Maxillary Central Teeth Research Articles

Reimplantation of Maxillary Central Teeth with Open Apices

Reimplantation of Maxillary Central Teeth with Open Apices

The effects of mineral trioxide aggregate and second-generation autologous growth factor on pulpotomy via TNF-α and NF-kβ/p65 pathways

This study aims to investigate the effect of Mineral Trioxide Aggregate (MTA), a bioactive endodontic cement, and Concentrated Growth Factor (CGF), a second-generation autologous growth factor, on pulpotomy-induced pulp inflammation. The study utilized the maxillary anterior central teeth of thirty-six young male Sprague Dawley rats. Forty-eight teeth were randomly assigned to two groups (12 rats/group; 24 teeth/group) based on the capping material (MTA or CGF). Subsequently, two subgroups (MTAG and CGFG) were formed per group (12 teeth/group) based on the time following pulpotomy (2-weeks and 4-weeks). The central teeth of the 12 animals assigned to the control group (CG) were not manipulated in any way, both in the 2-week group and in the 4-week group. Tissue samples extracted from rats at the end of the experiment were stained with H&E for histopathological analysis. For immunohistochemical analysis, primary antibodies for TNF-α and NF-kβ/65 were incubated. Data obtained from semi-quantitative analysis were assessed for normal distribution using Skewness-Kurtosis values, Q-Q plot, Levene’s test, and the Shapiro-Wilk test on statistical software. A P value < 0.05 was considered significant. When compared with the control group, both MTAG and CGFG showed increased edematous and inflammatory areas. In MTAG, edematous and inflammatory areas decreased significantly from the 2nd week (2(2–2), 2(1–2)) to the 4th week (1(1–1), 1(0–1)), while in CGFG, edematous areas decreased (2(2–3), 1.5(1–2)), and inflammatory areas increased significantly (2(2–3), 3(2-2.5)). When compared with the control group, TNF-α and NF-kβ/p65 positivity were higher in both MTAG and CGFG. In MTAG, TNF-α [2(1.5-2)] and NF-kβ/p65 [1.5(1–2)] positivity decreased significantly from the 2nd week to the 4th week [TNF-α: 1(1–1), NF-kβ/p65: 1(1–2)], while no significant change was observed in CGFG. In conclusion, this study revealed a reduction in cells showing TNF-α and NF-kβ/p65 positivity in the MTA treatment group compared to the CGF group. Although MTA demonstrated more favorable results than CGF in mitigating pulpal inflammation within the scope of this study, further experimental and clinical investigations are warranted to obtain comprehensive data regarding CGF.

Evaluation of stress distributions in endodontically treated anterior incisors under occlusal and trauma-induced forces following various restoration treatments: A finite element analysis.

The aim of this study was to calculate the stress distribution of fiberglass post associated with resin composite crown restoration and fiberglass posts with zirconia restorations in mature and immature endodontically treated central maxillary incisor under various loading conditions. The study created six different study models in a virtual environment: healthy mature maxillary central teeth, intact immature maxillary central teeth, mature maxillary central teeth with fiberglass post associated with resin composite crown restoration, immature maxillary central teeth with fiberglass post associated with resin composite crown restoration, mature maxillary central teeth with fiberglass posts and zirconia restoration, and immature maxillary central teeth with fiberglass posts and zirconia restoration. Loading conditions simulating mastication, trauma, and bruxism were applied to each of the models at different angles and amounts. The von Mises and the maximum and minimum principal stress values in tooth structures (dentin) and support structures (bone, PDL) and materials were observed using finite element stress analysis. The highest stress values in the tissue and the restoration structure were observed for masticating force and crowns rehabilitated with zirconia restorations. None of the compared loading conditions and restorations showed destructive stress values on periodontal ligament or bone. The mature and immature endodontically treated central maxillary incisors can be better rehabilitated using fiberglass post associated with resin composite crown restoration and may be preferred to zirconia restorations in order to reduce the stresses on the surrounding tissues and teeth. However, further clinical studies are needed to fully explore this topic.

Evaluation of stress distribution on an endodontically treated maxillary central tooth with lesion restored with different crown materials: A finite element analysis

ObjectivesThe biomechanical response of teeth with periapical lesions that have been restored using various substructure materials, as well as the stress mapping in the alveolar bone, has not been thoroughly described. In this context, the objective of this study is to investigate the structural stress distributions on root canal-treated maxillary right central incisors with lesions restored using different crown materials under linear static loading conditions through finite element analysis (FEA). MethodsIn the study, five FEA models were utilised to represent healthy teeth and teeth restored with different substructure materials: (A) a healthy tooth, (B) a lesioned, root canal-treated, composite-filled tooth, (C) a lesioned, fiber-posted, zirconia-based crown, (D) a tooth with lesions, a fiber post, and Ni–Cr infrastructure crown, (E) a tooth with a lesion, a fiber post, and an IPS E-max infrastructure crown. A force of 100 N was applied at an angle of 45° to the long axis of the tooth from 2 mm cervical to the incisal line on the palatal surface. Deformation behaviour and maximum equivalent stress distributions on the tooth sub-components, including the bony structure for each model, were simulated. ResultsDifferences were observed in the stress distributions of the models. The maximum stress values of the models representing the restorations with different infrastructures varied, and the highest value was obtained in the model of the E-max crown (Model E: 136.050 MPa). The minimum stress magnitudes were obtained from Model B the composite-filled tooth (80.39 MPa); however, it was observed that the equivalent stresses in all the models showed a similar distribution for all components with varying magnitudes. In periapical lesion areas, low stresses were observed. In all models, the cervicobuccal collar region of the teeth had dense equivalent stresses. ConclusionDifferent restorative treatment methods applied to root canal-treated teeth with periapical lesions can impact the stress in the alveolar bone and the biomechanical response of the tooth. Relatively high stress values in the cortical bone at the cervical line of the tooth have been observed to decrease towards the apical region. This observation may suggest a potential healing effect by reducing pressure in the periapical lesion area. Clinical significanceComposite resin restorations can be considered the first-choice treatment option for the restoration of root canal-treated teeth with lesions. In crown restorations, it would be advantageous to prefer zirconia or metal-supported prostheses in terms of biomechanics.

Micro-Computed Tomographic Evaluation of the Sealing Quality and Bond Strength of Different MTA Apical Plugs

Objective: This study aimed to compared the effects of different placement techniques to the sealing quality of mineral triokside aggregate (MTA) apical plugs at apexification technique by micro-computed tomography (micro-CT) and compared the bond strength to root dentin of an injectable MTA (BIOfactor MTA), MTA Angelus and AH Plus. Methods: Sixty dentinal root slices were obtained from 20 maxillary centrals.A canal-like hole was drilled into each slices canal space.The samples were divided into 3 groups (n=20).All materials were delivered into the holes. Push-out tests were performed and fracture types were analysed with a strereomicroscope. In the second part of the study,72 maxillary central teeth with standardised artificial divergent open apex were divided into 4 groups; MTA Angelus and BIOfactor MTA were mixed mechanically, and introduced to form 4 mm thick apical plugs by hand condensation or indirect-ultrasonic activation for 10 seconds. Incidence of external voids between dentin walls and MTA apical plugs and porosity inside MTA were determined by volumetric analysis with micro-CT. Results: No significantly difference was found between the bond strength values of the materials (p:0.370; p&gt;0.05).The external voids and porous voids are similar in both MTA (p: 0.685; p&gt;0.05).When indirect-ultrasonic activation was applied,there was significantly less porosity statistically than hand condensation (p:0.00; p&lt;0.05). Conclusion: MTA Angelus and BIOfactor MTA materials showed similar results in terms of bond strength to root dentin, fracture types, adaptation to dentin walls and structural porosity rate. Both MTA materials showed less structural porosity when placed by indirect ultrasonic activation technique compared to manual condensation.

3D finite element analysis of stress distribution as a result of oblique and horizontal forces after regenerative endodontic treatment part II: comparison of material thickness

AimThis study aimed to evaluate the stress distribution caused by secondary trauma forces after regenerative endodontic treatment (RET) using different thicknesses of coronary barrier material with three-dimensional finite element analysis(FEA).MethodA control model was created using the tomography image of the immature maxillary central tooth with computer software.Study models were created with the modulus of elasticity and Poisson’s ratio of the materials used in RET.Enamel, dentin, cementum, periodontal ligament, cortical, and cancellous bone were modeled. Coronary barrier materials were applied in 3 mm and 5 mm thicknesses (Model 1: control model, model 2:3 mm/Calcium Enriched Mixture(CEM), model 3:3 mm/Mineral Trioxide Aggregate(MTA), model 4:3 mm/Biodentin, model 5:5 mm/CEM, model 6:5 mm/MTA, model 7:5 mm/Biodentin). For the trauma force simulation, 300 N force in the horizontal direction was applied to the buccal surface of the tooth in the first scenario. For the second scenario, maximum bite force simulation, a force of 240 N in the oblique direction was applied to the palatal surface of the tooth. FEA was performed with Algor Fempro. The resulting stresses were recorded as Von Mises, maximum, and minimum principal stresses.ResultsLower stress values were obtained in 5 mm models compared to 3 mm models. However, the difference between them was insignificant. Lower stress values were obtained in all RET models compared to the control model. The lowest stress values in dental tissues and bone tissue were obtained in the CEM models.ConclusionThis is the first study in which the stress caused by different thicknesses of CEM on dental tissues was evaluated with FEA. RET strengthens immature teeth biomechanically. CEM and Biodentin are more successful materials in stress distribution than MTA. Considering the cost of treatment, 3 mm material thickness is ideal for RET since there is no significant difference between the stress values resulting from the use of 5 mm and 3 mm coronary barrier material.

Evaluation of Fracture Strength after Repair of Cervical External Resorption Cavities with Different Materials

IntroductionThe aim was to evaluate the stress distributions on dentin and repair materials caused by static force applied to teeth, with cervical external root resorption (CER) after repair with different materials using finite element analysis. MethodsThis study was performed with the 3-dimensional finite element analysis method. Access cavity, root canal cavity dimensions, and supporting tissues other than cementum were modeled in the maxillary central tooth. The CER cavity was created on the labial side of the tooth model. The coronal side of the resorption cavity was restored with composite, and the radicular side with different materials (MTA, Biodentine, BioAggregate, calcium-enriched cement [CEM], glass ionomer cement [GIC], and resin-modified glass ionomer cement [RMGIC]). A static force of 300 N was applied to the palatal surface of the crown at an angle of 135° to the long axis of the tooth. The stress distributions in dentin and repair materials were analyzed. ResultsThe highest stress in dentin was seen in the fFigmodel with unrepaired CER. In the models repaired with MTA, GIC, and RMGIC, von Mises stress values in dentin were greater than for repairs with Biodentine, BioAggregate, and CEM materials. The von Mises stress on the repair materials applied to the root were highest for the BioAggregate material. This was followed by CEM, Biodentine, MTA, RMGIC, and GIC materials, respectively. ConclusionThe repair of CER in the tooth significantly decreased the stress values in dentin. Biodentine, BioAggregate, and CEM absorbed more force and caused less stress to be transmitted to dentin compared to MTA, GIC, and RMGIC.

Çocuklarda Maksiller Anterior Dişlerin Kökleri ile Komşuluğundaki Anatomik Yapılar Arasındaki İlişkinin Değerlendirilmesi: Konik Işınlı Bilgisayarlı Tomografi Çalışması

ABSTRACT&#x0D; Background: In our study, we aimed to evaluate the distances between the roots of maxillary incisors and the nasopalatine canal and the floor of the nasal cavity, and the buccal cortical bone thickness at the apices of the roots of these teeth by Cone Beam Computed Tomography (CBCT) in children in the permanent dentition period.&#x0D; Materials and Methods: CBCT images of 49 patients aged 6-14 years were evaluated. In the sagittal plane, the distances of the apices of the maxillary central teeth with the nasopalatine canal and with the floor of the nasal cavity were evaluated. Buccal cortical bone thickness at the apex of the roots of maxillary anterior teeth was examined. These data were compared in terms of gender and whether the teeth had open or closed apices.&#x0D; Results: When the mean distance of the maxillary central teeth (11,21) to the nasopalatine canal was evaluated in terms of the open/closed apex status of the teeth and gender, there was no significant relationship (p&gt;0.05). Among the maxillary anterior teeth (11, 21,12, 22), the root apex of tooth 22 was the farthest from the floor of the nasal cavity and the root apex of tooth 12 was the closest. It was found that the mean buccal cortical bone thickness of maxillary anterior teeth 11 and 21 with open apex was significantly higher than those with closed apex (p

The Effect of Ferrule/Crown Ratio and Post Length on the Applied Stress and Strain Distribution to the Endodontically Treated Maxillary Central Teeth: A Finite Element Analysis.

Objectives: One of the most common methods used for the reconstruction of endodontically treated teeth is post and core and crown. Various factors such as the remaining tissue above the cutting margin (ferrule) affect the fracture resistance of teeth restored with post and core and crown. This study aimed to investigate the effect of ferrule/crown ratio (FCR) on the strength of maxillary anterior central teeth using finite element analysis. Materials and Methods: A 3D scan of a central incisor was obtained, and the data were transferred to Mimics software. Then, a 3D model of the tooth was designed. Next, 300N load was applied at a 135° angle to the tooth model. Force was applied to the model both horizontally and vertically. Ferrule height was considered to be 5%, 10%, 15%, 20%, and 25% in the palatal surface and 50% in the buccal surface. The length of post in the model was 11, 13, and 15mm. Results: By increasing the FCR, stress and strain distribution increased in the dental model and decreased in the post itself. As the horizontal angle of load application increased, the level of stress and strain created in the dental model increased as well. The closer the force application site to the incisal area, the higher the stress and strain would be. Conclusion: Maximum stress was inversely correlated with FCR and post length. In ratios of 20% and higher, insignificant changes occurred in stress and strain patterns in the dental model.

Bond strength of various post-core restorations with different lengths and diameters following cycle loading

PurposeThis in vitro study aims to evaluate the bonding strengths of Polyether ether ketone (PEEK), Polyether ketone (PEKK), Fiber, and Zirconia (ZrO2) post-core restorations with posts in different diameter and length following chewing simulator. Materials and methodsEndodontic treatment was performed on 256 intact maxillary central teeth. The test specimens were prepared in four groups according to the types of materials: Glass fiber post-composite core (FB-n:64), Zirconia post-core (Zr-n:64), PEEK post-core (PE-n:64), and PEKK post-core (PK-n:64). The groups were divided into four subgroups according to diameter and length (n:16): Group 1: 10 mm length 1.75 mm diameter, Group 2: 10 mm length 1.5 mm diameter, Group 3: 7 mm length 1.75 mm diameter, Group 4: 7 mm length 1.5 mm diameter. Custom PEKK, PEEK, Zirconia post-cores, and Zirconia crowns were milled on the CAD/CAM. The post-cores and crowns were cemented to the teeth with dual-cure resin cement. After that, all subgroups were divided into control and cyclic loading groups. During the cycling, the control test group was kept in distilled water at 37±1oC before the push-out test. Half of the specimens were loaded with 250,000 cycles and 50 N with a chewing simulator. All test specimens had 1.5 mm sections taken from their roots. Then, the push-out test was applied to these sections for bond strength. Data were analyzed by Mann-Whitney U test, Shapiro-Wilk, Kruskal-Wallis's test, and Chi-Square. The statistical significance level was determined as 0.05. ResultsThe bond strength of all test groups decreased after the cycling loading. The bond strength values of zirconia posts showed a statistically significant difference (p < 0.05). The 10 mm length 1.75 mm diameter posts made of Zirconium had the highest bond strength observed in all control and cyclic loading groups of test specimens (9.74 MPa-6.25 MPa). The PEEK test specimens with a 7 mm length and 1.75 mm diameter showed the weakest bond strength in all control and cyclic loading groups (5.44 MPa-3.37 MPa). The average of the cervical region's bond strength values was statistically significantly higher than the apical region (p < 0.05). ConclusionWithin the limitations of this study, one-piece custom-milled Zirconia post-cores appear promising, as they perform well under functional forces, especially in the anterior region. In addition, custom-milled PEKK post-cores might be considered a suitable alternative to prefabricated fiber-reinforced posts.

Comparison of the pull-out bond strength of endodontically treated anterior teeth with monolithic zirconia endocrown and post-and-core crown restorations.

The purpose of this study was to assess the pull-out bond strength (PBS) of endodontically treated anterior teeth that had been restored with monolithic zirconia endocrowns using different extension depths (EDs) and post-and-core crowns after chewing simulation. Thirty-six maxillary central teeth were used (n = 12). Group I: Glass fiber post-and-core crown, Group II: Endocrown with 3-mm EDs, Group III: Endocrown with 5-mm EDs. Restorations were fabricated from monolithic zirconia blocks using a CAM (computer-aided manufacturing) device. For cementation, conventional resin luting agent (Multilink N) was used. All samples were aged with a chewing simulator and PBS tests were conducted at a speed of 1 mm/min using an electromechanical servo universal testing machine. The values were recorded in MPa by dividing the failure load by the bonding area. One-way ANOVA and the post-hoc Tukey test were used for statistical analysis (P = 0.05). Group III demonstrated significantly greater PBS values than Groups I and II (P = 0.001). No significant difference was found between Groups I and II (P = 0.072). Increasing the ED of an endocrown influences the PBS of endodontically treated anterior teeth restored with monolithic zirconia endocrowns.

Evaluating the radiographic results of apexification treatment in children

Aim: This retrospective study aimed to evaluate the radiographic success of apexification treatments applied with different materials and techniques. Methodology: Periapical radiographs of 224 maxillary incisors in patients between 6 and 12 years of age who had undergone apexification treatment at the Dicle University, Faculty of Dentistry, Department of Pediatric Dentistry were retrospectively examined. Each apex was scored using the periapical index (PAI) on X-rays obtained at 12 months of follow-up after treatment, and the presence or absence of the apical barrier was evaluated. The Kruskal–Wallis H, Mann–Whitney U, and chi-square tests were used for the statistical analysis (p &lt; 0.05). Results: In the maxillary incisors, apexification was most commonly performed on the maxillary right central teeth (74.11%). The cause for this treatment was trauma in 97.77% of the patients. Enlargement in the periodontal space (95.98%), the presence of lesions (60.71%), loss of lamina dura (54.46%), and external resorption (43.75%) were observed. At 12 months of follow-up after treatment, apical closure (87.95%) was observed in all teeth with open apexes, and the ratio of patients with a PAI of &lt; 2 was 89.35% for calcium hydroxide (CH) apexification and 92.73% for mineral trioxide aggregate (MTA) apexification. Conclusion: The radiographic success of apexification treatments with CH and MTA was found to be high in 224 immature upper incisors. How to cite this article: Akleyin E, Polat Y, Harman EB, Çelenk S. Evaluating the radiographic results of apexification treatment in children. Int Dent Res 2022;12(3):158-64. https://doi.org/10.5577/intdentres.2022.vol12.no3.8 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

The effects of age on tooth color and of viewing distance on visual tooth color matching in aesthetic dentistry

Aim: This study aims to question the effect of visual distance on color selection by scoring the maxillary central tooth color with the visual color selection method and to investigate the relationship between tooth color and patient age. Methodology: Maxillary central tooth color was determined by a single operator using visual methods from two different distances, 35 cm and 70 cm, in a total of 100 people between the ages of 20-80 and of different genders. The value, hue and ages of the teeth were recorded using the VITA Toothguide 3D-MASTER color scale at 2 different viewing distances. Visual color selection was made in natural daylight, preferably between 10:00 and 12:00 in the morning. Subjects were observed at eye level, and all color assessments were performed rapidly (5-7 s). Independent T-test was used for independent groups and Chi-square test was used for dependent groups. Results: Considering the relationship of lightness with distance, there is a significant difference between the values ​​at 35 cm and 70 cm distances. It was observed that the lightness increased when the measurements made from 70 cm were compared with the measurements made from 35 cm. As the age increases, the ratio of the brightness value of 1, which is the highest lightness, decreases, and the ratio of the darker 3 and 4 lightness​​increases. R (reddish) hue was found to be higher in the 40-59 and over 60 age groups compared to the 20-39 age group. Conclusion: It was observed that the tooth color was determined lighter in the measurements made from 70 cm compared to the measurements made from 35 cm. It is important to determine the color at 35 cm so that the incorrect lightness (value) is not selected. It can be said that as the age increases, the tooth gets darker and the reddish and yellowish hue increases. How to cite this article: Kızılırmak B, Güntekin N, Tunçdemir AR. The effects of age on tooth color and of viewing distance on visual tooth color matching in aesthetic dentistry. Int Dent Res 2022;12(Suppl.1):29-33. https://doi.org/10.5577/intdentres.442 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Pre-eruptive intracoronal resorption of permanent dentition: A new classification and a multidisciplinary study.

The aims of this study were to develop a new classification for pre-eruptive intracoronal resorption(PIR) with different resorption areas and sizes and to compare the new classification scores among observers from different specialities and professional experience. The PIR was evaluated according to the new classification by two dentomaxillofacial radiologists and two endodontists. Information regarding the patient's age, gender, systemic diseases, the number of PIR, the affected tooth area and the size of the PIR was recorded. The new classification system showed that PIR six and seven defects were the most detected. Regarding jaw regions, the highest reliability was seen in the maxillary central teeth between observers I and IV, and maxillary premolar-molar teeth between observers II and III. This study revealed that PIR can be found in both root and crown dentine. Professional experience and specialty and awareness of the PIR defect may affect the diagnosis.

Self Cure Acrylic and Stapler Pin Retrieval from Maxillary Central Tooth: A Case Report

In dental practice, discovery of a foreign body entrapment within the root canal is not uncommon. The foreign object may have been accidently lodged due to traumatic injuries, iatrogenically during treatment or it may be a self-inflicted injury. The patient usually reports only when he/she experiences pain with foreign object discoverable on radiographic examination. In this report, a 20-year-old female was diagnosed with a stapler pin lodged in a permanent maxillary central incisor canal along with self cure acrylic. KEYWORDS: Apexification, Mineral trioxide aggregate, Stapler pin

EVALUATION OF MARGINAL ADAPTATION AND MICROLEAKAGE OF DIFFERANT ALL-CERAMIC PORCELAIN SYSTEMS

ABSTRACT Purpose: This study evaluated the marginal adaptation and microleakage of the İn-Ceram Alumina, In-Ceram Zirconia and Finesse press all-ceramic porcelain systems. Material and methods: Thirty maxillary Central teeth extracted for periodontal reasons without caries and cracks were divided equally into three group and there was no control group; only the three systems were compared. Sample teeth cemented were stored in distile water for 24 hours. Then, they were applied to a repeated thermal cycle for 500 times. The samples were left in %5 of basic fuchsin dye for 24 hours. For the marginal adaptation rankings, all of the sample teeth for which cross-sections were made were moved into the metal microscope (Scherr Turico St. James/ Minn./ USA) and the marginal adaptation degrees were measured in both the palatinal and vestibul regions by measuring twice with x10 enlargement at micron level. For the statistical evaluations of marginal adaptation and microleakage values, Kruskal Wallis test has been used (p&amp;gt;0.05). Results: The differences between the three all-ceramic porcelain systems are not significant (p&amp;gt;0.05), α=0.05). Conclusion: The Finesse porcelain system caused the least leakage in both regions. In second place in both regions was In-Ceram Alumina, In-Ceram Zirconia caused the most leakage in both regions. The biggest margin gap in the palatal region was seen in the Finesse porcelain system, In-Ceram Zirconia in second place. The least marginal gap was caused by the In- Ceram Alumina porcelain system.

Comparative evaluation of the relationship of teeth color and soft tissue color of the face in individuals with natural dentition

Introduction The aim of this study is to make it easier for dentists to choose artificial tooth color in fully and partially edentulous patients by evaluating the relationship between the color of the soft tissues of the face and the color of the teeth. Methodology The CIEL*a*b* color values of the maxillary central teeth of the volunteers participating in the study were measured by spectrophotometer, and skin, lip and eye color were measured from facial images containing ceramic blocks to standardize the light and color values using Adobe Photoshop software. The Kolmogorov-Smirnow test and Spearman Rank Correlation test were used to evaluate the data. Results It was observed that there was a higher correlation between the L* values of the teeth and the L* and b* values of the skin.When the analysis between the color measurements taken from the lip photographs and the teeth was examined, it was seen that there was a statistically significant positive correlation between the L* values of the upper central teeth and the a* values of the lip. Conclusion The results showed that the CIEL*a*b* parameters of skin color and lip color can be used in the selection of tooth color in case of loss of natural teeth or discoloration of existing teeth

Comparative evaluation of the relationship of teeth color and soft tissue color of the face in individuals with natural dentition

Introduction: The aim of this study is to make it easier for dentists to choose artificial tooth color in fully and partially edentulous patients by evaluating the relationship between the color of the soft tissues of the face and the color of the teeth. Methodology: The CIEL*a*b* color values of the maxillary central teeth of the volunteers participating in the study were measured by spectrophotometer, and skin, lip and eye color were measured from facial images containing ceramic blocks to standardize the light and color values using Adobe Photoshop software. The Kolmogorov-Smirnow test and Spearman Rank Correlation test were used to evaluate the data. Results: It was observed that there was a higher correlation between the L* values of the teeth and the L* and b* values of the skin.When the analysis between the color measurements taken from the lip photographs and the teeth was examined, it was seen that there was a statistically significant positive correlation between the L* values of the upper central teeth and the a* values of the lip. Conclusion: The results showed that the CIEL*a*b* parameters of skin color and lip color can be used in the selection of tooth color in case of loss of natural teeth or discoloration of existing teeth. Keywords: Color Measurement; Digital Camera; Spectrophotometer; Skin Color; Tooth Color.

CYCLIC FATIGUE RESISTANCE OF ROTATE, EDGEFILE PLATINUM, AND K3XF FILES EXPOSED TO INTRACANAL TEMPERATURE IN AN S-SHAPED CANAL

Aim: To evaluate the bond strength of resin-based sealer to dentin after using different final irrigation solutions, one of which is alexidine dihydrochloride (ALX). Material and method: A total of 90 human maxillary central teeth were used. The groups were designed according to the final irrigation solution applied, as follows: Group 1: 17% ethylenediamine tetra-acetic acid (EDTA), Group 2: QMix, Group 3: 2% chlorhexidine gluconate (CHX) , Group 4: 1% ALX, and Group 5: Distilled water (Control group). All canals were obturated with gutta-percha and AH Plus. For bonding strength measurement, three horizontal sections of 2 mm thickness were obtained from each sample towards the coronal to apical. Push-out force was applied until bond failure occurred. Modes of failure were classified by examining each sample using a stereomicroscope as follows: adhesive (sealer-dentin or sealer-gutta-percha interface), cohesive (failure within sealer or dentin), mixed (failure in both the sealer and dentin). The Kruskal-Wallis H test was used for comparison among the groups (p < 0.05). Results: The mean highest values were obtained from the coronal, middle and apical regions, respectively (p < 0.05). The highest significant values for bonding strength was obtained in the EDTA group and the lowest in the control group (p < 0.001). There are no statistical differences among QMix, CHX and ALX groups, except for the coronal third, where the bond strength for the QMix was higher compared to the other two groups (p=0.001). All samples showed the cohesive failure type in most. Conclusion: Bonding strength is high when EDTA is used in any of the three parts of the root canal. ALX showed similar bond strengths to CHX. Key Words : AH Plus, alexidine, bond strength, chlorhexidine, EDTA, Qmix

Comparison of Maxillary Central Incisor, Crown Angulation and Tooth Size Variation in Aesthetic and Non-aesthetic Smiles- A Cross Sectional Study

Background: An attractive smile is often attributed to incisor alignment and proclined or retroclined incisors could contribute to a less aesthetic smile. Objectives: This study was aimed to evaluate the maxillary central incisor crown inclination, crown angulation and tooth size variation in aesthetic and unattractive smiles. Methods: The study was conducted among 100 females (equally divided into aesthetic and unaesthetic smile groups), aged between 15 - 25 years, with Angle’s Class I normal occlusion and balanced profiles. Variations in maxillary central incisor crown inclination and angulation were measured on lateral cephalograms, photographs and the study models of the subjects. Variations in tooth morphology were also evaluated by measuring crown height and width in both groups. Mann-Whitney U test was performed to evaluate the difference between the aesthetic and unaesthetic smiles. P &lt; 0.05 was considered as significant. Results: This study showed that incisor angulation was significantly higher in the unaesthetic group compared to the aesthetic group (P &lt; 0.001). However, there was no statistically significant difference for the incisor inclination relative to the Palatal Plane between the aesthetic and unaesthetic smile groups (P = 0.086). In addition, there were significant differences between the aesthetic and the non-aesthetic groups regarding the central incisor height (P &lt; 0.05). Conclusions: The findings of this study indicate that the possible variations in aesthetics are related to the ethnic elements that are associated with differences in crown angulations, as well as tooth size.