T-Bar clasp-retained removable partial denture as an alternative to implant-based prosthetic treatment

This article reports the case of a 55-year-old female patient who presented with unsatisfactory temporary crowns in the right mandibular premolars and molars, and a premolar-to-molar fixed partial denture in the left side. The clinical and radiographic examinations revealed a fracture of the left first premolar that was a retainer of the fixed partial denture and required extraction. Initially, the acrylic resin crowns were replaced by new ones, and a provisional RPD was made using acrylic resin and orthodontic wire clasps to resolve the problem arising from the loss of the fixed partial denture. Considering the patient's high esthetic demands, the treatment options for the definitive prosthetic treatment were discussed with her and rehabilitation with implant-supported dentures was proposed because the clinical conditions of the residual alveolar ridge were suitable for implant installation, and the patient's general health was excellent. However, the patient did not agree because she knew of a failed case of implant-retained denture in a diabetic individual and was concerned. The patient was fully informed that implant installation was the best indication for her case, but the arguments were not sufficient to change her decision. The treatment possibilities were presented and the patient opted for a clasp-retained removable partial denture (RPD) associated with the placement of crowns in the pillar teeth. The temporary RPD was replaced by the definitive RPD constructed subsequently. Although RPD was not the first choice, satisfactory esthetic and functional outcomes were achieved, overcaming the patient's expectations. This case report illustrates that the dentist must be prepared to deal with situations where, for reasons that cannot be managed, the patient does not accept the treatment considered as the most indicated for his/her case. Alternatives must be proposed and the functional and esthetic requirements must be fulfilled in the best possible manner.

Bone quality associated with daily intake of coffee: a biochemical, radiographic and histometric study

Caffeine induces loss of calcium and influences the normal development of bone. This study investigated the effects of coffee on bone metabolism in rats by biochemical measurement of calcium, bone densitometry and histometry. Male rats, born of female treated daily with coffee and with coffee intake since born, were anesthetized, subjected to extraction of the upper right incisor, and sacrificed 7, 21 and 42 days after surgery. Blood and urine samples were taken, and their maxilla radiographed and processed to obtain 5-µm-thick semi-serial sections stained with hematoxylin and eosin. The volume and bone quality were estimated using an image-analysis software. The results showed significantly greater amount of calcium in the plasma (9.40 ± 1.73 versus 9.80 ± 2.05 mg%) and urine (1.00 ± 0.50 versus 1.25 ± 0.70 mg/24 h) and significantly less amount in bone (90.0 ± 1.94 versus 86.0 ± 2.12 mg/mg bone), reduced bone mineral density (1.05 ± 0.11 versus 0.65 ± 0.15 mmAL), and lower amount of bone (76.19 ± 1.6 versus 53.41 ± 2.1 %) (ANOVA; p≤0.01) in animals treated with coffee sacrificed after 42 days. It may be concluded that coffee/caffeine intake caused serious adverse effects on calcium metabolism in rats, including increased levels of calcium in the urine and plasma, decreased bone mineral density and lower volume of bone, thus delaying the bone repair process.

Electromyographic activity of masticatory muscles in women with osteoporosis

The purpose of this study was to analyze the electromyographic (EMG) activity and the maximal molar bite force in women diagnosed with osteoporosis in the maxillary and mandibular regions, considering the habits and conditions that lead to development of generalized skeletal bone loss, including on face bones, can disturb the functional harmony of the stomatognathic system. Twenty-seven women with mandibular and maxillary osteoporosis and 27 healthy controls volunteered to participate in the study. A 5-channel electromyographer was used. Muscle activity was evaluated by means of EMG recordings of the masticatory musculature (masseter and temporalis muscles, bilaterally) during the following clinical conditions: rest (5 s); right and left lateral excursions (5 s); protrusion (5 s); maximal dental clenching on Parafilm™ (4 s) and maximal voluntary contraction (4 s). This latter clinical condition was used as the normalization factor of the sample data. It was observed that individuals with osteoporosis presented greater EMG activity when maintaining mandible posture conditions and less activity during dental clenching and when obtaining maximal molar bite force. It may be concluded that facial osteoporosis can interfere on the patterns of masticatory muscle activation and maximal bite force of the stomatognathic system.

Anatomic variation of cranial parasympathetic ganglia

Having broad knowledge of anatomy is essential for practicing dentistry. Certain anatomical structures call for detailed studies due to their anatomical and functional importance. Nevertheless, some structures are difficult to visualize and identify due to their small volume and complicated access. Such is the case of the parasympathetic ganglia located in the cranial part of the autonomic nervous system, which include: the ciliary ganglion (located deeply in the orbit, laterally to the optic nerve), the pterygopalatine ganglion (located in the pterygopalatine fossa), the submandibular ganglion (located laterally to the hyoglossus muscle, below the lingual nerve), and the otic ganglion (located medially to the mandibular nerve, right beneath the oval foramen). The aim of this study was to present these structures in dissected anatomic specimens and perform a comparative analysis regarding location and morphology. The proximity of the ganglia and associated nerves were also analyzed, as well as the number and volume of fibers connected to them. Human heads were dissected by planes, partially removing the adjacent structures to the point we could reach the parasympathetic ganglia. With this study, we concluded that there was no significant variation regarding the location of the studied ganglia. Morphologically, our observations concur with previous classical descriptions of the parasympathetic ganglia, but we observed variations regarding the proximity of the otic ganglion to the mandibular nerve. We also observed that there were variations regarding the number and volume of fiber bundles connected to the submandibular, otic, and pterygopalatine ganglia.

Effectiveness of different final irrigation protocols in removing debris in flattened root canals

This study evaluated in vitro the capacity of debris removal from the apical third of flattened root canals, using different final irrigation protocols. Thirty human mandibular central incisors with a mesiodistal flattened root were prepared using rotary instrumentation by Endo-Flare 25.12 and Hero 642 30.06, 35.02, 40.02 files, irrigated with 2 mL of 1% NaOCl after each file. The specimens were randomly distributed into 5 groups according to the final irrigation of root canals: Group I: 10 mL of distilled water (control), Group II: 10 mL of 1% NaOCl for 8 min, Group III: 2 mL of 1% NaOCl for 2 min (repeated 4 times), Group IV: 10 mL of 2.5% NaOCl for 8 min, and Group V: 10 mL of 2.5% NaOCl for 2 min (repeated 4 times). The apical thirds of the specimens were subjected to histological processing and 6-μm cross-sections were obtained and stained with hematoxylin-eosin. The specimens were examined under optical microscopy at ×40 magnification and the images were subjected to morphometric analysis using the Scion image-analysis software. The total area of root canal and the area with debris were measured in square millimeters. Analysis of variance showed no statistically significant difference (p>0.05) among the groups GI (2.39 ± 3.59), GII (2.91 ± 2.21), GIII (0.73 ± 1.36), GIV (0.95 ± 0.84) and GV (0.51 ± 0.22). In conclusion, the final irrigation protocols evaluated in this study using the Luer syringe presented similar performance in the removal of debris from the apical third of flattened root canals.

Effect of eugenol-based endodontic sealer on the adhesion of intraradicular posts cemented after different periods

OBJECTIVE: This study evaluated in vitro the influence of an eugenol-based sealer (EndoFill) on the retention of stainless steel prefabricated posts cemented with zinc phosphate and resin-based (Panavia F) cements after different periods of root canal obturation, using the pull-out test. MATERIAL AND METHODS: Sixty upper canines were decoronated and the roots were embedded in resin blocks. The specimens were distributed into 3 groups, according to the period elapsed between canal obturation and post cementation: Group I - immediately; Group II - 72 h and Group III - 4 months. The groups were subdivided according to the type of cement used for post cementation: A - zinc phosphate and B - Panavia F. Following the experimental periods, specimens were subjected to pullout test in an Instron machine with application of tensile force at a crosshead speed of 0.5 mm/min until post dislodgement. The maximum forces required for post removal were recorded (kN) and means were subjected to statistical analysis by 2-way ANOVA and Tukey-Kramer test (α=0.001) RESULTS: There were statistically significant differences (p<0.01) between the posts cemented with zinc phosphate cement (0.2112 kN) and Panavia F (0.0501 kN). However, no statistically significant differences (p>0.05) were found between the three post cementation periods, regardless of the cement. CONCLUSIONS: It was concluded that the eugenol-based sealer influenced the tensile strength of the posts cemented with the resin cement, but had no influence on the time waited between root canal obturation and post space preparation/post cementation.

Papiloma invertido (Papiloma Schneideriano) com envolvimento da cavidade oral: relato de caso incomum

O papiloma invertido schneideriano é uma neoplasia de origem no epitélio de revestimento que surge da mucosa respiratória revestindo a cavidade nasal e os seios paranasais. Frequentemente, surge como uma lesão unilateral no septo nasal e estende-se secundariamente para o nariz e os seios paranasais. Este trabalho relata um caso incomum desta patologia, com o envolvimento da cavidade oral em um homem branco, de 61 anos de idade, cuja avaliação clínica revelou uma massa vegetante no rebordo alveolar direito da maxila, com duração de aproximadamente 4 meses. Após avaliação radiográfica, constatouse o envolvimento do seio maxilar. A análise microscópica, hibridização in situ e análise imunoistoquímica da peça cirúrgica levaram a um diagnóstico de displasia moderada em PIS associado à infecção por HPV

Bone response to a Ca- and P-enriched titanium surface obtained by anodization

This study evaluated bone response to a Ca- and P- enriched titanium (Ti) surface treated by a multiphase anodic spark deposition coating (BSP-AK). Two mongrel dogs received bilateral implantation of 3 Ti cylinders (4.1 x 12 mm) in the humerus, being either BSP-AK treated or untreated (machined - control). At 8 weeks postimplantation, bone fragments containing the implants were harvested and processed for histologic and histomorphometric analyses. Bone formation was observed in cortical area and towards the medullary canal associated to approximately 1/3 of implant extension. In most cases, in the medullary area, collagen fiber bundles were detected adjacent and oriented parallel to Ti surfaces. Such connective tissue formation exhibited focal areas of mineralized matrix lined by active osteoblasts. The mean percentages of bone-to-implant contact were 2.3 (0.0-7.2 range) for BSP-AK and 0.4 (0.0-1.3 range) for control. Although the Mann-Whitney test did not detect statistically significant differences between groups, these results indicate a trend of BSP-AK treated surfaces to support contact osteogenesis in an experimental model that produces low bone-to-implant contact values.

Cirurgias odontológicas em usuários de anticoagulantes orais

Em razão do crescimento do número de indivíduos submetidos à terapêutica anticoagulante também nos consultórios odontológicos, realizamos um levantamento retrospectivo de prontuários de pacientes anticoagulados com derivados cumarínicos e uma revisão sobre os protocolos de atendimento, a fim de procurar estabelecer diretrizes para um tratamento cirúrgico-odontológico adequado e seguro. A avaliação do paciente com relação ao seu nível de anticoagulação através do Índice Normatizado Internacional (INR) ou Tempo de Protrombina (TP) e a classificação da amplitude do trauma cirúrgico são fatores importantes a serem avaliados antes do procedimento cirúrgico. Nosso levantamento mostrou que, em 47 cirurgias, sem alteração da medicação sistêmica, apenas um caso apresentou hemorragia pós-operatória, controlada por manobras de hemostasia local. Desse modo, observamos que, dentre os vários protocolos propostos na literatura, a manutenção da terapia anticoagulante, com a utilização de hemostáticos locais se necessário, parece o mais adequado à maioria dos casos cirúrgicos ambulatoriais.

Effects of the unilateral removal and dissection of the masseter muscle on the facial growth of young rats

This study analyzed the effects of the unilateral removal and dissection of the masseter muscle on the facial growth of young rats. A total of 30 one-month-old Wistar rats were used. Unilateral complete removal of the masseter muscle was performed in the removal group, and detachment followed by repositioning of the masseter muscle was performed in the dissection group, while only surgical access was performed in the sham-operated group. The animals were sacrificed at three months of age. Axial radiographic projections of the skulls and lateral projections of the hemimandibles were taken. Cephalometric evaluations were made and the values obtained were submitted to statistical analyses. In the removal group, there were contour alterations of the angular process, and a significant homolateral difference in the length of the maxilla and a significant bilateral difference in the height of the mandibular body and the length of the mandible were observed. Comparison among groups revealed significance only in the removal group. It was concluded that the experimental removal of the masseter muscle during the growing period in rats induced atrophic changes in the angular process, as well as asymmetry of the maxilla and shortening of the whole mandible.

Clinical evaluation of desensitizing treatments for cervical dentin hypersensitivity

The aim of this study was to compare different treatments for dentin hypersensitivity in a 6-month follow-up. One hundred and one teeth exhibiting non carious cervical lesions were selected. The assessment method used to quantify sensitivity was the cold air syringe, recorded by the visual analogue scale (VAS), prior to treatment (baseline), immediately after topical treatment, after 1 week, 1, 3 and 6 months. Teeth were randomly assigned to five groups (n = 20): G1: Gluma Desensitizer (GD); G2: Seal&Protect (SP); G3: Oxa-gel (OG); G4: Fluoride (F); G5: Low intensity laser-LILT (660 nm/3.8 J/cm²/15 mW). Analysis was based on the non-parametric Kruskal-Wallis test that demonstrated statistical differences immediately after the treatment (p = 0.0165). To observe the individual effects of each treatment, data was submitted to Friedman test. It was observed that GD and SP showed immediate effect after application. Reduction in the pain level throughout the six-month follow-up was also observed. In contrast, LILT presented a gradual reduction of hypersensitivity. OG and F showed effects as of the first and third month respectively. It can be concluded that, after the 6-month clinical evaluation, all therapies showed lower VAS sensitivity values compared with baseline, independently of their different modes of action.

Shelf-life of a 2.5% sodium hypochlorite solution as determined by arrhenius equation

Accelerated stability tests are indicated to assess, within a short time, the degree of chemical degradation that may affect an active substance, either alone or in a formula, under normal storage conditions. This method is based on increased stress conditions to accelerate the rate of chemical degradation. Based on the equation of the straight line obtained as a function of the reaction order (at 50 and 70 ºC) and using Arrhenius equation, the speed of the reaction was calculated for the temperature of 20 ºC (normal storage conditions). This model of accelerated stability test makes it possible to predict the chemical stability of any active substance at any given moment, as long as the method to quantify the chemical substance is available. As an example of the applicability of Arrhenius equation in accelerated stability tests, a 2.5% sodium hypochlorite solution was analyzed due to its chemical instability. Iodometric titration was used to quantify free residual chlorine in the solutions. Based on data obtained keeping this solution at 50 and 70 ºC, using Arrhenius equation and considering 2.0% of free residual chlorine as the minimum acceptable threshold, the shelf-life was equal to 166 days at 20 ºC. This model, however, makes it possible to calculate shelf-life at any other given temperature.

Comparative study of intermaxillary relationships of manual and swallowing methods

This study compared the mandibular displacement from three methods of centric relation record using an anterior jig associated with (A) chin point guidance, (B) swallowing (control group) and (C) bimanual manipulation. Ten patients aged 25-39 years were selected if they met the following inclusion criteria: complete dentition (up to the second molars), Angle class I and absence of signs and symptoms of temporomandibular disorders and diagnostic casts showing stability in the maximum intercuspation (MI) position. Impressions of maxillary and mandibular arches were made with an irreversible hydrocolloid impression material. Master casts of each patient were obtained, mounted on a microscope table in MI as a reference position and 5 records of each method were made per patient. The mandibular casts were then repositioned with records interposed and new measurements were obtained. The difference between the two readings allowed measuring the displacement of the mandible in the anteroposterior and lateral axes. Data were analyzed statistically by ANOVA and Tukey's test at 5% significance level. There was no statistically significant differences (p>0.05) among the three methods for measuring lateral displacement (A=0.38 ± 0.26, B=0.32 ± 0.25 and C=0.32 ± 0.23). For the anteroposterior displacement (A=2.76 ± 1.43, B=2.46 ± 1.48 and C=2.97 ± 1.51), the swallowing method (B) differed significantly from the others (p<0.05), but no significant difference (p>0.05) was found between chin point guidance (A) and bimanual manipulation (C). In conclusion, the swallowing method produced smaller mandibular posterior displacement than the other methods.

Crown-down preflaring in the determination of the first apical file

In this study, scanning electron microscopy (SEM) was used to evaluate the adaptation of the first apical file after preflaring in mesiobuccal (MB) and mesiolingual (ML) canals of mandibular molars considering the tactile sensibility as a reference. The mesial canals (n = 22) of human mandibular molar teeth were used, and the first instrument to bind to the working length was determined after preflaring and crown-down shaping. Digital images of the root apex were acquired and a single examiner determined the contact of the file with the walls using Image J software. The results showed that the file was in contact in 47.83% and 31.71% in the MB and ML canals, respectively. When the apexes are fused, the average was 40.03%. A descriptive analysis showed that the first apical file did not touch all dentin walls in any of the samples.

Alterações bucais e cuidados orais no paciente transplantado de medula óssea

Os cuidados gerais relativos ao paciente submetido ao transplante de medula óssea (TMO) incluem avaliações odontológicas rotineiras, as quais devem estar inseridas em um contexto multiprofissional. A cavidade oral constitui um sítio propício a infecções com grande potencial de desenvolvimento de bacteremia, sendo que lesões infecciosas devem ser previamente tratadas e controladas pelo cirurgião-dentista. O objetivo desta revisão é discutir questões em destaque na literatura nacional e internacional referentes aos quadros inflamatórios e infecciosos orais de importância para o paciente transplantado de medula óssea, tanto os predisponentes a complicações durante o transplante, quanto os que ocorrem durante e após a terapia mielossupressora. Destaca-se na literatura a doença periodontal avançada, a qual constitui um quadro infeccioso crônico que deve ser evitado ou controlado durante o TMO, principalmente devido à presença de S. viridans. Os fatores de risco para mucosite oral (OM), doença do enxerto contra o hospedeiro (DECH) e xerostomia ainda não estão definidos, principalmente para OM e DECH. São citadas na literatura alternativas promissoras de tratamento para OM, tais como crioterapia, administração de fatores de crescimento e laserterapia. O risco aumentado de cárie é controverso e, dentre as lesões fúngicas e virais, destacam-se as infecções orais e de orofaringe por Candida e pela família de herpesvírus, de importância clínica considerável. Em pacientes pediátricos são relevantes as alterações craniofaciais e dentárias, decorrentes principalmente da radioterapia.