Retrospective Follow-up Assessment of Risk Variables Influencing the Outcome of Autologous Tooth Transplantation.

INTRODUCTION: This retrospective study aimed to identify which patient-, donor tooth-, recipient site-, and surgical procedure-related variables may influence the outcome of tooth autotransplantation. METHODS: The sample included 128 autotransplants performed in 122 patients. Single-visit clinical/imaging examinations were used to define the outcome as successful, survival, or failure. The association of potential indicators with the survival or failure categories was analyzed individually and adjusted for confounders through multivariate logistic regression models. RESULTS: After a follow-up period of 1 to 30.11 years, success was achieved in 71.8% of autotransplants, whereas the survival and failure groups had rates of 14.1% each, and the grouped success/survival rate reached 85.9%. An extraoral time >15 minutes and difficult handling/placement were strong/independent risk covariates for survival and failure categories (odds ratio >1, P < .05). Additionally, unerupted/partially erupted status of the donor tooth was a significant indicator for survival, whereas deficient bone level at the recipient site, surgical extraction, poor initial stability, and lack of prophylactic antibiotics were independently linked to failure (odds ratio > 1, P < .05). The root morphology and socket status acted as modifiers of the effect of the recipient site location on the survival group (P > .05). CONCLUSION: Based on the results of this study, unerupted/partially erupted status of the donor tooth, surgical extraction, total extraoral time >15 minutes, deficient recipient's bone level, difficult handling/placement of the autotransplant, poor initial stability, and lack of prophylactic antibiotics during the surgical procedure must be considered with caution when performing autotransplantation because of their deleterious influence on the outcome.

Dynamically guided transantral piezoelectric endodontic microsurgery: A case report with technical considerations.

AIM: Endodontic microsurgery (EMS) of maxillary molars may represent a complex challenge to the clinician due to the location of the roots and the proximity of the maxillary sinus floor. This report aimed to describe the simultaneous use of a computer-assisted dynamic navigation (C-ADN) system and piezoelectric bony-window osteotomy for the transantral microsurgical approach of a maxillary left first molar with adequate root canal filling and symptomatic apical periodontitis. SUMMARY: This case report highlights the importance of C-ADN to carry out a minimally invasive buccal surgical access to palatal roots affected by apical periodontitis and provides a practical example to help clinicians make treatment decisions based on the available evidence. Clinical and tomographic evaluations were performed before the surgical procedure and at 24-month follow-up. This case was treated using a C-ADN system fitted to a piezotome for the buccal approach of the buccal roots, maxillary sinus membrane lifting, and for transantral location, root-end resection, cavity preparation, and filling of the palatal root. The navigation system allowed to achieve an accurate apical canal terminus location and root-end filling of the three roots with a minimally invasive piezoelectric crypt approach. At the 24-month follow-up examination, the patient remains asymptomatic, with normal periapical structures, and regeneration of maxillary sinus walls. It was concluded that the combination of dynamic navigation with piezoelectric bony-window osteotomy offers enhanced accuracy, tissue preservation, diminished risk of iatrogenic complications, and could maximize success and survival rates in transantral EMS.

Application of computer-assisted dynamic navigation in complex root canal treatments: Report of two cases of calcified canals.

Root canal treatment and non-vital bleaching of teeth with pulp canal obliteration may represent a complex challenge to the clinician. This report describes the usefulness of the computer-assisted dynamic navigation system for the root canal treatment of two cases of teeth with a history of traumatic injury, extensively obliterated root canals and crown discoloration. Clinical and cone-beam computed tomographic evaluations were completed prior to procedures and 12 months after treatment. Both cases were treated using a computer-assisted dynamic navigation system coupled to a high-speed handpiece in order to establish the location and orientation of the partially obliterated canal and endodontic access route planning. The system allowed an accurate localisation of the root canal with a conservative access cavity. At the 12-month recall examination, the patients continue to be symptom-free, with a normal appearance of the mucogingival complex, adequate restoration of the tooth colour and intact periapical structures.

Vertical root fractures: A time-dependent clinical condition. A case-control study in two colombian populations.

BACKGROUND: This nested case-control study can be viewed as an efficient way to sample subjects from a large cohort study case-control study aimed to analyze the effect of different clinical factors on the appearance of vertical root fractures in endodontically-treated teeth (ETT) over time. MATERIAL AND METHODS: By matching 90 cases and 270 controls nested in a cohort of 450 patients. Incident "cases" included those ETT in which a confirmed VRF. The "controls" were ETT with clinical and radiographic evidence of normality. When an "incident case" was detected, three random "controls" according to the evaluation time registered in years were selected. Time interval corresponded to the exposure time from the end of the endodontic treatment until the tooth was included in the study. Demographic and clinical parameters included: age, gender, type, and location of the tooth, type of endodontic treatment, number of appointments necessary to complete the endodontic treatment, use of intra-canal medication, the apical extension of the filling, type of coronal restoration, the role of the tooth in the rehabilitation treatment, presence of intra-radicular posts, and presence of an adjacent implant, were analyzed over time. Statistical analysis: univariate descriptive analysis, Pearson's χ2 test, and a logistic regression model adjusted for the most significant variables with a 95% confidence interval. RESULTS: The prevalence of vertical root fractures was 16.42%. The multivariate analysis confirmed that re-treatment (OR:12.19; OR:4.28;P<0.05) lasting five to ten years and intra-canal medication (OR:6.16;P=0.004) for more than eleven years significantly more associated with the risk of vertical root fracture. For teeth with intra-canal post or direct coronal restorations, the risk of vertical root fracture was three times lower. CONCLUSIONS: Endodontic re-treatment and the use of intracanal medication such as calcium hydroxide should be considered primary and secondary risk factors, respectively, according to the appearance of VRF over time. Key words:Apical surgery, endodontic re-treatment, endodontically-treated teeth, risk factors, vertical root fracture.

Microstructural, microchemical, and mechanical changes associated with the clinical reuse of two nickel-titanium endodontic instruments.

BACKGROUND: Nickel-titanium (NiTi) instruments have represented a great technological development that enabled endodontists conforming irregular-shaped root canals. Notwithstanding, the repeated use of these instruments may lead to the fracture without any prior visible warning signs. This study aimed to evaluate how multiple clinical instrumentation/sterilization cycles of two NiTi mechanized instruments can affect their microstructural, microchemical, and mechanical characteristics. MATERIALS AND METHODS: In this observational descriptive study, a total of 140 NiTi instruments, 70 ProTaper Gold® (PTG) and 70 WaveOne Gold® (WOG) were analyzed. For each brand system, instruments were evaluated in the as-received condition (n = 10) and after one (n = 20), two (n = 20), and three (n = 20) instrumentation/sterilization cycles. Intraoperative instrumentation parameters were recorded for all used instruments. Afterward, the files were examined using scanning electron microscopy and energy-dispersive X-ray microanalysis. All of the instruments were tensile-fatigue tested until rupture in order to calculate the mechanical tensile strength and the maximum elongation percentage for the samples. Statistical analysis was completed using Chi-square, Kruskal-Wallis H-, or Mann-Whitney U-tests with a statistical significance set at P < 0.05. RESULTS: Significant increasing changes in surface topography (P < 0.05, Chi-square test) and chemical composition (P < 0.05, Kruskal-Wallis H-test) in both brand systems through instrumentation/sterilization cycles were detected. In addition, values of mechanical tensile strength and maximum elongation percentage increased significantly through instrumentation/sterilization cycles in the PTG group, whereas only the median values of mechanical tensile strength increased significantly in the WOG group (all P < 0.01, Kruskal-Wallis H-test). CONCLUSION: Although multiple instrumentation/sterilization cycles may render NiTi instruments more flexible and fatigue resistant, the significant changes detected in their surface topography and chemical composition should preclude their repeated clinical use in the routine endodontic practice as prevention for breakage.

In vivo detection of vertical root fractures in endodontically treated teeth: Accuracy of cone-beam computed tomography and assessment of potential predictor variables.

BACKGROUND: This study aimed: (a) to determine the diagnostic performance of cone-beam computed tomography (CBCT) for detection of vertical root fractures (VRFs); (b) to evaluate the predictive value of diagnostic criteria regarding the definition of VRFs; and (c) to examine the robustness of the association of patient-, tooth-, and treatment-related variables with VRFs. MATERIAL AND METHODS: 130 root-filled teeth with signs/symptoms of VRFs underwent clinical and CBCT assessments. Definite diagnosis of VRF was confirmed by endodontic microsurgical (EMS) exploration. Determination of diagnostic performance of CBCT was based on standard algorithms derived from two-way contingency table analysis. Predictive value of diagnostic criteria and the association between predictor variables with VRFs were analyzed using logistic regression models. RESULTS: VRFs were detected during EMS in 50% of the teeth. Based on the finding of fracture lines on CBCT scans, sensitivity, specificity, and accuracy were 86.2%, 13.8%, and 50%, respectively. Teeth having more than three diagnostic criteria present had significant higher odds for VRF diagnosis. After logistic regression analysis, parafunctional habits, one-canal roots, excessive root canal enlargement, and absence of intra-radicular posts remained as robust predictor variables of VRFs. CONCLUSIONS: Although the sensitivity of CBCT for VRFs detection is high, the risk of false-positive results related to its low specificity makes that all suspected cases must be confirmed by surgical exploration. VRFs cannot be reliably diagnosed by isolated clinical signs/symptoms; instead those teeth possessing more than three diagnostic criteria might be considered practically pathognomonic. The parafunctional habits, one-canal roots, excessive root canal enlargement, and the absence of intra-radicular posts may act strongly/independently for the occurrence of VRFs in endodontically treated teeth. Key words:Cone-beam computed tomography, diagnostic accuracy, diagnostic surgery, predictor variables, root canal treatment, vertical root fracture.

Cone-beam Computed Tomographic and Micro-computed Tomographic Evaluations of the Root Apexes of Teeth with Posttreatment Apical Periodontitis.

INTRODUCTION: This study evaluated the association of different variables that may influence the outcome of root canal treatment through cone-beam computed tomographic (CBCT) and micro-computed tomography (micro-CT) assessments of root apexes obtained by endodontic microsurgery of teeth with posttreatment apical periodontitis (AP), the agreement between CBCT and micro-CT findings, and the association of these variables with symptoms or lesion size. METHODS: Clinical and CBCT records and root apexes obtained by endodontic microsurgery from 11 cases of symptomatic AP and 22 cases of asymptomatic AP were available. Apical root specimens were further scanned using micro-CT imaging. CBCT parameters included periapical radiolucency size, apical extent/density of root canal filling, and occurrence of procedural errors. Micro-CT images evaluated the same parameters plus the presence of filling material in lateral canals and ramifications, the volume of the filled/nonfilled apical root canal, and the percentage of the nonfilled canal space. The agreement between CBCT/micro-CT observations was evaluated. RESULTS: Mandibular teeth, a lesion size <5 mm, a nonfilled volume <0.04 mm3, and the decreased percentage of the nonfilled canal volume were significantly associated with symptomatic AP. Maxillary teeth and inadequate apical filling density were significantly associated with larger lesions. Agreement between CBCT/micro-CT scores varied from fair (procedural errors) to satisfactory (extent/density of filling). CONCLUSIONS: Tooth location, lesion size, the nonfilled apical canal volume, and the percentage of the nonfilled apical canal volume were associated with symptomatic AP. In addition, lesion size was significantly associated with tooth location and apical root canal filling density. CBCT imaging may not provide a reliable evaluation of procedural errors associated with posttreatment disease.