Avaliação da capacidade de corte de um sistema rotatório assimétrico Durante o preparo biomecânico, quando alterados seus ângulos de corte e relaxamento / Cutting Capacity Assesment During Biomechanical Preparation Generated by changing the cutting angle of an asymmetric rotating system

O objetivo deste estudo foi avaliar a capacidade de remoção de dentina radicular utilizando diferentes angulações de corte de um instrumento com sistema reciprocante, em um determinado período de tempo. Quarenta e cinco raízes uniradiculares de dentes humanos foram selecionadas através de tomografia computadorizada e padronizados com preparo prévio, através de um instrumento manual (tipo k) #15. Os espécimes foram divididos em 3 grupos (n=15) para instrumentação com o sistema Genius, previamente alterada a angulação com o auxílio de um transferidor: Grupo 1 Genius (G1) - Sistema Genius 25.04 em 16 mm com ângulos de corte e relaxamento (90º/30º), preconizados pelo fabricante, por 30 segundos; Grupo 2 Genius (G2) - Sistema Genius 25.04 em 16 mm com ângulos de corte e relaxamento (120º/60) por 30 segundos; Grupo 3 Genius (G3) - os espécimes foram instrumentados com sistema Genius 25.04 em 16 mm com ângulos de corte e relaxamento (70º/10º) por 30 segundos. Os resultados foram avaliados através da pesagem dos espécimes e pela volumetria através da tomografia computadorizada ambas realizadas pré e pós-instrumentação, e em relação aos ângulos de corte e recuo, todos os grupos apresentaram alteração no preparo biomecânico, quando comparado as suas respectivas rotações programadas no motor endodôntico Genius (Ultradent,2005). Os dados obtidos foram submetidos a análise de variância (ANOVA) e ao teste de Kruskal Wallis, onde o mesmo não apresentou diferença estatística significante entre os grupos. Dessa forma pode-se observar que todos os ângulos de corte e recuo, apresentaram alterações, não mantendo um preparo individualizado para cada dente, de acordo com suas complexidades em relação a morfologia radicular(AU)

The aim of this study was to evaluate the ability to remove root dentin using different cutting angles of an instrument with a reciprocating system, in a given period of time. Forty-five uni-root roots of human teeth were selected using computed tomography and standardized with prior preparation, using a manual instrument (type k) # 15. The specimens were divided into 3 groups (n = 15) for instrumentation with the Genius system, previously changed the angle with the aid of a protractor: Group 1 Genius (G1) - Genius 25.04 system in 16 mm with cutting and relaxation angles ( 90º / 30º), recommended by the manufacturer, for 30 seconds; Genius Group 2 (G2) - Genius 25.04 system in 16 mm with cutting and relaxation angles (120º / 60) for 30 seconds; Group 3 Genius (G3) - the specimens were instrumented with the Genius 25.04 system in 16 mm with cutting and relaxation angles (70º / 10º) for 30 seconds. The results were evaluated by weighing the specimens and by volumetry using computed tomography, both performed pre- and post-instrumentation, and in relation to the cutting and receding angles, all groups showed changes in the biomechanical preparation, when compared to their respective programmed rotations. in the Genius endodontic engine (Ultradent, 2005). The data obtained were subjected to analysis of variance (ANOVA) and the Kruskal Wallis test, where it did not show a statistically significant difference between the groups. In this way, it can be observed that all the cut and setback angles showed alterations, not maintaining an individualized preparation for each tooth, according to their complexities in relation to root morphology(AU)

Abordaje quirúrgico combinado para la desinfección y regeneración de defectos periimplantarios. A propósito de tres casos / Combined surgical treatment for the decontamination and regeneration of peri-implant defects. A three cases series

Los implantes dentales sufren una alta incidencia de mucositis y periimplantitis, que pueden llevar a su fracaso. Existen múltiples abordajes terapéuticos no quirúrgicos y quirúrgicos para estas patologías, si bien en caso de periimplantitis deberá realizarse tratamiento quirúrgico. El tratamiento quirúrgico puede ser mediante cirugía de acceso, tratamiento resectivo o regenerativo. Para lograr la remoción del biofilm y la mejora de los tejidos periimplantarios, debe realizarse siempre la descontaminación previa del implante. Para ello pueden emplearse métodos mecánicos, químicos, antibióticos o láseres. En el presente artículo se presentan tres casos clínicos en los que se empleó un abordaje quirúrgico combinado de implantoplastia, descontaminación con clorhexidina y ácido ortofosfórico, aplicación de antibiótico local (piperacilina/tazobactam) y regeneración mediante hidroxiapatita sintética y membrana reabsorbible, que ha mostrado resultados favorables concordantes con la bibliografía

Dental implants suffer a high occurrence of mucositis and peri-implantitis, which may lead to implant failure. There are several therapeutical approaches both surgical and non-surgical for the treatment of these pathologies, though in peri-implantitis lesions a surgical procedure must be conducted. Surgical treatment can be trough: access surgery, resective or regenerative surgery. In order to remove the biofilm and to improve peri-implant tissues, decontamination of implant surface must be performed beforehand. For this, mechanical, chemical, antibiotics or lasers may be employed. In this article, we present three clinical cases of combined surgical treatment by implantoplasty, chemical decontamination with clorhexidine and orthophosphoric acid, local antibiotic (piperazilin/tazobactam) and regenerative treatment with synthetic hydroxyapatite and resorbable membrane. This treatment has shown favourable results, coinciding with the results found in the literature

The haemostatic efficacy and foreign body reaction of epinephrine-Impregnated polyurethane foam in osseous defects.

The objective of this study was to compare the haemostatic efficacy and foreign body reaction of epinephrine-impregnated cotton pellets with those of epinephrine-impregnated polyurethane (PU) foam cubes in osseous defects created in guinea pigs. Initially, these substances were randomly applied to the osseous defects in guinea pigs for 2 min and blood loss was measured. The animals were then sacrificed 7 weeks later and the degree of foreign body reaction was scored. The data were analysed by the independent-samples Kruskal-Wallis test. Epinephrine-impregnated PU foam cubes showed significantly better haemostatic effect compared to epinephrine-impregnated cotton pellets. The PU foam containing epinephrine specimens elicited significantly less foreign body reaction compared to epinephrine cotton pellets (P < 0.05). Based on the results of this study, it is concluded that epinephrine-impregnated PU foam cubes are a good alternative to epinephrine-impregnated cotton pellets as a local haemostatic agent in endodontic surgery.

Relation between periapical lesions and sinus membrane thickening assessed by Cone Beam Computed Tomography.

The aim of this study was to evaluate thickening of the Schneiderian membrane and to determine its association with periapical pathologies, using computerized cone beam tomography. An observational, analytical, cross-sectional retrospective study was conducted. A total 179 maxillary sinuses were evaluated using CBCT. The presence of sinus membrane thickening and its association with unhealthy teeth was analyzed. Results are shown as percentages with 95% confidence intervals (95%CI); Chi square test was used with a significance level of 5%.Sinus membrane thickening was detected in 70 cases (39%; 95%CI=32% to 46%) and no sinus membrane thickening was observed in 109 (61%; 95%CI = 54% to 68%) (p<0.05). The 70 cases showing sinus membrane thickening included 46 of odontogenic origin (66%; 95%CI = 54% to 76%) and 24 (34%; 95%CI = 24% to 46%) of non odontogenic origin (p<0.05). The frequency of odontogenic causes followed a heterogeneous distribution (p<0.05): penetrating caries, failing endodontic therapy, root remnants, deep restorations, implants, periodontal pathology. The main cause was caries (46%; 95%CI=32% to 60%) followed by failing endodontic therapy (26%, 95% CI=16% to 40%). The frequency distribution of involved teeth was uneven (p<0.05), with tooth 16 (33%; 95%CI=21% to 47%) being the most frequently involved, followed by tooth 26 (30%; 95%CI=19% to 45%).The high incidence of sinus pathology of odontogenic origin shows the need for interdisciplinary work involving dentists and ear-nose-throat specialists. Caries, inadequate restorations, periodontal lesions, implants, and the presence of root remnants are the main causes of Schneiderian membrane thickening. The use of CBCT for diagnosis and treatment planning allows detecting maxillary sinus membrane thickening and determining its association with an odontogenic etiology.

El objetivo del presente trabajo fue evaluar el engrosamiento de la membrana de Schneider y determinar su asociación con patologías periapicales, mediante tomografía computarizada cone beam (CBCT). Se realizó un estudio observacional, analítico, retrospectivo y transversal. Un total de 179 senos maxilares fueron evaluados utilizando CBCT. Se analizó la presencia de engrosamiento de la membrana sinusal y su asociación con piezas dentarias sin vitalidad pulpar. Los resultados se muestran como porcentajes con intervalos de confianza del 95% (IC del 95%). Se utilizó la prueba de Chi cuadrado con un nivel de significación del 5%. Se detectó engrosamiento de la membrana sinusal en 70 casos (39%; IC del 95% = 32% a 46%) y no se observó engrosamiento de la membrana sinusal en 109 (61%; IC del 95% = 54% a 68%) (p < 0.05). Los 70 casos que mostraron engrosamiento de la membrana sinusal incluyeron 46 de origen odontogénico (66%; IC del 95% = 54% a 76%) y 24 (34%; IC del 95% = 24% a 46%) de origen no odontogénico (p <0,05). La frecuencia de las causas odontogénicas siguió una distribución heterogénea (p <0.05): caries penetrantes, tratamiento endodóntico deficiente, restos radiculares, restauraciones profundas, implantes, patología periodontal. La principal causa fue la caries (46%; IC 95% = 32% a 60%), seguida por endodoncia deficiente (26%, IC 95% = 16% a 40%). La frecuencia se distribuyó en forma heterogénea entre las distintas piezas (p<0,05). Las piezas más afectadas fueron la 16 (33%; IC95=21% a 47%) y la 26 (30%; IC95=19% a 45%). La alta incidencia de patología sinusal de origen odontogénico implica la necesidad del trabajo interdisciplinario entre odontólogos y otorrinolaringólogos. Caries, restauraciones inadecuadas, lesiones periodontales, implantes y la presencia de restos radiculares son las principales causas del engrosamiento de la membrana de Schneider. El uso de CBCT para el diagnóstico y la planificación del tratamiento permite detectar el engrosamiento de la membrana del seno maxilar y determinar su asociación con una etiología odontogénica.

A six-year study of hydroxyapatite-coated root-form dental implants.

BACKGROUND: The effect of hydroxyapatite coating of dental implants is controversial. The long-term fate of hydroxyapatite-coated implants has been the subject of some criticism. PURPOSE: The aim of this retrospective study was to assess the clinical outcome of hydroxyapatite-coated cylindrical root-form endosseous Impladent dental implants (LASAK Ltd, Prague, Czech Republic) during a six-year course. METHODS: Three-hundred and ninety-one consecutively placed implants were used in 169 patients and followed for four to six years. Interval and cumulative success of implants and prostheses survival was tabulated. Marginal bone loss was measured RESULTS: Of the total number of implants, 98.5% achieved initial osseointegration. The cumulative success was 98.3% after one year, 97.0% after three years, 92.8% after five years and 90.4% after six years. The prostheses survival at the end of the study was 100% for fixed bridges totally supported by implants, 96.5% for fixed bridges with combined implant and tooth support, 94.2% for single crowns, 90.9% for mandibular overdentures and 81.3% for maxillary overdentures. Marginal bone loss averaged 2.4 +/- 0.8 mm at the end of five years. CONCLUSION: The success rate of the investigated hydroxyapatite-coated implants was comparable with the data presented in the literature and with the results of the similar implants without hydroxyapatite-coating. However, the marginal bone loss was of interest. Longer monitoring of the implants is necessary.

Autotransplantation of endodontically treated third molars.

OBJECTIVE: To determine the success rate in autotransplantation of endodontically treated third molars. DESIGN: A descriptive study. PLACE AND DURATION OF STUDY: This study was carried out at Armed Forces Institute of Dentistry (AFID), Rawalpindi (Pakistan) from January 2002 to December 2002. PATIENTS AND METHODS: A total of 50 patients meeting the inclusion criteria were selected who had their first or second molars in unrestorable condition with intact third molars. The donor teeth were extracted after the preparation of recipient site. After endodontically treated in vitro the donor teeth were carried to the recipient site and immobilized. Postoperative variables were recorded and analyzed on SPSS version 10. RESULTS: The overall success rate after six months of the transplantation of third molars was 88% with complete root formation after endodontic treatment. All the patients(12%) who had complaints were more than 35 years of age. CONCLUSION: Third molars are good substitute for the unrestorable first or second molars and would be as effective as endosseous implants. The procedure is likely to have complications in the advanced age group.

Management of the iatrogenically displaced anterior sublingual floor.

Trauma and neoplasms may be responsible for ablative procedures performed in the anterior mandibular region. This surgery, as well as alveoloplasty, ridge augmentation, and placement of subperiosteal implants, may be responsible for the anterior malpositioning of the floor of the mouth along with its adnexa, which brings Wharton's carunculae directly over the crest of the ridge. A technique has been devised to correct this problem.

Failure of an endodontic implant. Complications of removal and treatment.

The principal goal in the development of endodontic implants is to improve the stability of periodontally and traumatically compromised teeth. When excessive forces exist and periodontal conditions are suboptimal, however, the system breaks down and ultimately fails. We report such a failure, a sequela of which contributed to subsequent fracture of the mandible. The patient's hospital course and complications of treatment are discussed.

Resection of a sapphire endodontic stabilizer due to perforation of the maxillary sinus: report of a case.

A case is presented which involved resection of a sapphire endodontic stabilizer in a maxillary cuspid. This was necessary due to its perforation of the maxillary sinus. The implant was not readily identifiable upon viewing the preoperative radiograph and could only be resected using a diamond bur. Because of its limited degree of radiopacity, the use of sapphire as a material for endodontic stabilizers may be questioned from a diagnostic standpoint.

Stresses induced by endodontic stabilizers.

The force transmission of tapered, smooth-sided and parallel, threaded-sided single-crystal sapphire endodontic stabilizers was studied and the conclusions were: The stabilizer designs provided substantial fixation of the periodontically compromised model teeth and reduced tooth mobility from 3 to 0. Both stabilizer designs dramatically improved the stress distribution in the supporting structures caused by applied loads. The most distinct and highest intensity of stress concentrations were observed in the models immediately after insertion of the stabilizer. Stresses were reduced with the presence of the fibrous tissue simulation. The most favorable stress distributions were demonstrated, irrespective of configuration, in the models representing full bone-stabilizer encapsulation.