Evaluation of ultrasonically placed MTA and fracture resistance with intracanal composite resin in a model of apexification

The purpose of this study was to evaluate whether intracoronal delivery of an apical barrier of mineral trioxide aggregate (MTA) placed ultrasonically, non-ultrasonically, or ultrasonically with the addition of an intracanal composite resin provided a better seal against bacterial leakage. A second purpose was to determine whether intracanal composite resin or gutta-percha and sealer placed against an apical barrier of MTA provided greater resistance to root fracture. In a standardized in vitro open apex model, MTA was placed as an apical barrier at a thickness of 4 mm, with and without ultrasonic vibration. The barriers were challenged with bacteria exposure within a leakage model, and fracture resistance was assessed with increasing forces applied via an Instron machine. After 45 days, the addition of ultrasonics significantly improved the MTA seal, compared with the non-ultrasonics treatment (Kruskal Wallis nonparametric ANOVA with Dunn multiple comparison test p < 0.05). Bacterial leakage occurred in 6 (33%) of 18 in the non-ultrasonic MTA group, 2 (11%) of 18 in the ultrasonic MTA group, and 1 (6%) of 18 in the ultrasonic MTA-composite group. There were no significant differences at 90 days. A 4-mm thickness of MTA followed with an intracanal composite resin demonstrated a significantly greater resistance to root fracture than MTA followed with gutta-percha and sealer (one-way ANOVA with Newman-Keuls multiple comparison test, p < 0.01). The MTA-gutta-percha group was not significantly different than the MTA unrestored positive control.     

Health literacy impact on patient-provider interactions involving the treatment of dental problems

Health literacy-related problems can interfere with effective doctor-patient communication and effective patient care. This study examined several health literacy-related markers for patients seeking treatment in hospital emergency departments and physician and dentist offices for dental problems and injuries. Participants consisted of low-income white, black, and Hispanic adults who had experienced a dental problem or injury during the previous twelve months and who visited a hospital emergency department, physician, or dentist for treatment. A stratified random sample of Maryland households participated in a cross- sectional telephone survey. Interviews were completed with 94.8 percent of 423 eligible individuals. Multivariable logistic regression analyses were performed. Only 10.0 percent of the respondents expressed a difficulty understanding what they were told by the health provider, while 4.9 percent expressed a difficulty understanding the dental or medical forms they were asked to complete and 6.9 percent reported that they had difficulty getting the health provider to understand their dental problem or injury. Logistic regression analysis found that males and Hispanics were significantly (p<0.05) more likely to experience health literacy-related problems. In general, respondents did not express health literacy-related problems. Additional research is needed to identify health literacy-related barriers to effective patient-provider communication.     

Thymosin beta4 is cytoprotective in human gingival fibroblasts

Thymosin beta4 (Tbeta(4)) is a naturally occurring, ubiquitous, non-toxic protein with documented wound-healing, anti-inflammatory, anti-apoptotic, and tissue-repair properties in skin, the ocular surface, and the heart. The ability of Tbeta(4) to demonstrate similar protective properties in cells of the oral cavity was analyzed using an in vitro model of cultured human gingival fibroblasts. Thymosin beta 4 significantly suppressed the secretion of interleukin-8 (IL-8) following stimulation with tumor necrosis factoralpha (TNF-alpha), suggesting that it may suppress the inflammatory response initiated by pro-inflammatory cytokines. By contrast, Tbeta(4) was not effective in protecting fibroblasts from challenge with lipopolysaccharide purified from Porphyromonas gingivalis or Escherichia coli. Thymosin beta 4 was able to protect gingival fibroblasts against the known cytotoxic effects of chlorhexidine digluconate, a mouthrinse containing chlorhexidine digluconate, and carbamide peroxide. Additionally, Tbeta(4) was able to protect gingival fibroblasts from the apoptosis that is induced by stimulation with TNF-alpha or by exposure to chlorhexidine. Because of its multifunctional roles in protecting cells against damage, Tbeta(4) may have significant potential for use as an oral heathcare aid with combined antimicrobial, anti-inflammatory, anti-apoptotic, and cytoprotective properties.     

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.     

Oncocytoid artifact of the parotid gland: A newly reported artifact

Electrocautery can induce significant alterations in the connective tissues and epithelium of specimens removed for diagnostic or therapeutic purposes. When electrocautery is used during parotid surgery, it can cause an oncocytoid artifact. The alterations described in this article are enlarged, tightly packed serous acinar cells with coarse to granular eosinophilic cytoplasm, distinct cell borders, and round basal nuclei that on cursory microscopic examination resemble oncocytes with respect to morphology. These changes are seen in conjunction with other, more recognized changes secondary to electrocautery and are believed to occur as a consequence of the electrothermal discharge. On the basis of our findings, this artifact is common in parotid surgical specimens and was misdiagnosed as benign oncocytic lesions in 5 cases.     

Clinical and microbiological effects of localized ligature-induced periodontitis on non-ligated sites in the cynomolgus monkey

The purpose of this study was to examine the clinical and microbiological effects of localized ligature-induced periodontitis on non-ligated sites in a monkey model system. Ligature-induced periodontitis was produced in one quadrant in each of four Macaca fascicularis monkeys. Two additional monkeys without any ligatures served as control. The clinical condition and subgingival microflora of ligated, non-ligated, and control sites were monitored for 8–11 weeks. Ligated sites demonstrated an initial (1–2 weeks post-ligation) increase in inflammation, Gram-negative surface translocating bacteria (STB), and motile rods. Clinical and radiographic evidence of loss of attachment associated with increased proportions of Bacteroides gingivalis was evident 4–6 weeks post-ligation. No clinical changes were demonstrated in non-ligated and control sites throughout the experimental period. Non-ligated sites, however, demonstrated an increase from 4.6% to 13.7% in Gram-negative STB and motile rods by 4–6 weeks which continued to increase to 20.3%, by 8–11 weeks. Control sites showed no microbiological changes during the experimental period. In a second experiment pure cultures of B. gingivalis were implanted subgingivally at various times in non-ligated sites. It was only possible to recover increased proportions of B. gingivalis from non-ligated sites when implantation occurred while proportions of Gram-negative STB and motile rods were elevated. Loss of attachment in infected non-ligated sites was not seen within four weeks of implantation.     

Prosthodontic rehabilitation with a swing-lock removable partial denture and a single osseointegrated implant: a clinical report

This article details the use of a swing-lock removable partial denture and single osseointegrated dental implant in the prosthodontic rehabilitation of a partially dentate patient. Used together, these treatment options solved a difficult clinical problem with a satisfactory outcome.