Effect of sonic and ultrasonic activation on physicochemical properties of root canal sealers

Objective: To evaluate the effect of ultrasonic and sonic activation on physicochemical properties of AH Plus, MTA Fillapex, ADSeal, GuttaFlow Bioseal, and GuttaFlow 2 sealers. Methodology: Three experimental groups were formed: no activation (NA), ultrasonic activation (UA), and sonic activation (SA). The sealers were manipulated according to the manufacturers’ instructions. A 3-mL syringe was adapted to receive 1 mL of sealer. Activation was performed with a 20/.01 ultrasonic insert (20 s/1W) in the UA group. A size 35.04 sonic tip was used (20 s/10,000 cycles/min-1) in the SA group. The molds for physicochemical analysis were filled and evaluated according to ANSI/ADA specification no. 57: setting time (ST), flow (FL), dimensional change (DC), solubility (SB), and radiopacity (RD). Statistical analysis was performed by Kruskal-Wallis, one-way ANOVA, and Tukey's tests (P<0.05). Results: Regarding ST, only AH Plus and GuttaFlow 2 in the NA group met the ANSI/ADA standards. All FL values were greater than 20 mm in diameter, as determined by ANSI/ADA. The tested sealers and protocols did not comply with the ANSI/ADA standards for DC. As for SB, only MTA Fillapex, regardless of the activation protocol, did not follow the ANSI/ADA standards. All of the investigated sealers, regardless of the activation protocol, presented radiographic density higher than 3 mm Al, as proposed by ANSI/ADA. Conclusions: UA and SA promoted changes in the physicochemical properties of the evaluated root canal sealers, mainly in ST and F. Thus, it is important to evaluate the physicochemical properties of endodontic sealers associated with activation techniques prior to clinical application in order to determine whether the properties follow the parameters set by ANSI/ADA, ensuring safety and quality of root canal filling

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 (&#945;=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

Prosthetic rehabilitation in a patient with Singleton Merten syndrome and acrylic resin hypersensitivity

Singleton Merten Syndrome is a rare disease characterized by the presence of the dental dysplasia phenotype, calcifications in the aorta, progressive wear and loss of bone protein (osteoporosis) in the hands and feet. Patients have muscle weakness, poor motor development, abnormal dentition, deformities of thefeet and hands, and skin lesions. Objective: This report describes the maxillomandibular rehabilitation of a patient with Singleton Merten Syndrome and an allergic reaction to the acrylic resin through maxillary overdenture and mandibular partial removable denture. Case report: Female patient, 18 years old, with clinical characteristics of Singleton Merten Syndrome and allergic reaction to acrylic resin, with complaints of loss of function and esthetics dueto the absence of several teeth, but with the presence of unerupted maxillary and mandibular tooth buds. Maxillary overdenture and mandibular removable partial denture were made of polyethylene. Conclusion: The rehabilitation treatment with maxillary overdenture and mandibular partial removable denture provided better facial muscle support, restoring masticatory function and facial esthetics. With this treatment, it was possible to reestablish patient’s satisfactionand self-esteem due to the correct construction of the prostheses, and minimize hypersensitivity reactions in the oral mucosa, which allowed the use of these prostheses by the patient without any complications.Singleton Merten Syndrome is a rare disease characterized by the presence of the dental dysplasia phenotype, calcifications in the aorta, progressive wear and loss of bone protein (osteoporosis) in the hands and feet. Patients have muscle weakness, poor motor development, abnormal dentition, deformities of thefeet and hands, and skin lesions. Objective: This report describes the maxillomandibular rehabilitation of a patient with Singleton Merten Syndrome and an allergic reaction to the acrylic resin through maxillary overdenture and mandibular partial removable denture. Case report: Female patient, 18 years old, with clinical characteristics of Singleton Merten Syndrome and allergic reaction to acrylic resin, with complaints of loss of function and esthetics dueto the absence of several teeth, but with the presence of unerupted maxillary and mandibular tooth buds. Maxillary overdenture and mandibular removable partial denture were made of polyethylene. Conclusion: The rehabilitation treatment with maxillary overdenture and mandibular partial removable denture provided better facial muscle support, restoring masticatory function and facial esthetics. With this treatment, it was possible to reestablish patient’s satisfactionand self-esteem due to the correct construction of the prostheses, and minimize hypersensitivity reactions in the oral mucosa, which allowed the use of these prostheses by the patient without any complications

Influence of bioceramic intracanal medication on the bond strength of bioceramic root canal sealer

Abstract To investigate the influence of the remaining volume of a new intracanal medication based on bioceramic compounds on the bond strength (BS) and formation of an adhesive interface between calcium silicate-based and epoxy resin-based root canal sealers. For this purpose, the specimens were distributed according to the intracanal medication (n = 26): Bio-C Temp (BCT) and Ultracal XS (UXS). The roots were scanned in microCT, and after 7 days, the medication was removed. Then a new scan was performed to evaluate the volume of medication remaining. Subsequently, 40 specimens were redistributed into 2 subgroups (n = 10) and filled according to the sealer used: AH Plus (AHP) and Bio-C Sealer (BCS), to assess the bond strength by using the push-out test, and the adhesive interface by confocal laser fluorescence microscopy (CLSM) and scanning electron microscopy (SEM). The t test showed a smaller remainder of BCT (1.77 ± 0.86) compared with UXS (10.47 ± 5.78), irrespective of the root third evaluated. The BS showed that teeth with BCT + BCS had higher bond strength values (3.70 ± 1.22) when compared to the other groups: BCT + AHP (2.15 ± 1.07), UXS + BCS (3.18 ± 1.09) and UXS + AHP (2.11 ± 1.02) (p<0.001). The cervical third had higher BS when compared with the middle and apical thirds (p < 0.001), and higher number of adhesive failures. The adhesive interface in SEM and CLSM images showed better adaptation for the association between BCT + BCS. Intracanal medication and silicate-based endodontic sealer appeared to interact chemically by forming a biomineralizing layer, allowing for an increase in the bond strength and forming an adhesive interface between the materials, with no or less gap formation

Possibilidades restaurativas usando cerâmica de zircônia para coroas unitárias.

Two clinical cases are presented to explore technical differences and discusses the advantages and disadvantages of using veneered or monolithic zirconia to manufacture posterior single crowns. The first case describes the clinical steps in manufacturing a monolithic crown on a mandibular left second premolar using high translucency zirconia. It shows the use of a conservative tooth preparation based on the superior mechanical properties that this material presents as well as the final optical characteristics achieved by shading and staining. In the second case, a conventional bilayer restorative treatment was made using zirconia framework followed by veneering with feldspar ceramic on a mandibular left first molar. Recent literature indicates that each of these restorative alternatives presents specific advantages and disadvantages. Factors such as mechanical performance, fracture, esthetic characteristics, clinical success, complication rates, adhesion and antagonist wear performance are discussed comparing the two restorative assemblies. The data highlight that monolithic crowns prevent a major problem reported on bilayer restorations: the chipping of veneering ceramic. Monolithic crowns also allow minimally invasive tooth preparations, thus increasing tooth remnant preservation. However, data that support esthetic performance similarity between monolithic and bilayer assemblies are lacking, thus the predictability of use is restricted for the posterior region, as cases demanding high esthetic appeal continue to fundamentally use bilayer restorations. Failures were not found, and patient satisfaction was reported in both techniques after the 12-month follow up.Dois casos clínicos são apresentados para explorar as diferenças técnicas e discutir as vantagens e desvantagens do uso de zircônia folheada ou monolítica para confeccionar coroas únicas posteriores. O primeiro caso descreve as etapas clínicas na fabricação de uma coroa monolítica em um segundo pré-molar inferior esquerdo usando zircônia de alta translucidez. Mostra a utilização de um preparo dentário conservador baseado nas propriedades mecânicas superiores que este material apresenta, bem como nas características ópticas finais alcançadas pelo sombreamento e coloração. No segundo caso, foi realizado um tratamento restaurador convencional em bicamada com estrutura de zircônia seguida de estratificação com cerâmica de feldspato no primeiro molar inferior esquerdo. A literatura recente indica que cada uma dessas alternativas restauradoras apresenta vantagens e desvantagens específicas. Fatores como desempenho mecânico, fratura, características estéticas, sucesso clínico, taxas de complicações, desempenho de adesão e desgaste do antagonista são discutidos comparando os dois conjuntos restauradores. Os dados destacam que as coroas monolíticas evitam um grande problema relatado nas restaurações de duas camadas: o lascamento da cerâmica de recobrimento. As coroas monolíticas também permitem preparações dentárias minimamente invasivas, aumentando assim a preservação do remanescente dentário. No entanto, faltam dados que sustentem a similaridade do desempenho estético entre as montagens monolítica e bicamada, sendo a previsibilidade de uso restrita para a região posterior, pois casos que demandam alto apelo estético continuam a utilizar fundamentalmente as restaurações bicamada. Não foram encontradas falhas, e a satisfação do paciente foi relatada em ambas as técnicas após o acompanhamento de 12 meses

Enamel hypoplasia in a litter of rats with alloxan-induced diabetes mellitus

Enamel hypoplasia is an important clinical problem commonly seen in children born to diabetic women. We aimed to characterize the enamel hypoplasia in Wistar rats born to alloxan-induced diabetes mellitus rats. Groups consisted of pregnant rats supplemented (ISDR) or not (NISDR) with insulin and controls, in which sterile saline solution was administered instead of alloxan or insulin. The mandibular incisors of one-month-old rats born to these mothers were analyzed. Whitish defective enamel was found macroscopically in both experimental groups (ISDR = 37.5%, NISDR = 33.3%) but not in the control group. Mild to severe enamel hypoplasia was observed by scanning electron microscopy (ISDR = 93.8%; NISDR = 100%, control = 4.2%). The severity of hypoplasia correlated positively with the maternal level of blood glucose. In conclusion, the intensity of enamel hypoplasia in the teeth of the litter born to alloxan-induced diabetic rats was variable and was dependent on the glycemic level of the pregnant rat