Abordagem clínico-cirúrgica de cisto periapical: relato de caso / Clinical-surgical approach of periapical cyst: Case report

Introdução: o cisto periapical é classificado como cisto odontogênico inflamatório, sendo a lesão periapical de maior incidência na cavidade bucal. A lesão é assintomática, radiograficamente apresentando imagem radiolúcida, unilocular, bem definida, circundando o ápice de um dente desvitalizado. Para concluir o diagnóstico de cisto periapical, é necessário realizar, também, exame histopatológico. Métodos: o presente trabalho visou descrever o caso clínico de uma paciente com 12 anos de idade, sexo feminino, apresentando extensa restauração em resina composta e lesão no periápice do dente #16 (aproximadamente 15,2mmx 14,6mm), com presença de fístula palatina. A partir do diagnóstico clínico e radiográfico de cisto periapical, optou-se primeiramente pelo tratamento endodôntico convencional. Após sucessivas trocas de medicação intracanal (usando clorexidina gel 2% + hidróxido de cálcio), a fístula não regrediu e, assim, foi sugerida a enucleação da lesão, com encaminhamento do material para exame histopatológico. Resultados: após um acompanhamento de dois anos, foi possível constatar a efetividade do tratamento proposto. Conclusão: o correto diagnóstico depende de conhecimentos técnicos e experiência clínica, sendo necessária, muitas vezes, a atuação conjunta de várias especialidades para resolução do caso (AU).

Introduction: periapical cysts are classified as inflammatory, odontogenic cysts; periapical lesions are the most common lesions in the oral cavity. These lesions are asymptomatic; radiographically, they present radiolucent, unilocular, well-defined images and they surround the apices of devitalized teeth. To correctly diagnose a periapical cyst it is also necessary to perform a histopathological examination. Methods: the present study describes the clinical case of a twelve year-old female patient who presented an extensive restoration of composite resin and a periapical lesion in tooth No. 16 (approximately 15.2 x 14.6 mm), with the presence of palatine fistula. Based on the clinical and radiographic diagnosis of the periapcal cyst, we first opted for conventional endodontic treatment. After successive changes of intracanal medication (using 2% chlorhexidine gel and calcium hydroxide) the fistula did not regress and thus it was decided to enucleate the lesion; the material was then sent for histopathological examination. Results: after two years follow-up it was possible to verify that the treatment had been effective. Conclusion: a correct diagnosis depends on technical knowledge and clinical experience; it is often necessary to work jointly with several different specialists to solve a case (AU).

Influence of Alternative Restoration Technique with Different Composite Resins for Flared Root Reinforcement.

PURPOSE: To evaluate the influence of type and viscosity of composite resins used for root reinforcement in the adhesion of glass-fiber posts to flared root canals. MATERIALS AND METHODS: The crowns of 78 uniradicular permanent teeth were removed and the teeth were endodontically treated. After one week, the roots were prepared for root reinforcement and randomly divided into 6 groups (n = 13): positive control group ([PCG] the root canals were not enlarged), negative control group ([NCG] root canals were enlarged, no reinforcement), and in the remaining 4 groups, root canals were enlarged to receive root reinforcement according to a combination of the factors composite resin type (bulk-fill or conventional) and viscosity (flowable or regular). After fiber post cementation, six slices were obtained from each root (2 each from the cervical, middle, and apical thirds). For each group, 7 teeth underwent push-out bond strength testing, and 6 teeth were evaluated for nanoleakage and Vickers microhardness. Bond strength and nanoleakage data were submitted to two-way ANOVA and Tukey's test (α = 0.05), and microhardness data to one-way ANOVA and Tukey's test (α = 0.05). RESULTS: The root reinforcement groups with regular and flowable bulk-fill composite resins showed statistically superior adhesion results (higher bond strength and less nanoleakage) compared to the negative control in all root regions. Microhardness values were higher in the cervical third followed by the middle third. CONCLUSION: Regular or flowable bulk-fill composite resins should be chosen for root reinforcement of flared root canals prior to fiber post cementation.

Effect of Root Canal Sealers on Bond Strength of Fiber Posts to Root Dentin Cemented after one Week or six Months.

Eugenol-based root canal sealers (RCS) have been widely used by clinicians; however, their effect on resinous materials is still questionable. The objective of this study was to evaluate the influence of RCS at 1 week and 6 months' post obturation on the bond strength (BS) of glass fiber posts (GFP) to root dentin, using conventional and self-adhesive cementation systems (CS). The roots of 56 extracted human canines, were divided in eight groups (n=7) according to the combination of the following factors: RCS (with or without eugenol-Endofill and Sealer 26, respectively), storage period post obturation and prior GFP cementation (1 week and 6 months) and cementation systems (Variolink II - conventional resin cement or RelyX U200-self-adhesive resin cement). After one week, the specimens were transversely sectioned into six 1-mm-thick disks and were subjected to the push out BS test. The data were subjected to 3-way ANOVA and Tukey's tests (α=0.05). The BS were not affected by the RCS, neither the CS (P>0.05). Just the period post obturation showed statistically significant differences (P 0.05), where the GFP cemented 6 months after the endodontic treatment showed higher values than those cemented 1 week after it.

Influence of different burs and acid ultrasonic agitation on the bonding of fiber posts to root dentin

Aim: The objective is to evaluate the influence of different burs used to prepare the root canal space and acid ultrasonic agitation on bond strength (BS) between glass fiber posts (GFP) and root dentin. Methods: After endodontic treatment, the root canal spaces of 36 extracted human canines were prepared, according to the rotary instrument used (n=18): carbide bur (CB), provided by the post manufacturer and a diamond bur (DB). In both groups, the fiber posts were cemented with the adhesive system Ambar and resin cement Allcem, following the manufacturer`s instructions. Previously to the cementation procedures, the groups were subdivided into 2 groups (n=9), according to the phosphoric acid application mode: conventional etching (CE) and active etching (AE), performed by ultrasonic tip, both for 15s. Before the cementation procedures and after the acid application, 1 root of each group was randomly selected for ultrastructural morphological evaluation by SEM. After 1 week of the cementation, 8 specimens per group were transversely sectioned into six 1-mm thick slices, the root canal regions (cervical, medium and apical) were identified and the push-out test was performed to evaluate BS. Data were analyzed by 3-way ANOVA and Tukey test (α=0.05). Results: The results showed that the cross-product interaction of all factors was significant (P=0.035). Higher bond strength values were obtained when a DB with conventional etching, instead of CB, was used to prepare the root post space. Conclusion: It may be concluded that the use of diamond burs with conventional etching yields high BS values in all root canal thirds

Effect of bleaching agents containing fluoride or calcium on enamel microhardness, roughness and permeability

To evaluate the effect of different in-office bleaching agents on the permeability, roughness and surface microhardness of human enamel. Methods: For evaluation of roughness and microhardness, 40 hemi-faces of 20 premolars were subjected to initial roughness (Ra parameter) and microhardness (VHN) measurements. Thirty-two premolar's crowns were used for permeability test. Then, all specimens were randomly divided into four groups: C - without bleaching (control), HP35 - bleaching with 35% hydrogen peroxide (HP), HPF38 - 38% HP+fluoride, HPC35 - 35% HP+calcium. Final roughness (FR) and microhardness (FM) measurements were evaluated. For permeability, the 32 crowns were immersed in 1% sodium hypochlorite (20 min) and silver nitrate solutions (2 h) and subjected to developing solution under fluorescent light (16 h). Three sections from the crowns were analyzed in light microscope (100x) to evaluate the scores of permeability: Score 0 - no tracer agent penetration; Score 1 - less than half the thickness of enamel penetration; Score 2 - tracer agent reaching half the enamel thickness; Score 3 - entire enamel depth penetration, without reaching dentin and Score 4 - tracer agent reaching dentin. For roughness and microhardness evaluation were used one-way ANOVA and Dunnet post-test for independent samples, and t test for paired samples. For permeability, the data were analyzed by Kruskal Wallis and Dunn tests. Results: A significantly higher permeability and surface roughness were observed in groups HP35, HPF38 and HPC35 compared to the C group, as well as decreased microhardness (p<0.05). Conclusions: All bleaching agents increased permeability and surface roughness, and decreased microhardness of human enamel; thus, the addition of fluoride or calcium was not beneficial...