Computer-aided design and computer-aided manufacturing poly (methyl methacrylate) interim veneers for immediate esthetic restoration of autotransplanted teeth.

Autotransplanted teeth in the maxillary anterior region should be restored or reshaped as soon as possible for functional and esthetic reasons as well as the well-being of the patient. However, such tooth restorations are frequently not carried out immediately after tooth transplantation because the process could have a negative impact on the healing process. The development of a simple, immediate, and atraumatic esthetic interim restoration would be of great benefit to both the clinician and patient and address all the concerns caused by immediately preparing the tooth postoperatively and cementing a permanent restoration. This report describes the use of CAD-CAM technology to create poly (methyl methacrylate) veneers preoperatively that can be cemented extraorally on the extracted donor tooth for the immediate and interim recontouring of autotransplanted anterior teeth.

In vitro assessment of PEEK and titanium implant abutments: Screw loosening and microleakage evaluations under dynamic mechanical testing.

STATEMENT OF PROBLEM: Polyetheretherketone (PEEK) has been advocated to replace metal components in dentistry. Although PEEK is a high-performance polymer with a white color, adequate biological response, and resistance to fracture, data to support PEEK as an alternative material for implant abutments are lacking. PURPOSE: The purpose of this in vitro study was to assess the mechanical and functional properties of PEEK implant abutments as a nonmetallic alternative to titanium abutments, which presents esthetic limitations and greater difficulty to customize clinically. MATERIAL AND METHODS: Implant abutments manufactured by using PEEK (n=24) or titanium grade 5 (n=24) were attached to MIS Implants type M4 3.75×16 mm with an internal screw tightened to 25 Ncm. Screw loosening and microleakage was assessed by submersion in a 2% methylene blue solution for 48 hours at 37 °C. Both groups were compared with and without applying dynamic loading; fatigue testing was performed following the International Organization for Standardization (ISO) 14801:2016 standard. All specimens were observed under a stereomicroscope at ×8 magnification. Statistically significant differences among the PEEK and titanium implant abutments were tested with 2-factor ANOVA and the chi-square analysis for nonpaired and paired data, respectively (α=.05). RESULTS: The implant abutments made of titanium were better in all mechanical tests. The torque loss of titanium abutments was approximately 10%, while PEEK showed a significantly higher (P<.05) torque loss of up to 50%. Moreover, 91.6% of the titanium abutments did not present microleakage, while there was no specimen of PEEK abutments without microleakage, once subjected to dynamic loading (P<.05). CONCLUSIONS: Titanium implant abutments (Ti6Al4V) were better in all tests performed. However, PEEK abutments may be suitable for long-term interim restorations, especially in the anterior area, in patients without parafunction.

Evaluation of the WaveOne Gold and One Shape New Generation in Reducing Enterococcus faecalis from Root Canal.

The aim of this study was to evaluate the WaveOne Gold and One Shape New Generation systems regarding the bacterial removal from root canals infected with Enterococcus faecalis by comparing them to the conventional WaveOne and One Shape systems. Forty-eight distobuccal root canals of maxillary molars sterilized with ethylene oxide were infected with E. faecalis for 21 days, and then root canal initial bacterial sample was collected with paper cones and plated on M-enterococcus agar. The specimens were randomly divided into 4 groups according to the instrumentation: WaveOne Gold, One Shape New Generation, WaveOne and One Shape. After instrumentation, samples were collected with use of scraping and paper cones at immediate and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by Friedman test and intergroup analysis by Kruskal-Wallis with Dunn's post-hoc test, all at 5% significance. All techniques significantly reduced the number of bacteria in the root canal (p<0.05). WaveOne Gold and One Shape New Generation promoted higher bacterial reduction than WaveOne and One Shape systems (p<0.05), but no significant difference was found between WaveOne Gold and One Shape New Generation or between WaveOne and One Shape (p>0.05). Novel single-file systems promote better bacterial removal than the conventional single-file systems.

Evaluation of the waveone gold and one shape new generation in reducing enterococcus faecalis from root canal

Abstract The aim of this study was to evaluate the WaveOne Gold and One Shape New Generation systems regarding the bacterial removal from root canals infected with Enterococcus faecalis by comparing them to the conventional WaveOne and One Shape systems. Forty-eight distobuccal root canals of maxillary molars sterilized with ethylene oxide were infected with E. faecalis for 21 days, and then root canal initial bacterial sample was collected with paper cones and plated on M-enterococcus agar. The specimens were randomly divided into 4 groups according to the instrumentation: WaveOne Gold, One Shape New Generation, WaveOne and One Shape. After instrumentation, samples were collected with use of scraping and paper cones at immediate and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by Friedman test and intergroup analysis by Kruskal-Wallis with Dunn's post-hoc test, all at 5% significance. All techniques significantly reduced the number of bacteria in the root canal (p<0.05). WaveOne Gold and One Shape New Generation promoted higher bacterial reduction than WaveOne and One Shape systems (p<0.05), but no significant difference was found between WaveOne Gold and One Shape New Generation or between WaveOne and One Shape (p>0.05). Novel single-file systems promote better bacterial removal than the conventional single-file systems.

Resumo A proposta deste estudo foi avaliar os sistemas WaveOne Gold e One Shape New Generation em relação à remoção bacteriana de canais infectados com Enterococcus faecalis, comparando-os com seus sistemas convencionais WaveOne e One Shape. Quarenta e oito canais disto vestibulares de molares superiores esterilizados em óxido de etileno foram contaminados com E. faecalis por 21 dias, e então acoleta bacteriana inicial foi feita com cone de papel e plaqueadas em M-enterococcus agar. Os espécimes foram aleatoriamente divididos em quarto grupos de acordo com a instrumentação: WaveOne Gold, One Shape New Generation, WaveOne e One Shape. Após instrumentação, amostras foram coletadas utilizando limagem e cones de papel imediatamente e 7 dias após o preparo. A redução bacteriana foi calculada e então feita análise intra grupos com teste de Friedman, e entre grupos utilizando Kruskal-Wallis e teste de Dunn, todos a 5% de significância. Todas as técnicas reduziram significantemente o número de bactérias do canal radicular (p<0.05). WaveOne Gold e One Shape New Generation promoveram maior redução bacteriana que WaveOne e One Shape (p<0.05), mas nenhuma diferença significante foi encontrada entre WaveOne Gold e One Shape New Generation ou entre WaveOne e One Shape (p>0.05). Novos sistemas de lima-única promovem melhor remoção bacteriana que seus sistemas convencionais.

Análise de diagnósticos radiográfico periapicais sugestivos de lesões refratárias / Analysis of periapical radiographic diagnosis that suggest persistent lesion

Cicatrizes fibrosas periapicais podem ter aspecto radiográfico semelhante a lesões periapicais, levando ao plano de tratamento incorreto. Assim, o objetivo deste estudo foi realizar um confronto entre o diagnóstico radiográfico e histopatológico de dentes que foram tratados endodonticamente e apresentaram“lesões periapicais” detectadas radiograficamente após 18 meses do tratamento. Dez pacientes submetidos ao tratamento endodôntico adequado e apresentando imagem radiolúcia persistente 18 meses pós-tratamento, tiveram cirurgia paraendodôntica indicada. Durante a cirurgia, o tecido em volta do ápice foi removido e mergulhado em solução de formalina 10% para processamento histopatológico através de coloração de HE. O ápice removido na apicectomia foi mantido em glutaraldeído 2% e processado para análise por microscopia eletrônica de varredura. Dentre os 10 casos sugestivos de lesão periapical, em apenas um caso foi confirmado diagnóstico de cisto, um caso de granuloma, e os outros oito casos confirmaram cicatriz fibrosa. Em nenhum dos casos foi detectada a presença de bactéria extrarradicular, somente infiltrado inflamatório e presença de células de defesa como linfócitos e neutrófilos, além de hemácias, tecido conjuntivo e colágeno. Pode-se concluir que a radiográfica convencional não constitui ponto conclusivo no diagnóstico de lesões periapicais.

Periapical fibrous scars may have similar radiographic appearance of periapical lesions that canresult in incorrect diagnosis. The aim of this study was a confrontation between the radiographic and histopathologic diagnosis of teeth that were endodontically treated and presented “persistent periapical lesions” detected radiographically after 18 months of treatment. Ten patients under going adequate endodontic treatment and presenting persistent radiolucent image at 18 months post-treatment, had surgery Para endodontic indicated. During surgery, the tissue around the apex was removed and immersedin 10% formalin solution for histological processing by HE staining. The apex oh the tooth was removed and immersed in 2% glutaral dehyde for scanning electron microscopy processing. Among the 10 radiographically suggestive cases of persistent periapical lesion, only 1 case was confirmed diagnosis of cyst, 1 case of granuloma, and the other 8 cases were fibrous scar. In neither case was observed the presence of bacteria, only inflammatory infiltrate and the presence of defense cells such as lymphocytes and neutrophils, red blood cells, connective tissue and collagen. It can be concluded that the conventional radiography is not conclusive point in the diagnosis of periapical lesions.