Ana Helena Gonçalves de Alencar

Determination of the p-monochlorophenol residue in the calcium hydroxide + p-monochlorophenol combination used as an intracanal dressing in pulpless teeth of dogs with induced chronic periapical lesion

To determine the presence of p-monochlorophenol in the calcium hydroxide (Calen) + p-monochlorophenol combination after its use as intracanal dressing, periapical lesions were induced in 60 root canals of upper and lower premolars of four dogs. After biomechanical preparation, the root canals received the intracanal medication, which was removed from the apical third after 2, 4, 7, and 14 days for chemical analysis by spectrophotometry. The results showed a p-monochlorophenol loss of approximately 50.0% in the dressing after 48 h, with no further significant loss after longer periods of times. p-Monochlorophenol was still present in the medication after 14 days.

Microscopic evaluation of the effect of different storage media on the periodontal ligament of surgically extracted human teeth

The objective of this study was to microscopically evaluate the human periodontal ligament adhered to extracted teeth, after extra-alveolar period of 1 h using, as storage media, pasteurized milk (group I), chicken egg white (group II) and artificial saliva (group III). Forty intact premolars were selected, with indication of tooth extraction for orthodontic reasons. After the extraction of 30 teeth, they were maintained dried on a gauze at room temperature for 10 min, and then immersed in the selected storage media. After the established time, the teeth were washed with saline solution and placed in 10.0% buffered formalin. Ten teeth were extracted and immediately immersed in 10.0% neutral formalin (group IV). Thereafter, they were submitted to histological processing. After fixation and decalcification, the specimens were cut at the cervical, medium and apical thirds, inserted in paraffin and serially sectioned, with 6-mum thickness. They were stained by hematoxylin-eosin and analyzed under light microscopy. According to the results of quantitative analysis, there was no statistically significant difference in the number of cells per mm(2) between groups I, II and III. The qualitative analysis showed similar results in relation to the organization of collagen fibers and the number of cells in groups I and II, but group III displayed a higher disorganization of the collagen fibers and also a higher reduction in the number of cells. Based on these results, it was concluded that the quality of periodontal ligament was affected by the storage media, when compared with the control group. There was a statistically significant difference in the number of cells per mm(2) between the control group and groups I, II and III. There was no significant statistical difference in the number of cells per mm(2) between groups I, II and III.

Study of Anatomical Relationship between Posterior Teeth and Maxillary Sinus Floor in a Subpopulation of the Brazilian Central Region Using Cone-Beam Computed Tomography - Part 2

This study evaluated the anatomical relationship between posterior teeth root apices and maxillary sinus floor (MSF) on 202 cone beam computed tomography (CBCT) exams. The distance between the root apices and the MSF, as well as the MSF thickness of the cortical bone closest to root apices and furcation regions were measured. The vertical and horizontal relationships of the MSF with the molar roots were classified into categories adapted from the criteria proposed by Kwak et al. (14). The shortest distances between MSF and the root apices were observed in the mesiobuccal root of the second molar (0.36±1.17 mm) and the palatal root of the first molar (0.45±1.10 mm) and the widest in buccal roots of the first premolars (5.47±4.43 mm). Significant differences were observed between the distance of MSF to the root apices of single-rooted first and second premolars. The cortical thickness ranged from 0.65±0.41 mm over the mesiobuccal root of the second molar to 1.28±0.42 mm over the buccal root of the first premolar. The most observed vertical and horizontal relationships were type II and 2H, respectively. The maxillary molar roots showed greater proximity to the MSF. The thickness of the MSF cortical bone closest to the apices and furcation regions was found to be similar only for premolars.

Assessment of Oxygen Saturation in Dental Pulp of Permanent Teeth with Periodontal Disease

INTRODUCTION In individuals with periodontal disease, dental pulp status should be determined before a treatment plan is made. Pulse oximeters are promising diagnostic tools to evaluate pulp vascularization. This study used pulse oximetry to determine the level of oxygen saturation in dental pulp of intact permanent teeth with periodontal attachment loss (PAL) and gingival recession (GR) and to evaluate the correlation between periodontal disease and level of oxygen saturation in the pulp. METHODS This study included 67 anterior teeth of 35 patients; all teeth showed intact crowns, PAL, a periodontal pocket (PP), and GR. The teeth underwent periodontal examination, cold and electric pulp testing, and pulse oximetry measurements. The Pearson correlation coefficient and a linear regression coefficient were calculated to evaluate the degree of correlation between periodontal disease markers (PAL, PP, and GR) and the level of oxygen saturation in dental pulp. These tests also evaluated possible associations between oxygen saturation and cold and electric pulp testing. RESULTS PAL, PP, and GR had negative correlations with oxygen saturation in dental pulp. Conversely, no statistically significant association was found between oxygen saturation in dental pulp and the response to electric sensibility testing. CONCLUSIONS Oxygen saturation was lower in the pulp of permanent teeth with PAL, PP, and GR, indicating that periodontal disease correlates with the level of oxygen saturation in the pulp.

Oxygen Saturation in the Dental Pulp of Maxillary Premolars in Different Age Groups - Part 1

The aim of this study was to determine oxygen saturation levels in the dental pulp of maxillary premolars in different age groups. A total of 120 human maxillary premolars with normal dental pulps were selected covering the following age groups: 20-24, 25-29, 30-34, 35-39 and 40-44 years (n=24 each group). Oxygen saturation was assessed using pulse oximetry. Analysis of variance was used to assess differences in oxygen saturation levels and Tukeys test was used to identify the age groups that differed from each other. Significance was set at 0.05. Mean oxygen saturation of 120 premolars was 86.20% considering all age groups. Significantly reduced levels were found in the oldest group compared to the other groups: 40 to 44 years - 80.00% vs. 89.71, 87.67, 88.71, and 84.80% for age groups 20-24, 25-29, 30-34, 35-39 years, respectively. The mean oxygen saturation levels were similar between 20 and 39 years of age (86.20%) in the whole sample, but reduced significantly in the 40-44-year age group, suggesting that older patients present lower oxygen saturation results even in the absence of pulp tissue injury.

Oxygen Saturation in the Dental Pulp of Maxillary and Mandibular Molars - Part 2

This study determined the oxygen saturation (SaO2) in dental pulp of healthy maxillary and mandibular molars. Mean of SaO2 was evaluated in 112 maxillary and mandibular molars using pulse oximetry. Quantitative variables were described by mean and standard deviation. Variables with symmetric distribution were compared by Student t test and Mann-Whitney test. Pearsons correlation coefficient was used to correlate quantitative variables. Analysis of variance was used to assess differences in SaO2 levels between the molar groups, followed by post-hoc Tukey. The significance level established at p<0.05. Mean of oxygen saturation for the 112 molar dental pulps was 85.09%. There was no significant correlation (r=-0.007; p=0.977) between the mean of SaO2 of molar pulps with patient´s indicator finger (92.89%). There was a significant difference (p=0.037) between the mean of SaO2 of the first (85.76%) and second maxillary molars (81.87%), and it was not significant (p=0.1775) between the first and second mandibular molars. Maxillary molars had lower pulpal SaO2 (83.59%) than mandibular molars (86.89%) (p=0.018). The mean of the patients response time to the cold stimulus was 1.12 s (maxillary molars 1.25 s and mandibular molars 0.99 s)(p=0.052). There was no significant correlation between the time response of the patient to the cold stimulus and the SaO2 for molars. The mean oxygen saturation level was 85.09%. The mandibular molars presented higher SaO2 level than maxillary molars.