The prevalence of periodontal-related changes in adolescents with asthma: results of the Third Annual National Health and Nutrition Examination Survey

PURPOSE: The purpose of this study was to explore the association between asthma and periodontal disease in adolescents using oral examination and health interview data from the Third National Health and Nutrition Examination Survey (NHANES III) 1988-1994. METHODS: The study population comprised 1,596 adolescents 13 to 17 years of age: 253 (16%) asthmatics and 1,358 (84%) nonasthmatic controls who were examined for bleeding on probing (BOP), subgingival calculus (SBC), supragingival calculus (SPC), probing depth greater than or equal to 3 mm (PD), and loss of periodontal attachment greater than or equal to 2 mm (LPA). The authors fitted separate multivariate GEE Poisson regression models adjusting for parents' income, gender, race, exposure to potentially xerogenic drugs (antihistamines, corticosteroids, and inhalers), tobacco exposure, and dental examination within the past year. RESULTS: None of the periodontal measures was associated with asthma severity or with the use of antiasthmatic drugs. However, several covariates had statistically significant odds ratios (P < .05). CONCLUSIONS: There was no evidence to support the association between asthma and periodontal health in the adolescent population. Since the findings may be due to the inherent limitations of cross-sectional studies, the lack of knowledge about the daily dose of antiasthmatic medication, and the level of-compliance with the therapeutic regimen, future studies should be longitudinal and monitor medication use.     

Rigid external distraction of the midface with direct wiring of the distraction unit in patients with craniofacial dysplasia

The development of craniofacial distraction techniques represents a significant advancement in the management of craniofacial dysplasias. For distraction of the midface after Le Fort III osteotomy, two levels of anchorage to the moving segments are necessary. In this report, the authors connected the distraction forces directly to the infraorbital rims, using a surgical wire for superior anchorage. They performed this technique in four patients with craniofacial dysplasia for the management of severe maxillary hypoplasia using RED II system. This configuration not only simplified the placement of the system but also made the removal of the device much easier. The authors did not have any problems with the wire traction unit, such as wire breakdown or bony tunnel disruption. It is a cheap, simple, and effective configuration that can be easily performed without any complication.     

Calcium hydroxide as an intracanal medication: effect on posttreatment pain

Calcium hydroxide is advocated as an intracanal medication for various purposes, including prevention of posttreatment symptoms. This study assessed whether calcium hydroxide had a pain-controlling effect at different times when compared with no intracanal medication. One hundred forty patients participated. Conditions diagnosed were pulp/periapical pathosis with or without symptoms. At least partial cleaning and shaping was completed. At random, either Ca(OH)2 plus H2O paste or a dry cotton pellet was placed in the canals of half the teeth, respectively. All teeth were temporized with Intermediate Restorative Material. Patients assessed posttreatment pain up to 48 h as none, mild, moderate, or severe. The pain levels in each test group [Ca(OH)2 versus cotton pellet] at each time period were compared statistically with a multiple-regression analysis. There was no significant difference in posttreatment pain between the two groups at any time period or with any diagnosis or symptom. The use of calcium hydroxide as an intracanal medication was unrelated to the incidence and/or severity of posttreatment pain.     

Starvation survival,growth and recovery of Enterococcus faecalis in human serum

The ability of Enterococcus faecalis to survive starvation for long periods in the obturated root canal is likely to be an important factor in the pathogenesis and maintenance of a persistent infection after endodontic treatment. The response of E. faecalis to starvation survival in water and glucose‐, phosphate‐ or amino acid‐limited chemically defined medium was studied, along with the capacity for growth and recovery of starved cells of E. faecalis in pooled human serum. After an initial rapid fall in cell numbers, a small remaining population of E. faecalis was able to survive in water for over 4 months and in nutrient‐limited media for extended periods. A high cell density at the onset of starvation was critical for the ability of E. faecalis to endure prolonged nutrient limitation. Upon starvation, a static population of starved cells developed and were apparently in a minimal metabolic state, since blocking cell wall synthesis with penicillin G or inhibiting DNA synthesis with norfloxacin during starvation resulted in limited change in the rate of loss of viable cells. In 50% serum, E. faecalis grew, then stabilized at a relatively constant population of 10⁶ colony‐forming units/ml for 4 months, irrespective of the initial cell density. In summary, E. faecalis is capable of withstanding prolonged periods of starvation in a minimal metabolic state provided that there is a high cell density at the onset of starvation. Starved cells were capable of recovery upon addition of human serum.     

A laboratory comparison of three imaging systems for image quality and radiation exposure characteristics

AIM: To measure and compare the relationships between image quality and X-ray exposure for three types of intraoral imaging system (conventional film, phosphor plate system and CCD-based system). METHODOLOGY: Kodak 'Insight' F-speed film, Digora FMX (phosphor plate system) and Visualix USB (CCD system) were used to produce series of radiographic images of two tooth-bearing jaw specimens (maxillary molar and mandibular molar regions) at a range of X-ray exposures from 10 ms to 2000 ms (all at 6 mA and 60 kV). Digital images were viewed from a computer monitor and films viewed on a conventional light box. Five observers scored each image using a five-point subjective image quality scale (0-4). RESULTS: Optimum image quality (4) was seen for conventional film. Neither digital system achieved this score at any exposure, achieving in both cases a maximum mean score of 3.1 (adequate visualization). The two digital systems, however, provided adequate visualization at substantially lower exposure times. Dose reduction over conventional film for maximum quality images with Visualix USB was 20%, but for Digora FMX it was 70%. All three systems gave acceptable (quality score of two or higher) images over a broad range of exposures. CONCLUSIONS: In terms of subjective image quality, F-speed film performed better than the two digital systems, but this must be weighed against the ability of the two digital systems to give adequate image quality at lower radiation doses.     

Streptococci dominate the diverse flora within buccal cells

Previously, we reported that intracellular Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Tannerella forsythensis were present within buccal epithelial cells from human subjects, as lesser components of a polymicrobial flora. In this study, we further characterized that intracellular flora by using the same double-labeling techniques to identify Fusobacterium nucleatum, Prevotella intermedia, oral Campylobacter species, Eikenella corrodens, Treponema denticola, Gemella haemolysans, Granulicatella adiacens, and total streptococci within buccal epithelial cells. All those species were found within buccal cells. In every case, species recognized by green-labeled species-specific probes were accompanied by other bacteria recognized only by a red-labeled universal probe. Streptococci appeared to be a major component of the polymicrobial intracellular flora, being present at a level from one to two logs greater than the next most common species (G. adiacens). This is similar to what is observed in oral biofilms, where diverse species interact in complex communities that often are dominated by streptococci.     

Volumetric polymerization shrinkage of resin composites under simulated intraoral temperature and humidity conditions

This study measured the volumetric shrinkage of resin composites polymerized under temperature and humidity conditions simulating the oral cavity and compared them to those occurring under ambient room conditions. Small, semispherical specimens of a microhybrid (Z100), microfill (Filtek A110) and flowable microhybrid (4 Seasons Flow) resin composite were manually formed and light activated for 40 seconds using a halogen light-curing unit (Spectrum Curing Light). The volumetric polymerization shrinkage of 10 specimens of each brand of resin composite was measured using a drop shape analysis unit (Drop Shape Analysis System, model DSA10 Mk2) under each of two temperature/relative humidity conditions: room conditions (22 +/- 2 degrees C and 60 +/- 5%) and those simulating intraoral conditions (35 degrees C and 92 +/- 5%). Mean volumetric shrinkage values were calculated for each resin composite and the data were analyzed using two-way analysis of variance and t-test (a=0.05) to determine if significant differences existed between the amount of volumetric polymerization shrinkage that occurred under ambient room conditions and that which occurred under simulated intraoral conditions. Mean volumetric shrinkage values measured for the resin composites were: 2.26 +/- 0.04% (ambient) and 2.61 +/- 0.04% (intraoral) for Z100; 1.96 +/- 0.04% (ambient) and 2.28 +/- 0.04% (intraoral) for Filtek A110 and 4.53 +/- 0.06% (ambient) and 5.34 +/- 0.05% (intraoral) for 4 Seasons Flow. For each resin composite, statistical analysis indicated that the amount of volumetric shrinkage measured under simulated intraoral conditions was significantly greater than what was measured under ambient room conditions (p<0.0001).     

Management of prosthetic abutments respecting peri-implant soft tissues

Periodontal and peri-implant soft tissues are very similar in many aspects (phenotype, mucosal dimensions, biological width). In peri-implant tissue, the mucosal seal is localized apically to the gap existing between the fixture and the prosthetic abutment. This is due to mechanical trauma created by screwing and unscrewing the prosthetic components, to mechanical deformation produced under functional stress and to bacterial colonization. To reduce the effects of this gap on peri-implant soft tissues stability several options are available: supracresta fixture positioning, reduction of the fixture-abutment gap, and minimizing the prosthetic steps. A clinical case was illustrated. Abutments (Gingi-hue 3I with a fixture-abutment gap less than 2 mm and a fixture abutment angle rotation of 0.4 degrees ) were screwed on the fixtures after the second stage surgery and used as impression transfer. These abutments were prepared in the laboratory and definitively screwed after the impression session. The use of definitive abutments as transfer reduces the session number and allows the peri-implant soft tissues to heal without beeing troubled by screwing and unscrewing of the prosthetic components.     

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.     

Orthodontics and the upper airway

One of the general aims of orthodontic treatment and of the combination of orthodontics and orthognathic surgery is to achieve good occlusion and aesthetic improvement, especially in cases of severe dentoskeletal deformities. However, on many occasions, the parameters of the upper airways are not taken into account when the aims of conventional treatment are fulfilled. Patients with obstructive alterations during sleep represent for the orthodontist a type of patient who differs from the normal; for them, treatment should include the objective of improving oxygen saturation. Here, functional considerations should outweigh purely aesthetic ones. It is important, when making an orthodontic, surgical or combined diagnosis for a patient, to bear in mind the impact that treatment may have on the upper airways. Good aesthetics should never be achieved for some of our patients at the expense of diminishing the capacity of their upper airways.