PurposeTo evaluate the effects of radiation therapy on deciduous teeth.Materials and methodsThe enamel and dentin microhardness (n = 12) was evaluated at 3 depths, both before (control) and after each 10 Gy of irradiation and up to a dose of 60 Gy. The morphology was evaluated via scanning electron microscopy (SEM) (n = 8). The data were analyzed using a two-way analysis of variance (ANOVA) and Tukey’s test (α = 5%).ResultsThe enamel microhardness, as a whole, increased (p < 0.05) after a dose of 60 Gy (211.4 KH), mostly in the superficial enamel. There was a significant difference between the values of nonirradiated dentin microhardness (28.9 KH) compared with dentin that was irradiated with doses of 10 Gy (23.8 KH), 20 Gy (25.6 KH), 30 Gy (24.8 KH), and 40 Gy (25.7 KH) (p < 0.05). There was no difference between nonirradiated dentin and dentin irradiated with 60 Gy (p > 0.05). The highest mean value of microhardness (29.9 KH) (p < 0.05) was found in the middle dentin. The groups that were irradiated with doses of 30 and 60 Gy exhibited greater surface changes in their enamel and dentin compared with the nonirradiated groups for all regions, exhibiting an amorphous surface upon increase of the irradiation doses.ConclusionsThe enamel microhardness increased at a dose of 60 Gy, whereas the value of the dentin microhardness did not change. A progressive disruption of enamel and dentin morphology was found with the increased radiation dose.

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This study evaluated in vitro the shear bond strength of a resin-based pit-and-fissure sealant (Fluroshield -F) associated with either an ethanol-based (Adper Single Bond 2 -SB) or an acetone-based (Prime & Bond -PB) adhesive system under conditions of oil contamination. Mesial and distal enamel surfaces from 30 sound third molars were randomly assigned to 2 groups (n=30): I -no oil contamination; II -oil contamination. Contamination (0.25 mL during 10 s) was performed after 37% phosphoric acid etching with an air/oil spray. The specimens were randomly assigned to subgroups, according to the bonding protocol adopted: subgroup A -F was applied to enamel without an intermediate bonding agent layer; In subgroups B and C, SB and PB, respectively, were applied, light-cured, and then F was applied and light-cured. Shear bond strength was tested at a crosshead speed of 0.5 mm/min in a universal testing machine. Means (± SD) in MPa were: IA-11.28 (±1.84); IIA-12.02 (±1.15); IB-9.73 (±2.38); IIB-9.62 (±2.29); . It may be concluded that the oil contamination affected negatively the sealant bonding to enamel and the acetone-based adhesive system (PB) layer applied underneath the sealant was able to prevent its deleterious effects to adhesion.

Myelomeningocele (MMC) is a congenital malformation that occurs in the embryonic period, characterized by failure in closure of the caudal portion of the neural tube during central nervous system formation. Alterations and complications can be associated with this condition, such as hydrocephalus, neurogenic bladder, orthopedic problems, and motor and cognitive impairment. This patients with MMC also have predisposition to develop latex allergy and high caries risk and activity due to deficient oral hygiene, fermentable carbon hydrate-rich diet and prolonged use of sugar-containing oral medications. This paper reports the oral findings and dental treatment in a 15-year-old female patient diagnosed with MMC and describes the strategies used to improve dental treatment conditions and reduce the impact of associated risks to her health. The measures and precautions adopted in this case could be useful to reduce the barriers for patients with the same condition to access oral health care: regular visits to the dentist, initiating as early as possible; frequent reinforcement of oral homecare instructions and diet counseling; minor adaptions to the dental chair and dental office to improve ease of access due to patients' mobility problems; prevention of latex-related allergic reactions; reduction of gag reflex during dental procedures.

This study evaluated in vitro the influence of thermocycling and water storage (WS) on the shear bond strength (SBS) of composite resin in cavities prepared in primary tooth enamel with conventional bur or Er:YAG laser. The test surfaces were obtained from 48 primary molars and randomly assigned to 2 groups (n=24), according to cavity preparation: A: bur-preparation and B: Er:YAG laser irradiation. The specimens were restored with an etch-and-rinse adhesive system and composite resin. Each group was divided into 4 subgroups (n=6) according to WS duration and number of thermal cycles (TCs): I: 24 h WS/no thermocycling; II: 7 days WS/500 TCs; III: 1 month WS/2,000 TCs; IV: 6 months WS/12,000 TCs. The specimens were tested to failure in shear strength at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by two-way ANOVA and Tukey's test. SBS means (S.D.) in MPa were: AI: 17.45 (2.03), AII:16.38 (1.49), AIII: 6.88 (0.66), AIV: 7.77 (1.53), BI: 12.32 (0.99), BII: 15.37 (2.24), BIII: 15.05 (2.01) and BIV-5.51 (1.01). WS duration and number of TCs influenced significantly the SBS values only for BIV (p<0.05). AI presented the highest SBS value, which was statistically similar to those of AII, BII and BIII. In conclusion, the adhesion of an etch-and-rinse adhesive to Er:YAG laser-irradiated primary tooth enamel was affected by the methods used to simulate degradation of the adhesive interface only when 6 months WS/12,000 TCs were employed.

Crown dilaceration of permanent teeth occurs due to the non-axial displacement of the already formed hard tissue portion of the developing crown at an angle to their longitudinal axis due to trauma to the primary predecessors. This is a rare condition, representing only 3% of the total of injuries to developing teeth and usually occurs in permanent maxillary incisors because of the close proximity of their tooth germs to the primary incisors, which are more susceptible to trauma. This alteration frequently results from the intrusion of a primary tooth when the child is around 2 years of age, at which time half of the crown of the permanent successor is already formed. Teeth with dilacerated crowns may either erupt with buccal or lingual displacement or remain impacted. The treatment may involve endodontic, orthodontic, restorative and prosthetic procedures. This paper reports the restorative treatment proposed to reestablish the esthetics and function of the affected teeth in three cases of crown dilaceration in permanent maxillary incisors after trauma to their primary predecessors.

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Dedicatória À Deus por ter me guiado, me protegido e iluminado meu caminho. Obrigada pelos exemplos que recebi, e pela força que me deu os momentos de desânimos. À meus pais José Antonio Mellara e Julita Maria de Siqueira Mellara, por ser os dois grandes pilares da minha vida. Pelo amor incondicional e por todo apoio que me deram nesses anos. Pelos ensinamentos e exemplo de vida. O incentivo, dedicação e ainda mais pela fé que depositaram em mim, por ser essas pessoas que me fazem ir sempre para frente. Este esforço e esta conquista são seus também. Simplesmente eu os amo. E essa conquista é tão de vocês quanto minha. Ao meu irmão Thiago de Siqueira Mellara, pelo apoio, amor, força e incentivo. Agradeço por poder dividir com você várias coisas da minha vida. Amo você! Ao meu namorado Rafael Candido Pedroso e Silva que me apoiou, incentivou e me deu forças para continuar, mesmo nas horas de desanimo.