparable outcomes to those reported by other cleft centers. Clinical significance: This study evaluates maxillary growth in UCLP patients 5 and 10 years of age who underwent early primary lip and palate surgery. [ABSTRACT FROM AUTHOR]

Heleocola piceanus, a new, relatively large metatherian from Upper Cretaceous ('Edmontonian') strata of the Williams Fork Formation in northwestern Colorado is described, based on a recently discovered jaw fragment (MWC 9744), in addition to three isolated teeth initially referred by other studies to Aquiladelphis incus and Glasbius piceanus. Although sharing several morphologic characters with the Lancian genus Glasbius, H. piceanus lower molars are considerably larger than those of Glasbius and differ from the latter in lacking a buccal cingulid, possessing carnassiform notches on the cristid obliqua and entocristid, and bearing an entoconulid on m3. To examine the relationship of Heleocola piceanus to other metatherians, H. piceanus was scored into a previously existing taxon-character matrix. Our phylogenetic analysis recovers H. piceanus as the sister taxon to Glasbius, which is consistent with our morphologic comparisons. H. piceanus represents the oldest member of the Glasbiidae. A regression equation for predicting body mass of dentally conservative metatherians that utilizes the length of m1 estimates the mass of H. piceanus at 855–1170 g, which is comparable in mass to today's muskrat (Ondatra zibethicus) and large relative to other Late Cretaceous pediomyoids. Based upon its molar morphology, specifically the low inflated cusps, low height differential between the trigonid and talonid, and near-bunodont morphology, H. piceanus is interpreted as an omnivore with a plant-dominated diet. [ABSTRACT FROM AUTHOR]

Background: Regenerative endodontic procedures (REPs) offer the promise of restoring vitality and function to a previously necrotic and infected tooth. However, the nature of regenerated tissues following REPs remains unpredictable and uncontrollable. Decellularized extracellular matrix scaffolds have gained recent attention as scaffolds for regenerative endodontics. Objectives: Preparation and characterization of a bovine dental pulp-derived extracellular matrix (P-ECM) hydrogel for regenerative endodontic applications. Biocompatibility and regenerative capacity of the prepared scaffold were evaluated in vivo in a canine animal model. Methods: Fifteen freshly extracted bovine molar teeth were used to prepare P-ECM hydrogels following approval of the institutional review board of the faculty of dentistry, Alexandria University. Decellularization and lyophilization of the extracted pulp tissues, DNA quantification and histological examination of decellularized P-ECM were done. P-ECM hydrogel was prepared by digestion of decellularized pulps. Prepared scaffolds were evaluated for protein content and release as well as release of VEGF, bFGF, TGF-β1 and BMP2 using ELISA. Rabbit dental pulp stem cells' (rDPSCs) viability in response to P-ECM hydrogels was performed. Finally, proof-of-concept of the regenerative capacity of P-ECM scaffolds was assessed in an infected mature canine tooth model following REPs versus blood clot (BC), injectable platelet-rich fibrin (i-PRF) or hyaluronic acid (HA). Statistical analysis was done using independent t test, the Friedman test and chi-square tests (p value ≤ 0.05). Results: DNA was found to be below the cut-off point (50 ng/mg tissue). Histological evaluation revealed absence of nuclei, retention of glycosaminoglycans (GAGs) and collagen content, respectively. P-ECM hydrogel had a total protein content of (493.12 µg/µl) and protein release was detected up to 14 days. P-ECM hydrogel also retained VEGF, bFGF, TGF-β1 and BMP2. P-ECM hydrogel maintained the viability of rDPSCs as compared to cells cultured under control conditions. P-ECM hydrogel triggered more organized tissues compared to BC, i-PRF and HA when used in REPs for necrotic mature teeth in dogs. Periapical inflammation was significantly less in HA and P-ECM groups compared to blood-derived scaffolds. Conclusion: Bovine dental pulp-derived extracellular matrix (P-ECM) hydrogel scaffold retained its bioactive properties and demonstrated a promising potential in regenerative endodontic procedures compared to conventional blood-derived scaffolds. [ABSTRACT FROM AUTHOR]

Aim: The purpose of this study was to evaluate the performance of polyethylene fiber reinforced resin composite fillings compared to bulk fill resin composite fillings in endodontically treated teeth over a two-year monitoring period. Method: A total of 240 individuals with endodontically treated lower molars and a moderate amount of tooth structure were divided into two equal groups of 120 each. One group received polyethylene fiber reinforced bulk fill resin composite restorations while the other group received only bulk fill resin composite restorations, both applied as per manufacturer guidelines. Two proficient experienced blinded assessors assessed the restorations using modified USPHS criteria at baseline, 6, 12, and 24 months. Statistical analysis used: Data analysis involved the utilization of Mann-Whitney U, Friedman's test, and Nemenyi post hoc test, with age data being displayed as mean and standard deviation. The significance level was established as p < 0.05, and R software was utilized for statistical analysis. Results: There were no notable distinctions in any parameters or scores between the intervention and comparator groups at various time points. Alpha scores were present for retention, gross fracture, and secondary caries at all follow up intervals. Conclusion: Both direct resin composite restorations reinforced with polyethylene fibers and direct bulk fill resin composite restorations placed in endodontically treated molars with moderate remaining tooth structure demonstrated satisfactory clinical outcomes during a 24-month follow-up period. Clinical relevance: Bulk fill resin composites directly placed in endodontically treated molars with moderate remaining tooth structure showed promise as a treatment option over a two-year period. Clinical trial registration: (06-01-2022) on https://ClinicalTrials.gov with the ID (NCT05180903). [ABSTRACT FROM AUTHOR]

Background: The use of biological scaffolds in regenerative endodontics has gained much attention in recent years. The search for a new biomimetic scaffold that contains tissue-specific cell homing factors could lead to more predictable tissue regeneration. The aim of this study was to prepare and characterize decellularized bovine dental pulp-derived extracellular matrix (P-ECM) hydrogels for regenerative endodontic applications. Methods: Freshly extracted bovine molar teeth were collected. Bovine dental pulp tissues were harvested, and stored at -40º C. For decellularization, a 5-day protocol was implemented incorporating trypsin/EDTA, deionized water and DNase treatment. Decellularization was evaluated by DNA quantification and histological examination to assess collagen and glycosaminoglycans (GAGs) content. This was followed by the preparation of P-ECM hydrogel alone or combined with hyaluronic acid gel (P-ECM + HA). The fabricated scaffolds were then characterized using protein quantification, hydrogel topology and porosity, biodegradability, and growth factor content using Enzyme-linked immunosorbent assay (ELISA): transforming growth factor beta-1(TGF-β1), basic fibroblast growth factor (bFGF), bone morphogenetic protein 2 (BMP-2) and vascular endothelial growth factor (VEGF). Results: Decellularization was histologically confirmed, and DNA content was below (50 ng/mg tissue). P-ECM hydrogel was prepared with a final ECM concentration of 3.00 mg/ml while P-ECM + HA hydrogel was prepared with a final ECM concentration of 1.5 mg/ml. Total protein content in P-ECM hydrogel was found to be (439.0 ± 123.4 µg/µl). P-ECM + HA showed sustained protein release while the P-ECM group showed gradual decreasing release. Degradation was higher in P-ECM + HA which had a significantly larger fiber diameter, while P-ECM had a larger pore area percentage. ELISA confirmed the retention and release of growth factors where P-ECM hydrogel had higher BMP-2 release, while P-ECM + HA had higher release of TGF-β1, bFGF, and VEGF. Conclusions: Both P-ECM and P-ECM + HA retained their bioactive properties demonstrating a potential role as functionalized scaffolds for regenerative endodontic procedures. [ABSTRACT FROM AUTHOR]

Background: Robotic computer-assisted implant surgery (r-CAIS) is a revolutionary innovation in oral implantation; however, the clinical feasibility of r-CAIS for immediate implant placement (IIP) in posterior teeth has not been verified. Thus, this study aimed to evaluate the accuracy of r-CAIS for IIP in posterior tooth regions. Methods: Patients with posterior teeth to be extracted and indicated to undergo r-CAIS were evaluated. The patients had positioning markers installed in the oral cavity and underwent cone-beam computed tomography (CBCT). Subsequently, minimally invasive tooth extractions were performed, and an individualised surgical plan was generated in the robotic software. After marker registration, implantation surgery was performed by the robotic arm under the supervision and assistance of the surgeons. Finally, the deviations between the planned and placed implants were evaluated based on preoperative and postoperative CBCT data. Results: A total of 12 patients were evaluated. No adverse events occurred during the surgery. The mean global coronal, global apical, and angular deviations were 0.46 ± 0.15 mm (95%CI:0.36 to 0.56 mm), 0.46 ± 0.14 mm (95%CI:0.37 to 0.54 mm), and 1.05 ± 0.55° (0.69 to 1.40°), respectively. Conclusions: Under the limited conditions of this study, the r-CAIS exhibited high accuracy in posterior teeth IIP surgery. Further multicentre randomised controlled studies are required to confirm the feasibility of this technology. [ABSTRACT FROM AUTHOR]

Background: Molar–incisor hypomineralization (MIH) is a qualitative enamel defect that is highly prevalent in children. It has been reported that patients with MIH have higher caries occurrence with an increased need and frequency of dental treatment compared to patients without MIH. The objective of this study was to analyze the association between MIH and a series of factors related to maternal health status during pregnancy and children´s medical history in early childhood. Methods: A retrospective study of cases (patients with MIH) and controls (patients without MIH) was designed between 2023 and 2024. A total of 280 children (cases = 140; controls = 140) aged 6 to 14 years (138 boys and 142 girls) were examined according to the European Academy of Pediatric Dentistry (EAPD) criteria for MIH. A survey was carried out with mothers regarding the potential exposure of their children to etiological factors of MIH. Possible prenatal and postnatal etiological factors were obtained through a personal interview with the patients' mothers. The statistical analysis was carried out with the contrast test and the chi-square test. Results: During pregnancy, folic acid consumption, alcohol intake, systemic viral and/or bacterial infections, and gestational diabetes were statistically significantly related to MIH, as were breastfeeding, asthma, and corticosteroid consumption during childhood. Conclusions: Although there are different factors that may have statistically significant relationships with MIH, they cannot be predicted. Therefore, longitudinal studies, with a large sample size, are needed to determine the influence of prenatal and postnatal factors on the prevalence and severity of MIH in children. [ABSTRACT FROM AUTHOR]