In Vitro Evaluation of the Stabilization Time of Chemical Bonds During Setting Reaction and Microhardness of Preheated Glass-Ionomer Cements.

OBJECTIVES: To evaluate the effect of preheating glass-ionomer cement (GIC) restorative materials on stabilization time (ST) of their metal carboxylate bonds and on microhardness. METHODS AND MATERIALS: Two conventional high-viscosity GICs, Ketac Universal (3M ESPE) and Equia Forte (GC), were evaluated. The thermographic camera was used to measure the temperature inside the glass-ionomer cement capsules before and after heating. The preheating of capsules was performed at 54°C for 30 seconds in a commercial device. Characterization of ST in the GICs was determined by Fourier Transform Infrared (FTIR) spectroscopy. For this, 10 samples of each material were prepared, five in the non-preheated group (control) and five with preheating. FTIR spectra were obtained 10 minutes after mixing (control group) or after heating and then every 10 minutes for 120 minutes. For the microhardness test, 20 cylindrical specimens (3 mm height x 6 mm diameter) were prepared for each material (10 preheated, 10 control). The microhardness was determined at three time intervals: 10 minutes after mixing, after the ST as detected through the FTIR part of the study, and after one week. Knoop microhardness was assessed using a diamond indenter with a 25 g load and 15 seconds dwell time. RESULTS: Ketac Universal showed an increase in temperatures of 15.7°C for powder and 3.6°C for liquid, while Equia Forte showed 16.4°C for powder and 8.5°C for liquid. FTIR spectra indicated that preheating reduced the ST for Equia Forte but increased it for Ketac Universal. Preheating increased the initial microhardness (T1) of Equia Forte. With maturation over one week, it was observed that preheating significantly improved the microhardness of both materials compared with the control specimens. CONCLUSION: Preheating influenced the ST and the microhardness of Ketac Universal and Equia Forte. The ST and microhardness of Ketac Universal increased after seven days, whereas Equia Forte showed a reduced ST and increased microhardness from the outset.

Effects of Bioactive Agents on Dentin Mineralization Kinetics After Dentin Bleaching.

OBJECTIVES: This study evaluated effects of Bioglass 45S5 (BG) and Biosilicate (BS) remineralization on the chemical composition and bond strength of control dentin (CD) and bleached dentin (BD) surfaces. METHODS AND MATERIALS: Dentin bleaching treatment was performed using the walking bleaching technique with 0.01 g of sodium perborate and 0.5 mL of 3% hydrogen peroxide for 14 days. Remineralization treatment was carried out by rubbing a remineralization solution (0.015 g of BG or BS diluted in 1.35 mL of distilled water) on the etched dentin surface for 30 seconds. Micro-Raman spectroscopy (MRS) was used to quantitatively analyze the mineral matrix ratios of CD and BD (n=5) after remineralization treatment with BG and BS over 15 days of incubation in artificial saliva. The CD and BD discs (n=10) with and without remineralization treatment with BG and BS were restored using a two-step etch-and-rinse adhesive system (Optibond S, Kerr) and five layers of 1-mm-thick composite resin (Filtek Z250, 3M ESPE). The restored dentin discs were sectioned into nine bonded beams with cross-sectional areas of approximately 0.9 mm2 and tested for microtensile bond strength (µTBS). The dentin surface of one fractured beam per tooth was submitted to MRS to characterize the physicochemical composition (n=10) at the interface. The data were analyzed using one-way analysis of variance and the Tukey-Kramer post hoc test (p<0.005). RESULTS: MRS bioactive analyses revealed that both BG and BS promoted increased mineral matrix ratios in the CD and BD. Significantly higher µTBS values were found after CD treatment with BG (CD: 57 MPa±11; CD-BG: 78 MPa±15) and when BG and BS were applied to the BD (BD: 42 MPa±5; BD-BG: 71 MPa±14; BD-BS: 64 MPa±11) (p<0.005). The MRS analysis of the fractured dentin beam showed that the remineralization treatment significantly increased the dentin relative mineral concentration and promoted the appearance of new interface peaks, indicating a chemical interaction (p<0.005). CONCLUSION: Remineralization of BD is an effective therapy to restore damage caused by dentin bleaching and acid conditioning. This approach not only increases dentin mineral compounds but also improves dentin's ability to interact chemically with the adhesive system.

Minimally Invasive Adhesive Rehabilitation for a Patient With Tooth Erosion: Seven-year Follow-up.

Tooth wear is a multifactorial condition of growing concern. In clinical practice, it is often a challenge for prevention and treatment since many etiological factors may be involved. This case report describes an esthetic rehabilitation of a young patient presenting tooth wear due to erosion. The etiological factor of this case was the patient sucking on lemons, an acidic fruit. The main complaint of the patient was the appearance of short maxillary incisors. The treatment involved orthodontic and restorative dentistry techniques. First of all, an orthodontic device was used to increase the vertical dimension of occlusion and create an adequate space for the direct restorations. The posterior teeth were restored with two direct composite resin techniques; the anterior teeth were then restored using a balanced occlusion. The seven-year follow-up of the case is presented. Replicas of the restorations were made and visualized under scanning electron microscopy up to the 12-month evaluation. In the clinical follow-up at seven years, maintenance of the results and restorations can be clearly seen.

Chemical Interaction and Interface Analysis of Self-Etch Adhesives Containing 10-MDP and Methacrylamide With the Dentin in Noncarious Cervical Lesions.

OBJECTIVES: To characterize the chemical interactions and analyze the interface of adhesive systems containing 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) and N-methacryloyl glycine (methacrylamide) functional monomers with the dentin in noncarious cervical lesions (NCCLs) compared with artificial defects (ADs). METHODS AND MATERIALS: Twenty human teeth with natural NCCLs on the buccal surface were used. Class V cavities, similar to NCCLs, were created on the lingual surface to serve as controls. Teeth were randomly allocated to two groups according to the functional monomer in the adhesive (N=10): G1, 10-MDP; and G2, methacrylamide. NCCLs and ADs were characterized by their mineral composition (MC) and degree of demineralization (DD) using micro-Raman spectroscopy, adhesive/dentin chemical interactions (CIs) were assessed with infrared photoacoustic spectroscopy, and interface morphology was evaluated with scanning electron and light microscopy. MC, CI, and DD data were submitted to Shapiro-Wilk and Student t-tests ( p<0.05). RESULTS: Compared with ADs, dentin in NCCLs was hypermineralized ( p<0.05). In G1, CI, and DD in the first 2 µm, and adhesive projections in NCCLs and ADs interfaces were similar. Additionally, a thin layer of dentin collagen was observed in ADs, while it was hardly present in NCCLs. In G2, although CI could not be identified, changes in the mineral components were observed. The DD in the ADs and NCCLs were statistically similar, while SEM showed a lack of adhesion at NCCLs interface. DD and collagen exposure in the ADs and NCCLs were more pronounced than in G1. CONCLUSIONS: Results suggest that the G1 adhesive could be applied directly on the superficial sclerotic layer in NCCLs. In contrast, previous cavity preparation should be conducted to improve the micromechanical interaction of G2 with the dentin.

Chemical Interaction Analysis of an Adhesive Containing 10-Methacryloyloxydecyl Dihydrogen Phosphate (10-MDP) With the Dentin in Noncarious Cervical Lesions.

The purpose of this study was to evaluate the chemical bonds of a self-etch 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) adhesive to natural noncarious cervical lesions (NCCLs) and compare them with those occurring in sclerotic dentin in artificially prepared defects (APDs). Four human teeth with natural NCCLs on the buccal surface were selected. Artificial defects matching the natural lesions were prepared on the lingual surface of the same teeth serving as control. Micro-Raman (MR) spectroscopy was used to quantify mineral content in natural NCCLs and in APDs. Fourier transform infrared-photoacoustic spectroscopy (FTIR-PAS) readouts were taken before and after adhesive application to analyze the protein matrix/mineral (M:M) ratio and chemical interactions between 10-MDP adhesive and dentin. The MR and FTIR-PAS spectra collected from natural NCCLs demonstrated a larger area of the band (961 cm-1, PO4) and lower M:M ratio, respectively, characterizing a hypermineralized dentin, compared with APDs. FTIR-PAS demonstrated emergence of a peak (1179 cm-1, P=O) in spectra after adhesive treatment, demonstrating a more intense chemical interaction in natural NCCLs. The results demonstrated that chemical bonding of 10-MDP adhesive to natural NCCLs is more intense, due to the hypermineralized surface, and suggest that it is unnecessary to remove the hypermineralized layer with burs, as this may decrease the chemical bonding potential of 10-MDP.

Penetration of hydrogen peroxide and degradation rate of different bleaching products.

This study's aim was to evaluate the degradation rate of hydrogen peroxide (H2O2) and to quantify its penetration in tooth structure, considering the residence time of bleaching products on the dental enamel. For this study, bovine teeth were randomly divided according to the bleaching product received: Opalescence Xtra Boost 38%, White Gold Office 35%, Whiteness HP Blue 35%, Whiteness HP Maxx 35%, and Lase Peroxide Sensy 35%. To analyze the degradation of H2O2, the titration of bleaching agents with potassium permanganate was used, while the penetration of H2O2 was measured via spectrophotometric analysis of the acetate buffer solution, collected from the artificial pulp chamber. The analyses were performed immediately as well as 15 minutes, 30 minutes, and 45 minutes after product application. The data of degradation rate of H2O2 were submitted to analysis of variance (ANOVA) and Tukey tests, while ANOVA and Fisher tests were used for the quantification of H2O2, at the 5% level. The results showed that all products significantly reduced the concentration of H2O2 activates at the end of 45 minutes. It was also verified that the penetration of H2O2 was enhanced by increasing the residence time of the product on the tooth surface. It was concluded that the bleaching gels retained substantial concentrations of H2O2 after 45 minutes of application, and penetration of H2O2 in the dental structure is time-dependent.

Hydrogen peroxide diffusion dynamics in dental tissues.

The aim of this study was to investigate the diffusion dynamics of 25% hydrogen peroxide (H2O2) through enamel-dentin layers and to correlate it with dentin's structural alterations. Micro-Raman Spectroscopy (MRS) and Fourier Transform Infrared Photoacoustic Spectroscopy (FTIR-PAS) were used to measure the spectra of specimens before and during the bleaching procedure. H2O2 was applied to the outer surface of human enamel specimens for 60 minutes. MRS measurements were performed on the inner surface of enamel or on the subsurface dentin. In addition, H2O2 diffusion dynamics from outer enamel to dentin, passing through the dentin-enamel junction (DEJ) was obtained with Raman transverse scans. FTIR-PAS spectra were collected on the outer dentin. MRS findings revealed that H2O2 (O-O stretching µ-Raman band) crossed enamel, had a more marked concentration at DEJ, and accumulated in dentin. FTIR-PAS analysis showed that H2O2 modified dentin's organic compounds, observed by the decrease in amides I, II, and III absorption band intensities. In conclusion, H2O2 penetration was demonstrated to be not merely a physical passage through enamel interprismatic spaces into the dentinal tubules. H2O2 diffusion dynamics presented a concentration gradient determined by the chemical affinity of the H2O2 with each specific dental tissue.

[Cystic lymphangioma of the abdominal wall in childhood: case report]. / Linfangioma cistico della parete addominale in età pediatrica. Caso clinico.

Intra-abdominal lymphangiomas are rare benign tumours that can cause various symptoms, mainly during childhood. They are diagnosed by ultrasonography, CT scanning or at laparotomy; ultrasonographic examination often shows a voluminous tumoral cystic formation with septa. The location of the cyst may be determined either by ultrasonography alone or by CT scanning. The definitive histological diagnosis is confirmed by immunohistochemical staining techniques. Rarely intra-abdominal lymphangiomas can occur in the abdominal wall. Complete resection is the treatment of choice. The case of a 2-year-old-boy with a large lymphangioma involving the lower half of the abdominal wall is reported. The patient underwent the complete removal of lymphangioma with good cosmetic result.

Single-lead VDD-pacing system incorporating high impedance stimulation: a multicentre study.

AIM: The purpose of this study was to evaluate the performance of a new VDD pacing system incorporating a high impedance, single-pass VDD lead. The new lead is a bipolar, steroid-eluting, high impedance lead with a full-ring atrial dipole. METHODS AND RESULTS: The system was implanted in 46 patients with high degree atrioventricular (AV) block. Patients were followed at pre-discharge, 6 weeks, and 3 months. The mean measured P-wave amplitude was stable, with values between 1.18 and 1.43 mV. Atrial sensing was reliable during short-term evaluation at rest and in the sitting position, with AV-synchronous stimulation between 98.79 +/- 6.90% and 99.73 +/- 1.47%. Holter recordings after 6 weeks demonstrated AV-synchronous stimulation in 99.57 1.03% of all P-waves. Lead impedance was stable during follow-up, with mean values between 1000 and 1167 Q. Mean ventricular pacing thresholds (at 0.5 ms) were 0.47 V at implant, 0.49 V at pre-discharge, 0.74 V at 6 weeks, and 0.72 V at 3 months. R-wave amplitude remained stable between 14.9 and 16.7 mV during follow-up. CONCLUSION: This new single-pass VDD lead system provided reliable atrial sensing and stable high impedance stimulation during a 3-month follow-up period.

[The treatment of phimosis in childhood without circumcision: plastic repair of the prepuce]. / Studio per il trattamento della fimosi in età pediatrica senza circoncisione: la plastica del prepuzio.

BACKGROUND: To device a new surgical technique of preputial plasty for the treatment of phimosis, as an alternative to circumcision, easy to perform, which preserves the normal function of the prepuce. METHODS: The new technique consists of three lengthwise incisions of the stenosing wase and their diagonal suture, the triple incision preputial plasty, described by others, modified adding frenulotomy and two more incisions between the previous ones, which are left to heal spontaneously. This technique has been applied on 22 children over a period of 24 months, with a follow-up of six-twenty-four months. RESULTS: The technique is easy to perform. All check-ups show good cosmetic results, no recurrence, normal preputial anatomy and function. It is important to continue "preputial gymnastics" until stabilization. CONCLUSIONS: The devised technique fully succeeds in preserving a normal prepuce, it is easier to perform and safer than other preputial plasties and it may be carried out in all cases of phimosis in pediatrics. The good results achieved encourage us to continue along this path, hoping that the technique will be largely applied.

Effect of nail varnishes and petroleum jelly combinations on glass ionomer dye uptake.

PURPOSE: To evaluate the effectiveness of different brands of nail varnish alone or associated with petroleum jelly as surface protectors for glass ionomer cements by determining dye uptake spectrophotometrically. MATERIALS AND METHODS: Three hundred thirty six specimens, 3.0 mm in diameter and 1.0 mm thick, were made with Chelon-Fil (CF) and ChemFil II (CII) and divided into 14 groups for each material. Positive control (A) and negative control (B) specimens were not protected, while experimental specimens were protected with six brands of nail varnish used with and without petroleum jelly. The specimens were immersed in 0.05% methylene blue solution 10 minutes after mixing except for negative control specimens that were immersed in deionized water. RESULTS: Dye uptake (microgram dye/restoration) for CF was: A = 11.3 +/- 3.1; B = 0.0 +/- 0.0 with varnish groups ranging from 0.6 to 2.5 and for CII: A = 12.4 +/- 2.5; B = 0.0 +/- 0.0 with varnish groups ranging from 0.4 to 2.4. The data were analyzed by ANOVA. The dye uptake among the groups was not significantly different (P < 0.01), except for the control group (unprotected cements).

[Verneuil's suppurative hidradenitis. A case report]. / L'idrosadenite suppurativa di Verneuil. Contributo clinico.

The Authors reports a case of Verneuil's disease in a perineal location. They focus on etiopathogenetic aspects and problems of differential diagnosis, before reviewing the various therapeutic options. Surgery is the only effective therapy and takes the form of an extensive excision of the cutaneous zone affected with 2nd intention recovery, or a dermoepidermal auto-graft. A long follow-up is important to monitor the possible recurrence of lesions generally due to the incomplete removal of the area affected by the process.

[Motives for placement and replacement of dental restoration]. / Motivos da realização e substituição de restauraçoes dentárias.

Aiming to evaluate placement and replacement of dental restorations, a questionnaire has been elaborated and distributed in Clinics of the Operative Dentistry Department, Bauru Dental Scholl--USP, for the students to point out some information about the operatory procedures performed. The analysis of the results made possible the observation that of the 241 restorations achieved, 45.64% were made due to primary caries and 54.36% were replacement of deficient restorations. The reasons for replacement as well as the possible factors responsible for failure of tooth-colored and amalgam restorations are analyzed and discussed.

[Occlusal relation of upper canines in patients with complete unilateral clefts]. / Relação de oclusão dos caninos superiores em pacientes portadores de fissura transforame incisivo unilateral.

Aiming to evaluate the position variations of the upper canines in individuals with congenital cleft of the lip and palate which interfere in the final result of a prosthesis, we have done an analysis and a measurement of this alterations in casts of 208 patients with complete unilateral cleft before the prosthetic treatment. We have verified in the vertical direction, the infra-version and in the horizontal direction, the mesiodistal deviation of its relation of normal occlusion and the distance in relation to the mid line. The results obtained have become evident a frequent anterolateral openbite in the cleft side, besides a common deviation of the upper mid line, due to the general position of the upper canines on the side side of the cleft to the mesial.

[Role of splenectomy in Chediak-Higashi syndrome in its accelerated phase]. / Ruolo della splenectomia nella sindrome di Chediak-Higashi (SCH) in fase accelerata.

Chediak-Higashi (C.H.S.) syndrome is a rare immunodeficiency, due to defective granulocyte activity. The syndrome is characterized by large inclusion bodies in the leukocytes, albinism, photophobia, nystagmus, and recurrent infections. Some patients develop hepatosplenomegaly, lymphadenopathy, pancytopenia and widespread organ infiltrates with mononucleated cells. This phase is called "accelerated (or lymphoma-like syndrome) phase". A 5 years old girl with C.H.S. in accelerated phase received initially medical treatment without improvement. A splenectomy was performed to remove the hypersplenism and the mechanical compression of the spleen on the gut. Few days after the splenectomy the fever and the pancytopenia disappeared. The pathological examination of the spleen showed multiple intraparenchymal abscesses. Unfortunately, six months after the operation, she died after an acute episode of pneumonia, with normal hematological pattern. The splenectomy may play a role in the "accelerated phase" of C.H.S., but new treatments (bone marrow transplantation) are necessary to remove the basic disease.