Amputação radicular para preservação de elemento dentário / Root amputation for tooth preservation

A periodontite é uma doença inflamatória crônica dos tecidos de sustentação e proteção dos dentes. Em dentes posteriores, a perda de inserção pode resultar em vários graus de dano à furca, que se refere à destruição dos tecidos de suporte de dentes multirradiculares caracterizada por reabsorção óssea e perda de inserção no espaço interarradicular. Independente do grau de envolvimento da furca, o tratamento periodontal básico (RAR) é a primeira opção para estabilizar a periodontite, contudo, em algumas situações é utilizada uma terapia cirúrgica periodontal bastante conhecida: a rizectomia ou amputação radicular. O objetivo do trabalho é relatar o caso de uma amputação radicular de um dente comprometido periodontalmente, a fim de se preservar o elemento dentário. O dente 27 foi diagnosticado com periodontite, o que ocasionou a lesão de furca grau III. O tratamento endodôntico foi realizado prévio ao procedimento cirúrgico, viabilizando a amputação da raiz disto-vestibular deste elemento. A partir do relato deste caso, se pode concluir que a amputação radicular é considerada um procedimento conservador, capaz de manter em função molares com histórico de periodontite associado ao envolvimento de lesões de furca(AU)

Periodontitis is a chronic inflammatory disease of the supporting and protective tissues of the teeth. In posterior teeth, attachment loss can result in varying degrees of damage to the furcation, which refers to the destruction of the supporting tissues of multirooted teeth characterized by bone resorption and attachment loss in the interarticular space. Regardless of the degree of furcation involvement, basic periodontal treatment (RAR) is the first option to stabilize periodontitis; however, in some situations, a well-known periodontal surgical therapy is used: rhizectomy or root amputation. Rhizectomy is a treatment option for multirooted teeth. The technique preserves the crown and requires endodontic treatment of the affected tooth, preferably done before surgery(AU)

Frecuencia y tipología del segundo conducto mesiovestibular en primeros molares superiores / Frequency and typology of the second mesiobuccal canal in maxillary first molars

Objetivos: Evaluar mediante microscopia quirúrgica la presencia del segundo conducto mesiovestibular (MV2) en el piso de la cámara pulpar de los primeros molares superiores, determinar su abordabilidad, establecer el calibre de lima que llegó al tercio apical y tipificar radiovisiográficamente su morfología se-gún la clasificación de Weine. Materiales y métodos: Se utilizaron 48 primeros molares superiores huma-nos extraídos. Sé tomaron radiovisografías preope-ratorias (Carestream 5200) en sentido orto radial y mesio-distal. Se realizó apertura y se localizó entra-da del MV2 con microscopio quirúrgico (Newton MEC XXI, Argentina) a 16 x. Se cateterizó MV1 y MV2 con limas tipo K #10 y #15 (Dentsply Maillefer). Se cortó raíz distovestibular para mejorar visualización ra-diovisográfica. Se tomó conductometria en sentido mesio-distal para establecer la tipología. Se compa-raron frecuencias y porcentajes mediante test de Chi-cuadrado con corrección de Yates, prueba exac-ta de Fisher y test z para diferencia de proporcio-nes. Se calcularon intervalos de confianza 95% para porcentajes mediante método score de Wilson. Re-sultados: El 54% (26 casos) presentó MV2. De los 26 MV2, el 77% (20 casos) fueron abordables, porcen-taje significativamente mayor al 23% no abordable (z=3,62; P<0,05). Al hacer cateterismo, hubo asocia-ción significativa entre tipo de conducto (MV1 y MV2) y calibre de lima que llegó al tercio apical (Chi-cua-drado=29,12; gl=1; P<0,05). La tipología I (58%) fue significativamente mayor que las tipologías II (21%) y III (21%) (P<0,05 para ambas comparaciones). Con-clusión: El alto porcentaje de piezas que presentó MV2 evidencia la importancia clínica de detectarlo y tratarlo correctamente. Dado el alto porcentaje de piezas donde fue abordable, se concluye que el clíni-co debe tener conocimiento, destreza y la tecnología necesaria para poder abordarlo. Si bien la tipología I (58%) fue la más encontrada, cuando el MV2 termina en foramen independiente (tipo III), su omisión puede conducir al fracaso del tratamiento (AU))

Objectives: To evaluate by surgical microscopy the presence of second mesiobuccal canal (MB2) in the pulp chamber floor of the maxillary first molars, determine its approachability, establish the caliber of the file that reached the apical third, and radiographically typify its morphology according to Weine ́s classification. Materials and methods: 48 extracted human maxillary first molars were used. Preoperative radiovisographies (Carestream 5200) were taken in ortho-radial and mesio-distal direction. Coronal access was made and the entrance of MB2 was located with a surgical microscope (Newton MEC XXI, Argentina) at 16x. MB1 and MB2 were catheterized with K files #10 and #15 (Dentsply Maillefer). Distobuccal root was cut to improve radiovisographic visualization. Conductometry was taken in mesio-distal direction to establish the typology. Frequencies and percentages were compared using Chi-square test with Yates correction, Fisher's exact test and z test for difference in proportions. 95% confidence intervals were calculated for percentages using Wilson score method. Results: 54% (26 cases) presented MB2. Of the 26 MB2, 77% (20 cases) were approachable, a significantly higher percentage than those not approachable (z=3.62; P<0.05). When performing catheterization, there was a significant association between type of canal (MB1 and MB2) and file caliber that reached the apical third (Chi-square=29.12; df=1; P<0.05). Typology I (58%) was significantly higher than typologies II (21%) and III (21%) (P<0.05 for both comparisons). Conclusion: The high percentage of specimens that showed MB2 evidence the clinical importance of detecting and treating it correctly. Given the percentage of pieces where it was approachable (77%), it is concluded that the clinician must have the knowledge, skill and necessary technology to be able to approach it. Although typology I (58%) was the most found, when MB2 ends an independent foramen (type III), its omission can lead to treatment failure (AU)

Recubrimiento radicular de recesiones gingivales con matriz dérmica acelular / Root coverage of gingival recession with acellular dermal matrix

La recesión gingival es considerada como una deformidad o condición mucogingival, la Academia Americana de Periodontología, define a la recesión gingival como el desplazamiento del margen del tejido blando apical a la unión cemento-esmalte con la exposición de la superficie radicular. El tratamiento de las recesiones gingivales es un motivo de consulta común debido a razones estéticas, hipersensibilidad dentinaria, molestias durante el cepillado e incluso temor a la pérdida dentaria. Es una situación clínica común, 60% de la población humana tiene algún tipo de recesión gingival. Al realizar el examen clínico a paciente masculino de 55 años, se observó una recesión gingival tipo 1 (RT1) sin pérdida de inserción interproximal de la clasificación de Cairo. Se realizó el colgajo posicionado coronalmente (CPC) utilizando una matriz dérmica acelular (MDA) de origen humano OrACELL®. Se obtuvo resultado favorable en el recubrimiento de recesiones gingivales múltiples; considerándolos como una buena alternativa frente a los injertos gingivales autógenos. Concluyendo que, el uso de la matriz dérmica acelular para el tratamiento de la recesión gingival tipo 1 es una adecuada opción para el recubrimiento radicular. Se recomiendan más estudios a largo plazo para ver la estabilidad de los resultados obtenidos con la MDA (AU)

Gingival recession, considered a deformity or mucogingival condition, the American Academy of Periodontology, defines gingival recession as the exposure of the root surface resulting from migration of the gingival margin apical to the cementoenamel junction (CEJ). The treatment of gingival recessions is a common reason for consultation due to aesthetic reasons, dentin hypersensitivity, discomfort during brushing and even fear of tooth loss. It is a common clinical situation, 60% of the human population has some kind of gingival recession. Clinical examination of a 55-year-old male patient showed a type 1 gingival recession (RT1) without loss of interproximal insertion of the Cairo classification. Coronally advanced flap (CAF) was performed using an acellular dermal matrix (ADM) of human origin OrACELL®. Favorable results were obtained in the coating of multiple gingival recessions; considering them as a good alternative to autogenous gingival grafts. Concluding that, the use of the acellular dermal matrix for the treatment of gingival recession type 1, is a suitable option for root lining. Further long-term studies are recommended to see the elasticity of MDA outcomes (AU)

Quiste radicular residual / A residual radicular cyst

En la región cervicofacial los quistes de los maxilares de origen odontogénico constituyen una afección relativamente importante, los más frecuentes son los quistes radiculares. Se presentó un paciente masculino de 23 años de edad con un quiste radicular residual extenso que ocupaba la zona mandibular posterior izquierda, y acude a consulta estomatológica de la Clínica «Celia Sánchez Manduley» por un aumento de volumen que causa asimetría facial notable de la hemicara izquierda, de tres centímetros de diámetro, indoloro, asintomático, con 6 meses de evolución y consistencia dura; además refiere tratamiento de exodoncia de molar inferior en la zona (37) hace 2 años. Se indicó radiografía periapical y panorámica donde se observó zona radiolúcida bien definida de 35 a 38 con reabsorción de raíz mesial de 38, distal de 36 y movilidad dentaria grado II en ambos dientes. Se realizó exéresis de la lesión cuyo estudio histológico informó un quiste radicular residual.

Jaw cysts of odontogenic origin constitute a relatively important condition in the cervicofacial region, where radicular cysts are the most frequent. We present a 23-year-old male patient who come to "Celia Sánchez Manduley" Dental Clinic with an extensive residual radicular cyst that occupied his left posterior mandibular area and an increase in volume that caused him a notable facial asymmetry in the left side of his face, of three centimeters in diameter, painless, asymptomatic, with 6 months of evolution and hard consistency; he also mentions a lower molar extraction treatment in area (37) 2 years ago. Periapical and panoramic X-rays were indicated where a well-defined radiolucent zone of 35 to 38 was observed with mesial root resorption of 38, distal of 36 and grade II dental mobility in both teeth. Exeresis of the lesion was performed, whose histological study reported a residual radicular cyst.

Radix em molares decíduos inferiores: revisão sistemática com metanálise / Radix in lower primary molars: systematic review with meta-analysis

Objective: To estimate the prevalence of three roots in deciduous mandibular molars. Methodology: Electronic searches were carried out in PubMed and Scopus to identify cross-sectional studies published up to September 2023. The Joanna Briggs Institute tool was used to critically appraise the studies. STATA 16.0 was used to generate risk of bias figures and perform the meta-analysis. Results: Eighteen studies evaluating 9,067 patients (8,969 first molars and 10,765 second molars) were included in this review. The overall prevalence of radix in mandibular deciduous molars was 9.61% (3.67% for first molars and 18.72% for second molars). The prevalence rate of teeth diagnosed using Cone Beam Computed Tomography (CBCT) was similar to the diagnoses made using conventional radiographic techniques together (periapical, interproximal and panoramic). Final considerations: Lower deciduous molars with three roots have a prevalence of almost 10%, with a higher prevalence in second molars. The diagnosis of this morphological alteration can be made using conventional radiographic techniques, but the use of CBCT is recommended.(AU)

Objetivo: estimar a prevalência de três raízes em molares inferiores decíduos. Metodologia: foram realizadas buscas eletrônicas na PubMed e Scopus para identificar estudos transversais publicados até setembro/2023. Para a avaliação crítica dos estudos foi utilizada a ferramenta do Instituto Joanna Briggs. STATA 16.0 foi usado para gerar figura do risco de viés e realizar a metanálise. Resultados: dezoito estudos que avaliaram 9.067 pacientes (8.969 primeiros molares e 10.765 segundos molares) foram incluídos nesta revisão. A prevalência global de radix em molares decíduos inferiores foi de 9,61% (3,67% para primeiros molares e 18,72% para segundo molares). A taxa de prevalência de dentes com diagnóstico através de Tomografia Computadorizada Cone Beam (TCCB) foi semelhante aos diagnósticos realizados pelas técnicas radiográficas convencionais em conjunto (periapical, interproximal e panorâmica). Considerações finais: os molares decíduos inferiores com três raízes têm uma prevalência de quase 10%, com maior prevalência em segundo molares. O diagnóstico desta alteração morfológica pode ser feito através das técnicas radiográficas convencionais, porém recomenda-se a utilização de TCCB.(AU)

Analysis of the Internal and External Morphology of the Mandibular First Molar in a Chilean Sub-Population Using Cone-Beam Computed Tomography / Análisis de la Morfología Interna y Externa del Primer Molar Mandibular en una Subpoblación Chilena Mediante Tomografía Computarizada de Haz Cónico

SUMMARY: The mandibular first molar (MFM) commonly presents two roots with two canals in the mesial root and one or two canals in the distal root. However, morphological variations have been described in different populations, which must be considered when planning endodontic treatment. The aim of this study was to analyze the internal and external morphology of the MFM in a Chilean sub-population using cone-beam computed tomography (CBCT) images. An in vivo cross-sectional, descriptive, and observational study was conducted using CBCT exams from 351 right and left MFM. The data were analyzed by descriptive statistics using the Chi- Square test for categorical variables, Fisher's exact test, the Mann-Whitney U non-parametric test for two independent samples, and the Wilcoxon non-parametric test for related samples. Of the total sample, 1 root was observed in 2.27 % of the cases, 2 roots in 93.73 %, and 3 roots in 4 %. In relation to the number of canals, 71.23 % of the MFM showed 3 root canals, 16.81 % 4 canals, 9.69 % 2 canals, and 2.28 % 1 canal. Of all the studied cases, 2.3 % had a C-shaped anatomy. In terms of morphology, using Zhang's classification, variant 3 was observed in 71.23 %, variant 4 in 12.82 %, variant 1 in 9.67 %, variant 6 in 4 %, and variant 8 in 2.28 %. In conclusion, the morphology of the MFM is variable in a Chilean sub-population, and these variations must be considered before and during endodontic therapy. CBCT proved to be an effective tool for the in vivo study of tooth morphology.

El primer molar mandibular (MFM) comúnmente presenta dos raíces con dos canales en la raíz mesial y uno o dos canales en la raíz distal. Sin embargo, se han descrito variaciones morfológicas en distintas poblaciones, las que se deben tener en consideración al momento de planificar el tratamiento endodóntico. El objetivo de este estudio fue analizar la morfología interna y externa del MFM en una sub población chilena mediante el uso de imágenes de tomografía computarizada Cone Beam (CBCT). Se realizó un estudio transversal, descriptivo y observacional in vivo empleando exámenes CBCT de 351 MFM tanto derechos como izquierdos. Los datos se analizaron mediante estadística descriptiva empleando la prueba Chi-Cuadrado para variables categóricas, el test exacto de Fisher, la prueba no paramétrica de U-Mann-Whitney para dos muestras independientes y la prueba no paramétrica de Wilcoxon para muestras relacionadas. Del total de la muestra se observó 1 raíz en un 2.27 % de los casos, 2 raíces en 93.73 % y 3 raíces en un 4 %. En relación al número de canales un 71.23 % de los MFM mostraron 3 canales radiculares, un 16.81 % 4 canales, un 9.69 % 2 canales y un 2.28 % 1 canal. Del total de los casos estudiados un 2.3 % se presentó anatomía en forma de C. En relación a la morfología, empleando la clasificación de Zhang, se observó en un 71.23 % la variante tipo 3, en un 12.82 % la variante tipo 4, en un 9.67 % la variante tipo 1, en un 4 % variante tipo 6 y en un 2,28 % variante tipo 8. En conclusión, la morfología del MFM es variable en una subpoblación chilena y estas variaciones deben ser consideradas antes y durante la terapia endodóntica. El CBCT demostró ser una herramienta eficaz para el estudio in vivo de la morfología dentaria.

Cone beam computed tomography-based evaluation of the relationship between the inferior alveolar canal and the cortical plates and the mandibular molar roots in the saudi subpopulation / Evaluación basada en tomografía computarizada de haz cónico de la relación entre el canal alveolar inferior y las placas corticales y las raíces de los molares mandibulares en la subpoblación saudita

Aim: To assess the distance between the inferior alveolar canal and the roots of the mandibular second molar and the mandibula and cortex in a Saudi Arabian subpopulation through existing CBCT images. Materials and Methods: This retrospective study was performed based on 120 patients CBCT images in five age groups.The distances (D1 and D2) between the buccal cortex (BC), lingual cortex (LC), and mandibular molars and the distances (D3) between the root apices and inferior alveolar nerve canal (IANC) were measured for each dental root on the right and left of the mandible with the help of Vision iCAT software. A radiology specialist with a gap of 15 days twice carried out the measurements. Statistical analysis was carried out with the help of SPSS 24. to analyse variability Chi-square analysis was done, and the p value was fixed at > 0.05. To check inter-person variability, Cohen's variability was fixed at 0.8. Results: The distance between the outer surface of the buccal cortical plate and the buccal root surface ranged between 3.8 and 5.7 mm, whereas the distance between the root apices of the mandibular molars and the IANC ranged between 4.8 and 3.5 mm. The distance from the outer surface of the lingual cortical plate to the lingual root surface varied between 1.2 and 2.8 mm. The mean distance between the root apices and IANC increased with age, more so in males than females. Conclusions: Even though this study was conducted on a small sample size, it will help the dental practitioners in planning endodontic procedures, surgical extractions, and implant placements, and it should be repeated with a higher number of images.

Objetivo: Evaluar la distancia entre el canal alveolar inferior y las raíces del segundo molar mandibular, y la mandíbula y la corteza en una subpoblación de Arabia Saudita a través de imágenes CBCT existentes.Materiales y Métodos: Este estudio retrospectivo se realizó con base en imágenes CBCT de 120 pacientes en cinco grupos de edad. Las distancias (D1 y D2) entre la corteza bucal (BC), la corteza lingual (LC) y los molares mandibulares y las distancias (D3) entre los Se midieron los ápices radiculares y el canal del nervio alveolar inferior (IANC) para cada raíz dental a la derecha e izquierda de la mandíbula con la ayuda del software Vision iCAT. Un especialista en radiología, con un intervalo de 15 días, realizó dos veces las mediciones. El análisis estadístico se realizó con la ayuda del SPSS 24. Para analizar la variabilidad se realizó un análisis de Chi-cuadrado y el valor p se fijó en > 0,05. Para comprobar la variabilidad entre personas, la variabilidad de Cohen se fijó en 0,8. Resultados: La distancia entre la superficie exterior de la placa cortical bucal y la superficie de la raíz bucal osciló entre 3,8 y 5,7 mm, mientras que la distancia entre los ápices radiculares de los molares mandibulares y el IANC osciló entre 4,8 y 3,5 mm. La distancia desde la superficie exterior de la placa cortical lingual hasta la superficie de la raíz lingual varió entre 1,2 y 2,8 mm. La distancia media entre los ápices de las raíces y la IANC aumentó con la edad, más en hombres que en mujeres. Conclusión: Aunque este estudio se realizó con un tamaño de muestra pequeño, ayudará a los odontólogos a planificar procedimientos de endodoncia, extracciones quirúrgicas y colocación de implantes, y debe realizarse con más números.

Has the literature thoroughly categorized the lower third molars? A new classification of the various lower third molar root forms for a better understanding of their morphology / ¿La literatura ha categorizado minuciosamente los terceros molares inferiores? Una nueva clasificación de las diversas formas radiculares del tercer molar inferior para una mejor comprensión de su morfología

SUMMARY: Impacted lower third molars (IL3M) have different root shapes and numbers. This study aimed to create a classification for IL3M root forms, that should aid in understanding roots morphology. A retrospective cross-sectional study on patients had IL3M at the university clinics between 2017 and 2019. Panoramic radiographs were retrieved to classify the roots into fused roots (FR): one or two roots connected from furcation to apices, and separated roots (SR): two or more roots not connected from furcation to apical third, and each type has different forms. Statistical analysis was done by Chi-Square test. Five-hundred patients, males (54.6 %) and females (45.4 %) were included. SR were in 591 teeth (75.5 %), and FR in 192 teeth (24.5 %). Statistically significant associations emerged between SR and males (60 %) and between FR and females (66 %) (p = .000). SR forms were straight (45.8 %), joined roots (28.2 %), one straight and one curved (13.3 %), roots curved distal (9.1 %), roots curved mesial (2.5 %), and more than two roots (0.3 %). FR forms were straight (87.5 %), curved distal (9.4 %), S-shaped (2.1 %), and curved mesial (1 %). The common angulations of IL3M with SR were vertical (39 %) followed by mesioangular (25.7 %), while FR were mostly vertical (39.1 %) or horizontal (23.9 %). The classification is applicable on panoramic radiographs, and complements Winter and Pell & Gregory to provide a better description of IL3M status by adding root morphology to the angulation, occlusal, and ramus relationship.

Los terceros molares inferiores impactados (3MII) tienen diferentes formas y números de raíces. Este estudio tuvo como objetivo crear una clasificación para las formas de raíz 3MII, que debería ayudar a comprender la morfología de las raíces. Realizamos un estudio transversal retrospectivo de pacientes con 3MII en las clínicas universitarias entre 2017 y 2019. Se recuperaron radiografías panorámicas para clasificar las raíces en raíces fusionadas (RF): una o dos raíces conectadas desde la zona de furca a los ápices y raíces separadas (RS): dos o más raíces no conectadas desde la bifurcación al tercio apical, y cada tipo con formas diferentes. El análisis estadístico se realizó mediante la prueba Chi-Cuadrado. Se incluyeron 500 pacientes, hombres (54,6 %) y mujeres (45,4 %). RS se observó en 591 dientes (75,5 %) y RF en 192 dientes (24,5 %). Surgieron asociaciones estadísticamente significativas entre RS y hombres (60 %) y entre RF y mujeres (66 %) (p = .000). Las formas de RS eran rectas (45,8 %), raíces unidas (28,2 %), una recta y una curva (13,3 %), raíces curvas distales (9,1 %), raíces curvas mesiales (2,5 %) y más de dos raíces (0,3 %).). Las formas RF eran rectas (87,5 %), curvas distales (9,4 %), en forma de S (2,1 %) y curvas mesiales (1 %). Las angulaciones comunes de 3MII con RS fueron verticales (39 %), seguidas de mesioangular (25,7 %), mientras que RF fueron mayoritariamente verticales (39,1 %) u horizontales (23,9 %). La clasificación es aplicable en radiografías panorámicas y complementa a Winter y Pell & Gregory para proporcionar una mejor descripción del estado de 3MII al agregar la morfología de la raíz a la relación de angulación, oclusal y rama.

Effect of various intracanal materials on the diagnostic accuracy of cone-beam computed tomography in vertical root fractures / 北京大学学报(医学版)

OBJECTIVE@#To study the effect of various intracanal materials on the accuracy of oral maxillofacial cone-beam computed tomography (CBCT) for the diagnosis of vertical root fracture (VRF).@*METHODS@#A total of twenty-four structurally intact single root canal dried and isolated teeth extracted for orthodontic treatment or periodontal disease were collected. The teeth were decrowned along the cemento-enamel junction (CEJ) and then used as samples for the study after conventional root canal preparation and post preparation. The 24 samples were divided into two groups with 12 samples in each group. Group A was the control group (no VRF group). According to intracanal materials, they were divided into five subgroups: blank group, fiber post group, gutta-percha point group, titanium post group and gold-palladium post group. Group B was the experimental group (VRF group), and subgroups were grouped as above. The VRF model was prepared by a unified method in the VRF group: the root was completely fractured in the buccolingual direction with a custom root canal nail and then cemented and reset. The control group was not subjected to the simulation of VRF. Titanium post and gold-palladium post were made according to the individuality of the root canal preparation, and the tightness of the post to the root canal wall was confirmed by X-ray radiograph. Then all the samples were scanned by CBCT in the isolate swine mandibular alveolar sockets. The diagnostic accuracy was statistically analyzed via blind interpretation by experienced endodontic specialists and oral and maxillofacial medical imaging specialists.@*RESULTS@#The accuracy of the diagnosis of VRF in the blank group, fiber post group, gutta-percha point group, titanium post group, and gold-palladium post group in CBCT was 95.83%, 91.67%, 87.50%, 79.17%, and 45.83%, respectively. Compared with the blank group, the differences were not statistically significant in the fiber post group (P>0.999), the gutta-percha point group (P=0.500) and the titanium post group (P=0.125). The lowest diagnostic accuracy of VRF was found in the gold-palladium post group, and the difference was statistically significant compared with all other groups (P < 0.001).@*CONCLUSION@#Various intracanal materials have different degrees of influence on the diagnostic accuracy of VRF diagnosis in CBCT. The influence of fiber post, gutta-percha point and titanium post was small, while the influence of gold-palladium post was significant.

Intentional replantation for the retreatment of mandibular second molar: a case report / 华西口腔医学杂志

When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.

Comparison of the efficacy and long-term stability of tunnel technique and coronally advanced flap in the treatment of gingival recession: a Meta-analysis / 华西口腔医学杂志

OBJECTIVES@#This study aimed to evaluate the efficacy and long-term stability of tunnel technique (TUN) and coronally advanced flap (CAF) combined with connective tissue graft (CTG) in treating gingival recession.@*METHODS@#Databases including PubMed, Web of Science, Embase, and CNKI were electronically searched to collect randomized controlled trial (RCT) of CAF+CTG compared to TUN+CTG in the treatment of Miller class Ⅰ or Ⅱ gingival recession on September 1, 2022.@*RESULTS@#There were 8 RCTs with 305 patients (454 recession sites) participating. The results of the Meta-analysis revealed that, in terms of mean root coverage (MRC) of main indicators, no significant difference was found between the CAF group and the TUN group in both short- and long-term results, which were [MD: 1.45%, 95%CI (-2.93%, 5.82%), P=0.52] and [MD: -0.70%, 95%CI (-6.41%, 5.00%), P=0.81]. However, the CAF group outperformed the TUN group in the long term [MD: 5.69%, 95%CI (0.87%, 10.50%), P=0.02], and the results of complete root coverage (CRC) analysis were similar to those of MRC. In the short term, the TUN group grew keratinized gingiva significantly faster than the CAF group [MD: -0.38 mm, 95%CI (-0.67 mm, -0.10 mm), P=0.008]. Long-term findings revealed no significant difference between the two groups [MD: -0.26 mm, 95%CI (-0.94 mm, 0.43 mm), P=0.46]. The TUN group's secondary index root coverage esthetic score (RES) was statistically significantly higher than the CAF group's [MD: 0.62, 95%CI (0.28, 0.96), P=0.000 3]. Given that there were few results included in the literature and the heterogeneity was too great, no significant difference was observed in the postoperative VAS pain index score [MD: 0.53, 95%CI (-1.96, 3.03), P=0.68].@*CONCLUSIONS@#This study discovered that both CAF+CTG and TUN+CTG can achieve good root coverage in treating gingival recession, with CAF outperforming TUN and both groups achie-ving good long-term stability. After the operation, the TUN group had a higher RES than the CAF group. Given the limitations of this study, more high-quality studies are needed in the future to demonstrate the efficacy of TUN in gingival retraction surgery.

Spatiotemporal cellular dynamics and molecular regulation of tooth root ontogeny / 国际口腔科学杂志·英文版

Tooth root development involves intricate spatiotemporal cellular dynamics and molecular regulation. The initiation of Hertwig's epithelial root sheath (HERS) induces odontoblast differentiation and the subsequent radicular dentin deposition. Precisely controlled signaling pathways modulate the behaviors of HERS and the fates of dental mesenchymal stem cells (DMSCs). Disruptions in these pathways lead to defects in root development, such as shortened roots and furcation abnormalities. Advances in dental stem cells, biomaterials, and bioprinting show immense promise for bioengineered tooth root regeneration. However, replicating the developmental intricacies of odontogenesis has not been resolved in clinical treatment and remains a major challenge in this field. Ongoing research focusing on the mechanisms of root development, advanced biomaterials, and manufacturing techniques will enable next-generation biological root regeneration that restores the physiological structure and function of the tooth root. This review summarizes recent discoveries in the underlying mechanisms governing root ontogeny and discusses some recent key findings in developing of new biologically based dental therapies.

Atp6i deficient mouse model uncovers transforming growth factor-β1 /Smad2/3 as a key signaling pathway regulating odontoblast differentiation and tooth root formation / 国际口腔科学杂志·英文版

The biomolecular mechanisms that regulate tooth root development and odontoblast differentiation are poorly understood. We found that Atp6i deficient mice (Atp6i-/-) arrested tooth root formation, indicated by truncated Hertwig's epithelial root sheath (HERS) progression. Furthermore, Atp6i deficiency significantly reduced the proliferation and differentiation of radicular odontogenic cells responsible for root formation. Atp6i-/- mice had largely decreased expression of odontoblast differentiation marker gene expression profiles (Col1a1, Nfic, Dspp, and Osx) in the alveolar bone. Atp6i-/- mice sample RNA-seq analysis results showed decreased expression levels of odontoblast markers. Additionally, there was a significant reduction in Smad2/3 activation, inhibiting transforming growth factor-β (TGF-β) signaling in Atp6i-/- odontoblasts. Through treating pulp precursor cells with Atp6i-/- or wild-type OC bone resorption-conditioned medium, we found the latter medium to promote odontoblast differentiation, as shown by increased odontoblast differentiation marker genes expression (Nfic, Dspp, Osx, and Runx2). This increased expression was significantly blocked by anti-TGF-β1 antibody neutralization, whereas odontoblast differentiation and Smad2/3 activation were significantly attenuated by Atp6i-/- OC conditioned medium. Importantly, ectopic TGF-β1 partially rescued root development and root dentin deposition of Atp6i-/- mice tooth germs were transplanted under mouse kidney capsules. Collectively, our novel data shows that the prevention of TGF-β1 release from the alveolar bone matrix due to OC dysfunction may lead to osteopetrosis-associated root formation via impaired radicular odontoblast differentiation. As such, this study uncovers TGF-β1 /Smad2/3 as a key signaling pathway regulating odontoblast differentiation and tooth root formation and may contribute to future therapeutic approaches to tooth root regeneration.

Success and survival rates of immediate anatomic zirconia implants: a prospective clinical and radiographic evaluation

Modern immediate titanium implants have two major drawbacks which are the black metal appearance that might be seen through the mucosa and the gap between implant and extraction socket. Immediate anatomical zirconia implants were introduced to match the shape of the extracted root and fill the socket without gaps while still providing better metal-free appearance. Aim: This study aims to investigate success and survival rates of immediate anatomical zirconia implants. Methods: This prospective interventional study was held between 2017 and 2020 in the faculty of dental medicine, Damascus University, Syria. The sample consisted of 27 immediate anatomical zirconia implants in 21 patients from both genders. Implants were designed and manufactured starting from CBCT image and prior to extraction. Specialized software applications were used to modify implant design. Implants went through different processing procedures to make them ready for insertion immediately after tooth extraction. Restorations were made after a minimum period of 3 months, clinical and radiographic follow ups were performed after 10 - 13.5 months from restoring the implants in order to evaluate their success/ survival. Repeated measures ANOVA was used to assess marginal bone loss, t test for probing depth assessment. Results: Immediate anatomical zirconia implants showed success in (n=17) 63% of total cases, satisfactory survival (n=3) 11.1%, compromised survival (n=2) 7.4% and they failed in (n=5) 18.5%. Conclusions: Immediate anatomical zirconia implants had low success/survival rates when compared to conventional immediate implants. Therefore, they cannot be considered as a predictable alternative in their current form

Effect of dental follicles in minimally invasive open-eruption technique of labially impacted maxillary central incisors / 华西口腔医学杂志

OBJECTIVES@#To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles.@*METHODS@#Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy.@*RESULTS@#A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05).@*CONCLUSIONS@#In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.

Multi-disciplinary treatment of severe palatal radicular groove of maxillary lateral incisor: A case report and literature review / 中南大学学报(医学版)

Palatal radicular groove is a developmental malformation of maxillary incisors, lateral incisors in particular, which often causes periodontal destruction. This paper reports a case of combined periodontal-endodontic lesions induced by palatal radicular groove, which was initially misdiagnosed as a simple periapical cyst. After root canal therapy and periapical cyst curettage, the course of disease was prolonged, resulting in the absence of buccal and maxillary bone plates in the affected tooth area. After the etiology was determined, the affected tooth was extracted and guide bone tissue regeneration was performed at the same time, followed by implantation and restoration at the later stage, leading to clinical cure. The palatal radicular groove is highly occult, and the clinical symptoms are not typical. If the abscess of the maxillary lateral incisor occurs repeatedly, and the abscess of the maxillary lateral incisor has not been cured after periodontal and root canal treatment, cone-beam computed tomographic and periodontal flap surgery should be considered.

Analysis of morphometric changes in the anterior alveolar bone in bimaxillary protrusion adult patients after retraction with cone-beam CT / 中华口腔医学杂志

Objective: To measure and analyze the morphometric changes in the anterior alveolar bone during treatment and retention stage after retraction in bimaxillary adults using cone-beam CT(CBCT). Methods: Fifteen adult patients, four males and 11 females, aged 19 to 28 years[(22.2±3.1) years], who have completed orthodontic treatment and extracted four first premolar teeth for retraction in the Department of Orthodontics, The Affiliated Stomatological Hospital of Nanchang University from January 2016 to December 2018 were selected. CBCT was taken to assess the labial and palatal vertical bone level, total bone thickness at crest area, middle root area and apical area in pre-treatment (T1), post-treatment (T2) and at follow-up (maintained for more than two years) (T3). The differences in alveolar bone morphology at different stages were compared by single factor repeated measure ANOVA, and Pearson correlation analysis was performed on the amount of alveolar bone change in treatment stage and retention stage. Results: There were statistically significant differences in the alveolar bone height of the palatal side of maxillary anterior teeth, the labial side of maxillary lateral incisors and canine among three time points (P<0.05). The height difference of palatal alveolar bone of anterior teeth in T1-T2 stage was statistically significant (P<0.05). Palatal alveolar bone of upper and lower central incisors decreased by (1.52±0.32) and (4.96±0.46) mm, respectively. The height difference of anterior palatal alveolar bone was statistically significant in T2-T3 stage(P<0.05), the palatal alveolar bone height of central incisors increased by (1.20±0.27) and (3.14±0.35) mm respectively. The height difference of palatal alveolar bone in the anterior teeth of T1-T3 stage was statistically significant (P<0.05), and the height of palatal alveolar bone of central incisors was decreased (0.33±0.11) and (1.82±0.39) mm, respectively. There were statistically significant differences in the thickness of the cervical and middle root alveolar bone of anterior teeth among three time points (P<0.05). The difference of alveolar bone thickness of the cervical and middle root of anterior teeth at T1-T2 was statistically significant (P<0.05). decreased by (0.63±0.10) and (0.67±0.09) mm in lateral incisors, respectively. In the T2-T3 stage, the alveolar bone thickness of the crest area of the lower anterior teeth was significantly different (P<0.05), the alveolar bone thickness of mandibular central incisor crest area increased (0.09±0.03) mm. There were statistically significant differences in alveolar bone thickness in crest area and middle root of the incisors during T1-T3 stage (P<0.05), among which the middle root decreased by (0.38±0.16) mm and (0.63±0.13) mm, respectively. There was no statistically significant difference in other areas (P>0.05). The change of alveolar bone height in palatal side of upper anterior teeth at T2-T3 was very strongly negatively correlated with the change in T1-T2. The change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor root and neck were moderately strongly negatively correlated (r≤-0.8, P<0.001), the change of alveolar bone height in labial side of upper anterior teeth and lingual side of lower anterior teeth and the thickness of incisor crest area were moderately strongly negatively correlated (-0.8<r≤-0.4, P<0.05). Conclusions: For adult patients after retraction, anterior alveolar bone decreased significantly. In the retention stage, the same degree of bone apposition will occur, but still have alveolar bone loss compared with pre-treatment. The amount of alveolar bone change in the retention stage correlated with the amount of alveolar bone change in the treatment stage.

Diversity of root canal morphology in mandibular first premolars and its clinical strategies / 中华口腔医学杂志

It is a basic prerequisite for the successful completion of endodontic treatment to thoroughly understand the root canal space anatomy. With the development of dental devices in dentistry, the root canal morphology of the mandibular first premolars can be presented in more detail. Before conducting root canal therapy on the mandibular first premolar with complex root canal morphology, it should be necessary to evaluate the potential difficulties and risks for making an appropriate treatment plan. The present paper reviews the research progress on the diversities of root canal morphology in mandibular first premolars in recent years, and then makes technologic recommendations based on the morphology diversities.

Effect of intracanal diode laser irradiation on fracture resistance of roots restored with CAD/CAM posts

Aim: To evaluate the fracture resistance of roots restored with CAD/CAM-fabricated posts, receiving or not intracanal laser treatment, compared with glass fiber posts under mechanical cycling. Methods: Twenty-seven endodontically treated, single-rooted teeth were divided into 3 groups: group 1 (control), prefabricated glass fiber posts relined with resin composite; group 2, CAD/CAM-fabricated intraradicular posts using Resin Nano Ceramic (RNC) blocks; and group 3, CAD/CAM-fabricated intraradicular posts using RNC blocks in canals irradiated with a 940-nm diode laser (100 mJ, 300-um optic fiber, coronal-apical and apical-coronal helical movements, speed of 2 mm/second, 4 times each canal). After cementation of the coping, cyclic loading was applied at an angle of 135° to the long axis of the root, with a pulse load of 130 N, frequency of 2.2 Hz, and 150,000 pulses on the crown at a point located 2 mm below the incisal edge on the lingual aspect of the specimen. Every 50,000 cycles, the specimens were evaluated for root fracture occurring below or above the simulated bone crest. Results were analyzed by one-way ANOVA followed by Tukey's test (p<0.05). Results: Group 1 was the least resistant, while groups 2 and 3 were the most resistant. Group 1 differed significantly from groups 2 and 3 (p<0.01), but there was no difference between groups 2 and 3 (p<0.01). Conclusion: Treatment of the intracanal surface with diode laser had no influence on fracture resistance of roots restored with CAD/CAM-fabricated posts, but a longer cycling time is required to evaluate the real benefits of diode laser irradiation

Estudio de la morfología de los conductos radiculares de los primeros premolares superiores en tomografía computarizada de haz cónico / Study of the morphology of root canals of the first upper premolars in cone beam computed tomography

Objetivo: analizar, mediante tomografía computarizada de haz cónico (TC o CBCT [Cone Beam Computed Tomograph]) la frecuencia del tipo de morfología interna de los conductos radi- culares según la clasificación de Vertucci y el número de raíces de los primeros premolares superiores. Material y métodos: en una población argentina de 50 pacientes, 30 de sexo femenino y 20 masculino, que concurrieron a la Cátedra de Diagnóstico por Imá- genes de la Facultad de Odontología de la Universidad de Buenos Aires, se evaluaron 100 primeros premolares superiores con CBCT. Se estudiaron las variables: número de raíces, tipo de morfología interna, edad, sexo y lado. Fueron seleccionadas las tomografías de maxilar superior que incluyeron ambos primeros premolares en salud dental, periodontal y con ápice cerrado. Se realizó una adquisición volumétrica 100 × 90 mm y tamaño de vóxel de 150 µm. Se realizó la exploración de las imágenes en el plano axial de los tercios apical, medio y cervical de las piezas 1.4 y 2.4. Se utilizó un corte axial, observando en él, el tercio apical, medio y cervical de las piezas 1.4 y 2.4. Cada premolar fue analizado con 30 cortes transversales. Se utilizó la clasificación de Vertucci para agrupar las distintas variables anatómicas de los conductos radiculares de los primeros premolares superiores, la cual consta de VIII tipolo- gías. Resultados: el tipo más representativo entre los 100 primeros premolares superiores, dentro de la clasificación de Vertucci, fue el tipo IV (dos conductos separados desde la cámara al ápice). La coincidencia de tipos entre los lados derecho (78%; IC 95%: 65 a 87%) e izquierdo (70%; IC 95%: 56 a 81%) fue significativa. La distribución según el número de raíces en el lado derecho (χ 2 = 2.88) e izquierdo (χ2 = 0.72) no presentó una heterogeneidad significativa. La coincidencia del número de raíces entre los lados derecho e izquierdo fue significativa. Conclusión: se comprobó el tipo de morfología interna más frecuente, el número de raíces y su variabilidad de acuerdo al lado, sexo, y edad; lo cual es de una relevante importancia para realizar una correcta instrumentación y obturación del sistema de conductos radiculares (AU)

Objective: to analyze, using cone beam computed tomography (CBCT), the frequency of the type of internal morphology of the root canals according to the Vertucci classification and the number of roots of the first upper premolars. Material and methods: 100 first upper premolars were evaluated with CBCT, which corresponded to 30 female and 20 male patients in the Chair of Diagnostic Imaging of the Faculty of Dentistry, University of Buenos Aires. Variables were studied: number of roots, type of internal morphology, age, sex and side. The tomography of the upper jaw with both first premolars in dental, periodontal and closed apex health, a 100 × 90 mm volumetric acquisition and a voxel size of 150 µm were selected. An axial cut was used, observing the apical, middle and cervical third of pieces 1.4 and 2.4. Each premolar was analyzed with 30 paraxial cuts. The Vertucci classification was used to group the different anatomical variables of the root canals of the first upper premolars which consists of VIII typologies. Results: the most representative type among the top 100 upper premolars within the Vertucci classification was type IV (two separate ducts from the chamber to the apex). The type coincidence between the right (78%; 95% CI: 65 to 87%) and left (70%; 95% CI: 56 to 81%) los primeros premolares superiores, la cual consta de VIII tipolo gías. Resultados: el tipo más representativo entre los 100 primeros premolares superiores, dentro de la clasificación de Vertucci, fue el tipo IV (dos conductos separados desde la cámara al ápice). La coincidencia de tipos entre los lados derecho (78%; IC 95%: 65 a 87%) e izquierdo (70%; IC 95%: 56 a 81%) fue significativa. La distribución según el número de raíces en el lado derecho (χ 2 = 2.88) e izquierdo (χ2 = 0.72) no presentó una heterogeneidad significativa. La coincidencia del número de raíces entre los lados derecho e izquierdo fue significativa. Conclusión: se comprobó el tipo de morfología interna más frecuente, el número de raíces y su variabilidad de acuerdo al lado, sexo, y edad; lo cual es de una relevante importancia para realizar una correcta instrumentación y obturación del sistema de conductos radiculares (AU))