Gingival colonization with selective HACEK microbes in children with congenital heart disease

It was previously shown that children with congenital heart disease (CHD) harbored Hemophilus, Actinobacillus, Cardiobacter, Eikenella, and Kingella (HACEK) microbes to a greater extent and had more severe gingival inflammation than a normal group of children. The purpose of this study was to determine if HACEK microbes are more prevalent in children with CHD than in normal children when there is no difference in gingival inflammation. Two groups of 12 children were matched with respect to gingival inflammation. Each child had a gingival index recorded as described by Massler. The experimental group consisted of 12 children with CHD 2.5-10 years old (average 5.5) and the control group consisted of 12 healthy children 2-13 years old (average 5.6). Subgingival samples were obtained and cultured for HACEK microbes. Fischer's exact test was performed with the significance level defined at P<0.05. The average gingival indices for the experimental and control groups were 6.5 and 6.4, respectively (N.S.). Nine of 12 children with CHD had Eikenella corrodens (E.c.) compared to 3/12 control patients ( P<0.05). Three of 12 CHD patients but no control patient had Actinobacillus actinomycetemcomitans (A.a.) (N.S.). There were no significant differences in E.c. or A.a. presence between cyanotic and acyanotic CHD patients. This study found that the greater extent of specific HACEK microbes harbored by children with CHD is not associated with cyanosis or the degree of gingival inflammation. Further study is needed to delineate fully the medical significance of this observation.     

Eruption cyst formation associated with cyclosporin A

BACKGROUND: Cyclosporin A (CyA) is a potent immunomodulatory agent with a wide range of applications. Despite its therapeutic value, multiple adverse effects of CyA have been identified. This case report describes eruption cyst formation as a possible adverse effect of CyA administration during tooth eruption in a boy treated with CyA as a consequence of a cardiac transplantation. The clinical diagnosis of eruption cyst was confirmed by histopathological examination. TREATMENT: The periodontal treatment consisted of supragingival and subgingival scaling, followed by surgical removal of the tissues overlying the crowns of the teeth associated with eruption cysts, and flap surgery in the region of gingival overgrowth. The patient was then placed on quarterly periodontal supportive therapy and his immunosuppressive medication was switched from CyA to tacrolimus. RESULTS: Twenty months after therapy, neither new cyst formation nor recurrence of gingival overgrowth was registered. CONCLUSION: Formation of an eruption cyst may be an adverse effect of CyA in children with erupting teeth.     

Effects of local cooling rate and processing variables on leucite in dental porcelain

PURPOSE: This research determined whether there is a measurable effect of local geometry factors on leucite content of dental porcelain in fixed partial dentures (FPD). MATERIALS AND METHODS: Four-unit FPD frameworks (n = 36) were fabricated using a nickel-chromium alloy (Rexillium III). Body porcelain (Crystar, shade A2) was applied in one increment and subjected to two simulated body firings, followed by a simulated glaze firing to achieve a thickness of 1.5 to 2.0 mm. The completed FPD specimens were randomly assigned to three groups of 12 specimens each: (1) simulated post-soldering, (2) multiple firing, and (3) control. The FPDs from each test group were sectioned into individual units: canine retainer, premolar pontic, molar pontic, and molar retainer. The porcelain was removed from each unit, and the leucite content was measured via quantitative x-ray diffraction. RESULTS: Porcelain cracking indicated that the soldering simulation had successfully reproduced conditions in the dental laboratory that result in porcelain cracking during soldering. The leucite content was not significantly different between the retainer and pontic units for either the soldering simulation or control FPDs, although the canine retainer units did have a slightly lower leucite content than the pooled values of the other units. Comparison of the pooled data for the three groups indicated statistically significant differences among the leucite contents. CONCLUSION: Compared to the control, the simulated post-soldering procedure produced a significant increase in leucite, and the multiple firing group exhibited a significant decrease in leucite. Increases in leucite weight fraction during post-soldering operations-and the larger thermally induced stresses that accompany these leucite increases-are responsible for the cracking that occurs.