Shear bond strength evaluation of bonded molar tubes on fluorotic molars.

OBJECTIVE: To study the shear bond strength (SBS), sites of failure, and micromorphology of bonded molar tubes used on teeth affected by dental fluorosis. MATERIALS AND METHODS: This in vitro study included 140 first molars classified according to Dean's index for dental fluorosis. Samples were divided into seven groups: (1) healthy teeth etched for 15 seconds, (2) teeth with moderate fluorosis (MOF) etched for 15 seconds, (3) teeth with MOF etched for 150 seconds, (4) teeth with MOF microabrasion etched for 15 seconds, (5) teeth with severe fluorosis (SEF) etched for 15 seconds, (6) teeth with SEF etched for 150 seconds, and (7) teeth with SEF microabrasion etched for 15 seconds. All samples were incubated and were then submitted to the SBS test and evaluated with the modified adhesive remnant index (ARI) and analyzed by using a scanning electronic microscope. RESULTS: The SBS mean value for healthy enamel was 20 ± 10.2 MPa. For the group with MOF, the etched 150-second mean value was the highest (19 ± 7.6 MPa); for the group with SEF treated with microabrasion and etched for 15 seconds, the mean value was (13 ± 4.1 MPa). Significant differences (P ≤ .05) were found in the ARI between healthy and fluorosed groups. CONCLUSIONS: Fluorotic enamel affects the adhesion of bonded molar tubes. The use of overetching in cases of MOF and the combination of microabrasion and etching in SEF provides a suitable adhesion for fixed appliance therapy.

Analysis of the molecular structure of human enamel with fluorosis using micro-Raman spectroscopy.

The aim of this study was to analyze the molecular structure of enamel with fluorosis using micro-Raman spectroscopy and compare it with that of healthy enamel. Eighty extracted human molars were classified into four fluorosis groups according to the Thylstrup-Fejerskov Index (TFI) [TFI: 0, Healthy enamel; 1-3, mild; 4-5, moderate; 6-9, severe fluorosis]. All samples were analyzed by micro-Raman spectroscopy. The integral areas of ν(1) (960 cm(-1)) phosphate peak as well as B-type carbonate peak (1070 cm(-1)) were obtained to analyze structural differences among the specimens. Although the differences were not statistically significant (P > 0.05), the mean of integral areas of ν(1) phosphate peak among groups indicated greater mineralization in the severe fluorosis group. However, there were statistically significant differences in the intensities, and the integral areas of B-type carbonate peak among groups (P < 0.05). Therefore, mineralization of the carbonate peak at 1070 cm(-1) decreased significantly in fluorotic groups, suggesting that carbonate ions are easily dissolved in the presence of fluoride. Although structurally fluorotic teeth are not more susceptible to dental caries, serious alteration in its surface topography may cause retention of bacterial plaque and formation of enamel caries. Micro-Raman spectroscopy is a useful tool for analyzing the molecular structure of healthy and fluorotic human enamel.

Nanostructure evaluation of healthy and fluorotic dentin by atomic force microscopy before and after phosphoric acid etching.

The aim was to characterize by atomic force microscopy (AFM) the nanostructure of human dentin surfaces affected by dental fluorosis (DF) before and after phosphoric acid etching. This study included 240 human dentin samples classified according to the severity of DF, which were divided into four groups using the Thylstrup-Fejerskov Index (TFI). Samples were analyzed by AFM before and after acid etching for 15, 30, and 60 s. The roughness (R(a)) for healthy dentin, and dentin with mild, moderate, and severe fluorosis were 440 nm, 442 nm, 445 nm, and 449 nm, respectively. After 15, 30, and 60 s of acid etching, all healthy and fluorotic dentin samples increased in roughness (p<0.05). The diameter of dentinal tubule orifices (D(t)) in healthy human dentin increased after acid etching for 60 s. We conclude that effective etching times are 15 s for healthy and mild dentin fluorosis, 30-s for moderately fluorosed dentin, and 45-60 s for severe fluorotic dentin.

Characterization of healthy and fluorotic enamel by atomic force microscopy.

The aim was to characterize the external structure, roughness, and absolute depth profile (ADP) of fluorotic enamel compared with healthy enamel. Eighty extracted human molars were classified into four groups [TFI: 0, control (C); 1-3, mild (MI); 4-5, moderate (MO); 6-9, severe fluorosis (S)] according to the Thylstrup-Fejerskov Index (TFI). All samples were analyzed by atomic force microscopy.The mean values of enamel surface roughness (ESR) in nm were: Group C, 92.6; Group MI, 188.8; Group MO, 246.9; and Group S, 532.2. The mean values of absolute depth profile in nm were: C, 1,065.7; MI, 2,360.7; MO, 2,536.7; and S, 6,146.2. The differences between mean ESR and mean ADP among groups were statistically significant (p < 0.05). This structural study confirms at the nanometer level that there is a positive association between fluorosis severity, ESR, and ADP, and there is an association with the clinical findings of fluorosis measured by TFI as well.

Atomic force microscopy observation of the enamel roughness and depth profile after phosphoric acid etching.

The aim was to compare the enamel surface roughness (ESR) and absolute depth profile (ADP) (mean peak-to-valley height) by atomic force microscopy (AFM) before and after using four different phosphoric acids. A total of 160 enamel samples from 40 upper premolars were prepared. The inclusion criterion was that the teeth have healthy enamel. Exclusion criteria included any of the following conditions: facial restorations, caries lesions, enamel hypoplasia and dental fluorosis. Evaluations of the ESR and ADP were carried out by AFM. The Mann-Whitney U-test was used to compare continuous variables and the Wilcoxon test was used to analyze the differences between before and after etching. There were statistically significant differences (P

Dental treatment under general anesthesia in healthy and medically compromised developmentally disabled children: a comparative study.

AIM: To compare the type, number of procedures and working time of dental treatment provided under dental general anesthesia (DGA) in healthy and medically compromised/developmentally disabled children (MCDD children). DESIGN: This cross-sectional prospective study involved 80 children divided into two groups of 40 children each. Group 1 consisted of healthy and Group 2 consisted of MCDD children. RESULTS: Healthy children needed more working time than MCDD children, the means being 161 +/- 7.9 and 84 +/- 5.7 minutes, respectively (P = 0.0001). Operative dentistry and endodontic treatments showed a significant statistical difference (P = 0.0001). The means of procedures were 17 +/- 5.0 for healthy children and 11 +/- 4.8 for MCDD children (P = 0.0001). CONCLUSIONS: Healthy children needed more extensive dental treatment than MCDD children under DGA. The information from this sample of Mexican children could be used as reference for determining trends both within a facility as well as in comparing facilities in cross-population studies.

A new classification system for dental treatment under general anesthesia.

The provision of comprehensive care for patients with special needs using dental general anesthesia (DGA) has changed over time, and now includes more complex procedures and the participation of many services. As a result, it is necessary to integrate, organize and describe all of the procedures that are carried out in different DGA settings. The aim of this study was to propose a systematic classification for dental treatment procedures be delivered under DGA, and to compare this classification system with an existing system. This new classification system has three distinct components: type, frequency and length of time needed to complete dental procedures for both primary and permanent teeth. A wide range of oral surgery procedures and endodontic treatment was also included. A retrospective cohort study utilizing 84 subjects was used to develop and compare the two classification systems. When comparing the different categories of procedures by both classifications, there were significant statistical differences between them (p < 0.05). Oral health care for patients with special needs has evolved, with more complex and extensive interventions that require teamwork by personnel from different dental or medical specialties. The classification system in this study includes detailed information regarding the procedures involved in the DGA. This helps to provide a clear understanding and specific information that enables the comparison of clinical experiences across populations where a DGA has been used for patients with special needs.

Oral rehabilitation under dental general anesthesia, conscious sedation, and conventional techniques in patients affected by cerebral palsy.

The purpose of this report is to find the use of different alternatives for dental treatment, from general anesthesia to conventional techniques, in patients affected by cerebral palsy (CP) in a dental school setting. The sample was divided into two groups: (1) children, and (2) adolescents and young adults; 38 patients (20 female and 18 male) with diagnostic of CP were included. Risks and benefits of conscious sedation and general anesthesia were written into a consent form and these were discussed with parents or guardians of each affected patient. The mean age was 7.14+/-2.2 years for children's group and 18.5+/-3.06 years for adolescent and young adult group. Most children (77.3%) were classified as ASA II with a level of behavior I-II according to Frankl's scale and these patients were treated under general anesthesia (GA). For patients that were classified as of positive behavior with little necessity of dental procedures, independent of the medically compromised level, dental treatment was done with conventional techniques or with conscious sedation. Dental frequency procedures were as follows: composites, dental prophylaxis, and dental extractions in children; in adolescents and adults, important to point out is that in anterior teeth and molars endodontic treatment, and surgical procedures increased in frequency. The mixture sevoflurane-propofol worked well during pre-, peri-, and post-operative procedures. During the discharge process, most patients needed a recovery of 20-40 minutes after which they were awake and oriented, breathing comfortably with stable vital signs. It was concluded that GA with sevoflurane-propofol and conscious sedation are an excellent tool to provide dental treatment in CP patients in a dental school setting without most of the major postoperative complications, such as nausea and vomiting.