Evaluation of penetration effect of resin infiltrant using optical coherence tomography.

OBJECTIVE: The aims of this in vitro study were to investigate whether optical coherence tomography (OCT) could analyze infiltration of resin infiltrant (RI) into early dental caries (EC), and to confirm the correlation between the results of OCT and confocal laser scanning microscopy (CLSM) for evaluation of RI infiltration into EC. METHODS: Sound bovine permanent teeth were used to produce sixty specimens by making two windows on the teeth. Each 20 specimens were demineralized for 20, 30, and 40 days, and the RI was treated on one of the windows. As a result, the images of the fifty-two specimens were taken by OCT and CLSM. The demineralized lesion depth (LDOCT and LDCLSM) and the infiltrated depth of RI into lesion (IDOCT and IDCLSM) obtained from the OCT and the CLSM were analyzed. The correlations between the LDOCT and the LDCLSM, and between the IDOCT and the IDCLSM, were analyzed by Pearson correlation and intra-class correlation. Also, Bland-Altman plot was constructed to assess the agreement between the IDOCT and the IDCLSM, and the IDOCT divided by refractive index of RI and the IDCLSM. RESULTS: The Pearson correlation coefficient and intra-class correlation of 0.75 and 0.83 (95% CI: 0.71-0.91) respectively were confirmed between the LDOCT and the LDCLSM (p<0.001), and 0.59 and 0.71 (95% CI: 0.50-0.84) respectively were observed between the IDOCT and the IDCLSM (p<0.001). The lower bias was confirmed in Bland-Altman plot between adjusted IDOCT and the IDCLSM than between the IDOCT and the IDCLSM. CONCLUSION: The OCT was the promising quantitative evaluation method for RI penetrated into EC. CLINICAL SIGNIFICANCE: The OCT would be used as a nondestructive and real-time evaluation method for RI penetrated into EC on clinical procedure.

The analysis of characteristics of elderly people with high VSC level.

OBJECTIVE: The purpose of this study was to examine the characteristics of elderly subjects who had objectionable levels of volatile sulfur compound (VSC). SUBJECTS AND METHOD: In 2002, a total of 115 85-year-old persons in Japan were subjected to oral examinations, tongue coat collections, measurements of VSCs levels inside the mouth using a portable gas chromatography (Oral Chroma, Abilit, Japan), and assessments of quality of life (QOL) using an SF-36 questionnaire. RESULTS: Sixty-six of the subjects were edentulous and 49 were dentulous. They were divided into two groups by VSC levels, those with oral malodor (both H2S > 112 ppb and CH3SH > 26 ppb; subjects with oral malodor, OM group; n = 7) and those without (n = 108). Our results showed that tongue coat deposit amounts and proportion of dentulous subjects were significantly higher in the OM group. Further, in an analysis of QOL, the SF-36 scores for vitality, social functioning and mental health were significantly higher in OM. CONCLUSION: We found that elderly subjects with oral malodor tended to be dentulous and had large deposits of tongue coating. However, oral malodor in the OM group subjects did not appear to cause a disadvantage in their social lives.

A computer-assisted videodensitometric method to visualize mineral distributions in in vitro and in vivo formed root caries lesions.

A computer-assisted videodensitometry (CAV) method is presented for the microradiographical mineral determination and mineral visualization of in vitro and in vivo formed dentin lesions. The method employs as essential steps (1) image digitizing by a CCD camera, (2) conversion of gray values to equivalent aluminium thicknesses and (3) conversion of aluminium thickness to vol% of mineral. Procedure and accuracy are described. The CAV method is illustrated for dentin lesions formed in vitro as well as for clinical root caries lesions. The CAV method is especially advantageous for clinical lesions because it can be employed for very complex mineral distributions and irregular lesion outlines. In given areas of interest, the mineral distribution (in vol%) can be plotted in 3D form in pseudo-colors. Conventional microradiographical profiles can be obtained directly from the CAV images. For in vitro lesions, the mineral distribution parameters, lesion depth, mineral loss, and mineral acquisition values can be generated from CAV images with a reproducibility of better than 7%. The CAV method is a valuable tool in quantitative mineral studies of clinical lesions in extracted teeth as well as in in situ lesion investigations.

Major topics in quantitative microradiography of enamel and dentin: R parameter, mineral distribution visualization, and hyper-remineralization.

Three aspects of quantitative transverse microradiography are described and discussed: (1) the average mineral loss parameter of enamel or dentin lesions (R) in vol%; (2) mineral distribution visualization of lesions by means of a computer-assisted videodensitometric (CAV) method; and (3) the microradiography of hyper-remineralized lesions. "R", defined as the average amount of mineral lost (or gained) in a lesion per unit lesion length, is a useful parameter in dental caries. The results show that, in vitro, R is about constant over the demineralization period for enamel and dentin. This was found even for quite different dissolution kinetics. R is strongly reduced by the presence of small amounts of fluoride in the demineralizing system. R of dentin lesions is smaller than for enamel lesions. We conclude that the mineral loss value (delta Z) and the lesion depth (ld) are in general dependent parameters during in vitro or in situ studies on enamel or dentin. During lesion formation, mineral loss from the lesion and acid penetration in the tissue are obviously linked. This is possible only if the mineral content in the lesion does not change very much after passage of the lesion front. The CAV method presented is illustrated for enamel lesions formed in vitro and in situ.

Effect of sodium hypochlorite treatment on remineralization of human root dentine in vitro.

Dentine consists simplified of mineral and of several organic components. Sodium hypochlorite (NaOCl) is a well-known nonspecific proteolytic agent capable to remove organic material. The aim of this study was to investigate the influence of organic material removal from artificial dentine lesions by means of NaOCl pretreatment on subsequent remineralization with and without fluoride. Human root dentine samples were demineralized in an acidic gel (pH = 5) at 37 degrees C for 2 weeks. After 2 min of pretreatment with a 0.4, 2 or 10% NaOCl solution, the samples were remineralized in a 20 mM HEPES buffer (pH = 7) containing 1.5 mM Ca(2) and 0.9 mM phosphate with or without addition of 10 ppm F(-) as NaF at 37 degrees C for 8 days. Mineral profiles were assessed by means of transversal microradiography after diol treatment to avoid shrinkage caused by drying. In a separate experiments the dentine contraction caused by 10% NaOCl was assessed. The contraction (negligible for sound dentine) was found to be about 12% for the lesions. The remineralization results showed that pretreatment with a 10% NaOCl solution for 2 min, increased lesion remineralization. After NaOCl treatment, the amount of accumulated mineral increased by about 27% without F in the remineralization solution, and by about 4% with 10 ppm in solution. The in vitro results suggest that removal of organic materials from dentine lesions is an interesting approach to enhance remineralization.

The effects of a sodium hypochlorite treatment on demineralized root dentin.

The effects of a 10% NaOCl treatment for 2 min on demineralized human root dentin were investigated by means of: microradiography (MR), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and secondary ion mass spectroscopy (SIMS). MR measurements revealed that NaOCl caused a tissue contraction not related to water loss but to removal of organic substance(s), resulting in reductions of the lesion depth and mineral loss values by 15% and 42%, respectively. CLSM observations on wet dentin showed that the dentinal tubules underneath the surface are clearly observable and not deformed substantially by the NaOCl, except near the outermost surface. This indicates the importance of wet as well as of dried (high vacuum) observations. SEM micrographs (high vacuum) showed definite changes in the outer dentin surface structure; 85% of the originally open dentinal tubules were closed after NaOCl treatment. No marked changes were observed in the dentin ultrastructure inside lesions, as shown by SEM on fractured surfaces. SIMS data, pertaining to samples in high vacuum, showed a remarkable increase of chlorine (Cl) content in the entire lesion due to the NaOCl, indicating deep penetration of the original OC1 ions. The results suggest that the 2-min treatment of demineralized dentin by NaOCl solutions removes and/or changes part of the dentin matrix in nearly the whole lesion. As a consequence the mineral is somewhat redistributed, the outermost surface of a few mu m is changed, but the main dentin structure and element composition are still intact. These findings indicate that NaOCl treatments are of interest in remineralization and hyper-remineralization studies of dentin.

The influence of air-drying on hyper-remineralization of demineralized dentine: a study on bulk as well as on thin wet section of bovine dentine.

The influence of air-drying on the remineralization of demineralized bovine dentine was examined in wet bulk samples, in dried bulk samples as well as in wet thin sections. Bulk samples of bovine dentine were first demineralized in an acidic gel (pH = 5) at 37 degrees C for 3 weeks. After 24-hour pre-treatment of either air-drying or immersion in water, the bulk samples were remineralized in a solution containing 1.5 mM Ca, 0.9 mM phosphate and 10 ppm F (pH = 7) at 37 degrees C for 2, 4 or 8 days. Separately thin sections prepared from demineralized bulk dentine were immersed in water for 24 h and were also exposed to the remineralization solution for 2, 4 or 8 days. The results show that air-drying of the bulk samples increased remineralization of dentine considerably; the microradiographic parameters (ld, delta Z and la) show that the degree of remineralization ranks: thin wet sections > bulk dried > bulk wet. Especially, the remineralization inside lesions was greatly enhanced in thin sections and dried samples. It is presumed that the increased remineralization in dried samples is caused by a 'sponge effect', in which the remineralization fluid is sucked up in a dried shrunken lesion, resulting in fast and deep penetration of remineralization solution and/or presumably increased nucleation.

Shame, guilt, and depression in men and women in recovery from addiction.

Men and women in recovery from addiction were compared on levels of depression and self-conscious affect including proneness to shame, guilt, externalization, detachment, and pride. The sample consisted of 130 subjects (88 men and 42 women; mean age 33.04), 90 of whom were active participants in a 12-step recovery program, and 40 of whom were in a residential treatment community. Subjects completed The Beck Depression Inventory and The Test of Self-Conscious Affect. Significant differences between the sexes were found for proneness to shame, detachment, and depression. Women were significantly higher on shame and depression; men were significantly higher on detachment. The subjects were compared to subjects who were not chemically dependent. It was found that these recovering drug-addicted subjects scored significantly higher in proneness to shame and externalization and significantly lower on proneness to guilt. Treatment implications of proneness to shame in the drug-addicted population, and particularly in women, are discussed. The use of confrontational drug treatment strategies may be contraindicated.

An impingement plate method to detect deposits of pyrethroid insecticides.

A silica gel impingement plate for monitoring pyrethroid deposits in environmentally sensitive areas is described. The plate is simple, commercially available, and inexpensive. A residue analysis method is given for deltamethrin deposits with 83.3% mean recovery and a minimum quantifiable limit of 0.005 microgram/plate. Pyrethroid deposits are strongly adsorbed to the silica gel, which prevents wash-off by rainfall and slows photodegradation. In two field experiments, deltamethrin was readily detected 3 weeks after direct spray applications at 6 and 10 g ai/ha. Deltamethrin dissipation on the plates was first-order with a half-life of 2.9-3.7 d. Photoisomers of deltamethrin were also detected on the plates and the ratio of photoisomers to deltamethrin increased over time. This ratio will indicate the age of deposits in monitoring situations.

Persian heroin in the San Francisco Bay area: 1977-1980.

A new type of heroin has increased in frequency in the San Francisco Bay Area in the past three years. "Persian" heroin, coming to this country from Southwest Asia, differs from commonly-seen heroin in several ways: (1) distinctive marketing channels, (2) different routes of administration, (3) increased purity, (4) more severe withdrawal, and (5) different demographic characteristics of users. "Persian" heroin users tend to be younger and more likely to be White and unemployed as compared to other heroin users.

NAGD regimen for the coma of drug-related overdose.

A specific arousal therapy with NAGD (Naloxone, Activated Charcoal, Glucagon, Doxapram) is outlined for victims of drug overdose in comatose and semi-comatose states. Several direct benefits accrue if early awakening or lightening of such patients is safely accomplished. There are: 1) elimination of need for prolonged intubation or tracheostomy; 2) patient's ability to tell which drug(s) were taken; 3) excessively frantic and vigorous supportive treatment is obviated; and 4) the overall hospital stay is shortened. The NAGD regimen has been found to effectively, safely, and predictably reverse coma. Therapy consists of: naloxone 0.8 mg to 1.6 mg intravenously; large-bore orogastric tube instillation of 100 gm to 120 gm activated charcoal slurry; glucagon 1 mg to 2 mg intravenously; and, in selected cases, doxapram 1 mg/kg to 2 mg/kg intravenously.

Treating acute heroin and methadone toxicity.

Acute heroin and methadone overdose reactions are seen with increasing frequency in E.R.s servicing middle-class white suburbia. The authors give step-by-step procedures for the management of this life-threatening medical emergency.