Cervical Thirds Research Articles

Time-Dependent Morphological Changes in Traumatic Immature Teeth With Necrotic Pulps Following Regenerative Endodontic Treatment: A Retrospective Study.

Regenerative endodontic treatment is a promising approach for healing periapical lesions and continuous root maturation. Although previous studies have reported its outcomes, the dynamics of morphological changes over time remain unclear. Therefore, this study aimed to evaluate changes in the periapical status and root dimensions over a 60-month follow-up period. The follow-up duration, periapical status changes, calcific barrier formation, degree of apical closure and radiographic root area changes were compared with those of the last follow-up in this retrospective study. Radiographic root area changes were calculated as the difference between the total root and total canal areas. Fifty-eight patients (81 teeth) underwent regenerative endodontic treatment during the study period, of whom 32 patients (36 teeth, 62%) were included. The survival and success rates of the treated teeth were 100% and 94.4%, respectively. All teeth developed a calcific bridge in the cervical third of the root canal, indicating the presence of vital tissue. Apical narrowing (partial or total) was observed in 75% of the cases. The root maturation stage affected the percentage increase in the radiographic root area. Teeth in Cvek stages II-III showed a higher radiographic root area increase than more mature teeth. All tooth radiographic root areas increased significantly in the initial 20 months of the treatment and moderately thereafter. Regenerative endodontic treatment is a safe approach for traumatised immature teeth. The presence of a radiographic calcified bridge may be an early indication of treatment success. The main complete tooth morphological changes occur after approximately 20 months posttreatment. These findings may help clinicians better understand the time-dependent changes in the root morphology after treatment, improve the follow-up schedule and predict the progress of healing during follow-up visits.

Bonding and Cleaning Effects of Irrigation Protocols Using Calcium Hypochlorite on the Post-space Radicular Dentin.

This study evaluated the effect of 2.5% sodium hypochlorite (SH) or calcium hypochlorite (CH) submitted to passive ultrasonic irrigation (PUI) or conventional irrigation (CI) on the incidence of residues and the bond strength of the cementation system to post-space dentin. Distilled water (DW) and 2.5% SH followed by 17% EDTA (SH-ED) were used as negative and positive control groups, respectively. The cervical, middle, and apical thirds of the post space were evaluated. One hundred and twenty bovine incisors were endodontically treated and post-space preparation was performed. The specimens were randomly assigned to six groups, according to the solution and irrigation method: DW-CI, SH-ED-CI-SH, SH-CI, SH-PUI, CH-CI, and CH-PUI. The incidence of residues (n=10) over the dentin was evaluated by scores using SEM images. Other specimens were irrigated as previously described and the post cementation was immediately performed using a conventional dual resin cement and a two-step etch-and-rinse adhesive system. Push-out and failure modes were performed for bonding evaluation. Kruskal-Wallis and Dunn test for incidence of residues data and one-way ANOVA and Tukey tests for bond strength data were used at a significance level of 5%. The protocols that showed a lower incidence of residues were: SH-ED-CI-SH, SH-PUI, and CH-PUI for the cervical third and SHED-CI-SH for the middle third (p<0.05). In the apical third, the protocols were similar to each other (p>0.05). Bond strength values were higher after irrigation with DW-CI for all thirds (p<0.05). 2.5% sodium or calcium hypochlorite negatively impacted the adhesion interface and exhibited a greater incidence of residues over the post-space radicular dentin.

Testing a new micro-osteoperforation modality on the rate of orthodontic tooth movement in a rabbit model

Objectives. The current study objective was to test and compare the impact of a new micro-osteoperforation (MOP) modality with 2 other modalities on the rate of tooth movement (RTM) in rabbits. Methods. The sample comprises 45 adult male albino rabbits aged 24 weeks and divided equally into 3 groups regarding MOP modalities; a single vertical MOP (1V-MOP), a single vertical MOP + 2 horizontal MOPs (1V+2H-MOP), as the new MOP design; and 3 horizontal MOPs (3H-MOP). The first right mandibular premolar (RMP1) received MOP(s) + orthodontic force 50g by traction spring. The contralateral tooth on left (LMP1), as positive (+ve) control, received only 50g orthodontic force by another spring. Both springs were fixed by a mini-screw between the 2 lower incisors. Evaluations of the clinical RTM and histopathology with H and E stain of the compressed PDL at the cervical, middle, and apical thirds of MP1 root were performed for comparing after 1, 2, and 3 weeks of OTM respectively. Results. The RTM (P&lt;0.001) and number of osteoclasts, osteoblasts, blood vessels and PDL width (P&lt;0.001 to P=0.039) significantly increased in the MOP groups; the 1V+2H-MOP was in between the higher 1V-MO P and the lower 3H-MOP. Conclusion. All MOP modalities could efficiently accelerate RTM and increase the activity of the compressed PDL, but with a variant rate. The new 1V+2H-MOP modality can be chosen as the best modality for faster RTM, because it showed moderate RTM after the 1V-MOP.

The Push-Out Bond Strength, Surface Roughness, and Antimicrobial Properties of Endodontic Bioceramic Sealers Supplemented with Silver Nanoparticles.

This study evaluated push-out bond test (POBT), surface roughness, and antimicrobial properties against Enterococcus faecalis of bioceramic sealers supplemented with silver nanoparticles (AgNPs). The sealers tested were CeraSeal®, EndoSequence® BC SealerTM, and Bio-C® Sealer. The POBT was measured with a Universal Testing Machine, and the type of failure was evaluated with a stereomicroscope. The roughness average (Sa) and peak-valley height (Sy) values were evaluated by atomic force microscopy. The bacterial growth inhibition was evaluated using a disk diffusion test, and antimicrobial activity was determined with the plate microdilution method. The POBT showed no significant difference between sealers with and those without NPs in cervical and apical thirds (p > 0.05). In the middle third, the adhesion force was significant for Endosequence BC Sealer® (p < 0.05). The results showed that the Sa and Sy parameters, when AgNPs were added, did not show a statistically significant difference compared to the groups without nanoparticles (p > 0.05). All tested sealers showed bacterial growth inhibition, but no significant difference was found. Their efficacy, in descending order of antibacterial activity when AgNPs were added, is as follows: EndoSequence® BC SealerTM > Bio-C® Sealer > CeraSeal®. The incorporation of AgNPs into bioceramics improves antimicrobial activity without affecting mechanical properties.

Aspects of glass and hybridization protocols for bonding of fiber posts to root dentine.

This study evaluated bond strength of glass fiber posts to root dentin using push-out (PO) and diametral compression (DC), testing glycolic acid as a conditioner and varying dentin moisture. An additional aim was to test whether DC can be an alternative test to PO for bond strength assessment. Eighty bovine teeth were divided into eight groups (n=10) defined by the use of either 37% glycolic acid or 37% phosphoric acid (PA) on moist or wet dentin before bonding with either Adapter SingleBond/RelyX ARC or One Step Plus/Duo-Link Bisco. Each tooth provided discs with an internal diameter of 2mm, external diameter of 5mm, and height of 2mm, which underwent PO and DC. Finite element analysis (FEA) was carried out on 3D models. When analyzing PO results through linear regression, the highest values of bond strength were observed using glycolic acid on wet dentin in the cervical and middle thirds of the teeth. Analyzing DC results, the only statistical influence on values was the dental thirds. The scatterplot of the DC results and the PO bond strength values indicated no relationship between the results of the two tests (r=0.03; p=0.64). PO test detected more sensitive changes in bond strength values than DC.

The morphology of alveolar bone of the mandibular second and third molars in skeletal Class III patients.

To investigate the alveolar bone morphology of the mandibular second and third molars in skeletal Class III patients from a buccolingual direction. Sixty skeletal Class III patients were recruited. The alveolar bone width, buccal cortical bone thickness and lingual cortical bone thickness were measured in five planes from mesial to distal and at five depths from gingival to root. The effects of the gender of the patients, the second molar lingual inclination and the third molar on alveolar bone width and cortical bone thickness were evaluated. To explore the effect of third molar extraction on alveolar bone morphology, the measurements before and after third molar extraction were compared. The impacted third molar had significantly greater alveolar bone width and thicker buccal cortical bone at the cervical third of the molar, while the erupted third molar had greater alveolar bone width at the apical third. Three weeks after third molar extraction, these advantages would weaken owing to the reconstruction of the alveolar bone. Patients with lingually inclined molar were observed to own thicker lingual cortical bone. Males tended to have greater alveolar bone width, but no significant differences were shown in this study. The growth of the third molar and the second molar lingual inclination affect the alveolar bone morphology of the mandibular second and third molars significantly, but gender has trivial effects on the morphology. The alveolar bone morphology of the mandibular second and third molars would change 3 weeks after third molar extraction.

Evaluation of the relationship between periodontal bone destruction and mesial root concavity of the maxillary first premolar

BackgroundThe purpose of this study was to investigate the morphology of maxillary first premolar mesial root concavity and to analyse its relation to periodontal bone loss (BL) using cone beam computed tomography (CBCT) and panoramic radiographs.MethodsThe mesial root concavity of maxillary premolar teeth was analysed via CBCT. The sex and age of the patients, starting position and depth of the root concavity, apicocoronal length of the concavity on the crown or root starting from the cementoenamel junction (CEJ), total apicocoronal length of the concavity, amount of bone loss both in CBCT images and panoramic radiographs, location of the furcation, length of the buccal and palatinal roots, and buccopalatinal cervical root width were measured.ResultsA total of 610 patients’ CBCT images were examined, and 100 were included in the study. The total number of upper premolar teeth was 200. The patients were aged between 18 and 65 years, with a mean age of 45.21 ± 13.13 years. All the teeth in the study presented mesial root concavity (100%, n = 200). The starting point of concavity was mostly on the cervical third of the root (58.5%). The mean depth and buccolingual length measurements were 0.96 mm and 4.32 mm, respectively. Depth was significantly related to the amount of alveolar bone loss (F = 5.834, p = 0.001). The highest average concavity depth was 1.29 mm in the group with 50% bone loss. The data indicated a significant relationship between the location of the furcation and bone loss (X2 = 25.215, p = 0.003). Bone loss exceeded 50% in 100% of patients in whom the furcation was in the cervical third and in only 9.5% of patients in whom the furcation was in the apical third (p = 0.003).ConclusionsAccording to the results of this study, the depth of the mesial root concavity and the coronal position of the furcation may increase the amount of alveolar bone loss. Clinicians should be aware of these anatomical factors to ensure accurate treatment planning and successful patient management.

Trabecular Bone Component Assessment under Orthodontic Loads and Movements during Periodontal Breakdown-A Finite Elements Analysis.

This numerical analysis, by employing Tresca and Von Mises failure criteria, assessed the biomechanical behavior of a trabecular bone component subjected to 0.6, 1.2, and 2.4 N orthodontic forces under five movements (intrusion, extrusion, tipping, rotation, and translation) and during a gradual horizontal periodontal breakdown (0-8 mm). Additionally, they assessed the changes produced by bone loss, and the ischemic and resorptive risks. The analysis employed eighty-one models of nine patients in 405 simulations. Both failure criteria showed similar qualitative results, with Tresca being quantitatively higher by 1.09-1.21. No qualitative differences were seen between the three orthodontic loads. Quantitatively, a doubling (1.2 N) and quadrupling (2.4 N) were visible when compared to 0.6 N. Rotation and translation followed by tipping are the most stressful, especially for a reduced periodontium, prone to higher ischemic and resorptive risks. In an intact periodontium, 1.2 N can be safely applied but only in a reduced periodontium for extrusion and intrusion. More than 0.6 N is prone to increasing ischemic and resorptive risks for the other three movements. In an intact periodontium, stress spreads in the entire trabecular structure. In a reduced periodontium, stress concentrates (after a 4 mm loss-marker for the stress change distribution) and increases around the cervical third of the remaining alveolar socket.

Guided endodontic treatment of the upper premolar with calcification in the cervical third: A case report

Guided endodontic treatment of the upper premolar with calcification in the cervical third: A case report

Stress distribution pattern in two different no-post systems in endodontically treated maxillary central incisors: A three-dimensional finite element analysis.

This study aimed to evaluate the stress distribution in an endodontically treated tooth restored with two different reinforcing fibers followed by direct composite restoration using a finite element analysis (FEA). FEA. Two three-dimensional models of endodontically treated maxillary central incisors were restored with two reinforcing fibers: the polyethylene fibers (PFs) and the short fiber-reinforced composite (SFRC), respectively. The restoration was carried out without any intraradicular preparation using direct composite restoration. The models were generated using SolidWorks. The elastic modulus and Poisson's ratio for various structures and materials were installed into the simulation software, Abaqus. A FEA was then conducted. Each model received a mixed-mode loading of 150 N as distributed pressure to the specified region, and stress distribution was evaluated using the von Mises criteria. Both the reinforcing materials, PF and SRFC, showed maximum concentration of stresses in the cervical third of the tooth. The calculated values of the von Mises stresses for the PF and the SFRC models were 1.7 Mpa and 1.9 Mpa, respectively. Moreover, the stresses generated were of low intensity and were uniformly distributed, suggesting that by using this technique, stresses may be very well tolerated by the remaining tooth structure without any fracture. This no-posttechnique, using the two reinforcing fibers, showed minimal stress concentration in the cervical region of the tooth. Thus, using this ultraconservative approach that aims to preserve and reinforce the pericervical dentin and restore the remaining tooth structure with direct composite restoration could be a promising treatment option for the rehabilitation of badly mutilated teeth.

In Vitro Efficacy of Apical Negative Pressure Irrigation in Primary Teeth: A Smear Layer Analysis.

This study aimed to assess the efficacy of root canal debris removal in primary teeth through irrigation using the Endo-Irrigator Plus (CWAIS). A total of 25 primary mandibular first molars were divided into five groups, with five teeth in each group. After determining the working length and performing biomechanical preparation, groups I and II were subjected to hand and rotary instrumentation (ProTaper, Dentsply, United States of America) with conventional syringe irrigation with positive pressure, while groups III and IV were instrumented using hand and rotary instrumentation with positive and negative pressure irrigation employing the Endo-Irrigator Plus (CWAIS) system. Sodium hypochlorite (5.25%) and ethylenediaminetetraacetic acid (EDTA) (17%) were used as irrigants. Group V served as the control group, undergoing only root canal access opening. The removal of the smear layer was analyzed at the cervical, middle, and apical thirds of the canal using environmental scanning electron microscopy (SEM). Statistical significance was set at p < 0.05. Statistically significant differences were observed among all groups at the cervical, middle, and apical levels (p < 0.05). Groups III and IV exhibited significantly lower smear scores at all levels, particularly in the apical third, as observed through SEM examination. The use of the Endo-Irrigator Plus (CWAIS) system demonstrated superior debridement of intracanal debris in primary teeth compared to the positive pressure irrigation method. Badnaware SD, Kakade A, Takate V, et al. In Vitro Efficacy of Apical Negative Pressure Irrigation in Primary Teeth: A Smear Layer Analysis. Int J Clin Pediatr Dent 2024;17(6):653-657.

Evaluation of Minimally Invasive Preparation of Curved Mesial Canals of Mandibular Molars – An In Vitro Study

IntroductionCurved mesial roots can be challenging for different stages of endodontic treatment. Preparation aims to enlarge, clean, and shape the root canal system, and hundreds of systems are available to carry it out. Aiming to maintain pericervical dentin, minimally invasive preparation was proposed, and with it, instruments with lower tapers emerged. This study aimed to evaluate the increase in canal volume, the centering ability of the instruments, and root canal transportation of two different rotary systems with lower tapers. MethodsEighteen curved mesial roots of extracted mandibular molars were scanned by micro-CT at 3 moments: initial and after the 2 stages of endodontic preparation. The canals were prepared using TruNatomy (TN) and ProDesign Logic 2 (PDL2) instruments up to sizes 25.04 and 26.04, respectively, and after 36.03 and 35.05, respectively. The data were analyzed using parametric and nonparametric tests with a significance level of 5%. ResultsTN and PDL2 systems showed no difference regarding the increase in the volume of the canals with the first instruments, but after preparation with a diameter size of 35 or 36, there was a difference (P < .01) between the systems in the cervical and middle thirds. ConclusionBoth systems shaped the mesial canals of mandibular molars while keeping low transportation and good centering ability in enlargements up to diameter size 35 or 36 with tapers of 3 or 5%.

Cone-beam computed tomography evaluation of shaping ability of kedo-S square and fanta AF™ baby rotary files compared to manual K-files in root canal preparation of primary anterior teeth

BackgroundPediatric rotary file systems were developed to solve manual file limitations. With many systems available, it may be tricky to select the most appropriate one.Aimto assess & compare Kedo-S Square, Fanta-AF™-Baby rotary files with manual K-file concerning removed dentin amount, canal transportation, centric ability & root canal taper using CBCT in primary anterior teeth.DesignExtracted Seventy-five upper primary anterior teeth with intact 2/3 root length were collected and divided into three groups based on root canal instrumentation, group-I: prepared using K-file, group-II: prepared using Kedo-S Square, and group-III: prepared using Fanta AF™ Baby file. The teeth were imaged with CBCT before & following canal instrumentation. Then, the removed dentin amount was calculated at each root-canal level. The Kruskal-Wallis test was utilized to statistically analyze study data.ResultThe difference among the three groups was highly statistically significant at cervical & apical thirds concerning dentin thickness changes on both mesial & distal sides following canal preparation with the least removed dentin in the Kedo-S Square group(P < 0.0001). Regarding transportation & centering ability, a non-significant difference between the three groups was found. 80% of the Fanta AF™ Baby group had good-tapered preparation compared to the Kedo-S Square (72%) and K-file (40%) groups(P < 0.05).ConclusionKedo-S Square was preferable to Fanta-AFTM-Baby & manual K-files in primary root canal preparation.

Effect of material composition and thickness of orthodontic aligners on the transmission and distribution of forces: an in vitro study.

To investigate the effects of material type and thickness on force generation and distribution by aligners. Sixty aligners were divided into six groups (n = 10): one group with a thickness of 0.89mm using Zendura Viva (Multi-layer), four groups with a thickness of 0.75mm using Zendura FLX (Multi-layer), CA Pro (Multi-layer), Zendura (Single-layer), and Duran (Single-layer) sheets, and one group with a thickness of 0.50mm using Duran sheets. Force measurements were conducted using Fuji® pressure-sensitive films. The lowest force values, both active and passive, were recorded for the multi-layered sheets: CA Pro (83.1N, 50.5N), Zendura FLX (88.9N, 60.7N), and Zendura Viva (92.5N, 68.5N). Conversely, the highest values were recorded for the single-layered sheets: Duran (131.9N, 71.8N) and Zendura (149.7N, 89.8N). The highest force was recorded at the middle third of the aligner, followed by the incisal third, and then the cervical third. The net force between the incisal and cervical thirds (FI-FC) showed insignificant difference across different materials. However, when comparing the incisal and middle thirds, the net force (FI-FM) was higher with single-layered materials. Both overall force and net force (FI-FM) were significantly higher with 0.75mm compared to those with a thickness of 0.50mm. Multi-layered aligner materials exert lower forces compared to their single-layered counterparts. Additionally, increased thickness in aligners results in enhanced retention and greater force generation. For effective bodily tooth movement, thicker and single-layered rigid materials are preferred. This research provides valuable insights into the biomechanics of orthodontic aligners, which could have significant clinical implications for orthodontists. Orthodontists might use this information to more effectively tailor aligner treatments, considering the specific tooth movement required for each individual patient. In light of these findings, an exchangeable protocol for aligner treatment is suggested, which however needs to be proven clinically. This protocol proposes alternating between multi-layered and single-layered materials within the same treatment phase. This strategy is suggested to optimize treatment outcomes, particularly when planning for a bodily tooth movement.

Effect of canal medicaments triple antibiotic paste, Bio-C Temp, and Nano-silver gel activated by visible blue light on canal dentin microhardness and extrusion bond strength of AH plus sealer: A SEM and EDX analysis

AimAssessment of contemporary canal medicaments (Triple antibiotic paste (TAP), Bio-C Temp, and Nano silver gel activated by visible blue light on the dentin microhardness (MH) and push-out bond strength (PBS) of AH plus endodontic sealer. MethodSixty extracted premolars were obtained and decontaminated. Canal cleaning and shaping were performed. The samples were randomly allocated into four groups based on the intracanal medicaments. Group 1= CH paste, Group 2= TAP, Group 3= Bio-C Temp, and Group 4= Nano-silver gel activated by visible blue light. MH assessment was performed using a Vickers Microhardness tester. Forty specimens, ten from each group underwent root canal obturation. PBS and failure mode evaluation were performed. ANOVA and Post Hoc Tukey test were utilized to conduct intra and inter-group comparisons. ResultsThe maximum outcome of surface hardness was presented by Group-3 (Bio-C Temp®) specimens. However, minimum scores of MH were displayed by Group 1 (CH) treated teeth. The highest outcomes of EBS were exhibited by the cervical third of Group 3 (Bio-C Temp®) samples. The apical section of Group 4 Teeth with Nano Silver gel activated by visible blue light revealed the lowest scores of bond integrity. ConclusionBio-C Temp and TAP proved to be better intracanal medicament than other tested groups in terms of the push-out bond strength of the sealer. TAP displayed lower microhardness as compared to the Bio-C Temp.

Identification of the Ideal Reference Site and Pain Threshold Values for the Placement of Electric Pulp Testers in Permanent Upper and Lower Anterior Teeth: A Cross-Sectional Study.

Electric pulp testers (EPTs) are widely used diagnostic tools for diagnosing traumatized teeth. Several factors can affect the result of an electric pulp test. One such factor that will affect the diagnosis is the electrode tip placement. Hence, the current study aims to identify the most painful site and response time threshold in healthy anterior teeth. A total of 90 individuals, 48 male and 42 female, aged 19 to 25 years,were recruited. An EPT was placed on three different sites: the cervical, middle, and incisal third of the labial surface of both upper and lower anterior teeth (central incisor, lateral incisor, and canine) with an appropriate electrolyte as a conducting medium. Later, the threshold values were recorded, and pain assessment was done using the Memojis pain scale (MPS). Finally, the data was analyzed statistically using the Mann-Whitney U test. Mean and standard deviation values of reaction time were collected from 540 EPT readings (three sites from 180 teeth).Among the three sites tested, the difference between the upper and lower central incisors was statistically insignificant (p > 0.05). Similarly, when upper and lower lateral incisors and canines were compared, a statistically significant difference was observed among the three sites (p<0.05). There was a significant difference (p<0.05) in the pain scores only on the incisal and cervical thirds of the upper and lower central incisors. Only the incisal third showed a statistically significant difference (p<0.05) between the pain scores in the upper and lateral incisors. At the same time, a statistically significant difference in the pain scores was observed among the three tested sites between the upper and lower canines (p<0.05). Conclusion: Lower threshold values were appreciated at the incisal third of all the upper and lower anterior teeth for placing the EPT. Most individuals have experienced a score of 2 (hurts little bit) for the perceived pain using EPTs for both the upper and lower anterior teeth.

PEEK and glass fiber post pushout bond strength and vickers hardness of canal disinfected with curcumin photosensitizer activated by microbubble emulsion and sodium-hypochlorite with EDTA

AIMSImpact of different post-space disinfectants (Saline, Sodium hypochlorite (NaOCl) followed by ethylene-diamine-tetra-acetic acid (EDTA) and curcumin activated by microbubble emulsion (MBE) on the Vickers hardness (VH) of root canal dentin and extrusion bond strength (EBS) of Glass fiber post (GFP) and PEEK post. MethodsNinety maxillary central incisors having fully formed roots were included. After the specimen's disinfection, root canal treatment was completed. Post space was prepared by removing gutta-percha using gates glidden drills. Teeth were then arbitrarily allocated into three groups based on the methods of disinfection regime used. Group 1: Saline, Group 2: NaOCl+ EDTA and Group 3: Curcumin activated by MBE (n = 30). Analysis of VH of radicular dentin was performed using a micro-Vickers tester on ten samples from each group. After post-space disinfection, twenty specimens from each group were further divided into two subgroups (n = 10) In group-1A 2A, and 3A, GFP was used. Whereas, prefabricated PEEK posts were used in 1B, 2B, and 3B subgroups. The PBS and failure modes were performed using a universal testing machine and stereomicroscope respectively. Data was analyzed using ANOVA and Tukey post hoc test to identify significant variations among groups concerning the MH and EBS of the different posts used (p = 0.05). ResultsGroup 2 (5.25 % NaOCl + 17 % EDTA) (0.15 ± 0.02 GPa) treated specimens presented lowest scores of VH. However, Group 1 (Saline) irrigated canals displayed the highest scores of surface hardness (0.25 ± 0.07 GPa). Additionally, a cervical third of 3A (CP activated by MBE + GFP) (11.22 ± 0.79 MPa) presented the highest scores of bond integrity. Whereas Group 1B (Saline + PEEK post) treated specimens presented the lowest scores of PBS (4.15 ± 0.15 MPa). ConclusionCurcumin activated by microbubble emulsion for disinfection of canal dentin demonstrated favorable VH. Similarly, glass fiber post-cemented in radicular walls disinfected with curcumin activated with MBE showed promising post-bond integrity to the canal dentin.

In vitro evaluation of the bleaching effect on the change of color match of omnichroma composite resin

Aim To in vitro evaluate the bleaching effect on the color match of Omnichroma composite resin restorations to the teeth color. Materials and methods Thirty freshly extracted intact human premolars were collected and mounted in acrylic resin blocks (only roots were embedded). The shade of the selected teeth was measured by (VITA Easyshade V). Class V cavities (4 mm width, 2 mm length, and 2 mm depth) were prepared 2 mm coronal to cement-enamel junction on the cervical third of the facial surface of each tooth. Specimens were randomly divided into two equal groups (n = 15): group I: was restored with nano hybrid Tetric N- ceram while group II: was restored with Omnichroma supra-nano filled composite resin using their respective adhesives. All the specimens were thermocycled for 500 cycles from 5 to 55°C with 15 s dwell time, and 20 s transfer time. The initial data of color measurements for tooth and restoration surfaces were recorded after thermocycling using VITA Easy Shade V. Specimens were then bleached using 40% HP by White smile power whitening YF according to the manufacturer instructions and kept in artificial saliva for 1 week before color re-measuring. All data were collected, tabulated, and statistically analyzed at 95% significance level using a software statistical package for social sciences (SPSS version 26). Results Before bleaching, higher mean ΔΕ values were recorded for the teeth (3.38 and 2.74) compared to (2.24 and 1.82) of the restorations in group I (Tetric N) and group II (Omnichroma) respectively with no statistically significant difference (P = 0.26 and 0.43) in either of the groups denoting the color match between the restorations and the teeth in both groups. After bleaching there was a highly statistically significant difference (P = 0.039) between the mean ΔΕ values of teeth (5.56) and restorations (3.23) in group I, denoting the color mismatch. While in group II there was no significant difference (P = 0.249) between the values of teeth (5.25) and restorations (4.49) denoting the persistence of the color match after bleaching. No significant difference was found between the ΔΕ values of teeth used in both groups neither before (P = 0.62) nor after bleaching (P = 0.802). While there was a significant difference between the recorded values of the restorations after bleaching (P = 0.026) although the difference was not significant before bleaching (P = 0.619). Bleaching significantly affected the teeth color (P = 0.013 and 0.038), and the restoration color (P = 0.049 and 0.012) in groups I and II, respectively. Conclusions Omnichroma class V composite restorations matched the shades of teeth before and after bleaching where it was changed to a lighter shade with the teeth enamel that was within the acceptable clinical range. The color matching of the Tetric N restorations after bleaching was lost where the teeth were lighter in a clinically detectable manner, which necessitates restoration replacement.

Morphometric Measurements of Root Anatomic Areas of Maxillary First Premolar Teeth in a Representative Nepalese Population

Background The prognosis of furcation involved maxillary first premolar is typically guarded to poor. The presence of concavities in the root trunk and the positioning of the roots in the buccal and palatal regions of the teeth are responsible for its challenges during instrumentation and control plaque. We aimed to access the presence of concavities on the root surface as well as morphometric measurement of the root trunk dimensions in the maxillary first premolar teeth in Nepalese population.MethodsA cross-sectional quantitative study was conducted in the Department of Periodontics and Oral Implantology, College of Medical Sciences (CoMS). Extracted Maxillary first premolar teeth were evaluated for the number of roots, morphometric measurement of the root trunk, root divergence, and root length. The presence of concavities was recorded on the mesial and distal root surface at cervical, middle, and apical thirds of the root.ResultsThe overall mean root trunk length was less on the mesial aspect than on the distal aspect (6.39 ± 2.54 and 8.08 ± 3.48 respectively). The prevalence of root surface concavity on the cervical third at the mesial aspect (90 %) was found to be higher than in the distal aspect (15%) Conclusions Owing to the higher prevalence of root surface concavity on the cervical third of mesial aspect, use of mini-bladed curettes is recommended for the effective root surface debridement of the periodontally involved maxillary first premolar tooth. Patients with periodontally involved maxillary first premolar should be advised to use interdental brushes rather than dental floss.

Three-dimensional evaluation of interproximal contacts of permanent dentition: a cone beam computed tomography study.

To assess the various patterns of the inter-proximal contact areas of the permanent dentition using the available cone beam computed tomography (CBCT) images. A retrospective cross-sectional study was performed on existing CBCT images from a University hospital and teaching department. Three thousand two hundred and fifty inter-proximal contacts were assessed from 125 existing CBCT scans of patients (age range: 14years 3months-29years 9months) who had matched the eligibility criteria. The types of inter-proximal contacts of the permanent dentition were scored at occlusal, middle, and cervical thirds, according to the OXIS inter-proximal contacts classification. Chi-square test was used to assess the contacts and gender/arches. The most prevalent contact was type I for the posterior teeth contacts, and types S1 and S2 for the anterior teeth contacts. Statistical significance was not observed between the contacts on the left and right sides (P > 0.05), while statistical significance was observed between the inter-proximal contacts of the maxilla and mandible (P < 0.05). The CBCT-based three-dimensional assessment of the inter-proximal contact areas of the permanent dentition is representative of the OXIS classification. The occlusal level contact was predominantly representative of the overall type of the contact.