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Background: Resin-based materials are the popular restorative material in dentistry. The majority of these materials are light cured with a major disadvantage: marginal leakage. Objective: To evaluate the gap width of different resin-based materials at the cervical dentin when achieved mechanical force. Methods: Class II cavities were prepared on extracted premolar teeth with the gingival margin 1 mm below the Cementoenamel Junction (CEJ). In the first three experimental groups, three different lining materials (flowable resin composite, bulk-fill flowable resin composite, and resin-modified glass ionomer cement) were placed at the cervical dentin with a thickness of 1 mm. The rest of the cavities were restored with conventional resin composite. The other two groups were restored with conventional resin composite (control) or high viscosity bulk-fill resin composite, respectively. All groups were thermocycled and underwent vacuum pressure 2.6 KPa for 30 min in a Scanning Electron Microscope (SEM). Results: There was no gap formation at the cervical dentin on the external surface when restored with high-viscosity bulk fill resin composite. Almost all gaps occurred at the interface between restorative materials and the hybrid layer. The flowable bulk fill resin composite showed a significantly smaller gap width on both the external and internal surfaces compared to the other groups (p< 0.05). The resin-modified glass ionomer cement showed the largest gaps in the cervical dentin (p < 0.05). Conclusion: The different types of resin-based materials demonstrated a different failure of gap width under mechanical force. It clearly occurred at the restorative material-hybrid layer interface.

Aim: The aim of this study was to assess the influence of Proanthocyanidin (PA) application on bond strength of glass fiber posts to root canal dentin using self-etch adhesive luting system. Materials and Methods: Twenty single rooted mandibular premolars, freshly extracted for orthodontic purpose, were decoronated below the cementoenamel junction, and standardized to 14mm in length. Post space preparation was done upto No 3 Peeso reamer during which canals were irrigated with conventional irrigation protocol. Teeth were randomly divided into two groups (n=20 each) Group 1: Pre-treatment with PA and Group 2 served as the control group. Both Groups were restored with fiber posts bonded with RELYX U200 self-etch adhesive system. Teeth were then stored in distilled water for three months at 37° C. One mm slices were obtained and push-out bond strength testing was performed. Failure patterns were assessed under stereomicroscope at 20x magnification. Results: Individual bond strength values were calculated and statistically analysed with the chi-square test and independent-t-test. A statistically significant difference existed between the two Groups (p

The aim of this study is to investigate the stress distributions of different restoration options for class II mesio-occluso-distal (MOD) cavities. A class II MOD cavity with proximal box gingival floor 1 mm below cementoenamel junction was designed in a mandibular first molar tooth model. 3D finite-element analysis (FEA) and 3D-CAD modelling were used to examine the occlusal stresses distributed to the remaining buccal enamel (RBE), remaining lingual enamel (RLE), adhesive surfaces, and restorative materials by direct and indirect materials resulting from a 600 N of static occlusal load stimulating foodstuff. von Mises (VM) and maximum principal (Pmax) stresses were evaluated for two CAD/CAM materials and three direct materials. CAD/CAM materials exerted less stress than the direct restorative materials. Significant von Mises and Pmax stress value differences were seen among all restoration models on RBE. Reducing RLE and including it into the cavity would be a more effective option for this model in this scenario. As VM and Pmax stresses of PIHC CAD/CAM material for RBE and dentin were significantly lower than other tested materials, it may be the choice of material for indirect MOD restorations.

AIM: This study evaluated the effect of preheated irrigants (EDTA, QMix), then use of various activation techniques such as ultrasonic system and laser on push-out bond strength (POBS) of fiber posts to root dentin. Methodology: One hundred and twenty extracted human teeth were decoronated below the cementoenamel junction. All the root canals were instrumented, irrigated using sodium hypochlorite and normal saline, dried with paper points, and filled with gutta-percha and AH Plus sealer. Post spaces were prepared. The irrigating solutions QMix and EDTA were heated to 60°C. Normal QMix and EDTA served as control. The irrigants were activated with Laser and Ultrasonic system. Then, the fiber posts were cemented, roots were sliced to thickness of 2 mm and mounted for measurement of POBS. Results: Preheated irrigants group showed maximum POBS as compared to Normal irrigants. QMix group showed better results as compared to EDTA. Irrigants when activated with laser and ultrasonics showed comparable results. Conclusion: Within the limitations of the study, it can be concluded that preheated irrigants(QMix, EDTA) increase the POBS of fiber post to root dentin. Both laser and ultrasonic are equally effective for increasing the POBS.

Introduction New tricalcium silicate cements have been shown to induce less coronal discoloration. The purpose of this in vitro study was to evaluate the degree of color change induced by various silicate materials in the presence and absence of blood. Methods One hundred human extracted anterior single-canal teeth were sectioned to standardized root lengths, accessed, and instrumented. Eight random experimental groups and 2 control groups were created wherein specimens were filled with experimental materials below the buccal cementoenamel junction as follows: EndoSequence RRM putty (Brasseler USA, Savannah, GA), EndoSequence RRM fast set putty (Brasseler USA), Biodentine (Septodont, Saint-Maur-des-Fosses, France), and white mineral trioxide aggregate (Dentsply Sirona, York, PA) either with the presence or absence of blood. Blood-only and saline-only samples were used for the positive and negative controls. After incubation in 100% humidity at 37°C, color changes were evaluated with a spectrophotometer (Ocean Optics, Dunedin, FL) on days 0, 30, 60, and 180 after material placement. Data were transformed into Commission International de I'Eclairage's L∗a∗b color values, and corresponding ΔE values were calculated. The 1-way analysis of variance test was performed for statistical analysis. Results Discoloration was observed in all specimens in the presence of blood. There was no statistical significance when comparing different materials in contact with blood. Intragroup observation at various time points, Biodentine, and EndoSequence RRM fast set putty showed significant difference between the presence and absence of blood at 180 days (P Conclusions Contamination with blood of tricalcium silicate materials has the potential to cause coronal tooth discoloration.

The aim of this study was to investigate the impact of the incision type, with or without a coronally repositioning flap (CRF), on soft tissue healing and crestal bone remodeling after endodontic microsurgery (EMS).Clinical pictures and cone-beam computed tomography images from 47 patients (120 teeth) taken before surgery and at the follow-up appointment were included in this study. Clinical pictures were qualitatively evaluated by 2 endodontists for the gingival marginal level (GML) (recession, same position, or coronal root coverage), papillary height (same position/receded), and for presence/absence of scars for each tooth. Cone-beam computed tomography images were used to calculate the changes in the distance between the cementoenamel junction and the crestal bone level (CBL) between the preoperative and follow-up scans. Statistical analyses were performed to determine a correlation between patient-related factors (age, sex, tooth type, position, and presence/absence of a crown), incision techniques, and changes within the CBL.Gingival recession was more prevalent in mandibular teeth, molar teeth, and teeth that received intrasulcular or papilla-based incisions (P .05). Scar formation was affected by the flap design (P .05). CRF was the only technique resulting in coronal root coverage (P .05). There were no changes observed in the papillary height between the various flap designs. There was also no statistically significant difference in the crestal bone height between the preoperative and follow-up scan measurements (P .05).Soft tissue changes are evident after EMS and can be affected by the flap design selected, as well as the site being treated. Application of CRF can improve the position of GML after EMS. There are insignificant changes within the CBL at the facial aspect of the root after EMS.

Periodontitis is one of most common oral disease. Chronic periodontitis is characterised by gingival inflamation, periodontal pocket, lost of attachment, and alveolar bone loss. Smoking is a risk factor of periodontal disease that has direct effect to periodontal tissue. Smoking prevalence in Indonesia during 2013 was about 56,7% among men and about 1,9% among women. Smoking modifies the periodontal microbial challenge and host cytokine levels. Some studies showed that smoker has greater alveolar bone loss than non-smoker, and teeth that have the greatest alveolar bone loss are incisor and followed by molar. The aim of this study is to know the upper incisor and upper molar alveolar bone loss differences between smoker and non-smoker patient with chronic periodontitis. The study’s samples are 92 chronic periodontitis statuses and 200 periapical radiographs that selected by purposive sampling techinque. This study will measure the distance between cementoenamel junction to alveolar bone crest, cementoenamel junction to tooth apex, and alveolar bone loss percentage at upper incisor and upper molar. To compare the differences upper incisor and upper molar alveolar bone loss at patient with chronic periodontitis between smoker and non-smoker will be analyzed by independent t test and Mann-Whitney U test. The result showed that smoker has greater alveolar bone loss than non-smoker. There is no significant differences at upper incisor alveolar bone loss and there is significant differences at upper molar alveolar bone loss between smoker and non-smoker patient with chronic periodontitis.

Gingival recession is the exposure of the root surface resulting from migration of the gingival margin apical to the cementoenamel junction (CEJ). It may be localized or generalized and can be associated with one or more tooth surfaces. Even though gingival recession may occur without any symptoms it can give rise to pain from exposed dentin, patient concern about loss of the tooth, poor esthetics or root caries. The denuded root surfaces cause deterioration in the esthetic appearance, dentin hypersensitivity, and inability to perform proper oral hygiene procedures. The Bernotti V-Y flap is a coronally advanced flap technique with a “VY” flap design, which consist of a microsurgery technique with or without connective tissue graft, that will improve mucosal biotype and keratinized band in a predictable way for isolated mucosal recession, dehiscence and translucent tissue at teeth or implant sites. It is a conservative flap design, inspired by Semilunar and Modified Semilunar Tarnow’s technique, to minimize interproximal crestal bone loss and possible loss of papillae around teeth or implants, marginal mucosal position is stabilized avoiding adverse aesthetic outcomes. Miller’s Class I and II recession defects with a minimum height of (two) 2 mm are suitable to be selected to perform the Bernotti V-Y flap. The Bernotti V-Y flap consist of a pedicle flap, making a ¨V ¨incision apically to the recession defect and the flap is coronally advanced. Stability and aesthetic outcomes are achieved with the Bernotti V-Y flap. Keywords: Bernotti VY, Gingival recession, Root coverage.

To explore and evaluate the application of a surgical guide in the extraction of impacted mesiodentes. Patients with impacted mesiodentes approachable from the labial side of the maxilla were randomly divided into three groups. The surgical guide for group I was made using cone beam computed tomography (CBCT) and dental cast, whereas the surgical guide for group II was only made using CBCT data. Group I and group II were first evaluated to determine whether guide use could accurately locate the cementoenamel junction (CEJ) of the mesiodentes, and the impacted mesiodentes were extracted with the help of the surgical guide. Group III underwent an operation without a guide. For all patients, the preoperative design time, tooth searching time, operation time, complications, and costs were measured. The guides for group I and group II could locate the CEJ of the mesiodentes accurately, with good application effect during the operation. Group I and group II required additional preoperative design time compared with group III. However, the tooth searching time and operation time in groups I and II were significantly reduced compared with those in group III. Group I and group II showed no intraoperative complications, and two cases in group III showed imprecision during localization. The overall cost for group III was higher than that of group I or group II. But group I and group II required extra visits and costs. Despite some limitations, the surgical guide assisted with mesiodentes extraction and can improve the quality of the operation quality as well as reducing its economic burden, difficulty, and duration. Through proper design, we can create a high-quality surgical guide using only CBCT data. The surgical guide can be used as an important assistive tool in alveolar surgery.

Dentigerous cyst is a common type of odontogenic cyst of the oral and maxillofacial region. It commonly occurs in the second or third decades and rare cases appear in the first decade of age. It is a developmental cyst associated with unerupted/impacted tooth. Radiographically, it appears as unilocular, radiolucent area along the cementoenamel junction of the associated tooth. Larger dentigerous cysts may be treated with marsupialization, and smaller dentigerous cysts are treated with enucleation of the cyst and extraction of the associated tooth. This case report presents a case of dentigerous cyst in the right maxillary region in a young child and was diagnosed using radiographs and removed by surgical excision.

A 9-year-old child reported with chief complaint of broken teeth (11 and 21) and discolored tooth (21). Diagnosis of pulp necrosis with apical periodontitis with regard to 11 and 21 was made based on clinical and radiographic examination. The canals were irrigated with sodium hypochlorite and then dried with paper points. Disinfection of canals was done using photoactivated disinfection (PAD). Platelet-rich fibrin (PRF) was placed as scaffold in canals till the cementoenamel junction (CEJ). A 2-mm thick layer of white MTA was placed, followed by dual seal using glass–ionomer cement (GIC) and composite resin. Follow-up examination was done for 1 year. Clinical examination showed no pain, tenderness on percussion, and no mobility and improvement in color of teeth. Radiographic evaluation revealed continued thickening of the dentinal walls, root lengthening, regression of the periapical lesion, and partial apical closure. This report of pulp revascularization shows that disinfection with photodynamic therapy combined with PRF resulted in satisfactory root development in necrotic immature teeth.

(1) To evaluate the effectiveness of the static-guided (SG) endodontics technique for accessing the root canal through the mineral trioxide aggregate (MTA) and (2) to evaluate the effect of this technique on the fracture strength of teeth. Thirty mandibular premolars were used in the present study. After standard coronal access cavity preparation, root canals were prepared up to size #80 to simulate an immature root apex. White MTA was placed approximately 3 mm below the cementoenamel junction (CEJ), as placed in regenerative endodontic procedures. After the MTA had set, the cavity was restored with a resin composite material. The teeth were randomly divided into two groups (n = 15). In the control group, the composite resin and MTA were removed without any guide. In the SG-access group, a cone beam computed tomography (CBCT) scan was performed, 3D-printed guides were designed and fabricated, and then the composite resin and MTA were removed with a guide. One inexperienced operator performed the removal of the composite resin and MTA in all groups. Pre- and post-operative periapical radiographs were taken. The mishaps and time to penetration to root canal were recorded. After that, the root canals were filled, and the access cavities were restored. The samples were subjected to a fracture strength test. Data were analyzed using Mann-Whitney U, independent samples of T test, and chi-square tests at 95% confidence level (P = 0.05). There were significant differences between the control and SG-access groups in terms of mishaps and time to penetration to the root canal through the MTA barrier (P < 0.05). The SG-access group required the shorter time as compared with the control group. Mishaps did not occur in the SG-access group. The SG-access group exhibited the significantly preserved fracture resistance of the teeth as compared with the control group (P < 0.05). Non-restorable failure occurred more frequently in the control group than in the SG-access group. Within the limitations of the present study, the SG endodontic technique yielded favorable results with respect to time, mishaps, and fracture strength. The static-guided endodontics technique may provide advantages to the clinician for MTA removal.

Background: Factors that influence anchorage of the orthodontic miniscrew implants are interradicular areas and cortical bone thickness. Aims and Objectives: The aim of this study was to evaluate the three-dimensional interradicular areas and the buccal cortical bone thickness in Indian patients using cone beam computed tomography (CBCT) images, and to find the suitable and safe sites for orthodontic miniscrew implant placement. Materials and Methods: CBCT images of 20 patients were divided into three planes as axial, coronal, and sagittal. Measurements, that is, mesiodistal distance and buccal cortical bone thickness were taken at five different heights from the cementoenamel junction (CEJ) toward apical region. Results: In the maxilla, the safe sites for placing miniscrew implant were between the second premolar and first molar at 10-mm height, whereas in the mandible, the safe sites for placing miniscrew implant were between the first and second premolar at 6-, 8-, and 10-mm height, between the second premolar and first molar at 10-mm height, and between the first and second molar at 8- and 10-mm height. Conclusion: CBCT can be effectively used to evaluate interradicular areas and cortical bone thickness in predicting the safe and suitable sites for placing orthodontic miniscrew implants.

Purpose: to show the effect of different concentrations of double antibiotics paste (DAP) 1, 0.1,0 .01mg/ml used in regenerative endodontic on microhardness and fracture resistance of radicular dentin. Material and methods: Forty single rooted teeth were prepared and randomized into three groups according to DAP concentration (10 samples each) and ten samples were availed as control group. Group I: root canal contained 1mg /ml DAP. Group II: root canal contained 0.1mg /ml DAP. Group III: root canal contained 0.01 mg/ml DAP. Samples were stored at 37 0c with 100% humidity for three weeks then DAP was removed by irrigation with 1.5% NaoCl followed by 17 % EDTA, finally flushed with distilled water. After removal of DAP, each tooth was decoronated at the level 0.5 mm radicular to the facial cementoenamel junction with isomet saw under water cooling. Two root cylinders were attained, one cylinder for fracture resistance assessment and the other cylinder for microhardness assessment. Results: For microhardness test, there was a statistically significant difference among different concentrations of DAP (P≤ 0.05).The highest mean value of microhardness was recorded in group III (DAP 0.01mg/ml). For fracture resistance test, there was statistically significant difference among different concentration of DAP (P≤0.05), group III (DAP 0.01mg/ml) showing the highest mean value of fracture resistance. However group III (DAP 0.01mg/ml) showing no significant difference with control group. Conclusion: Lower concentration of double antibiotic (0.01mg/ml) increases microhardness and fracture resistance of radicular dentin in revascularization procedure

PURPOSE: The stability of the periodontal attachment distal to the mandibular second molar after coronectomy of the third molar is still unclear. This study addressed the question of whether periodontal measures are stable over time among patients undergoing coronectomy. MATERIALS AND METHODS: This prospective cohort study enrolled 30 patients treated at the Unit of Oral and Maxillofacial Surgery of the University of Bologna. The predictor variables were the probing pocket depth (PPD), distance between the marginal crest and the bottom of the osseous defect (BOD), and distance between the cementoenamel junction and the BOD. Three points on the distal surface of the second molar were recorded: distobuccal, distomedial, and distolingual sites. The distobuccal site was used as the statistical unit. The Wilcoxon test for paired data and Kendall τb were used to evaluate all variables. The significance level was set at P < .05. RESULTS: The 3-year follow-up was completed by 27 patients (7 male and 20 female patients; mean age, 28 ± 7 years) with 30 third molars. At 3 years, the PPD was 4 ± 1.25 mm; no significant changes in PPD were recorded for all sites from 9 months to 3 years. For the marginal crest-BOD distance and the cementoenamel junction-BOD distance, significant reductions were evident between preoperative values and those at 9 to 36 months (P = .001) and between values at 9 and 36 months (P = .02). CONCLUSIONS: A clinical healthy periodontium distal to the second molar was observed 36 months after coronectomy. However, further studies are necessary to confirm these preliminary clinical results.

Purpose Cavity disinfection, in addition to routine caries removal methods, is recommended to eliminate the microorganisms. The aim of this study was to compare the effect of various systems Er,Cr:YSGG lasers, diode lasers and FotoSan and agents Corsodyl; Cervitec and Cervitec Plus and Fluor Protector—on the nanoleakage of compomer restorations when used for cavity disinfection. Materials and Methods A total of 40 intact human deciduous molar teeth containing Black V cavities (3×2×1.5 mm) on the buccal and lingual surfaces parallel to the cementoenamel junction were randomly divided into 8 groups according to the cavity disinfection methods. The antibacterial agents and systems were applied according to the manufacturer’s instructions. Restorations were completed using a compomer. The restored teeth were then subjected to thermocycling for 500 cycles in a water bath at 5°C and 55°C with a dwell time of 30 seconds. After the thermocycling procedures, 1-mm sticks were obtained from the center of each cavity to prepare for the nanoleakage test. After the teeth were sectioned, they were immersed in 50 wt % ammoniacal silver nitrate solution for 24 hours and dipped in photo-developing solutions for 8 hours with fluorescent light irradiation. The samples were examined under a scanning electron microscope (SEM). The non-parametric Kruskal-Wallis and Mann-Whitney U test (p0.05). The Corsodyl (p

The aim of this present prospective study was to evaluate the outcomes of the multiple coronally advanced flap (MCAF) with a site-specific application of connective tissue graft (CTG) for the treatment of multiple gingival recession defects with or without the presence of noncarious cervical lesions (NCCLs). Analysis of periodontal conditions was performed in order to determine if the cementoenamel junction (CEJ) restorations could affect adequate plaque control as well as maintenance over time. A total of 93 gingival recessions were treated, 61% of which presented a NCCL restored with composite resin positioned 1 mm apical to the position of the anatomical CEJ. The surgical treatment involved MCAF+CTG for 54 sites and MCAF alone for 39 sites. At 12 months, complete root coverage (CRC) and periodontal parameters of restored and nonrestored teeth were assessed, and the differences between the two groups were not significant. It can be concluded that the proposed treatment modality does not produce a negative effect on periodontal condition and amount of CRC, thus resulting in a satisfactory esthetic result.

Objective: To compare simultaneous working length determination efficiency and electrical resistance of thermally treated NiTi files and their counterfeits.Methods: Access cavities were prepared for sixty human mandibular premolar teeth, which were then numbered with a marker. Actual working length was determined visually by introducing a #10 K-file into the root canal and the reference point was marked for further steps. By using flowable composite, the teeth were fixed at the cementoenamel junction to a hole in the center of a glass bottle cap and a second hole prepared on it for lip clip. Alginate impression material was filled into glass bottle then the tooth was embedded into it. Experimental models randomly divided into 6 groups as Group WOG (WaveOne Gold), Group WO (WaveOne), Group W+ (Superline W+), Group RB (Reciproc Blue), Group R (Reciproc), Group V (Superline V). Root canals were prepared until the endomotor stopped when reaching the apical foramen and the silicon stopper was moved to the previously marked reference point to determine the simultaneous working length. The electrical resistance of the files (from tip of file to notch of the shaft) was measured using a multimeter.Results: No readings could be obtained via apex locator for Group V. Group W+ was significantly less accurate compered the other groups (p0.05).Conclusion: Thermal treatments of NiTi alloys had no effect on the accuracy of simultaneous working length determination. However, Counterfeit endodontic files failed to show of accurate simultaneous working length determination.

AIM: This study was conducted to evaluate the effect of different remineralizing agents on micro-shear bond strength (SBS) of nanohybrid composite resin to dentin. METHODS: Thirty-six human molars were divided into four main equal groups (nine teeth each) according to the type of remineralizing agent used; nanohydroxyapatite, sodium fluoride, fluorohydroxyapatite, and control without remineralizing agent. Each group was divided into three equal subgroups (three teeth each) according to the storage time; 1 day, 1 month, and 3 months. Specially fabricated cylindrical plastic mold was made, and teeth were embedded vertically in the mold to the level of cementoenamel junction of the tooth leaving the occlusal surface projecting above the surface of the mold. Cylindrical fissure carbide bur was used in teeth preparation. Teeth were trimmed perpendicular to the long axes of them. Demineralizing agents (Nano hydroxyapatite, sodium fluoride, and fluorohydroxyapatite) were applied then adhesive system applied then composite resin was applied using five sections of a pediatric intravenous tube to act as molds for composite specimen then the specimens stored in artificial saliva at 37°C for different storage times in an incubator. The micro-SBS was assessed using universal testing machine. Then, the mode of failure for each group was determined using stereomicroscope device. Then, the obtained data were tabulated and statistically analyzed. One-way ANOVA was used to compare between more than two non-related samples. The significance level was set at p ≤ 0.05. Statistical analysis was performed with IBM SPSS Statistics. RESULTS: There was statistically significant difference between the four studied groups regarding bond strength at different storage times. Fluorohydroxyapatite had the highest bond strength mean values followed by nanohydroxyapatite, while the lowest value was the sodium fluoride group. CONCLUSION: Fluorohydroxyapatite and nanohydroxyapatite had a positive effect on micro-SBS to dentin, but sodium fluoride had a negative effect. The storage time increase had a positive effect on the micro-SBS of dentin with fluorohydroxyapatite and nanohydroxyapatite, also it had adverse effect on the dentin bond strength with sodium fluoride and control groups.

Digital flow has become a part of currently practiced dentistry. Virtual planning ensures predictable aesthetic and functional rehabilitation, painless postoperative recovery, and better communication with patients, thus meeting their expectations. The purpose of this case report is to demonstrate the digital planning for the correction of a gummy smile with a personalized preparation using a piezoelectric surgical guide (PerioGuide) for gingival contouring and flapless osteotomy. The guide was designed using Nemo Studio software, based on the patient’s facial aesthetic analysis, through photos, videos, and facial scanning. These images were aligned with the scan and placed over the cone beam computed gingival tomography for prediction of results, based not only on the distance from the cementoenamel junction to the bone crest but also on the best gingival margin contour according to virtual aesthetic planning. Digital planning, combined with the use of a piezoelectric device, allows for a flapless guided surgical technique for gingival contouring and osteotomy. As a result, the surgical procedure is safer, faster, and more predictable with better postoperative outcomes.

The aim of the current study was to evaluate the impact of a new silicate-based capping material on healing potential of traumatically exposed healthy dog's dental pulp. Materials and Methods: Two pulp capping materials were evaluated in this study; Mineral trioxide aggregate (MTA), and Five mineral oxides (5MO). Glass ionomer as overlying restorative material. Six adult healthy dogs with intact permanent dentition were selected for the study. A total of sixteen anterior teeth were used in each dog. Both pulp capping materials were used in the same dog. Class V cavities were prepared on the teeth. After pulp exposure, the pulp capping materials were applied directly to the exposed pulp. All cavities were sealed with glass ionomer restorative material. The used six dogs were divided into two groups; three dogs each, according to the capping periods to 7 days and 90 days. At the end of each period the dogs were sacrificed by injecting an overdose of pentobarbital sodium. Teeth were separated from bone with immediate sectioning of their roots in the mid-way between cementoenamel junction and apex. The teeth were fixed in 10% neutral buffered formalin. Then the teeth were demineralized in Morse's solution (50% formic acid and 20% sodium citrate) for 3 months. In the last, the teeth were embedded in paraffin wax and serially sectioned buccolingually and stained with hematoxylin-eosin. The specimens were examined under optical light microscope to estimate the amount of pulp inflammation and dentin bridge formation at the interface of the capping materia

The purpose of this study was to evaluate the tooth structure theoretically required to be removed in the coronal and cervical regions to accomplish 3 different endodontic access preparations in a novel digital model. The deviation of the center of access cavity from the central fossa will also be measured and compared among the 3 endodontic cavity designs, which in turn may serve as suggested points of entry for different access openings.Twenty-one maxillary molars and 15 mandibular molars were selected and 3-dimensionally imaged with cone-beam computed tomographic imaging. Three-dimensional (3D) volume reconstructions were made and converted into stereolithography files. Digital access cavity preparation was performed on each 3D reconstruction model with the 3 most commonly used endodontic access preparations: minimally invasive (MI), modified straight-line (MS), and traditional straight-line (TS) techniques. After the access cavity outlines were determined, digital sectioning of each reconstructed 3D tooth model was performed orthogonal to the long axis of the tooth at 3 levels: (1) passing through the central fossa, (2) 1.5 mm apical to the central fossa, and (3) 2 mm apical to the cementoenamel junction. The linear distance from the centroid of the access opening to the central fossa was measured to calculate the point of entry, and the amount of tooth structure removal at the pericervical area was measured to calculate the theoretically minimum amount of linear dentin removal required. Two-way repeated measures analysis of variance was performed for the interactions between different access designs and the amount of cervical dentin removal. Other data were statistically analyzed with 1-way repeated measures analysis of variance. The Tukey post hoc test was used for multiple comparisons. Significance was set at .05.The amount of deviation of the center of the access cavity from the central fossa in all test groups was less than 1 mm. The dimensions of access openings differed significantly among the 3 access forms (TS MSMI, P.0001). The amount of required cervical dentin removal was the greatest in the TS method followed by the MS and MI methods (P.0001).The central fossa could serve as good starting points in all access preparations in both maxillary and mandibular molars. Dentin removal in the coronal and cervical regions was the greatest in the TS design followed by the MS and MI designs. When comparing different canals in the same access form, less cervical dentin was sacrificed in the palatal canals of maxillary molars and the distal canals of mandibular molars.

Objective To analyze the prevalence of distal caries in mandibular second molars (M2Ms) and its correlation with the three-dimensional position of mandibular third molars (M3Ms) by cone beam computed tomography (CBCT) images. Materials and methods CBCT scans involving 421 M3Ms were assessed. The presence of distal caries of M2Ms, patient age and gender, impaction depths and mesial angulation of M3Ms, the cementoenamel junction (CEJ) distances and contact point localization, and the horizontal positions of M3Ms were assessed. Risk factors were identified by multivariate logistic regression analysis. Results The overall prevalence of distal caries in M2Ms was 31.6%. Mesial angulation (16°–75°) of M3Ms, contact point localization at or below the CEJ of M2Ms, and a buccal or lingual position of M3Ms relative to the molar line were identified as risk factors for the prevalence of distal caries in M2Ms (p p Conclusions Buccal or lingual position of M3Ms may represent a new risk factor for the distal caries in M2Ms. Mesial angulation (16°–75°) of M3Ms is a predictive parameter for both the presence and severity of distal caries in M2Ms. Clinical relevance As the presence of distal caries in M2Ms is significantly associated with the three-dimensional position of M3Ms, watchful monitoring or prophylactic removal of M3Ms should be deliberated when M3Ms are mesially angulated (16°–75°), buccally or lingually positioned, and with the contact point localization at or below the CEJ of M2Ms.

Background Enamel is a highly mineralized tissue of the body which is composed of 96% inorganic salts and 4% organic matter. Enamel is permeable to water and ions, particularly cations and low molecular weight substances. The enamel continues to mature even after eruption with mineral replacing protein. Recently, the interest on the development of calcium phosphate-based remineralization technology has been increased that led to the development of various remineralizing agents like Fluoride, CPP-ACP (Tooth Mouse plus), Bioglass (Novamin), Ozone, Xylitol, Sensistat etc. Aim Aim of the present in vitro study was to evaluate and compare the remineralizing effect of Organic fluoride (AmF) and inorganic fluoride (NaF) by evaluating Vickers microhardness and quantitative analysis of Calcium and Phosphorus ratio on enamel surface using Scanning Electron Microscope-Energy Dispersive X-ray analysis. Materials and methods Sixteen maxillary central incisors were decoronated at the cementoenamel junction and mounted in cylindrical moulds filled with self-cure acrylic resin. Artificial demineralized lesions were created on the enamel surface by suspending them in 0.1 M Citric acid buffer at pH of 3.2 for 72 hrs. The samples were then randomly divided into two groups and labelled, Group A – remineralized with NaF for 3 minutes twice daily for one week and Group B - remineralized with AmF for 3 minutes twice daily for one week. Microhardness and SEM-EDX analysis were done before demineralization, after demineralization and after remineralization. Results Data were analyzed by comparing the mean values between the groups using independent sample t-test. The intra-group analysis was done using repeated-measures ANOVA with posthoc Bonferroni test, and a p-value of

AIM The present study aimed to evaluate the sealing potential and marginal adaptation of different root canal sealers to dentin. MATERIALS AND METHODS A total of sixty human lower premolars of the permanent dentition that were extracted were used for this study. The visible debris and calculus were removed from the extracted teeth ultrasonically and were kept for 2 hours in 2.5% sodium hypochlorite and stored in normal saline till next use. A low-speed diamond disc was used to section all the teeth samples at the cementoenamel junction. Later, cleaning and shaping of the canals was done. Based on the sealer used, the samples (each group consisting of 20 samples) were divided randomly into three groups: group I-bioceramic sealer, group II-resin-based sealer, group III-MTA-based sealer. All split samples were visualized under scanning electron microscope (SEM) at apical and coronal thirds of root canal, the marginal gap at root dentin and sealer interface were assessed. RESULTS The highest marginal adaptation (5.60 ± 0.12) was demonstrated by EndoSequence BC sealer, followed immediately by ProRoot MTA sealer (4.48 ± 0.12) and EndoREZ sealer (2.10 ± 0.54). A statistically significant difference (p = 0.001) was seen between the EndoSequence BC and ProRoot MTA sealer for apical and coronal marginal adaptation. Also, a statistically significant difference (p < 0.05) was found between EndoSequence BC sealer vs EndoREZ sealer at coronal and EndoSequence BC sealer vs EndoREZ sealer and EndoREZ sealer vs ProRoot MTA sealer at apical third. CONCLUSION The present study concluded that significant and better sealing ability and marginal adaptation was demonstrated by EndoSequence BC (bioceramic sealer) when compared to ProRoot MTA sealer (MTA-based sealer) and EndoREZ sealer (resin-based sealer). CLINICAL SIGNIFICANCE Numerous endodontic sealers enter the market with various factors to attain acceptable seal. According to current study bioceramic sealer, is the appropriate sealer that hermetically seals all the margins.

celik, Cigdem/0000-0002-5936-0196 WOS:000575915100005 PubMed: 33132390 Objectives: The purpose of the present study was to evaluate the microleakage of conventional glass-ionomer, resin modified glass-ionomer and glass hybrid ionomer Class II open sandwich restorations with or without saliva contamination. Material and methods: Sixty extracted sound human molar teeth were used and 120 class II slot cavities were prepared in mesial and distal surfaces. The gingival margins were located 1 mm below the cementoenamel junction. All specimens were randomly divided in 4 groups (n=15): Group I: High-Viscous Glass Ionomer (Fuji IX GP) Group II: Resin Modified Glass Ionomer (Fuji II LC) Group III: Glass Hybrid Ionomer (Equia-fil Forte), Group IV: Composite Resin (G'aenial Posterior). In open sandwich restoration groups, glass ionomer materials were placed to gingival floor in 1 mm thickness and rest of the cavity was filled with resin composite. After the restorations in mesial surfaces had been performed, distal cavities were restored with the same protocol after saliva contamination. The specimens were thermo-cycled for 10000 cycles at 5 degrees C to 55 degrees C and immersed in methylene blue dye solution (% 0,5) for 24 hours. Then, they were sectioned vertically through the center of the restorations from mesial to distal surface with a water-cooled diamond saw with 1mm thickness. Subsequently, the dye penetration was evaluated with image analysis software. Data were statistically analyzed (p0.05). Additionally, there was not a statistically significant difference between the no contamination and saliva contaminated groups regardless of dental materials tested (p>0.05). Conclusion: Within the limitations of this study, in open sandwich restorations, saliva contamination did not show an adverse effect on microleakage irrespective of dental materials tested. Glass hybrid ionomers and resin modified glass ionomers showed lower microleakage scores in gingival margins compared to high-viscous glass ionomer material in no contamination groups.

AIM To compare the angulation of maxillary left (UL) and right (UR) incisors and the width of alveolar bone. MATERIALS AND METHODS This study was conducted using archived cone-beam computed tomography (CBCT) images of 50 male and 50 female patients. The UL and UR incisors were compared in terms of incisor/palatal plane angle, collum angle, labiopalatal crown-root position, and alveolar bone width (ABW). The comparison, with reference to gender and age, was analyzed using one-way analysis of variance and independent sample t test. RESULTS There is no substantial variance in the average differences of the assessed variables for UR and UL central incisors (p > 0.05). No significant association was found between crown labial to root and root labial to crown positions for both central incisors (p > 0.05). Statistical analyses revealed that tooth type has no significant association with the central incisors-related variables. Alveolar bone width, at various areas assessed, showed significant relation to gender. On the other hand, incisor/palatal plane angle and ABW at the cementoenamel junction and at level of Point A (subnasale) were significantly affected by age. CONCLUSION Gender can significantly affect the development of ABW. Also, incisor/palatal plane angle and ABW at certain areas are correlated with age. CLINICAL SIGNIFICANCE Understanding the similarities or differences between right and left maxillary central incisors may give better indication if cephalometric images are accurate in attaining such measurements. This in turn will also help orthodontist to choose the proper tool for treatment decision-making related to incisor tooth movement.

Background: The complex structure and irregularities of root canal walls are liable for infection by several bacterial species. Thus, the use of irrigants and auxiliary chemical solutions associated with instrumentation is necessary for effective eradication of the biofilm as well as complete removal of the smear layer. Aim: To evaluate the effects of calcium hypochlorite and chitosan oligosaccharide (COS) in disinfecting Enterococcus faecalis root canal biofilm and smear layer removal with minimal erosion. Materials And Methods: A total of 70 mandibular premolars were decoronated at the cementoenamel junction. The samples were biomechanically prepared, sterilized in an autoclave, and incubated with E. faecalis (ATCC-29212) bacteria for 21 days. Cleaning and shaping were done till maximum apical file size of #45 K. Specimens were randomly divided into 4 groups: GROUP I: Control Group, GROUP II: 5% Sodium Hypochlorite (NaOCl) solution followed by 17% EDTA solution, GROUP III: 5% Calcium Hypochlorite [Ca(OCl)2] solution followed by 17% EDTA solution and GROUP IV: 5% Ca(OCl)2 solution followed by 1% COS. The samples were subjected to microbial count followed by smear layer removal under scanning electron microscope (SEM) at coronal, middle and apical third. Statistical Analysis Used: Kruskal–Wallis Test and post-hoc Scheffe's test. Results: It was observed that Group IV showed the lowest amount of CFU count/mL and the highest amount of smear layer removal with a statistically significant difference (P < 0.05) when compared with the other three Groups. Conclusion: 5% Ca(OCl)2 solution with 1% COS solution effectively removed the Enterococcus faecalis biofilm and smear layer from the root canals with minimal erosion.

AIM The aim of the study was to assess the conditioning efficacy of photodynamic therapy (PDT) and Er,Cr:YSGG laser (ECYL) to dentin compared with conventional regime bonded to resin-modified glass ionomer (RMGIC). MATERIALS AND METHODS Forty mandibular teeth were cleaned, disinfected, and mounted vertically within the segments of polyvinyl pipes up to cementoenamel junction. The occlusal surfaces were flattened, and samples were divided into four groups according to conditioning protocols. Samples in groups I and II underwent PDT, samples in group III were conditioned with low-level laser therapy (LLLT) using Er,Cr:YSGG laser (ECYL), and samples in group IV were conditioned using polyacrylic acid (PAA). Fuji II LC was applied incrementally and light cured for 20 seconds. All samples were placed in universal testing machine for shear bond strength (SBS) testing. The fracture surface was analyzed using stereomicroscope at 50× magnification to determine mode of failure. Among different investigational groups Tukey test was used as post hoc along with analysis of variance (ANOVA). Significance level was established at p 0.05). Fracture analysis revealed that in PDT group adhesive failure type was in majority. However, admixed failure type was commonly presented in groups III and IV. CONCLUSION PDT of dentin using photosensitizers MBP and CP deteriorates bond values when bonded to RMGIC. The use of LLLT to condition dentin has the potential to improve SBS. CLINICAL SIGNIFICANCE Dentin conditioning with LLLT using ECYL may improve, is of utmost importance for better treatment outcome, predictable prognosis, and improved bond integrity to RMGIC.

Aim This study aimed to investigate the influence of using dual-cure composite core materials for fiber post luting on the fracture resistance of endodontically treated maxillary central incisors. Materials and methods Fifty sound and recently extracted maxillary central incisors were endodontically treated and distributed into five groups. In the control group, access cavities were restored with the composite resin. Experimental groups had the coronal structure trimmed 2 mm above the cementoenamel junction. Teeth were restored with fiber posts and different combinations of luting and core materials: RelyX Unicem for post luting and MultiCore for core buildup; MultiCore for post luting and core buildup; RelyX Unicem for post luting and LuxaCore for core buildup; or LuxaCore for post luting and core buildup. All teeth were restored with zirconium crowns and subjected to thermocycling (6000 cycles 5/55°C). Loading of the teeth was applied at 135° to the palatal surface, using a universal testing machine at a cross-speed of 0.5 mm/minute until failure. The mode of failure was analyzed under a digital microscope. Results The fracture resistance of the control group was significantly higher than the experimental groups (p 0.05). All teeth demonstrated nonrestorable failures. Conclusion With the presence of the ferrule effect and crown restoration, the selected materials for post luting and core buildup have no significant influence on the fracture resistance of the endodontically treated teeth. Clinical significance The use of the same dual-cure composite core materials for fiber post luting and core buildup would simplify the clinical procedure without enhancement of the fracture resistance of the endodontically treated tooth.

Aim The purpose of this in vitro study was to determine the effect of different composite placement techniques on gingival microleakage of giomer restorations. Materials and methods Sixty class II preparations were created in 30 extracted molar teeth with cervical margins 1 mm below the cementoenamel junction. The teeth were divided into three groups of 10 teeth each. In group I, teeth were restored with open sandwich technique using Beautifil II and Beautifil II Flow. In group II, teeth were restored with snowplow technique using Beautifil II and Beautifil Flow. In group III, teeth were restored with oblique increment technique using Beautifil II. After thermocycling and immersion in 2% methylene blue, the teeth were sectioned and dye penetration was evaluated. Results Statistically significant reduction in microleakage was found along the gingival walls in snowplow restorations compared to sandwich restoration and oblique increment restorations. Clinical significance Microleakage was reduced along the gingival walls in snowplow restorations. Conclusion Microleakage was significantly lower in the snowplow restorations.

Introduction: Buccal shelf bone screws have become increasingly popular as a preferred method of skeletal anchorage in the mandibular arch. Anatomic variations and clinical experience suggest that width and slope of the bone at buccal shelf vary in different population groups, with some individual variations. Aims and Objectives: The objective of this study was to evaluate angulation of the bone screw of mandibular buccal shelf area, total bone width, thickness of the cortical bone, and proximity to neurovascular structures. Materials and Methods: Cone-beam computed tomography scans were used to obtain measurements of the buccal shelf region of 35 patients (18 females, 17 males; mean age, 23.6 years). Measurements were taken at three locations (L1, L2, and L3) and total bone width was measured at two levels from the cementoenamel junction (CEJ, H1 and H2). Bone screws were virtually placed and their proximity evaluated from digitally traced inferior alveolar neurovascular bundle. Results: Permissible angulation for placement of buccal shelf bone screw considering the safety distance from the root and avoiding excessive buccal projection to minimize cheek irritation was found to be 74.48 (SD ± 4.26). Total bone width was maximum at the distobuccal cusp of mandibular second molar (L3H2; 6.40 ± 1.35) when measured at the level of 8 mm from the CEJ. Bone screws were well within the safety range from causing any iatrogenic damage to the inferior alveolar neurovascular bundle at all the three aforementioned locations. Conclusion: Thus, area buccal to the mandibular second molar region seems to be the most favorable site for placement of buccal shelf bone screws in Indian patients.

Introduction In our society, with the advances in cosmetic consciousness, well-aligned, properly contoured, white and clean teeth are a symbol of health and standard of beauty. Thus, tooth bleaching has become popular cosmetic therapy among patients and dentists. Microleakage is a major challenge to the success rate for all type of restorations. Materials and Methods Eighty maxillary human molars were collected and evaluated and Class V cavities 5×3×2 mm size were prepared with straight carbide bur (SS White) on the buccal and palatal surfaces at the cementoenamel junction of all the samples, so that the upper margin would be in enamel and lower margins on root surface. In total, 160 class V cavities were prepared on maxillary molars. Then samples were randomly divided into 3 groups (microfilled and nanohybrid composite resins and control group) and 3 subgroups (Pola Office, Whiteness HP Blue, Whiteness Perfect) according to the type of composite resins and bleaching agents used. After application of bleaching agents, all samples were immersed in a contrast solution of rhodamine B fluorescent dye for 24 hours. Then using a diamond disc samples were sectioned buccolingually through the center of the restorations and sectioned teeth were evaluated for marginal microleakage under confocal laser scanning microscope to check the extent of dye penetration. Results When all composite resin groups were compared with all the bleaching agents, at occlusal and gingival levels, lowest marginal leakage scores were obtained with the microfilled composite resin bleached with Whiteness HP blue, and in nanohybrid composite lowest microleakage score were obtained with Pola office bleach at both levels.

Introduction: Overzealous application of endodontic irrigants affects the root canal dentin mechanical properties. The effect of volume of endodontic irrigants on the microhardness of root canal dentin has not been studied. Aim: This study assessed the effect of volume of endodontic irrigants used in different final irrigation activation techniques on root canal dentin microhardness (RCDM). Methodology: Sixty human maxillary central incisors were embedded in acrylic resin in Kuttler's endodontic cube to the level of cementoenamel junction. The root samples were randomly divided into 4 experimental groups (n = 15): Group-NI-needle irrigation, Group-PUI–continuous passive ultrasonic irrigation, Group-EndoVac–apical negative pressure system, Group combination– EndoVac + PUI irrigation. Root canals were instrumented up to size 40 (F4). The resin mounted specimens were sectioned longitudinally into two halves and were reassembled in Kuttler's kube to carry out final irrigation activation. A predetermined standardized volume of irrigants was used in each group. The RCDM was measured after root canal instrumentation and after final irrigation using Vicker microhardness tester (coronal, middle, and apical third). The reduction in RCDM values (p < 0.0086) were analyzed using Kruskal Wallis and Mann Whitney-U tests. Results: Reduction in RCDM was observed with all the endodontic irrigating techniques tested. EndoVac and combination irrigation techniques showed maximum reduction in RCDM in all thirds of root canal. Conclusion: It is concluded that the volume of irrigants and agitation plays a role in reducing RCDM. The overall volume of irrigants to cause maximum reduction was 25 ml, beyond which neither volume nor agitation affects RCDM.

Periodontal disease affects nearly 50% of Americans but diagnostic methods have remained the same for decades. Periodontal examination via physical probing provides critical metrics such as pocket depth, clinical attachment level, and gingival recession; however, this practice is time consuming, variable, and often painful. In this study, we investigated high-frequency ultrasound (40 MHz) for the image-based measurement of periodontal metrics. Imaging was performed at midbuccal sites for a set of periodontally healthy (n = 10) and diseased (n = 6) subjects and image-based measurements were compared to gold-standard physical probing measurements. Human operators identified relevant markers (e.g., cementoenamel junction, gingival margin, alveolar bone crest) in B-mode ultrasound images from 66 teeth to calculate gingival height and alveolar bone level. These metrics were correlated to clinical measurements of probing pocket depth and clinical attachment level for disease staging (1.57-mm bias and 0.25-mm bias, respectively). Interoperator bias was negligible (

The retromolar canal is an anatomical variation that occurs in the mandibular bone. The retromolar canal typically originates in the mandibular canal on the distal side of the third molar and extends forward and upward to the retromolar foramen (RMF), which contains the neurovascular bundle. Accidentally damaging the neurovascular bundle in the retromolar canal during the extraction of the third molar, dental implant surgery, or maxillofacial orthognathic surgery may lead to subsequent complications such as incomplete local anesthesia, paresthesia, and bleeding during operation. The objective of this study was to investigate the prevalence of the RMF in the Taiwanese population in a medical center by using dental cone-beam computed tomography (CBCT) and to identify the position of the RMF in the mandibular bone. The dental CBCT images for the mandibular bone of 68 hemi-mandible were uploaded to the medical imaging software Mimics 15.1 to determine the prevalence of the RMF in the Taiwanese population and the three positional parameters of the RMF in the mandibular bone: (1) The diameter of the RMF, (2) the horizontal distance from the midpoint of the RMF to the distal cementoenamel junction of the second molar, and (3) the vertical distance from the midpoint of the RMF to the upper border of the mandibular canal. Seven RMFs were observed in the 68 hemi-mandibles. Thus, the RMF prevalence was 10.3%. In addition, the diameter of the RMF was 1.41 ± 0.30 mm (mean ± standard deviation), the horizontal distance from the midpoint of the RMF to the distal cementoenamel junction of the the second molar was 12.93 ± 2.87 mm, and the vertical distance from the midpoint of the RMF to the upper border of the mandibular canal below second molar was 13.62 ± 1.3487 mm. This study determined the prevalence of the RMF in the Taiwanese population in a medical center and its relative position in the mandibular bone. This information can provide clinicians with a reference for posterior mandible anesthesia and surgery to ensure medical safety.

Objective: To assess and quantify coronal tooth discolouration by ProRoot MTA, Biodentine and MTA repair HP as pulpotomy agents and to identify colour stability of these materials in presence of blood contamination. Methods: 120 human premolar teeth were used in the study. The teeth were sectioned horizontally 1 mm apical to the cementoenamel junction. A retrograde cavity extending within 2 mm of the incisal edge was prepared. The specimens were randomly distributed as; Control; Group 1, ProRoot MTA: Group 2, Biodentine: Group 3 and MTA repair HP: Group 4. The groups werefurther subdivided on basis of exposure to saline (subgroup A) or blood (subgroup B). The access was sealed with light cured Glass ionomer cemet and the specimens were stored in artificial saliva at 37°C. The Colour change was evaluated with a spectrophotometer at: day 0 (T0), day 1 (T1), day 7 (T7), 1 month (T30), 2 months (T60), and 6 months (T180). The colour measurements were recorded using the Commission Internationale de l’Eclairage L*a*b* value. Results: For all groups, there was a sharp increase in L* parameter at T1. At 6 months, Group 1B (Control + blood) showed maximum decrease in luminosity followed by Group 2A (ProRoot + saline) > Group 4B (MTA repair HP + blood) > Group 2B (ProRoot + blood). Group 3A (Biodentine + saline) showed the least amount of decrease in luminosity followed by Group 4A (MTA repair HP + saline) and Group 3B (Biodentine + blood). No significant difference was found in ∆E change between any of the groups from baseline to 180 days (P>0.05). Conclusion: Relative to L* parameter, it was possible to observe a statistically significant decrease in luminosity in the Group1B (Control + blood) followed by ProRoot MTA (Group 2A and 2B) and MTA repair HP (Group 4A and 4B). Biodentine (Group 3A and 3B) showed least tooth discolouration in terms of L* parameter.

Made available in DSpace on 2022-05-01T08:44:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 The presence of a tooth-surface defect, such as a non-carious cervical lesion (NCCL), associated with sites of gingival recession (GR) defects creates a combined soft tissue/tooth defect (CD) that requires a different treatment plan. This study aimed to critically review the literature regarding the available treatment protocols for CDs and suggest a new decision-making process. NCCLs were classified as Class A-: the cementoenamel junction (CEJ) was visible and the root surface discrepancy was < 0.5 mm (no step); Class A+: CEJ was visible and the root surface discrepancy was > 0.5 mm (with a step); Class B-: unidentifiable CEJ without a step; Class B+: unidentifiable CEJ with a step. NCCLs affecting both root and crown surfaces (Class B) lead to CEJ destruction and consequently eliminate an important landmark used before and after root coverage procedures. The depth of the root surface discrepancy is vital owing to its possible impact on soft tissue adaptation after healing, which, in turn, may influence the treatment options, namely the use of graft and/or composites to compensate for the discrepancy. Clinically, a step with horizontal depth greater than 0.5 mm should be recognized as the minimum threshold value to define this condition. Extremely deep defects tend to assume a V-shaped topography. Therefore, extremely deep V-shaped defects were classified into subclasses A+V, a V-shaped defect, and B+V, a V-shaped defect with loss of CEJ, for management considerations. The treatment options, supported by the literature, and a decision-making process to deal with each condition are presented. Universidade Estadual Paulista — Unesp Institute of Science and Technology Department of Diagnosis and Surgery Universidade Estadual de Campinas — Unicamp Piracicaba Dental School Department of Prosthodontics and Periodontics Universidade de São Paulo — USP School of Dentistry Department of Stomatology Tuscany Academy of Dental Research — ATRO Universidade Estadual Paulista — Unesp Institute of Science and Technology Department of Diagnosis and Surgery

Human dentin consists of a primary layer produced during tooth formation in early childhood and a second layer which first forms upon tooth eruption and continues throughout life, termed secondary dentin (SD). The effect of attrition on SD formation was considered to be confined to the area subjacent to attrition facets. However, due to a lack of three-dimensional methodologies to demonstrate the structure of the SD, this association could not be determined. Therefore, in the current study, we aimed to explore the thickening pattern of the SD in relation to the amount of occlusal and interproximal attrition. A total of 30 premolars (50–60 years of age) with varying attrition rates were evaluated using micro-computerized tomography. The results revealed thickening of the SD below the cementoenamel junction (CEJ), mostly in the mesial and distal aspects of the root (p &lt, 0.05). The pattern of thickening under the tooth cervix, rather than in proximity to attrition facets, was consistent regardless of the attrition level. The amount of SD thickening mildly correlated with occlusal attrition (r = 0.577, p &lt, 0.05) and not with interproximal attrition. The thickening of the SD below the CEJ coincided with previous finite element models, suggesting that this area is mostly subjected to stress due to occlusal loadings. Therefore, we suggest that the SD formation might serve as a compensatory mechanism aimed to strengthen tooth structure against deflection caused by mechanical loading. Our study suggests that occlusal forces may play a significant role in SD formation.