Mineralization differences between human deciduous and permanent enamel measured by quantitative microradiography

The mineralization levels of erupted buccal enamel from 24 deciduous teeth were compared to those of 28 permanent teeth. Sections were prepared in a defined plane using a lapping machine which gave plano-parallel sections. Mineralization levels were recorded by quantitative microradiography at 25 equivalent anatomical sites in each section. Deciduous incisors and canines were compared with their homologous successors: overall mineralization levels were lower in the deciduous dentition, with no significant differences being found close to the amelo-dentinal junction, but highly significant differences being found in the outermost sites. Deciduous molars were compared with premolars, and were also relatively less mineralized. However, deciduous molars did not show the consistent diminishing occlusocervical gradient observed in all other tooth types tested; on the contrary, they showed a cervical reversal with higher values than permanent premolar enamel. These results confirm the generally lower mineral levels in deciduous enamel, and provide quantitative information on site-specific mineralization levels.     

Bursitis: a factor in the differential diagnosis of orofacial neuralgias and myofascial pain dysfunction syndrome

A woman had pain on swallowing and talking when initially seen. Previous diagnoses of glossopharyngeal, neuralgia and myofascial pain dysfunction syndrome had been made. Appropriate treatment for these conditions failed to produce any improvement. Palpation revealed two tender areas bilaterally, overlying the hamulus. Treatment with an injection of 1 ml of dexamethasone (Decadron) 4 mg/ml into each area of tenderness resulted in a dramatic improvement. An anatomic review disclosed the presence of a bursa on the hamulus to protect the tendon of tensor veli palatini. A diagnosis of bursitis was made because of the dramatic improvement in the patient's condition as the result of corticosteroid therapy. Bursitis should therefore be considered in the differential diagnoses of orofacial neuralgias, temporomandibular joint dysfunction, and myofascial pain dysfunction syndrome.     

IgG anti HSV I antibodies in saliva in a drug dependent population

It is known the presence of receptors for the morphine products on the Lymphocytes B. These receptors could have a modulator action on the production of antibodies in drug addicts. We have determined the existence of IgG anti-HSV I in saliva and serum in a heroin population. Our results show that here is not significant differences between the heroin population and the control group, when the antibodies are detected in serum. But significant differences do exist between the number of people with antibodies anti-HSV I in saliva.     

Quantitative determination of salivary components in the pellicle on PMMA denture base material

The formation of a salivary pellicle is a protective mechanism of the body for all surfaces in the oral cavity. The nature of the substrate may influence the composition of the pellicle. The aim of this study was to investigate the quantitative composition and individual variation of the salivary pellicle formed on denture base material (PMMA). Cylindrical specimens of PMMA were carried in the mouth and then desorbed with a 0.5-M sodium chloride solution. The solution was analysed for total protein, alpha-amylase, total proteases, protease inhibitors, secretory immunoglobulin A, immunoglobulin G, peroxidases, thiocyanate, lysozyme, and calcium content. All investigated salivary components could be found unequivocally in the desorption solution, indicating that a salivary pellicle had formed on the surface of the PMMA. Large coefficients of variation indicate large individual variations in the adsorbed amounts. The data also point to large intraindividual variations for the bound salivary components. Only the protease inhibitors revealed a strong positive correlation of the bound activity to the salivary activity. It is hypothesised that differences in the bound amounts of antimicrobial components might influence the microbial colonisation of denture bases and that protease inhibitors could be meaningful for the spread of the yeast Candida albicans from denture base material to the oral mucosa and thus might be an explanation for different susceptibility to denture base stomatitis.     

Shear bond strengths of saliva contaminated 'one-bottle' adhesives

The aim of this study was to investigate the effect of saliva contamination on the bond strengths of three one-bottle bonding systems. The dentin of 90 recently extracted, non-carious human molar teeth was exposed and ground wet on 500 grit silicon carbide (SIC) paper to establish a bonding surface in superficial dentin. Specimens were randomly assigned to nine groups of 10 teeth each. Three testing conditions are: (i) contamination with fresh saliva (pH 5.5) after acid etching, (ii) contamination with fresh saliva after bonding application, and (iii) no contamination. Three adhesive systems are: syntac single component, prime & bond NT, and gluma one bond. Cylinders of composite were applied via PTFE (polytetrafluroethylene) split mould and light cured to the dentin surfaces. All specimens were thermocycled (5000 cycles) between baths of 5 and 55 degrees C. Shear bond strengths were measured using an Instron Universal testing machine at a crosshead speed of 1 mm min-1. Two-way ANOVA was used to analyse the data. The results of this study indicated that the saliva contamination of dentin has no adverse effect on the bonding efficiency of one-bottle adhesive systems (P > 0.05). No statistically significant differences were found between the shear bond strengths of tested adhesives.     

Reliability of assessing interproximal bone loss by digital radiography: intrabony defects

AIM: The aim of the present study was to assess the reproducibility and validity of linear measurements of interproximal bone loss in intrabony defects on digitized radiographic images after application of different filters and magnifications. METHODS: Immediately before surgery 50 radiographs of 50 periodontally diseased teeth exhibiting interproximal intrabony defects were obtained by a standardized technique in 50 patients. Intrasurgically the distances from the cementoenamel-junction (CEJ) to the alveolar crest (AC) and from the CEJ to the deepest extension of the bony defect (BD) were assessed. All radiographs were digitized by a flatbed scanner (resolution: 600x1200 dpi). Using the FRIACOM-soft ware, the linear distances CEJ to AC and CEJ to BD were measured at 50 intrabony defects on digitized but unchanged radiographic images and also after use of 2 different basic image processing modes (filters: enhancement of grey level differences, spreading of grey values) with 7-fold and 14-fold magnification by 2 different examiners. RESULTS: Repeated measures MANOVA revealed reproducibility of the measurement of the distance CEJ to AC to be significantly influenced by examiner (p=0.027) and filter in combination with the height of 2 wall component of the intrabony defect (p=0.066). For the distance CEJ to BD filters had significant influence on reproducibility in correlation with vertical angulation difference (p=0.001). On the average in this study radiographic measurements tended to overestimate the amount of bone loss as assessed by intrasurgical measurements (CEJ-AC: 0.74-1.91 mm; CEJ-DB: -0.04-0.77 mm). Validity of measurement of the distance CEJ-AC was shown to be significantly influenced by the depth of the intrabony defect (p<0.003). Validity of the distance CEJ-BD was significantly influenced by intrasurgically assessed bone loss (p=0.029), horizontal angulation (p=0.066). Filters influenced the validity only in combination with examiner (p<0.001). CONCLUSIONS: In this study, the chosen digital manipulations (filters: spreading, structure) of radiographic images failed to result in statistically significantly more reproducible or valid measurements of interproximal bone loss within intrabony defects when compared to the digitized but unchanged images. All radiographic assessments on the digitized images except for use of enhancement of grey level differences (structure) came close to the intrasurgical gold standard.     

Tooth-implant supported fixed prostheses: a retrospective multicenter study

PURPOSE: The purpose of this retrospective multicenter study on implants combined with natural teeth was to investigate the implant survival rate and loss of marginal bone, as well as indications and complications pertinent to this form of implant therapy. MATERIALS AND METHODS: The study comprised 185 implants in 111 patients from six different clinics in Sweden. Gathering of data, which were taken from patient records, followed a strict protocol. The registrations included indications for treatment, failure of implants, radiographs from baseline and follow-up, and information on complications. RESULTS: The cumulative implant survival was found to be 95.4% (standard error 4.5%) up to 3 years of follow-up. The marginal bone level at baseline was lower in the maxilla compared with the mandible (P = .015), but any further loss did not differ between the jaws. The most severe complication other than loss of osseointegration (6/185) or periimplant infections (4/183) was intrusion of the abutment teeth, which occurred in 5% of the cases. In all instances, the intrusion was seen in constructions with nonrigid forms of connection between the implants and teeth. CONCLUSION: The tooth-implant supported prosthesis using the Br?nemark system is in the short term an equally predictable treatment as the completely implant-supported prosthesis concerning implant survival and loss of marginal bone. When combining implants and teeth, a rigid form of connection should be used to prevent tooth intrusion.