Radiographic diagnosis of incipient proximal caries: an ex-vivo study

The aim of this ex vivo study was to compare visual clinical and radiographic examinations to the histological analysis for proximal caries diagnosis in extracted permanent molars and premolars. The relationship between clinical aspects and carious lesions was also evaluated. Eighty-eight proximal surfaces (44 freshly extracted teeth) were longitudinally sectioned with a 370-microm diamond disk, thinned with wet silicon carbide paper and observed with a stereomicroscope at x40 magnification. Sensitivity and specificity were 65.6% and 83.3% for clinical examination and 29.7% and 95.8% for radiographic examination, respectively. Kappa values ranged from 0.64 to 0.91. The white spots corresponded to lesions restricted to enamel, while the dark spots corresponded to lesions that reached the dentinoenamel junction. In most cases, cavitation corresponded to dentin lesions. It may be concluded that interproximal radiographic examination is not a reliable method for detection of incipient proximal carious lesions.     

Progressive dental development in regional odontodysplasia

Regional odontodysplasia (RO), also known as ghost teeth, is an unusual nonhereditary developmental anomaly of tooth formation that characteristically affects enamel and dentin formation of the primary and/or permanent dentition. In the present paper, we report a case of RO affecting a 7-year-old boy, with 9 years of follow-up. During this time, progressive development of dental tissue was observed, including complete root formation. However, delayed dental eruption was evident. In view of these findings, we discuss the clinical presentation, pathogenesis, differential diagnosis, and treatment of RO.     

The effect of one session of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis

Supragingival plaque control is a requisite for the success of any periodontal procedure. However, little is know about the effect of this procedure alone on periodontitis. The aim of this study was to determine the effect of supragingival plaque control on clinical and biochemical parameters of chronic periodontitis. Twenty-five subjects exhibiting at least 4 pockets > 5mm, non-smokers and with no relevant systemic diseases, were selected for the study. The clinical and biochemical assessments were done before and 21 days after removal of plaque retentive factors, extraction of affected teeth and instruction in oral hygiene. The statistical analysis was done with the Student paired t-test (p<0,05) and demonstrated a reduction on the percentage of sites with bleeding on probing from 42.72 ± 15.83 to 35.87 ± 13.30 (p=0.002). Reduction in probing depth was detected on anterior teeth (initial/final mean: 2.88 mm/2.78 mm; p=0.01) and interproximal sites (initial/final mean: 3.80 mm/3.65 mm; p=0.001). There was an increase from 66.81% to 68.65% in the number of sites with probing depth of 1 to 3mm and a decrease from 26.21% to 24.17% in those with probing depth of 4 to 6mm. The BAPNA results showed a decrease from 51.44 ± 20.78 to 38.64 ± 12.34 (p=0.04). This study demonstrated that supragingival plaque control provides a reduction in gingival inflammation and alterations in the subgingival microflora detected by the BAPNA test.     

Intracanal reinforcement fiber in pediatric dentistry: a case report.

A technique for the restoration of carious primary maxillary incisors using indirect resin composite crowns and intracanal reinforcement fiber is described. Endodontic treatment was previously performed on each tooth. The advantages of using an intracanal reinforcement fiber include resin composite crown reinforcement, translucency, and relative manipulation facility. In addition, the use of indirect resin composite crowns provides good shape and esthetics, as well as reduced chair time for the child. The technique is illustrated in a case report in which indirect resin composite crowns and an intracanal reinforcement fiber are placed in a 3-year-old girl.     

Speech intelligibility of patients with cleft lip and palate after placement of speech prosthesis.

OBJECTIVE: To evaluate the speech intelligibility of patients with clefts before and after placement of a speech prosthesis. DESIGN: Cross-sectional. SETTING: Hospital for Rehabilitation of Craniofacial Anomalies, University of S?o Paulo (HRAC/USP), Bauru, Brazil. PATIENTS: Twenty-seven patients with unoperated cleft palate or operated cleft palate presenting with velopharyngeal insufficiency (VPI) after primary palatoplasty, treated with speech prosthesis, aged 8 to 63 years. INTERVENTIONS: Patients were fitted with palatopharyngeal obturators or pharyngeal bulbs, suitable to their dental needs. Five speech-language pathologists blindly evaluated speech samples of the patients with and without the prosthesis. MAIN OUTCOME MEASURES: Classification of speech samples according to a scoring system developed for speech intelligibility problems: 1 (normal), 2 (mild), 3 (mild to moderate), 4 (moderate), 5 (moderate to severe), and 6 (severe). Results were evaluated by the calculation of means of all judges for each patient in both situations. RESULTS: The judges presented significant agreement (W=.789, p<.01). Speech intelligibility was significantly better after placement of the prosthesis for both unoperated patients (Z=1.93, p=.02) and operated patients with VPI after primary palatoplasty (Z=1.78, p=.03). CONCLUSIONS: Speech intelligibility may be improved by rehabilitation of patients with cleft palate using a speech prosthesis. Speech therapy is needed to eliminate any compensatory articulation productions developed prior to prosthetic management.     

Hydrophobicity of graphene as a driving force for inhibiting biofilm formation of pathogenic bacteria and fungi

Objective

To evaluate the surface and wettability characteristics and the microbial biofilm interaction of graphene coating on titanium.

Vibrational study of adsorbed phosphate ions on rhodium single crystal electrodes

The adsorption of H₂PO₄^? ions was studied on low Miller index rhodium single crystal electrodes by in situ FTIR spectroscopy. It is found that for Rh(1 0 0) and Rh(1 1 0), H₂PO₄^? ions are the major species at low potentials, but at higher potentials, some of the H₂PO₄^? ions undergo a potential induced deprotonation and probably there is a mixture of H₂PO₄^? and HPO₄^2? ions. On Rh(1 1 1) the deprotonation starts at very low potentials and at higher potentials the H₂PO₄^? is fully converted to HPO₄^2?. The behavior of the band center and of the band intensity with the applied potential was also analyzed. It is found that the adsorption increases from 0.08 V vs. a Pd–H₂ electrode up to 0.5 V and then it decreases when the OH starts to be adsorbed.     

Bone density around titanium implants may be influenced by intermittent cigarette smoke inhalation: a histometric study in rats

PURPOSE: This study investigated the influence of cigarette smoke on bone healing around titanium implants placed in rats. MATERIALS AND METHODS: After administration of anesthesia, the tibia surface was exposed and screw-shaped titanium implants (4.0 mm in length and 2.2 mm in diameter) were placed bilaterally (1 each side). The animals (n = 32) were randomly assigned to either group 1 (control, n = 18) or group 2 (intermittent cigarette smoke inhalation, n = 14). After 60 days, the animals were sacrificed and undecalcified sections obtained. Bone density (the proportion of mineralized bone in a 500-microm-wide zone lateral to the implant) was measured in the cortical (zone A) and cancellous bone (zone B) areas. RESULTS: In zone A, a slight difference in bone density was noted between the groups (96.18% +/- 1.08% and 95.38 +/- 1.17% in groups 1 and 2, respectively; P > .05) but was not statistically significant. In contrast, bone density was significantly decreased in zone B in the animals that were exposed to cigarette smoke (17.57 +/- 6.45% and 11.30 +/- 6.81% for groups 1 and 2, respectively; P < .05). DISCUSSION: Whether different results would be observed if animals were exposed to cigarette smoke for a longer period of time and/or before implant placement remains to be investigated. CONCLUSION: Although intermittent cigarette smoke exposure may not seriously affect cortical bone density, it may jeopardize bone quality around titanium implants in the cancellous bone area.     

Effect of estrogen replacement and calcitonin therapies on bone around titanium implants placed in ovariectomized rats: a histometric study

PURPOSE: The aim of the present study was to evaluate whether hormone replacement therapy (HRT) and calcitonin (CT) administration could influence bone healing around implants placed in ovariectomized (OVX) rats. MATERIALS AND METHODS: One screw-type titanium implant was placed bilaterally in OVX rats. The animals were assigned to one of the following groups: group 1 (n = 15), sham surgeries; group 2 (n = 15), OVX rats; group 3 (n = 14), OVX rats administered CT 4 days/week (16 IU/kg); group 4 (n = 14), OVX rats administered 17beta estradiol daily (20 microg/kg). After 60 days, the animals were sacrificed and undecalcified sections obtained. Bone-to-implant contact (BIC) and bone area (BA) around the implants were determined separately for the cortical (zone A) and cancellous (zone B) bone areas. RESULTS: In zone A, intergroup analysis did not reveal a significant difference regarding BIC. In contrast, the HRT group (group 4) presented greater BA than groups 2 and 3 (P < .05). Data from zone B revealed that HRT eliminated the negative effect of the ovariectomy on BIC and BA (P < .05), while CT had no effect (P > .05). DISCUSSION: It was the first study to evaluate and demonstrate the impact of HRT and CT on bone around titanium implants in an estrogen-deficient model. CONCLUSION: Within the limits of the present study, it may be concluded that HRT may prevent the influence that estrogen deficiency exerts on bone healing around titanium implants.     

Resistance to maxillary premolar fractures after restoration of class II preparations with resin composite or ceromer.

OBJECTIVE: The aim of this study was to evaluate the resistance to fracture of intact and restored human maxillary premolars. METHOD AND MATERIALS: Thirty noncarious human maxillary premolars, divided into three groups of 10, were submitted to mechanical tests to evaluate their resistance to fracture. Group 1 consisted of intact teeth. Teeth in group 2 received mesio-occlusodistal cavity preparations and were restored with direct resin composite restorations. Teeth in group 3 received mesio-occlusodistal cavity preparations and were restored with ceromer inlays placed with the indirect technique. After restoration, teeth were stored at 37 degrees C for 24 hours and then thermocycled for 500 cycles at temperatures of 5 degrees C and 55 degrees C. RESULTS: Statistical analysis revealed that group 3 (178.765 kgf) had a significantly greater maximum rupture load than did group 1 (120.040 kgf). There was no statistically significant difference between groups 1 and 2 or between groups 2 and 3. CONCLUSION: Class II cavity preparations restored with indirect ceromer inlays offered greater resistance to fracture than did intact teeth. The fracture resistance of teeth restored with resin composite was not significantly different from that of either the ceromer or intact teeth.