Morphological measurements of anatomical landmarks in human maxillary first molar pulp chambers and evaluation of number of pulp canal orifices using spiral computed tomography: An in vitro study.

CONTEXT: Comprehensive understanding of the anatomic position of pulp canal orifices and the measurements of the molar pulp space may maintain the pulp health during conservative tooth preparation and minimize the possibility of mishaps during endodontic therapy. AIMS: The idea of the present study was to analyze the morphological measurements of anatomical landmarks in human maxillary first molar pulp chambers and evaluation of number of pulp canal orifices using three-dimensional spiral computed tomography (SCT). SUBJECTS AND METHODS: One hundred and thirty extracted intact human adult maxillary first molars were chosen from the North Indian population and were analyzed using SCT in axial and coronal sections. STATISTICAL ANALYSIS USED: Standard deviation, mean, and coefficient of variance were calculated. Interobserver reliability was evaluated using kappa value to avoid any bias. RESULTS: The results from our study showed that 69.23% of the sample teeth had four canal orifices, the mesial and distal pulp horns were present at an average distance of 0.80 ± 0.36 mm and 0.41 ± 0.34 mm, respectively, above the cementoenamel junction (CEJ), and the mean distance from the central groove of central fossa to furcation and the central groove of central fossa to the pulp chamber's roof was 8.37 ± 0.33 mm and 3.87 ± 0.29 mm, respectively. The average distance of the pulp chamber's floor from the furcation was found to be 2.47 ± 0.11 mm. The highest degree of variance was observed in case of relation of CEJ to pulp horns, i.e., 44.85% and 82.60%. CONCLUSIONS: The dimensions observed in this study and its resemblance to the various studies reported in literature shift the fundamental anatomic approach to a more systemic quantifiable approach to the endodontic maxillary first molar access preparation.

Racial predilection of C-shaped canal configuration in the mandibular second molar.

AIM: The purpose of this article is to determine the racial predilection of C-shaped canal configuration in a mandibular second molar. BACKGROUND: Unusual root canal anatomy always poses a diagnostic and treatment challenge. Identification of such variation is important for the success of root canal treatment outcome. C-shaped canal configuration is such an aberrant morphology of molar teeth that vary in different population and is commonly seen in a mandibular second molar. Thus, knowledge of racial predilection of C-shaped canal configuration in different population for early diagnosis is obligatory. MATERIALS AND METHODS: An exhaustive search was undertaken to identify published research articles related to C-shaped canal configuration in mandibular second molars. Forty-three research articles were analyzed which included 12,481 mandibular second molars. Chi-square test using value of P < 0.05 was performed to assess the statistical significance of this anomalous anatomic variation among the different population. RESULTS: Statistical test revealed a significant variation between the Asian and nonAsian population. The highest incidence of racial predilection was observed in China (Asia) with 93.1%, and the minimum was observed in America with 2.7%. CONCLUSION: This research reported that racial predilection of C-shaped canal configuration in mandibular second molar varies significantly.

Reattachment of complex fractures; a reality by advances in self-etch bonding systems.

An 18-year-old female patient reported to the Department of Conservative and Endodontics with the chief complaint of fractured tooth with respect to 21 and increased pain and mobility tooth with respect to 22. Intraoral periapical radiograph of 21 revealed coronal loss of tooth structure involving enamel, dentin, and pulp, suggestive of split tooth with respect to 21. Intraoral examination revealed a fracture of coronal structure of 22 and increased mobility in the coronal aspect, suggestive of horizontal crown-root fracture. For management of 21, after endodontic phase, placement of fiberpost, and coronal buildup, intentional reimplantation was done to expose and reattach the vertically fractured root fragment. For management of 22, after endodontic phase, crown lengthening was done, and the fractured fragment was reattached by making it a Natural Richmond's Crown. Radiographs revealed a complete sealing of the fractured fragment and proper positioning of the tooth.

Comparison of canal transportation and centering ability of Twisted Files, HyFlex controlled memory, and Wave One using computed tomography scan: An in vitro study.

AIM: The aim of the present study was to compare the canal transportation and centering ability of three rotary nickel-titanium (NiTi) systems (Twisted Files [TF], HyFlex controlled memory [CM], and Wave One [WO]) in curved root canals using computed tomography (CT). MATERIALS AND METHODS: Sixty freshly extracted single-rooted teeth having curved root canals with at least 25-35 degrees of curvature were selected. The teeth were randomly divided into three experimental groups of twenty each. After preparation with TF, HyFlex CM, and WO, all teeth were scanned using CT to determine the root canal shape. Pre- and post-instrumentation images were obtained at three levels, 3 mm apical, 9 mm middle, and 15 mm coronal above the apical foramen were compared using CT software. Amount of transportation and centering ability were assessed. The three groups were statistically compared with analysis of variance and post hoc Tukey's honestly significant difference test. RESULTS: Least apical transportation and higher centering ability were seen in HyFlex CM file system in all the three sections followed by TF. WO file system showed maximum transportation. CONCLUSIONS: The canal preparation with HyFlex CM file system showed lesser transportation and better centering ability than TF, WO file system.

Effect of Different Composite Restorations on the Cuspal Deflection of Premolars Restored with Different Insertion Techniques- An In vitro Study.

INTRODUCTION: This study was conducted to assess the effect of different composite materials on the cuspal deflection of premolars restored with bulk placement of resin composite in comparison to horizontal incremental placement and modified tangential incremental placement. AIM: The aim of this study was to evaluate the cuspal deflection caused by different composite materials when different insertion techniques were used. MATERIALS AND METHODS: Two different composite materials were used that is Tetric N Ceram (Ivoclar Vivadent marketing, India) and SonicFillTM (Kerr Sybron Dental). Forty standardized Mesio-Occluso-Distal (MOD) preparations were prepared on maxillary first premolars. Each group was divided according to composite insertion technique (n=10), as follows: Group I - bulk insertion using Tetric N Ceram, Group II - Horizontal incremental insertion technique using Tetric N Ceram, Group III- Modified tangential incremental technique using Tetric N Ceram, and Group IV- bulk insertion using SonicFillTM. Preparations were acid-etched, and bonded with adhesive resin to provide micro mechanical attachment before restoration using a uniform etching and bonding protocol in all the groups. All groups received the same total photo-polymerization time. Cuspal deflection was measured during the restorative procedure using customized digital micrometer assembly. One-way ANOVA test was applied for the analysis of significant difference between the groups, p-value less than 0.05 was considered statistically significant. RESULTS: The average cuspal deflections for the different groups were as follows: Group I 0.045±0.018, Group II 0.029±0.009, Group III 0.018±0.005 and Group IV 0.017±0.004. The intergroup comparison revealed statistically significant difference. CONCLUSION: A measurable amount of cuspal deflection was present in all the four studied groups. In general, bulkfill restoration technique with conventional composite showed significantly highest cusp deflection. There were no significant differences in cuspal deflection among sonicFillTM and modified tangential incremental insertion techniques.

A conservative management of iatrogenically damaged distal root of the mandibular second molar.

Trauma to the adjacent hard and soft tissue is the most common iatrogenic injury during extraction of the mandibular third molar. As every functional component of the dental arch is of prime importance in contemporary dental practice, the major concern must be in conserving the tooth and its structure as much as possible. The present case discusses the application of this conservative approach for management of iatrogenically damaged distal root of the mandibular second molar during extraction of impacted third molar, in which excessive guttering of alveolar bone and fractured apical third of distal root of 37 was observed radiographically. A conservative and noninvasive approach was successfully achieved to restore the damaged root by the bioactive material. Sealing of the remaining root with mineral trioxide aggregate allowed regeneration of soft and hard tissue around it.

Splinting of Longitudinal Fracture: An Innovative Approach.

Trauma may result in craze lines on the enamel surface, one or more fractured cusps of posterior teeth, cracked tooth syndrome, splitting of posterior teeth, and vertical fracture of root. Out of these, management of some fractures is of great challenge and such teeth are generally recommended for extraction. Literature search reveals attempts to manage such fractures by full cast crown, orthodontic wires, and so forth, in which consideration was given to extracoronal splinting only. However, due to advancement in materials and technologies, intracoronal splinting can be achieved as well. In this case report, longitudinal fractures in tooth #27, tooth #37, and tooth #46 had occurred. In #27, fracture line was running mesiodistally involving the pulpal floor resulting in a split tooth. In teeth 37 and 46, fractures of the mesiobuccal cusp and mesiolingual cusp were observed, respectively. They were restored with cast gold inlay and full cast crown, respectively. Longitudinal fracture of 27 was treated with an innovative approach using intracanal reinforced composite with Ribbond, external reinforcement with an orthodontic band, and full cast metal crown to splint the split tooth.

Management of Grossly Decayed Mandibular Molar with Different Designs of Split Cast Post and Core.

Mandibular molar with extensive loss of tooth structure, especially where no cavity wall is remaining, and insertion of posts in both the roots appear necessary so as to achieve proper retention for the core material. A single unit metal casting with two posts, one in the mesial root and the other in the distal divergent root, is difficult to fabricate due to difference in the path of insertion of the two posts. Multisection post and core or single cast post and core with auxiliary post can be an effective design to manage grossly decayed mandibular molars.

Influence of Ultrasonic Irrigation and Chloroform on Cleanliness of Dentinal Tubules During Endodontic Retreatment-An Invitro SEM Study.

BACKGROUND: Ultrasonic irrigation has been proved for its remarkable cleaning efficiency in the field of endodontics. But its role in endodontic re-treatment has been understated. There is not much data available to understand the effect of ultrasonic irrigation for the evaluation of cleanliness of dentinal tubules when it is used with or without chloroform, a gutta percha solvent during endodontic retreatment. AIM: To compare the influence of ultrasonic irrigation with syringe irrigation on cleanliness of dentinal tubules after gutta perch removal for endodontic retreatment with or without the use of chloroform a gutta percha solvent using scanning electron microscope (SEM). MATERIALS AND METHODS: Freshly extracted 45 human mandibular premolar teeth for periodontal and orthodontic reasons were taken and were occlusally adjusted to a working length of 19 mm. The root canals of all teeth were prepared chemo mechanically to a master apical file size 40 and were divided in various groups. In Group 1 (n = 5; control group), the canals remained unfilled. In Groups 2 and 3 (n = 20 each), the canals were filled using lateral compaction with gutta-percha and AH plus sealer, removal of root fillings was undertaken after 2 weeks using Gates Glidden drills and H files without chloroform in Group 2 and with chloroform in group 3. The specimen of Group 2 and 3 were further divided into two subgroups I and II (n=10). In subgroup I, irrigation was done using side vented needles and sodium hypochlorite. In subgroup II irrigation was done using passive ultrasonic irrigation with sodium hypochlorite. Thereafter, the roots were split and the sections were observed under SEM. The number of occluded dentinal tubules /total number of dentinal tubules were calculated for the coronal, middle and apical third of each root half. Statistical analysis was performed using one-way ANOVA followed by Tukey's test using standardized technique. RESULT: Results indicated that the cleanest dentinal tubules were found in the control group (Group 1 where the canals were unfilled) followed by the non chloroform group with ultrasonic irrigation (Group 3 subdivision II) followed by chloroform group with ultrasonic irrigation (Group 2 subdivision II), the non chloroform group with syringe irrigation (Group 3 subdivision I) and least cleanliness was found in the chloroform group with syringe irrigation (Group 2 subdivision I). CONCLUSION: Under the limitations of this study it could be concluded that both ultrasonic and syringe irrigation showed cleaner canals when chloroform was not used. Irrigation when done with ultrasonics leads to cleaner tubules than syringe irrigation. Hence, mechanical methods of retrieval in conjunction with use of passive ultrasonic irrigation should be a part of retreatment protocol.