Mesial Side Research Articles

Evaluation of a platform-switched Morse taper connection for all-on-four or six treatment in edentulous or terminal dentition treatment: A retrospective study with 1-8 years of follow-up.

The survival rate, marginal bone loss and soft tissue health of the Ankylos implants and the balanced base abutments in all-on-four or six implant restoration of edentulous or terminal dentition patients has not been reported in the clinical research. This retrospective study aimed to evaluate the Ankylos implants and the balanced base abutments in all-on-four or six implant restoration of edentulous or terminal dentition patients after 1-8 years of follow-up. A retrospective study was conducted based on the medical records of 33 patients who received all-on-four or six treatments from April 2014 to May 2020. Four radiographic examinations [immediate postoperative (T0), definitive restorations (T1), 1-3 years after prosthetic restorations (T2), and more than 3 years after prosthetic restorations (T3)] were obtained to evaluate vertical bone height (VBH). We also calculated the survival rate and examined the condition of soft tissue with this implant system in edentulous or terminal dentition patients. Three-level linear model analyses were used to explore potential risk factors for VBH changes on the mesial and distal sides. The generalized linear model was used to analyze the influencing factors of BOP and plaque. A total of 218 implants were included in this study. The cumulative survival rate of the implants was 97.25% before the definitive prosthesis, 96.33% within 3 years of follow-up and 95.32% after more than 3 years of follow-up. The mean ± standard deviation (SD) bone losses of the VBH were 0.27 ± 0.05 mm (T1-T3) on the mesial side and 0.49 ± 0.06 mm (T1-T3) on the distal side. During 1-8 years of follow-up, the height and angle of the abutment (p < 0.001), the mandible implant site (p < 0.001), the length of the implant (p = 0.014 < 0.05) and age (p = 0.029 < 0.05) showed statistically significant effects on vertical mesial bone height (VMBH) and vertical distal bone height (VDBH). The risk of BOP among participants who brushed three times a day was lower than those who brushed less than three times. The plaque risk of short abutment height was higher than the long abutment. The current study showed that the Ankylos implants with the balanced base abutments in all-on-four or six implants treatment is a viable and predictable option with a high survival rate and low marginal bone loss in edentulous or terminal dentition patients. VBH around the implants was strongly associated with the mandible implant site, abutment height and angle, the length of the implant and age. Moreover, teeth-brushing times and abutment height significantly affect soft tissue health.

COMPARATIVE EVALUATION OF INITIAL CRESTAL BONE LOSS AROUND DENTAL IMPLANTS USING FLAPLESS OR FLAP METHOD: AN IN VIVO STUDY

Purpose:The objective of this study was to compare the effect of flapless implant insertion on initial bone loss with that of conventional placement after elevation of a mucoperiosteal flap. Materials and Methods:Total of 20 implants were replaced in the edentulous area within the mouth randomly categorized under two groups which differ in flap or flapless surgical placement. Group 1(n=10) Patients with dental implants using flap method. Group 2 (n=10) Patients with dental implants using flapless method. To assess changes in the peri-implant bone level, the height of the mesial and distal peri-implant bone was measuredwith digital radiograph taken at the time of implant placement and 3month and 6month afterward. Results: The crestal bone loss on mesial side and distal side was higher in the flap elevation methods at baseline, 3month and 6month as compared to the flapless methods and the difference was statistically significant at the 3month. Conclusion: Within the limitations of this study, it can beconcluded that flapless implant surgery results in lesser lossof marginal bone and also results in better patient comforthowever, proper patient selection and technique is essentialfor a successful flapless implant surgery.

Effects of Flapless Laser Corticotomy in Upper and Lower Canine Retraction: A Split-mouth, Randomized Controlled Trial.

Aim One of the major difficulties in orthodontic treatment is the lengthy course of therapy, particularly in situations involving extractions. Hence, various methods for accelerating tooth movement rate had been devised. Flapless corticotomy is one of those methods. This study aimed to evaluate the effects of flapless laser corticotomy (FLC) compared to the conventional retraction (CR) method on the rate of canine retraction. Methods A split-mouth, randomized controlled trial included 56 canines from 14 patients (12 females and two males) with a mean age of 20.4 ± 2.5 years, who were complaining of bimaxillary protrusion requiring extraction of four premolars. All canines were randomly assigned to four groups (maxillary FLC, maxillary control CR, mandibular FLC, and mandibular control CR). Randomization was performed by creating two equal, random computer-generated lists with a 1:1 allocation ratio-one list for the right side and one for the left. The allocation concealment was achieved using opaque sealed envelopes until the time of intervention. FLC was applied on the experimental sides before canine retraction by drilling six holes penetrating 3 mm into the bone on the mesial and distal sides of the canines. Subsequently, all canines were retracted employing closed coil springs to deliver a force of 150 g using indirect anchorage from temporary anchorage devices (TADs).All canines were assessed at T0 (before retraction), T1 (one month after retraction), T2 (two months), and T3 (three months) using three-dimensional (3D) digital models. Additionally, canine rotation, molar anchorage loss assessed using 3D digital models, root resorption assessed using cone beam computed tomography (CBCT), probing depth, plaque, gingival indices, and pulp vitality were all evaluated as secondary outcomes. It was possible to blind only the outcome analysis expert (single-blinded). Results The measurementsof canine retraction during the follow-up period from T0 to T3 were 2.46 ± 0.80 mm and 2.55 ± 0.79 mm in maxillary FLC and control groups, respectively, and 2.44 ± 0.96 mm and 2.31 ± 0.95 mm in mandibular FLC and control groups, respectively. The results demonstrated a statistically non-significant difference in the distance of canine retraction between the FLC and control groups at all time points. Moreover, no differences were observed between groups in canine rotation, molar anchorage loss, root resorption, probing depth, plaque, gingival indices, and pulp vitality (p > 0.05). Conclusion In the FLC procedure performed in this study, the rate of upper and lower canine retraction could not be accelerated and no significant differences were observed between FLC and control groups in canine rotation, molar anchorage loss, root resorption, periodontal condition, and pulp vitality.

Finite Element Analysis of Maxillary Teeth Movement with Time during En Masse Retraction Using Orthodontic Mini-Screw

Introduction: The aim of this study was to determine the placement of an orthodontic mini-screw (OMS) and the length of an anterior retraction hook (ARH) with en masse retraction. Continuous maxillary tooth movement pattern was simulated by finite element analysis (FEA). Materials and methods: Extraction of the first premolar was hypothesized with a finite element model. The placement of OMS was analyzed for the following two groups: (1) a high OMS (HOMS) group with OMS placed horizontally at the mesial side of the second premolar and apically 10 mm above the arch wire, and (2) a low OMS (LOMS) group with OMS placed horizontally between the second premolar and the first molar and apically 8 mm above the arch wire. According to the height of ARH, each group was divided into three subgroups. Results: When the extraction space of the first premolar was closed, anterior teeth were intruded in the HOMS group but extruded in the LOMS group. In all cases, the first molar was intruded. According to the intrusion of the first molar and extrusion of anterior teeth, the occlusal plane rotated clockwise (CW) in the LOMS group. However, in the HOMS1 group, the occlusal plane rotated counterclockwise (CCW) due to more intrusion of anterior teeth than that of the first molar. Conclusion: By analyzing six cases of different OMS and ARH, changes of incisor and molar in en masse retraction with the extraction of the first premolar could be predicted. In addition, OMS placement and ARH length can be determined based on results of incisal showing. This study can also help esthetic orthodontic results.

Preclinical evaluation of the effect of periodontal regeneration by carbonate apatite in a canine one-wall intrabony defect model.

This study aimed to histologically compare periodontal regeneration of one-wall intrabony defects treated with open flap debridement, β-tricalcium phosphate (β-TCP), and carbonate apatite (CO3Ap) in dogs. The mandibular third premolars of four beagle dogs were extracted. Twelve weeks after the extraction, a one-wall bone defect of 4mm×5mm (mesio-distal width×depth) was created on the distal side of the mandibular second premolar and mesial side of the fourth premolar. Each defect was randomly allocated to open flap debridement (control group), periodontal regeneration utilizing β-TCP, or CO3Ap. Eight weeks after the surgery, histologic and histometric analyses were performed. No ankylosis, infection, or acute inflammation was observed at any of the experimental sites. Newly formed bone and cementum were observed in all experimental groups. The mineral apposition rate of the alveolar bone crest was higher in the CO3Ap group than in the control and β-TCP groups. The ratio of the new bone area was significantly higher in the CO3Ap group than in the control group (P<0.05). The bone contact percentage of the residual granules was significantly higher in the CO3Ap group than in the β-TCP group (P<0.05). Although this study has limitations, the findings revealed the safety and efficacy of CO3Ap for periodontal regeneration in one-wall intrabony defects in dogs, and CO3Ap has a better ability to integrate with bone than β-TCP.

Radiographical Evaluation of Morphological Alterations of Mandibular Third Molars: A Cone Beam Computed Tomography (CBCT) Study.

Introduction Morphological changes or variations in the lower third molar can be of concern during the endodontic, orthodontic, or prosthetic intervention. The goal of the present study was to evaluate the morphological alterations in the roots and root canal of a mandibular third molar in Bhopal, Central India, on cone beam computed tomography (CBCT) images. Methodology CBCT scans of 277 mandibular molars, of both genders, between the ages of 18 and 60 yearswere assessed for the presence of root numbers, the configuration of the canal based on Vertucci's categorization, and a C-shaped canal. Scan results were analyzed for differences in canal configuration between the roots and topographical distribution. A chi-square test was applied to find any significant differences between the teeth at p0.05. Results Scans analyzed for variations in the third molar had a mean age of 38.64 + 5.71 years. The majority (95.3%) of the molars had two roots, 1.5% had three roots, and 0.4% had five roots. The mesial side of double-rooted teeth predominantly had Type II canal configuration (67.0%), while it was Type I (79.2%) in the distal aspect of the root. C-shaped canals were detected in 21 teeth, and no significant topographical difference was noted in the CBCT images. Conclusion The majority of the current population showed two roots with the same number of canals in the studied tooth. CBCT can be used as a diagnostic aid in identifying the canal numbers and their configuration so as to render appropriate intervention and minimize subsequent failure.

A Study of 42 Partially Edentulous Patients with Single-Crown Restorations and Implants to Compare Bone Loss Between Crestal and Subcrestal Endosseous Implant Placement.

BACKGROUND The purpose of the study was to evaluate the influence of dental implant placement at different bone levels upon the resultant postoperative peri-implant bone loss. MATERIAL AND METHODS Forty-two partially edentulous patients seeking implant-supported single-crown restorations were screened followed by segregation into 2 groups (GP), GP E (equicrestal) and GP S (subcrestal) (n=21 each). Sixty endosseous implants (30 each) (Adin Tourage-S, Israel), size 3.5/8 and 4/10 mm for mandibles, were placed using a 2-stage surgical procedure. At 4 to 6 months, straight abutments were attached followed by restoration (Vita Zahnfabrik, Germany). Crestal bone levels (mesial/distal) of implant fixtures were assessed at 5 time intervals (after surgery, and at 3, 6, 9, and 12 months) using digital radiography. Means and standard deviations were calculated, following which the differences were statistically analyzed using ANOVA at P value of <0.05. RESULTS The mean annual bone loss for GP S (1.96 mm) was higher than GP E (1.10 mm). At all studied time intervals, the bone loss for implants in GP S was higher than in GP E (P<0.05). Between time intervals, lowest bone loss was observed on the distal side in GP E (0.11 mm/6-9 month) and the highest bone loss was observed on the distal side of GP S (0.6 mm/9-12 month). Differences in the means between the 2 groups on mesial and distal sides were statistically significant at all time intervals (P<0.05). CONCLUSIONS Subcrestal implant placement was associated with more bone loss than when implants are placed at the crestal level.

Periodontal tissue regeneration by recombinant human collagen peptide granules applied with β-tricalcium phosphate fine particles

ObjectivesRecombinant human collagen peptide (RCP) is a recombinantly created xeno-free biomaterial enriched in arginine-glycine-aspartic acid sequences with good processability whose use for regenerative medicine applications is under investigation. The biocompatibility and osteogenic ability of RCP granules combined with β-tricalcium phosphate (TCP) submicron particles (β-TCP/RCP) were recently demonstrated. In the present study, β-TCP/RCP was implanted into experimental periodontal tissue defects created in beagles to investigate its regenerative effects. MethodsAn RCP solution was lyophilized, granulated, and thermally cross-linked into particles approximately 1 mm in diameter. β-TCP dispersion (1 wt%; 500 μL) was added to 100 mg of RCP granules to form β-TCP/RCP. A three-walled intrabony defect (5 mm × 3 mm × 4 mm) was created on the mesial side of the mandibular first molar and filled with β-TCP/RCP. ResultsA micro-computed tomography image analysis performed at 8 weeks postoperative showed a significantly greater amount of new bone after β-TCP/RCP grafting (2.2-fold, P < 0.05) than after no grafting. Histological findings showed that the transplanted β-TCP/RCP induced active bone-like tissue formation including tartaric acid-resistant acid phosphatase– and OCN-positive cells as well as bioabsorbability. Ankylosis did not occur, and periostin-positive periodontal ligament-like tissue formation was observed. Histological measurements performed at 8 weeks postoperative revealed that β-TCP/RCP implantation formed 1.7-fold more bone-like tissue and 2.1-fold more periodontal ligament-like tissue than the control condition and significantly suppressed gingival recession and epithelial downgrowth (P < 0.05). Conclusionsβ-TCP/RCP implantation promoted bone-like and periodontal ligament–like tissue formation, suggesting its efficacy as a periodontal tissue regenerative material.

Comparison of marginal bone loss in SLA and RBM implants: A prospective cohort study.

The study aims to answer the following question: Among the patients who received a dental implant, is there any difference in marginal bone loss (MBL) between sandblasted and acid-etched (SLA) and resorbable blast media (RBM) implants? The study aimed to evaluate marginal bone loss in SLA and RBM implants one year after loading. A Prospective Cohort Study. In this prospective cohort study with a pre-protocol population, subjects were assigned into two groups: Subjects received SLA implants in group 1 and RBM in group 2. MBL was assessed 12 months after loadings through digital parallel radiographs. An Independent t-test was used to compare MBL between the two groups. Sixty-six implants were studied (each group 33 implants). The mean of MBL in the RBM group was significantly higher than the SLA group (1.39 ± 0.31 mm, 0.89 ± 0.26 mm, respectively, P < 0.001). MBL in the mesial sides of implants in the RBM group was significantly higher than the SLA group (1.28 ± 0.29 mm, 0.8 ± 0.29 mm, respectively, P < 0.001). Analysis of the data demonstrated a significantly higher mean of MBL in the distal sides of implants in the RBM group than in the SLA group (1.51 ± 0.35 mm, 0.97 ± 0.27 mm, respectively, P < 0.001). In both groups, the mean of MBL on the distal side was significantly higher than on the mesial side (P < 0.05). Within this study's limitation, RBM implants showed significantly more MBL than SLA implants.

Comparative evaluation of implant stability and crestal bone level between tapered and cylindrical implants in the posterior regions of the mandible: A prospective, randomized, split-mouth clinical trial.

To compare the clinical outcome of tapered and cylindrical implants placed in the posterior region of mandible by measuring implant stability and crestal bone level at the healing period. A prospective clinical study was conducted on 15 patients who were included in the study based on the inclusion and exclusion criteria. A total of 30 dental implants were placed in both groups: 15 implants in Group I (tapered implants) and 15 implants in Group II (cylindrical implants) in the posterior region of mandible. Implant stability assessment by periotest was done at the time of implant placement (baseline) and after 3 months. The crestal bone level was measured with the help of radiovisiography (RVG) at the time of implant placement (baseline) and at 3 and 6 months. At baseline, there was statistically significant (P < 0.01) difference in primary implant stability. Tapered implants had higher primary implant stability than cylindrical implants. However, at 3 months, there was no statistically significant (P > 0.05) difference in the secondary implant stability of both the groups. Also, the crestal bone level on the mesial and distal sides of dental implant for tapered and cylindrical implants was statistically nonsignificant (P > 0.05) at all time intervals, that is, at baseline and at 3 and 6 months. Tapered implants had higher primary stability than cylindrical implants, and no difference was found in secondary stability. The crestal bone level was similar for both groups during early healing and early post-loading periods.

Comparative evaluation of the effect of conventional and truss access cavities on remaining dentin thickness, canal transportation, and canal centering ability in mandibular molars using cone-beam computed tomography

Aim: To evaluate and compare the effect of conventional and truss access cavity preparations on remaining dentin thickness (RDT), canal transportation, and centering ability in mandibular molars using cone-beam computed tomography (CBCT). Methods: Ethical approval was obtained before the commencement of the study. Thirty extracted mandibular molars were selected, disinfected, and stored in normal saline. Preoperative CBCT scans were taken for all the samples and randomly divided into two groups. (n = 15). Group A; Conventional access preparation group; Group B; Truss access preparation group. Cleaning and shaping were performed with the mesiobuccal canal of all the samples. Postoperative CBCT scans were compared with preoperative CBCT scans to evaluate the RDT, canal transportation, and canal centering ability in mandibular molar with conventional and truss access cavity preparation. Results: Data obtained from CBCT were analyzed by independent sample t-test with the P < 0.05 and found that RDT was higher in Group A as compared to Group B at the 3 and 9 mm levels, whereas it was higher in Group B at 6 mm level in both the mesial and distal side, but it was statistically insignificant at 3, 6, and 9 mm level. Canal transportation was higher in Group B than in Group A, but it was statistically insignificant at 6 and 9 mm levels but statistically significant at 3 mm. Canal centering ability was higher in Group A than in Group B, but it was not statistically significant at 3, 6, and 9 mm levels. Conclusion: Regarding RDT and canal centering ability, there is no statistically significant difference at all levels. Both groups present a statistically significant difference at 3 mm from the apex when comparing canal transportation. This suggests that conventional access cavity preparation is better than truss access preparation to maintain original canal anatomy.

Effect of deep margin elevation on fracture resistance of premolars restored with ceramic onlay: In vitro comparative study.

This in vitro comparative study aimed to compare the influence of two levels of deep margin elevation (2 and 3 mm) with either bulk-fill flowable composite or short fiber-reinforced flowable composite on the fracture resistance of maxillary first premolars restored with ceramic onlays. Fifty sound-extracted maxillary first premolar teeth were selected to prepare mesio-occluso-distal cavities with standardized dimensions. The cervical margins were extended 2 mm below the cemento-enamel junction on both mesial and distal sides. These teeth were randomly divided into five groups: Group I: no box elevation (control group). Group II: 2 mm marginal elevation with bulk-fill flowable composite. Group III: 2 mm marginal elevation with short fiber-reinforced flowable composite. Group IV: 3 mm marginal elevation with bulk-fill flowable composite. Group V: 3 mm marginal elevation with short fiber-reinforced flowable composite. After cementation, all teeth were subjected to a fracture resistance test using the universal testing machine, and the mode of failure was analyzed using a digital microscope at 20x magnification. The result showed a non-significant difference in the fracture resistance between 2 and 3 mm marginal elevation (p>0.05) with respect to each restorative material used for deep margin elevation. However, the fracture resistance of teeth elevated with short fiber-reinforced flowable composite was significantly higher than those elevated with bulk-fill flowable composite at both levels 2 and 3 mm, p=0.041 and 0.038 respectively. The fracture resistance of premolars restored with a ceramic onlay was not influenced by the levels of deep margin elevation (2 or 3 mm). However, marginal elevation with short fiber-reinforced flowable composites provided higher fracture resistance than those elevated with bulk-fill flowable composites, and those without marginal elevation. Key words:Fracture Resistance, Short fiber reinforced flowable composite, Bulk-fill flowable composite, Ceramic onlay, Cervical margin elevation.

Influence of anxiety and catastrophizing on pain perception in orthodontic treatment and its association with inflammatory cytokines.

Pain is common in orthodontic treatment, is subject to individual variation, and is associated with anxiety and stress, which can potentially become catastrophizing. The aim of the present study was to determine the variability of pain response after the insertion of orthodontic separators and to assess the association of pain levels with dental anxiety, catastrophizing, tooth sensitivity, and genetic expression of cytokines. To this end, 70 patients of both genders were divided into two equal groups according to the elastomeric separator used: G1 (Dentaurum) and G2 (Orthometric). Two separators were inserted in the mesial and distal sides of the lower right first molar. Participants were instructed to rate the level of pain at T0 (before insertion), T1 (just after insertion), and T2 (24 hours after insertion) on a visual analog scale. The gingival crevicular fluid was collected at T0 and T2. The levels of anxiety, catastrophizing, tooth sensitivity, and cytokine expression were also assessed. Statistical analysis was performed with the Fisher-Freeman-Halton, chi-squared, Spearman's correlation, and dependent and independent t tests (α=5%). Pain intensity was higher at T2 than at T1, in both groups (P<.05). An association was established (P<.05) between pain intensity at T1 and catastrophizing, and at T2 with anxiety and catastrophizing. Within-group differences in cytokine expression were found between T0 and T2. There was no correlation between cytokine expression and pain levels, anxiety, catastrophizing, and sensitivity at T2. Tooth separation produced variable pain levels, which were influenced by anxiety and catastrophizing, however, pain level was not correlated with increased cytokine expression.

Predictability of Proximal Enamel Thickness Assessment using Intraoral Periapical Radiographs: A Cross-sectional Study

Introduction: Measurements of tooth crown dimensions and enamel thickness are useful guides for interproximal stripping procedures aimed at creating space. In borderline non extraction orthodontic treatment cases, interproximal stripping is performed to gain space. Intraoral periapical radiographs and bitewing radiographs are commonly used to determine Proximal Enamel Thickness (PET). Aim: To determine the predictability of using IOPA-based PET measurements for assessing real/anatomic PET. Materials and Methods: This was a single-centre, crosssectional study conducted at Saveetha Dental College and Hospital, Chennai, Tamil Nadu, India, between March 2022 and April 2022. Digital Intraoral Periapical Radiographs (IOPAs) of 40 premolar teeth with intact crown structures were obtained using the paralleling technique. The PET of both the mesial and distal sides of the same teeth was measured using Carestream Imaging software. Subsequently, the extracted teeth were sectioned and examined under a Stereomicroscope (SM), and PET measurements of the mesial and distal surfaces were obtained along the heights of contour using ImageJ analysis software. Pearson’s correlation, along with linear and polynomial regression analyses, was performed using International Business Machines (IBM) Statistical Package for Social Sciences (SPSS) software. Results: A low but significant positive correlation between the PET of the sectioned teeth and the PET measured from IOPAs was observed (p=0.002, R=0.55). A significant difference in PET between the two methods for both sides was noted (p&lt;0.05). The mean distal enamel thickness was significantly greater than the mean mesial enamel thickness for both the IOPA and SM methods (p&lt;0.05). A polynomial regression equation, Y=2.084- 1.234X+0.318X3 , was established to predict PET of the sectioned teeth (Y) based on PET measured from IOPAs (X). Conclusion: The present study establishes a correlation between the true PET of teeth measured using cut-sections and PET measured from IOPAs, which are readily available in clinical practice. A correlation coefficient was determined, and PET can be predicted using IOPAs, although not with absolute accuracy. Distal PET was found to be higher than mesial PET, with no significant difference in enamel thickness between the two sides.

Orthodontic miniscrew supported correction of partially impacted mandibular 2nd molar- A case report

A wide range of clinical procedures have been introduced and practiced to correct mesially inclined mandibular molars which is a common situation among young adults, occurring usually due to inadequate space in the arch for its eruption. There are two major treatment options available for the correction of impacted / partially impacted molars and this depends on several factors. The objective was to treat a 15-year-old male patient having a lower right partially impacted 2nd molar using skeletal anchorage system. The lower right 3 molar was surgically excised, and the partially impacted 2 molar was uprighted using an orthodontic miniscrew which was placed between lower right 1 and 2 premolars on the mesial side. The use of skeletal anchorage system has an excellent advantage over conventional methods since there is prevention of unwanted movement of anchor teeth leading to successful correction without any delay in the treatment duration.

To Evaluate the Accuracy Between Two Different Electronic Apex Locators to Detect the Root Canal Perforation During Retreatment - An Ex-Vivo Study

Objectives: To evaluate the accuracy between two different electronic apex locators in detecting the root canal perforation in the middle and apical portion during retreatment. Methods: Sixty freshly extracted mandibular premolars were taken in to this study, which were divided into three groups of twenty each. Group I: Control Group, Group II: Positive control without perforation, Group III: Negative control with perforation. In all the groups, access cavity preparation was done followed by cleaning and shaping using X smart Endomotor and Protaper Gold file system (Dentsply Maillefer, Switzerland). The specimens were prepared such that perforation was made in group III on the mesial side of the root at middle portion approximately 5mm from the apex after determining working length by direct visualization and stored for the database. All the specimens were obturated by using AH plus sealer and F3 Protaper gold gutta percha points and later stored in incubator at temperature of 37°C for 7days. After 7 days, gutta percha was removed from group III samples using gutta percha solvent (Xylene), Neo-Endo retreatment files. These teeth were mounted on Protrain Endodontic training kit (Simit Dental, Italy) and perforation were detected using apex locators Dentaport Root ZX (J,Morita) and Propex Pixi (Dentsply Maillefer, Switzerland). The apical perforation were made at a distance 2mm from apex after the middle perforation were restored by using Type II GIC by keeping the 35 K file inside the canal and apical perforations were detected and the reading were recorded and stored for the database. Statistical Analysis: The data obtained were analyzed by using descriptive statistics, ANOVA (Analysis of Variance), Paired t test through SPSS for window (version 22.0). Findings: In case of middle third perforation of the root canal Dentaport Root ZX showed accuracy of 87.37% and Propexpixi 82.89%. In apical perforations the accuracies of Root ZX and Propex Pixi are 89.28% and 79.76% respectively. In the both the perforations, there was a statistically significant difference (P < 0.05). In both the perforations, Dentaport Root ZX showed more accuracy in detecting the perforation when compared with Propex Pixi apex locator. Novelty : This study provides a novel approach as it compares the accuracy between the Dentaport Root Zx and Propex Pixi in detection of middle and apical perforation during retreatment in Ex Vivo study. Keywords: Dentaport root ZX; Electronic apex locator (EAL); Propex pixi; Protrain endodontic training kit; Root canal perforation

Correlation of implant position and crestal bone loss in 2-implant mandibular overdentures with immediate loading protocols: A prospective clinical study

Statement of problemThe 2-implant mandibular overdenture (2IMO) is a popular treatment for patients with an edentulous mandible, but information on the effect of the optimum implant position on the peri-implant crestal bone level with immediate loading protocols is lacking. PurposeThe purpose of this prospective clinical study was to evaluate correlations between different implant positions and crestal bone loss and between interimplant distance and the crestal bone loss in patients with 2IMOs with immediate loading protocols at 1-year follow-up. Material and methodsA total of 24 participants (13 men, 11 women, mean ±standard deviation age 63.25 ±10.76 years) were treated with 2IMOs (48 Ti-Zr implants) by a single operator between August 2015 and October 2020. The implant diameters (3.3 mm or 4.1 mm) and lengths (10 mm or 12 mm) were selected based on the crestal bone width, and the implants were placed, if possible, in the canine regions. Implant positions and interimplant distance (mm) were measured intraorally with dividers. Prefabricated mandibular dentures were immediately loaded with the LOCATOR-attachments by using a direct intraoral pickup procedure. Crestal bone-level changes were measured with a software program on the mesial and distal sides of each implant from periapical radiographs made with a paralleling technique (at baseline and 1-year follow-up). The measurement values were normalized. The Spearman rho correlation test and paired samples t tests were used for data analysis (α=.05). ResultsThe mean ±standard deviation position of the implants from the midline was 8.78 ±2.25 mm (9.00 ±2.22 mm right side, 8.56 ±2.31 mm left side), and the mean interimplant distance was 16.94 ±4.03 mm. At 1-year follow-up, the mean ±standard deviation crestal bone loss was 0.50 ±0.47 mm (n=48) (0.57 ±0.65 mm mesial, 0.43 ±0.53 mm distal). The mean ±standard deviation crestal bone loss was 0.46 ±0.4 mm with Ø3.3-mm implants (n=42) and 0.9 ±0.8 mm with Ø4.1-mm implants (n=6) (P=.005). Implant positions were negatively correlated (rs=-0.37) with the crestal bone loss, and the correlation was significant (P=.009). Interimplant distances were also negatively correlated with crestal bone loss (rs=-0.60; P=.002). Bone loss on the mesial side was positively correlated with that on the distal side rs=0.20; however, the correlation was not significant (P=.16). ConclusionsA weak and negative correlation was found between the implant position from the midline and the crestal bone loss and also between the interimplant distance and crestal bone loss in patients provided with 2IMOs with immediate loading protocols.

Manual and mechanical stripping-induced enamel roughness and elemental composition in vivo.

Interproximal enamel reduction (IPR) is routinely used in orthodontics to generate small to moderate amounts of space within the dental arch. Aim of this ex vivo study was to evaluate the effect of two different IPR systems on the enamel surface's waviness, roughness, and elemental composition after 6 months of intraoral exposure. Fifteen orthodontic extraction patients were included in the present study. The 39 healthy premolars, which were scheduled to be extracted, were subjected to IPR at least 6 months before their extraction. IPR was performed on their mesial side with two different methods: (1) instrumented method with the Ortho-Strips system (on handpiece) and (2) manually with the Intensiv ProxoStrip (strips)-each with four different grits for contouring, finishing, and polishing. The distal side of each premolar served as its own internal control. Treated and untreated tooth surfaces were evaluated by optical profilometry, Raman, and scanning electron microscope/X-ray energy-dispersive (EDX) analyses. Data were analysed with descriptive statistics and generalized linear models at alpha = 5%. Both IPR methods significantly reduced the waviness of the enamel surface (P < 0.001), with manual IPR leading to smaller waviness reductions than the instrumented IPR (P ≤ 0.001). On the other side, both IPR methods led to a significant increase in enamel surface roughness (P < 0.001), with no significant differences between IPR methods. EDX and Raman analyses did not demonstrate any alterations on elemental composition of enamel after at least 6 months of intraoral exposure. Both stripping systems led to a flatter but rougher enamel surface. Further polishing is needed to restore the initial enamel smoothness. The elemental composition of the stripped enamel returns to the baseline level after 6 months of intraoral exposure.

Soft tissue phenotype modification impacts on peri-implant stability: a comparative cohort study.

Soft tissue phenotype modification (STPM) could be performed to maintain peri-implant health. Therefore, the aim of the study was to analyze tissue alteration around implants following soft tissue phenotype modification during implant uncovering surgery. Patients who had STPM (either pouch roll or modified roll technique) during implant second-stage surgery with at least 12-month follow-up were included. Clinical and radiographic parameters including mucosal tissue thickness (MTT), recession (REC), keratinized mucosa width (KMW), probing pocket depth (PPD), marginal bone loss (MBL), emergence profile, and emergence angle were extracted from 2-week, 2-month, and 12-month visits after second-stage surgery. Twenty-eight patients with 33 implants that fulfilled the inclusion criteria were included. After soft tissue phenotype modification, at 2weeks, REC was negatively correlated to mean MTT at mid-buccal site (r = - 0.41, p = 0.018) and borderline correlated at mid-lingual site (r = - 0.343, p = 0.051). Stable KMW was maintained from 2weeks to 12months with minimal shrinkage rate (3 ~ 14%). MBL change was limited (0.24 ~ 0.47mm) after STPM. All implants had shallow PPD (≤ 3mm) with the absence of bleeding on probing. Emergence angle at the mesial side, however, was significantly correlated to surgical techniques, which indicated pouch roll technique would have 6.96 degrees more than modified roll technique (p = 0.024). Soft tissue phenotype modification, either pouch roll or modified roll technique, during uncovering surgery resulted in favorable clinical outcomes. Thin mucosal tissue thickness and pouch roll technique are the factors related to more recession at 2weeks. Pouch roll technique could influence the restorative design by having a wide emergence angle at the mesial side. Modified and pouch roll techniques during uncovering surgery were viable methods to yield favorable peri-implant health, while the preciseness of pouch roll technique was required to avoid mucosal recession and inadequate restorative design.

The Assessment of Different Gingival Management Materials for Immediate Implant Treatment in the Esthetic Zone: A Clinical and Biochemical Study.

To observe the effect of different prosthetic materials (polymethyl methacrylate [PMMA] and flowable composite [FC]) on marginal bone loss, pink esthetic score (PES), and cytokine levels (receptor activator of nuclear factor kappa-Β ligand [RANKL] and osteoprotegerin [OPG]). A total of 46 patients (31 women, 15 men) were treated with immediate implant therapy after tooth extraction. For standardization, only the maxillary premolar tooth of each patient was restored, and also, both of the adjacent teeth were present in the dental arch. Provisional crowns were prepared before the surgery on patient models with two different materials (24 PMMA, 22 FC). Following the surgical procedure, provisional crowns were adjusted on polyetheretherketone (PEEK) abutments as nonfunctional in centric and eccentric movements. After the surgery, patients were evaluated monthly for 3 months. At each follow-up, periapical radiography was obtained by the parallel technique, and peri-implant crevicular fluid (PICF) was collected. Pink esthetic scoring was done. MBL was calculated for the mesial and distal sides separately. Cytokine levels were analyzed from PICF. Statistical analyses (Shapiro-Wilk, Mann-Whitney U, independent-samples t test, Wilcoxon t test, paired-samples t test, and Friedman two-way analysis of variance with Bonferroni correction) were completed (α = .05). PES was increased significantly within groups (P < .01). However, there was no statistically significant difference between groups. According to the Mann-Whitney U test, no significant difference was found for the MBL (P > .05). When the RANKL/OPG values were evaluated within the group by using the Friedmann two-way analysis of variance test, no significant difference was found (P > .05). Similar pink esthetics, cytokine levels, and bone loss can be achieved using a protocol including immediate implants, particle grafts, soft tissue graft, PEEK abutments, and provisional restorations fabricated using PMMA and FC.