INTRODUCTION Taurodontism is a morphoanatomical change in the shape of a tooth. An enlarged body of a toothwith smaller than usual roots is a characteristic feature. Internal tooth anatomy correlates with this appearance, which means that a taurodontal tooth has a large pulp chamber and apically positioned furcations. This dental anomaly may be associated with different syndromes and congenital discoders.
Buccal bifurcation cyst is an unusual inflammatory odontogenic cyst of unknown etiology which occurs at the buccal region of the permanent mandibular first molars in children and adolescents aged 6-15 years old. The aim of this manuscript is to present two clinical cases of buccal bifurcation cyst incidentally detected in adolescents referred for tomographic exams (CBCT) as part of the treatment planning for the management of impacted mandibular molars. The first case is very interesting due to the proximity of the lesion to the inferior alveolar canal. In the second case the inferior alveolar canal was not in close proximity to the lesion, but in contact with the mesiobuccal rootof the second molar. The diagnosis of Buccal bifurcation cyst is of utmost importance in order to avoid complications during surgical procedures. In addition, the present case reports have highlighted the importance for dental practitioners to be aware of the possibility of a buccal bifurcation cyst being present as an incidental finding in CBCT images, especially in young patients. Indexing terms: Cone beam computed tomography. Diagnosis. Odontogenic cysts. Surgery, Oral.
An 11-year-old boy was admitted to the Department of Endodontics at PUCRS, Brazil, presenting a vestibular sinus tract in the periapical area around the mandibular right secondpremolar. Radiographic tracking with a gutta-percha point revealed its origin to be in the wide-open apical end of an invaginated canalof this tooth (Fig. 1A). The anomalous internal structure was consistent with Oehlers’ Type III dens invaginatus. Clinically, this tooth showed an unusual coronal anatomy, with greater mesiodistal width, normal color, normal gingival tissues and probing depth (<3 mm), and deficient composite resin restoration on the occlusal surface (Fig. 1B). Radiographic examination of the contralateral tooth did not reveal malformation.
The anatomy of teeth is not always normal. A great number of variations could occur in formation, number of roots, and their shape. Most dentists get used to treating normal roots with similar traits; as a result, many failures can occur. However, it must be noticed that abnormalities are rare, but it is possible that some patients may have one of these rare anatomic variations. The complex nature of the root and rootcanal morphology of the mandibular premolars has been Underestimated (1). Slowey (3) reported that root canals are frequently left untreated because clinicians often fail to identify their presence, particularly in teeth that have anatomical variations or additional root
In the 16 root ca nals from this group, which had a Calen PMCC intracanal dress ing for 15 days and were sealed with Sealer Plus, to tal api cal clo - sure was ob served in only 2 roots, par tial seal ing, in 8 roots and lack of seal ing, in 6 spec i mens. Among these 6 spec i mens, 4 were over filled. In the api cal ce men tum, the la cu nae were fre quently empty and en larged. The ce men tum sur face near the api cal fo ra men was re paired by newly formed tis sue and de marked by ba so philic lines. Some ar - eas of ce men tum re sorp tion per sisted lat er ally to the api cal fo ra men, es pe cially in the re gions near sec ond ary ca nals, with a mod er ate pres ence of ad - ja cent in flam ma tory cells. The periodontal lig a - ment was mod er ately thicker in 7 roots and slightly thicker in 9. In this re gion, there was in - com plete re pair in 10 spec i mens, rep re sented by a
The lack of long-term pulpotomy effectiveness studies in permanent teeth, both in young and adult populations, and its impact on dental care has motivated the aim of this research. For this purpose, 273 pulpotomies performed by a single endodontic specialist were analyzed, and data on success rates was collected. Additionally, possible explanatory variables were noted such as: age, gender, clinical findings (teeth, kind of restoration after pulpotomy), radiographic findings (dentin bridge formation) and systemic conditions. The follow-up period varied from 1 to 29 years, and the results were analyzed by Kaplan-Meier survival curves and also by Cox Regression. It was conclud- ed that: pulpotomies are a successful treatment at any age, not just for young permanent teeth; additionally, the formation of dentin bridge is a strong protective factor (HR 0,16). The most successful kind of restoration after pulpotomy is prosthetic crown followed by amalgam restoration, and the direct composite restoration is associated with a higher failure rate.
Este tipo de alterações tem implicações clínicas importantes no planeamento dos tratamentos em Medicina Dentária. Uma técnica anestésica inadequada pode ocorrer em qualquer tipo de bifurcação do canalmandibular mas especialmente no Tipo IV, que inclui dois buracos mandibulares. Variações na posição anatómica destes buracos podem explicar o porquê de as técnicas padrão de anestesia serem ineficazes em alguns pacientes (Rossi et al., 2009). Convencionalmente, a presença de formigueiro nos tecidos moles, na pele, lábio e dentes é sinal de um bloqueio do IAN correctamente administrado. Se o paciente sentir um leve anestesiar mas apenas no local da injecção é porque a técnica falhou. No entanto, se os tecidos moles experienciarem a anestesia mas não os dentes, deve ser considerada a presença de uma possível variação anatómica e, portanto, tentar outro tipo de técnica anestésica (Wadwani et al., 2008).
a conservative treatment was undertaken. Under local anesthesia, the fractured coronal fragment of the maxillary left central incisor was gently removed, exposing the vital pulp. Then, a cervical pulpotomy was performed aiming to achieve apexogenesis. Pulpotomy was carried out with a diamond bur at high speed under normal saline irrigation (12), and a calcium hydroxide paste wad used to cover the pulp tissue (12). Afterwards, the coronal fragment was bonded with a rigid splint and light-cured composite resin (TPH Spectrum; Dentsply Ind. e Com. Ltda., Petrópolis, RJ, Brazil). Subsequently, the teeth were splinted with a coaxial wire and composite resin. The parents and the patient were informed about the importance of maintaining meticulous oral hygiene and regularly returning for clinical and radiograph follow-up. The splint was removed after 2 weeks and the tooth was assessed for mobility. Surprisingly, the tooth was not mobile even after the removal of splint. Pulp vitality of both central incisors was checked again and both teeth gave vital responses to the tests. The teeth were followed up clinically and radiographically during 1 year. One year after the initial procedures, the radiographic examination showed a periapical lesion on the maxillary left central incisor and no evidence of complete root formation. The rootcanal was prepared chemomechanically and dressed with a calcium
This chapter describes the used methodologies for analyzing the crack propagation in a tooth using the mesh fragmentation technique. After providing the model geometry, the process starts by defining the material properties, loading conditions, boundary condition, and finally discretizing the geometry. A meshing software, the GiD pre- and post-processor software (GiD software, 2016), is used to discretize the model. After having the discretized model, the input file for Matlab code must be prepared, which includes the whole interface element and fragmentation formulation. The Matlab code refers to the whole implementation regarding to the mesh fragmentation technique, developed and implemented by Manzoli et al. (2012, 2016). This input file must be saved in ‘mfl’ format and it has different parts in which all of them will be described here. The first part is the CONTROL_DATA, which is shown in Figure 4.1.
A 16-year-old Caucasian girl with recessive dystrophic EB presented to our dental school for routine treatment. According to the clinical interview, hemorrhagic blisters in the mouth had been detected since early infancy. With the patient’s growing and physical development, lesions extended to the face, feet and hands. Due to her great difficulty in performing adequate oral hygiene, almost all of her teeth had been destroyed by caries lesions and were covered with dental plaque (Figure 1A and B). Her oldest sister had died one year before as a consequence of the same disease.
Objective: To compare dental and skeletal anchorages in mandibular canine retraction by means of a stress distribu- tion analysis. Methods: A photoelastic model was produced from second molar to canine, without the first premolar, and mandibular canine retraction was simulated by a rubber band tied to two types of anchorage: dental anchorage, in the first molar attached to adjacent teeth, and skeletal anchorage with a hook simulating the mini-implant. The forces were applied 10 times and observed in a circular polariscope. The stresses located in the mandibular canine were recorded in 7 regions. The Mann-Whitney test was employed to compare the stress in each region and between both anchorage systems. The stresses in the mandibular canine periradicular regions were compared by the Kruskal-Wallis test. Results: Stresses were similar in the cervical region and the middle third. In the apical third, the stresses associ- ated with skeletal anchorage were higher than the stresses associated with dental anchorage. The results of the Kruskal- Wallis test showed that the highest stresses were identified in the cervical-distal, apical-distal, and apex regions with the use of dental anchorage, and in the apical-distal, apical-mesial, cervical-distal, and apex regions with the use of skeletal anchorage. Conclusions: The use of skeletal anchorage in canine retraction caused greater stress in the apical third than the use of dental anchorage, which indicates an intrusive component resulting from the direction of the force due to the position of the mini-implant and the bracket hook of the canine.
The aim of this study was to evaluate the nonsyndromic tooth agenesis in DF, Brazil, through the epidemiological study of its prevalence in deciduous teeth and its relationship with the permanent dentition, and also describe its clinical characteristics, and analyze the sequences of the candidate genes MSX1, PAX9, RUNX2 e WNT10A potentially involved in the etiology of this condition in families with nonsyndromic tooth agenesis, through familial study approach. The prevalence oftooth agenesis in the primary dentition was 0.29%. Five of the 1718 children examined had one or more primary teeth affected, with no statistical difference between sexes. They were cases of lateral incisor agenesis. Eighty percent of children withtooth agenesis in the primary dentition also had the same condition in the succedaneous permanent teeth. There was an association between tooth agenesis in the primary and permanent dentition, especially in cases of bilateral agenesis. Sixteen families with nonsyndromic tooth agenesis were studied, nine with hypodontia and seven with oligodontia. The autosomal dominant mode of inheritance was observed in 13 out of 16 families. The presence of other dental anomalies was observed, especially microdontia/peg-shaped teeth, taurodontia and supernumerary teeth. In families which premolars and molars were missing in patients with oligodontia, individuals had a higher risk of having taurodontia, even those with complete dentition. Four variants were found in tooth agenesis patients [rs12881240 (PAX9 c.C717T; p.His239His), rs4904210 (PAX9 c.G718C; p.Ala240Pro), rs149245953 (WNT10A c.667C> T; p.Arg223Cys) and rs121908120 (WNT10A c.682T> A p.Phe228Ile)], but not in relatives with complete dentition. Further studies are needed to complete the genetic diagnosis oftooth agenesis in these families.
Considering the results of the present study, PAD did not produce significant differences in the scores for apical inflammation for the specimens irrigated with NaOCl, Sterilox and SS. Yet the findings are in agreement with the in vitro study of Souza et al. (19) disagree with the in vivo study of Silva et al. (13). The authors (19) suggested that the results could be explained because the effect of PAD was probably restricted to the rootcanal areas already reached by the irrigating solutions. Another study investigated the antimicrobial effect of PAD in vivo (13). The authors (13) evaluated the apical response to PAD alone and with the chemomechanical debridement in root canals of dogs’ teeth with AP. They found no inflammatory cells and moderate neoangiogenesis when PAD was used after chemomechanical preparation of the rootcanal. The used methodology (13) was similar to the present study, except for the mechanical preparation, which was performed up to #55 size. Maybe the greater apical preparation achieved in the present work is responsible for the absence of significant differences with the use of PAD therapy.
8- Cvek M, Granath LE, Hollender L. Treatmentof non vital permanent incisors with calcium hidroxide 3. Variation of occurrence of ankylosis of reimplanted teeth with duration of extra-alveolar period and storage environment. Odontol Revy. 1974;25(1):43-56. 9- Ehnevid H, Lindskog S, Jansson L, Blomlölf L. Tissue formation on cementum surfaces in vivo. Swed Dent J. 1993;17(1-2):1-8. 10- Flores MT, Andreasen JO, Bakland LK, Feiglin B, Oikarinem K, Gutmann SL, et al. Guidelines for the evaluation and management of traumatic dental injuries. Dent Traumatol. 2001;17(5):193-8. 11- Gedalia I, Shulman LB, Albert M, Goldhaber P, Sciaky I. The fluoride content in root layers of fluoride immersed teeth. Pharmacol Ther Dent. 1970;1:151-6.
secondary infections and AP, the outcomes of therapeutic protocols were not compared. However, whenever possible, non-surgical retreatment must be the first choice for failures of RCT. Sundqvist et al. (25) verified the microbiota present in teeth after failed RCT and established the outcome of 45 root-filled teeth with persisting periapical lesions. The results showed mainly single species of predominantly Gram-positive organisms. The most commonly recovered isolates were bacteria of the Enterococcus faecalis species. The overall success rate of re-treatment was 74%. Infection at the time ofroot filling and size of the periapical lesion were factors that had a negative influence on the prognosis. Three of four endodontic failures were successfully managed by re-treatment. Del Fabbro et al. (10) considered a systematic review to analyze the results of surgical and non-surgical therapy for retreatment of AP. It was reported that there is little evidence for a decision- making process. Well-designed randomized controlled trials should be conducted with monitoring of at least four years, and a sample size consistent for detecting a true difference between the long term results of two alternative treatments. Torabinejad et al. (11) compared the success rates of nonsurgical endodontic retreatment with those of periapical surgery using systematic review. It appears that periapical surgery shows more favorable initial healing, which declines with increasing recall periods. Nonsurgical retreatment offers a more favorable long-term outcome. Limited amount of comparative evidence was observed and there is an apparent need for high-quality randomized controlled trials.
The aim of this study was to quantify radiographically the periapical bone resorption in dogs’ teeth contaminated with bacterial endotoxin (LPS), associated or not with calcium hydroxide. After pulp tissue removal, 60 premolars were randomly assigned to 4 groups and were either filled with LPS (group 1), filled with LPS plus calcium hydroxide (group 2) or filled with saline (group 3) for a period of 30 days. In group 4, periapical lesion formation was induced with no canaltreatment. Standardized radiographs were taken at the beginning of the treatment and after 30 days and the Image J Program was used for measurement of periapical lesion size. Periapical lesions were observed in groups 1 (average of 8.44 mm 2 ) and 4 (average of 3.02 mm 2 ). The lamina dura was intact and there
Rootcanal length was determined radiographically and conirmed with an electronic apex locator (Root ZX; J Morita Co, Kyoto, Japan). Chemomechanical prepara- tion was performed with hand Flexoile iles (Maillefer) and irrigation with 1% sodium hypochlorite at each change of ile. The instrumented root canals were illed with gutta-percha cones and an epoxy resin-based rootcanal sealer (Sealer 26; Dentsply/Maillefer) according to Tagger’s hybrid technique (Figs. 2a and 2b). The inal radiographs showed two well-obturated canals ending at the electronically located apexes.The 6-month posttreatment follow-up showed apparent clinical and radiographic success.
Controlling the amount of dentin removal during rootcanal instrumentation is not an easy task; rather, it depends on dental anatomy, operator’s experience and pulp conditions. In teeth with necrotic pulp and contamination of the rootcanal system, greater removal of dentin is required to ensure disinfection, whereas less dentin can be removed when the pulp is vital and the canal is not contaminated. In clinical practice, making the right decisions in hand and mechanized instrumentation requires good skills and professional experience. Rootcanal preparation has been changing greatly, not in terms of its principles, but in terms of replacement of hand instrumentation by reciprocating and rotary systems. The use of automated systems, however, are only part ofrootcanal therapy (9,10,11,15). This study investigated whether canal preparation with an NSK reciprocating handpiece powered by an electric motor would be performed in distinct ways by operators with different skills, background knowledge and experience. This system uses hand files, similarly to the system evaluated by Tepel et al. (16). Mandibular premolars were chosen for this study because of certain anatomic features, such as easy-to-negotiate, wide and straight canals that are slightly flattened proximally. These characteristics allow standardizing the assessment of the behavior of mechanized systems used by different operators (17). The teeth were decoronated to eliminate the cervical curvature and the canals were standardized before initial weighing by hand instrumentation up to a #30 file. These procedures were intended to rule out some potentially confusing factors that might have interfered with the results (18).
From the results of the present study it became evident that the presence of non-prepared regions occurs due to the incompatibility between the file configuration and the rootcanal anatomy. The endodontic instruments and techniques are mostly designed to fit the conical configuration of the rootcanal usually observed in BL radiographs, thus ignoring the different canal configurations found in MD radiographs. In a MD view of the mandibular incisors, there is a constriction at the cervical third that could affect the action of files on the rootcanal walls, thus establishing critical instrumentation areas. Irrespective of the system, endodontic files are tapered, which results in conical preparations in root canals that mostly present a three-dimensional irregular configuration (6,18). One solution would be to instrument canals with SAF, which can result in fewer unprepared areas during instrumentation (9), especially in the coronal root third (12). Some authors reported no differences for the percentage of instrumented area in the apical third when using NiTi and SAF rotary systems (12). However, the use of SAF generates more contact to the dentin walls in the apical third, consequently removing more debris (9). Presence of debris (smear layer) obliterating rootcanal was verified in the non-prepared areas with the µCT scans (Fig. 2C). This fact may influence the success of endodontic treatment, because bacterial film still remains organized at these sites (1,22,23). Bacteria in the rootcanal biofilm may remain protected from the antimicrobial therapeutics when canal walls are not completely reached by endodontic instruments and irrigating solutions (23).