Does dynamic navigation system preserve more dentine? - A systematic review.

OBJECTIVE: This systematic review aims to comparatively analyse the amount of dentin removal by free hand and static guided endodontics with dynamic navigation system (DNS) in endodontic access cavity preparation. METHODS: The systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines. Based on the structured PICO framework of "Comparative evaluation of dynamic navigation system (I) to freehand (C) and static guided endodontics (C) in endodontic access cavity preparation on the preservation of tooth structure (O) when assessed on permanent human teeth (P)", the keywords were formulated and the articles were retrieved from three databases namely PubMed, Scopus and Embase, based on the keywords from the time of inception of DNS till June 2023. The risk of bias assessment was done using a modified Joanne Briggs Institute checklist, which evaluated domains such as randomisation, sample size, image acquisition using CBCT, angulation, accuracy and time taken. As the data was heterogenous, a quantitative meta-analysis was not performed. RESULTS: Initially, 174 articles were retrieved from the three databases, 30 duplicates were removed, after title check 108 articles were excluded and following abstract check only 10 articles qualified for full text analysis. On reviewing the 10 full text articles, 5 articles were excluded and the remaining 5 articles were subjected to the risk of bias analysis which showed that 2 articles displayed low risk of bias and three articles showed high risk of bias. The RoB analysis revealed that only 2 studies evaluated the preservation of dentin in terms of accuracy, angulation and time taken proving the increased precision with minimal loss of tooth structure using DNS. In both the studies, DNS proved to be superior to free hand technique in terms of precision, accuracy and efficiency in locating the canals during access cavity preparation with maximal preservation of tooth structure. CONCLUSION: With the minimal literature evidences, the present systematic review highlights maximal preservation of dentin using DNS. However, further invitro and invivo studies comparing the free hand, static guided endodontics to DNS must be carried out for its translation into clinical practice. CLINICAL SIGNIFICANCE: Dynamic navigation system provides maximal preservation of dentin during access cavity preparation.

Machine learning assisted 5-part tooth segmentation method for CBCT-based dental age estimation in adults.

BACKGROUND: The utilization of segmentation method using volumetric data in adults dental age estimation (DAE) from cone-beam computed tomography (CBCT) was further expanded by using current 5-Part Tooth Segmentation (SG) method. Additionally, supervised machine learning modelling -namely support vector regression (SVR) with linear and polynomial kernel, and regression tree - was tested and compared with the multiple linear regression model. MATERIAL AND METHODS: CBCT scans from 99 patients aged between 20 to 59.99 was collected. Eighty eligible teeth including maxillary canine, lateral incisor, and central incisor were used in this study. Enamel to dentine volume ratio, pulp to dentine volume ratio, lower tooth volume ratio, and sex was utilized as independent variable to predict chronological age. RESULTS: No multicollinearity was detected in the models. The best performing model comes from maxillary lateral incisor using SVR with polynomial kernel ( = 0.73). The lowest error rate achieved by the model was given also by maxillary lateral incisor, with 4.86 years of mean average error and 6.05 years of root means squared error. However, demands a complex approach to segment the enamel volume in the crown section and a lengthier labour time of 45 minutes per tooth.

Enhancement of mineral density and mechanical properties in root caries treated with silver diammine fluoride and glass ionomer cement, with emphasis on silver ion distribution.

OBJECTIVES: This study aimed to measure the distribution of silver ion (Ag+), mineral recovery, and nanohardness in carious lesions and comprehensively evaluate the degree of dentin restoration. METHODS: Sixty human teeth with root caries were randomly assigned to the control, silver diammine fluoride (SDF) [Safo], and SDF+Glass ionomer cement (GIC) treatment [Safo+Fuji] groups. Micro-computed tomography (micro-CT) was performed at five time points for each sample before/after treatment to evaluate mineral density within and around carious lesions. Three months following treatment, 12 samples were selected for synchrotron radiation X-ray fluorescence analysis to evaluate Ag+ distribution, while 15 samples were selected for nanoindentation. Data were analyzed using Dunnett's T3 test for micro-CT and Wilcoxon rank sum test with Bonferroni correction (p = 0.017) for nanoindentation. The correlation between hardness and mineral change was analyzed using the Spearman rank correlation coefficient. RESULTS: The Safo and Safo+Fuji groups showed significantly higher mineral recovery rates than did the control group (p < 0.001). In the Safo group, Ag+ accumulated in the deeper layers rather than the superficial layer of caries. In the Safo+Fuji group, Ag+ was found evenly distributed throughout caries, with only a few Ag+ detected in the GIC layer. Hardness in the Safo+Fuji group was significantly higher compared with the Safo group at depths in the range of 10-50 µm. CONCLUSION: In the presence of GICs, SDF exhibited high remineralization capacity when diffusing throughout carious lesions over time. Combined treatment with SDF and GIC could strengthen root dentin even in the presence of caries. CLINICAL SIGNIFICANCE: We found that combination treatment with SDF and GIC could increase mineral density in caries and improve the hardness of the tooth structure compared with fluoride-based agents alone. These findings might pave the way for future clinical trials to determine the therapeutic potential of nanotechnology-based restorative materials.

Technical note: Micro-computed tomography calibration using dental tissue for bone mineral research.

Computed tomography (CT) and microcomputed tomography (µCT) require calibration against density phantoms scanned with specimens or during routine internal calibration for assessment of mineral concentration (MC) and density. In clinical studies involving bone, alternative calibration methods using bodily tissues and fluids ("phantomless" calibration) have been suggested. However, such tissues are seldom available in archeological and osteological research. This study investigates the potential of dental tissue as internal reference for calibration of µCT scans, facilitating the analysis of bone MC. We analyzed 70 molars from 24 extant primate species, including eight human teeth, each scanned with density phantoms for calibration. Our findings indicate that sampling specific regions of molars (lateral aspects of the mesial cusps) yields low variation in enamel and dentine MC values, averaging 1.27 g/cm3 (±0.03) for dentine and 2.25 g/cm3 (±0.03) for enamel. No significant differences were observed across molar types or among scanning procedures, including scanner model, resolution, and filters. An ad hoc test on 12 mandibles revealed low variance in MC between the conventional phantom and dental tissue calibration methods; all 36 measurements (low, medium, and high MC for each mandible) were within 0.05 g/cm3 of each other -81% were within 0.03 g/cm3 and 94% within 0.04 g/cm3. Based on these results, we propose a new "phantomless" calibration technique using these mean enamel and dentine MC values. The presented phantomless calibration method could aid in the assessment of bone pathology and enhance the scope of studies investigating bone structure and physical property variations in archeological, osteological, and laboratory-based research.

Comparative evaluation and patient satisfaction with an electrical impedance-based device versus digital radiography in the estimation of remaining dentin thickness in carious posterior permanent teeth: (Diagnostic accuracy study).

BACKGROUND: Accurate assessment of remaining dentin thickness (RDT) is paramount for restorative decisions and treatment planning of vital teeth to avoid any pulpal injury. This diagnostic accuracy study compared the validity and patient satisfaction of an electrical impedance based device Prepometer™ (Hager & Werken, Duisburg, Germany) versus intraoral digital radiography for the estimation of remaining dentin thickness in carious posterior permanent teeth. METHODS: Seventy patients aged 12-25 years with carious occlusal or proximal permanent vital posterior teeth were recruited. Tooth preparation was performed to receive an adhesive restoration. Pre- and post-excavation RDT were measured radiographically by two calibrated raters using the paralleling periapical technique. Prepometer™ measurements were performed by the operator. Patients rated their satisfaction level with each tool on a 4-point Likert scale and 100 mm visual analog scale (VAS). Inter and intragroup comparisons were analyzed using signed rank test, while agreement between devices and observations was tested using weight kappa (WK) coefficient. RESULTS: the intergroup comparisons showed that, before and after excavation, there was a significant difference between measurements made by both techniques (p < 0.001). After excavation, there was a weak agreement between measurements (WK = 0.2, p < 0.001), whereas before excavation, the agreement was not statistically significant (p = 0.407). Patients were significantly more satisfied with Prepometer™ based on scales and VAS (p < 0.001). CONCLUSION: Prepometer™ could be a viable clinical tool for determining RDT with high patient satisfaction, while radiographs tended to overestimate RDT in relation to the Prepometer™.

Progression of proximal caries in primary molars using the radiographic ICDAS: a retrospective cohort study.

PURPOSE: To evaluate the proximal caries progression in primary molars using the radiographic International Caries Detection and Assessment System (ICDAS). METHODS: A study was conducted on 196 children aged 3-9 years old who underwent the clinical examination and bitewing radiography during baseline and 6-month (and over) follow-up visits. The primary molars bitewing radiographs with initial enamel caries (RA1 and RA2) or outer dentine caries (RA3) of proximal surfaces were included. Caries advancement was scored using ICDAS criteria and statistical analyses with the chi-square test. Median survival time was evaluated using Kaplan-Meier survival curves and log-rank tests. RESULTS: A total of 439 surfaces of primary molars were included in this study and an averaged follow-up period of enamel and dentine caries group were 18.3 ± 9.6 months and 16.5 ± 9.5 months respectively. The progression of proximal enamel lesions significantly differed between primary maxillary and mandibular molars (p = 0.002) and among each patient's primary mandibular second molar and the others (p = 0.002). On the contrary, the outer dentine caries of each group of primary molars was not different. The median survival time of the initial enamel proximal caries (23.30 months) was non-significantly longer than that of the dentine (20.80 months). CONCLUSIONS: Progressions of the initial enamel proximal caries were significantly different among primary molars at the average 18.3-month follow-up. The median survival period of the enamel proximal caries was more extended than that of dentine but without statistical difference. These results provide essential information for dentists regarding an appropriate appointment for bitewing examinations.

Natural canal deviation and dentin thickness of mesial root canals of mandibular first molars assessed by microcomputed tomography.

The aim of this study was to assess the centralization and dentin thickness of mesial root canals of the first mandibular molars by microcomputed tomography (micro-CT). Material and methods: Ninety-nine mandibular molars of Vertucci's type IV canals were scanned by micro-CT. The mesiodistal deviation and centroid were assessed, in both mesiobuccal (MB) and mesiolingual (ML) canals, for the apical 4mm and the full canal length. Results: The dentin thickness was similar for both MB and ML canals. The narrowest thickness was in the distal wall of an MB canal (0.07mm), while the widest was found in the mesial wall of an MB canal (2.46mm). In centroid analysis, both the MB and ML canals exhibited deviations when compared to the root centroid, along the full canal length and the apical 4mm. For the MB canal, the mean deviation was 0.83mm (0.02 mm-2.30 mm) for the full canal and 0.18mm (0.01 mm-1.01 mm) for apical 4mm. Similarly, for the ML canal, the mean deviation measured 0.83 mm (0.05mm-3.99mm) for the full canal and 0.21 mm (0.01mm-1.01mm) for the apical 4 mm. Overall, deviations were observed towards the mesial of the roots, with 69% for MB and 57% for ML canals for the full canal, and 51% for MB canals within the 4 mm. The exception was the ML canal, which exhibited a higher deviation towards distal in the apical 4mm, accounting for 52% of cases. The dentin thickness was consistent between the mesial canals of mandibular molars. However, there is no centrality of mesial canals in their roots, with frequent deviation to mesial.

Pericervical Dentin Metrics in Mandibular First Molars Determined with Digital Periapical Radiography and Cone-beam Computed Tomography.

INTRODUCTION: Pericervical root dentin is decisive for the long-term mechanical integrity of root-filled teeth. Current treatment protocol does not include a customized step to determine the pretreatment residual pericervical root dentin. OBJECTIVE: To determine and compare the residual root dentin and canal width using digital periapical radiography (DPR) and cone-beam computed tomography (CBCT) at the apical limit of the pericervical area (PCA) in mandibular first molars. METHODS: DPR and CBCT images of 60 patients with age between 22 and 76 years were used to determine (a) the mesiodistal widths of the root canal (pericervical dimensions [PCL]-C) and the root (PCL-R) of mandibular first molars at the apical limit of the PCA and (b) the intracanal distance from the apical limit of the PCA to the radiographic apex (intracanal distance [ICD]). The correlation between the PCL and ICD measurements obtained from DPR and CBCT were evaluated. RESULTS: Values between 0.10-0.80 mm and 0.00-1.10 mm were obtained for PCL-C using DPR and CBCT respectively (95% CI). The PCL values between 0.90-2.30 mm and 0.00-2.30 mm were obtained from DPR and CBCT respectively (95% CI). The ICD ranged between 4.6-12.3 mm in DPR and 4.40-12.0 mm in CBCT (95% CI). The comparative analysis showed differences from -0.9 to 0.5 mms for PCL and -2.00 to 1.5 mms for ICD between DPR and CBCT techniques respectively. CONCLUSION: The PCL and ICD determined from DPR and CBCT provided the pericervical dentin metrics that could be utilized clinically as a guideline for decision-making in endodontic treatment.

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.

Mechanism of dentin hardness measurements using a dentin hardness measuring device with a light-emitting diode.

Significance: Managing caries is imperative in a rapidly aging society. Current diagnoses use qualitative indices. However, a quantitative evaluation of hardness in a clinical setting may lead to more accurate diagnoses. Previously, hardness meter using indenter with light for tooth monitoring (HAMILTOM) was developed to quantitatively measure tooth hardness. Herein, the physical interpretation of dentin hardness measured using HAMILTOM and the dentin hardness measurement mechanism are discussed. Aim: This study evaluates the mechanism of dentin hardness measurements using HAMILTOM physically and compare the invasiveness to dentin by HAMILTOM with those using a dental probe for palpation. Approach: Eleven bovine dentin samples were used to create caries models. HAMILTOM measured the dark areas, and its indentations were observed using scanning electron microscopy. Also, its invasiveness was evaluated by comparing the results with those from dental probe palpation. Results: The indentation areas were smaller than the dark areas in HAMILTOM, which may be due to exuded water from the dentin sample and the elastic recovery of dentin sample. Additionally, the dental probe indentation was deeper than the HAMILTOM indentations. Conclusions: The results demonstrate that the indentation areas were smaller than the dark areas measured by HAMILTOM, which might contain the influence of exuded water and the deformation of dentin sample. Also, HAMILTOM is less invasive than dental probe palpation. In the future, HAMILTOM may become a standard hardness measuring method to diagnose root caries.

The Impact of Coronal Flaring Files on Pericervical Dentin Thickness in Mandibular Molars.

INTRODUCTION: This study aimed to assess the influence of different coronal flaring files on dentin removal in mandibular teeth using cone-beam computed tomographic (CBCT) images. METHODS: CBCT images of 48 mandibular molar teeth were acquired and randomly divided into 2 main groups, with each main group further divided into 3 subgroups. In the first main group, root canal preparation was performed using TruNatomy (Dentsply Sirona, Ballaigues, Switzerland), ProTaper Gold (Dentsply Sirona), and One Curve (Micro-Mega, Besancon, France) files without the use of coronal flaring files. In the second main group, root canal preparation was performed using the same files with the use of coronal flaring files. After the completion of root canal preparation, a second set of CBCT images was obtained. Subsequently, the dentin removal and remaining critical dentin were assessed by measuring at 4 distinct points below the furcation level. Data were compared between groups using the Mann-Whitney U and Kruskal-Wallis tests with alpha set at 5%. RESULTS: The ProTaper Gold files demonstrated higher dentin removal compared with the TruNatomy files. In the no-flaring groups, the One Curve files exhibited greater dentin removal than the TruNatomy files at specific levels. The use of coronal flaring files generally did not significantly impact dentin removal, except for certain cases in the TruNatomy and ProTaper Gold groups. CONCLUSIONS: The TruNatomy instrument group was more effective in preserving pericervical dentin compared with the other instrument groups. Coronal flaring files can be confidently used to preserve critical dentin during root canal treatment.

Effect of Three Chemical Agents on Stain Removal from Dentin Caries Lesions Treated with Silver Diamine Fluoride.

INTRODUCTION: This in vitro study aimed to evaluate the effect of three different chemical agents on stain removal and mineral uptake of artificial dentin caries (ADC) lesions treated with silver diamine fluoride (SDF). METHODS: Baseline L*a*b* values were determined in polished human permanent dentin blocks, and ADC lesions were induced with an acid gel for 1 week. Samples were assigned to four groups; in three groups, half of each sample received SDF (30% SDF for 3 min), while the other half received SDF followed by a bleaching treatment protocol (garlic extract, bentonite, or 35% hydrogen peroxide). The fourth group had one SDF-treated half and one half without SDF. Color changes (ΔE) were measured by spectrometry, and transversal microradiography was used to quantify integrated mineral loss (ΔZ) 24 h after treatment (SDF or SDF + bleaching). A two-way mixed ANOVA was applied to thirty percent. RESULTS: SDF application increased mineral uptake by ADC (p = 0.001). The type of chemical agent evaluated (p < 0.0001), time (p = 0.01), and their interaction (p < 0.0001) bleached the ADC treated with SDF. However, 35% hydrogen peroxide was the only compound with a bleaching effect (p < 0.001), without returning to baseline color. None of the compounds altered the mineral uptake effect of SDF (p = 0.30). CONCLUSION: This in vitro study showed mineral uptake effect in ACD within 24 h after SDF application and the ability of hydrogen peroxide to partially remove (reduction of 24%) the staining caused by SDF without affecting its mineral uptake effect.

The impact of long-term storage conditions on the development of experimental dentinal microcracks.

This study evaluated the impact of long-term storage conditions (medium and time) on the development of experimental dentinal microcracks through micro-computed tomography. Sixty freshly extracted premolars were stored in formalin, water, or dry conditions (n = 20) and scanned after 72 h, 30 days, 6 months and 3 years of extraction. The effect of the storage medium and time on the occurrence of dentinal defects was statistically evaluated. A total of 211 000 images were screened revealing the existence of 11 519 slices with dentinal defects. Dry conditions significantly contributed to the development of new defects in all time points. During the 3-year follow-up period, no new defects were detected in the teeth that were stored in water and, in a single tooth, in the formalin group, after 6 months of storage.

Sensitivity and specificity of the ICDAS II system and bitewing radiographs for detecting occlusal caries using the Spectra™ caries detection system as the reference test in children.

BACKGROUND: Most studies assessing the sensitivity and specificity of caries detection methods have been performed in vitro using the histological method as the gold standard showing inconsistent values. The aim of this study was to compare the sensitivity and specificity in detecting occlusal caries using the International Caries Detection and Assessment System (ICDAS II) with the radiographic method (RM), while using the Spectra™ Caries Detection System (SCDS) as the reference test. METHODS: One hundred sixty children, ages 7-12 years, participated in the study. Five zones in the occlusal surfaces of 859 primary and 632 first permanent molars were examined visually using ICDAS-II, the RM using bitewing radiographs and SCDS. The descriptive statistics of sensitivity and specificity were calculated and compared. RESULTS: For all molars combined and for primary molars only, the sensitivity of ICDAS II was higher for detecting total caries (p < 0.001), caries in enamel (p < 0.001), and caries in dentin (p = 0.016), but it was not different for detecting caries in the dentin of permanent first molars (p = 0.214), and primary second molars (p = 0.761). The specificity of RM was higher for detecting total caries, caries in enamel for all molars combined and for permanent first molars (p < 0.001). For caries in dentin, the specificity of ICDAS II was higher for all molars combined and for primary molars only (p < 0.001). For total caries in primary molars only, and caries in dentin of permanent first molars only, the specificity was not different (p = 0.156 and p = 0.181 respectively). CONCLUSIONS: The sensitivity and specificity of ICDAS II and RM changes depending on whether the carious lesion compromises the enamel or dentin, and if the caries detection is performed in the primary molars or permanent first molars.

Nano-CT characterization of dentinal tubule occlusion in SDF-treated dentin.

Dentin hypersensitivity is an oral health concern affecting a large percentage of the world's adult population. Occlusion of the exposed dentinal tubules is among the treatment options available, and silver diammine fluoride (SDF) is an occluding agent used for interrupting or dampening the stimulus of the dental pulp nerves that produce pain. In addition to dentin permeability testing, the evaluation of desensitizing agents occluding dentinal tubules strongly relies on microscopic techniques, such as scanning electron microscopy (SEM). Limitations of SEM are that it provides only surface images that lack detailed information on the depth of penetration and amount of material present within the treated specimen, and it is prone to sample preparation artifacts. Here, we present high-resolution X-ray computed tomography (nano-CT) as a potential method for investigating dentin specimens with occluded tubules. We studied human dentin treated with SDF as an exemplary dentinal occlusion treatment option. We evaluated the silver deposits formed on the dentin surface region near the dentinal tubules and in the tubular regions using cross-section SEM, Energy Dispersive X-ray (EDX) analysis, and nano-CT. The resulting images obtained by SEM and nano-CT had comparable resolutions, and both techniques produced images of the tubules' occlusion. Nano-CT provided three-dimensional images adequate to quantitate tubule size and orientation in space. Moreover, it enabled clear visualization of dentinal tubules in any virtual plane and estimation of the amount and depth of occluding material. Thus, nano-CT has the potential to be a valuable technique for evaluating the occluding effects of virtually any material applied to dentinal tubules, supporting deciding between the best occluding treatment options.

Selective Removal to Soft Dentine versus Full Pulpotomy for Management of Proximal Deep Carious Lesions: A Randomized Controlled Non-Inferiority Trial.

The management of the deep carious lesion with reversible pulpitis is a dilemma for the dentist. The current study compared selective removal to soft dentine (SRSD) and full pulpotomy (FP) for treating proximal deep carious lesions in teeth with reversible pulpitis. Visual-tactile examination and bitewing radiographs were used to determine the depth of carious lesion, and American Association of Endodontists recommendations were used to formulate pulp diagnosis. Sixty mandibular molar teeth from healthy patients between the ages of 16-35 years and a diagnosis of proximal deep carious lesion with reversible pulpitis were included. Teeth were randomly allocated to two study groups. SRSD group (n = 30): soft dentine was preserved over the pulpal aspect. A hard-setting calcium hydroxide cement liner and resin-modified glass ionomer cement base were applied over the remaining soft carious dentine. FP group (n = 30): complete caries removal followed by mineral trioxide aggregate FP was performed. The teeth in both groups were restored with composite resin restoration. The established criteria for outcome assessment of SRSD and pulpotomy were used. Accordingly, only asymptomatic teeth with no radiological evidence of periapical rarefaction were considered successful at the 12-month follow-up. Two-sample t test, Pearson χ2 test/Fisher's exact test, and percentage agreement were used for statistical evaluation. According to the per-protocol analysis, the success rate of both SRSD and FP treatment was 95.45% and 95.65%, respectively, and the actual difference between the two treatments was 1% (95% CI: [-10, 9]). The data suggests that both treatments (SRSD and FP) appear to have a good success rate (>95%) when used to manage permanent mandibular molar teeth with proximal deep carious lesion and reversible pulpitis. As SRSD is a noninvasive procedure, it should be favored over FP in these instances.

Underlying Dentin Shadows (ICDAS 4) in Occlusal Surface of Permanent Teeth Have Low Progression Rate after 1-2 Years.

The aim of this prospective cohort study was to assess the radiographic progression of underlying dentin shadows (UDS) on the occlusal surfaces of permanent posterior teeth of adolescents and young adults over 1-2 years and to identify possible risk factors. A total of 149 UDS lesions (from 101 individuals) were included at baseline. Each participant had to present at least one UDS to be considered eligible for the study. Data collection included the application of a questionnaire, clinical examination, and bilateral bitewing radiographs, performed at baseline and after 1-2 years. The association between possible predictors and UDS progression (defined radiographically as an increase in the radiographic score from baseline to follow-up) was assessed using Weibull regression models. Hazard ratios (HRs) and their 95% confidence intervals (CIs) were estimated. A total of 81 individuals (mean age: 24.0, standard deviation: 8.03) were reexamined after 1-2 years (742 occlusal surfaces, of which 118 were UDS). The overall progression rate was 8.6% after 1-2 years, being 12.6% for UDS without baseline radiolucency and 20% for UDS with baseline radiolucency. The risk analysis showed that UDS without radiolucency at baseline had a similar likelihood of progression (adjusted HR = 1.71, 95% CI = 0.68-4.32, p = 0.26) while UDS with radiolucency at baseline were more likely to progress (adjusted HR = 2.96, 95% CI = 1.06-8.26, p = 0.04) than the reference category (sound occlusal surfaces without radiolucency). These estimates were adjusted for caries prevalence, tooth type, and arch. This study showed low progression rates of UDS after 1-2 years. The presence of radiolucency at baseline was found to predict UDS progression.

Clinical And Radiographic Assessment Of Autogenous Dentin Nanoparticles In Treatment Of Stage Iii Periodontitis: A Split-Mouth Clinical Study.

Objectives: To compare autogenous dentin nanoparticles with allograft bone grafts in the treatment of stage III periodontitis. Method: The randomised study was conducted at the Department of Oral Medicine and Periodontology, Faculty of Oral and Dental Medicine, Kafrelsheikh University Hospital, Egypt, from January 2021 to January 2022, and comprised adult patients of either gender with stage III periodontitis. Each patient's bilateral intrabony defect was randomly treated with an allograft on one side and a graft made of dentin nanoparticles on the testside. Each patient'sremoved tooth was ground into these nanoparticles. Both groups had their probing pocket depth and clinical attachment loss evaluated at baseline and six months aftersurgery. Additionally, digital periapical films were collected in both groups at baseline and six months after therapy to assess vertical bone loss. Data was analysed using SPSS 20. RESULTS: Of the 20 patients, 8(40%) were males and 12(60%) were females with overall mean age 31.00±4.06 years(range: 18-50 years). Of the 40 sites, 20(50%) each were in test and control groups. Compared to baseline values, both groups showed significant improvement in probing pocket depth, clinical attachment loss and vertical bone loss post intervention (p<0.05). There was no significant difference between the postoperative outcomes of the two groups(p>0.05). CONCLUSIONS: Autogenous dentin nanoparticles were found to be an effective and promising biomaterial for bone regeneration in intrabony defects. Clinical Trial: NCT05258006 link: https://clinicaltrials.gov/ct2/show/NCT05258006, Registration date of the Trial 10/2/2022.

Microcomputed tomography analysis of the radicular residual dentin thickness in mandibular second molars after virtual fiber post placement: Identification of danger zones.

STATEMENT OF PROBLEM: Mandibular second molars have variable root, pulp chamber floor, and radicular groove morphologies, potentially affecting residual dentin thickness and post placement suitability. However, an identification of the danger zones is lacking. PURPOSE: The purpose of this in vitro study was to investigate the residual dentin thickness in the danger zone of mandibular second molars after virtual fiber post placement by using a simulation method based on microcomputed tomography (µCT). MATERIAL AND METHODS: A total of 84 extracted mandibular second molars were scanned using µCT and classified according to root morphology (separate or fused) and pulp chamber floor morphologies (C-shaped, non-C-shaped, or no pulp chamber floor). Fused-root mandibular second molars were further classified based on the radicular groove type (V-, U-, or Ω-shaped). All specimens were accessed, instrumented, and rescanned with µCT. Two types of commercial fiber posts were also scanned. Clinical fiber post placement was simulated in all prepared canals by using a multifunctional software program. The minimum residual dentin thickness of each root canal was measured and analyzed by using nonparametric tests to identify the danger zone. Perforation rates were calculated and recorded. RESULTS: Larger fiber posts decreased minimum residual dentin thickness (P<.05) and increased perforation rate. In regard to mandibular second molars with separate roots, the distal root canal exhibited a significantly higher minimum residual dentin thickness than the mesiobuccal and mesiolingual root canals (P<.05). However, no significant difference in minimum residual dentin thickness was found between the different canals in fused-root mandibular second molars with C-shaped pulp chamber floors (P<.05). Fused-root mandibular second molars with Ω-shaped radicular grooves had a lower minimum residual dentin thickness than those with V-shaped radicular grooves (P<.05) and demonstrated the highest perforation rate. CONCLUSIONS: The morphologies of the root, pulp chamber floor, and radicular groove were correlated with residual dentin thickness distribution in mandibular second molars after fiber post placement. A comprehensive understanding of mandibular second molar morphology is essential for determining the suitability of post-and-core crown restorations after endodontic treatment.

Accuracy of age estimation using root dentin translucency in Peruvian adults. A pilot study.

INTRODUCTION: Age estimation is an important forensic resource in human identification. Amongst the different methods of dental age estimation, root dentin transparency (RDT) is considered a reliable parameter, as well as an indicator of chronological age at time of death in human adult remains. The aim of this study was to estimate the age of individuals using the Bang and Ramm method and to derive a new formula suitable for age estimation in the Peruvian population by assessing the length and percentage length of RDT. MATERIALS AND METHODS: The sample consisted of 248 teeth collected from 124 deceased individuals, between the ages of 30 and 70 years. RDT length was digitally measured from sectioned and photographed teeth. Linear and quadratic regressions were made to derive Peruvian formulae and the new formulae were applied to another group of samples (n=30). RESULTS: Data showed a significant correlation (p<0.01) between chronological age and translucency length (Pearson´s correlation=0.775) and percentage length (Pearson´s correlation=0.778). Linear and quadratic regressions for obtaining Peruvian formulae showed that quadratic equations expressed greater determination coefficients. Comparisons between estimated age using Peruvian formulae showed that dental age from percentage of length of RDT a higher percentage of estimates with errors <± 05 and <± 10 years. The accuracy of the new Peruvian formula using the percentage of length of RDT (MAE=7.83) can be considered acceptable. CONCLUSION: As shown in the results, age estimation using the Peruvian formula derived from the percentage of length of RDT has proven to be more accurate than estimates using the Bang and Ramm method. Thus, it could be used in age estimation for Peruvian individuals, as it is the most accurate methods and provides a larger number of acceptable estimates.