Robert J. Boylan

TNF-α and antibodies to periodontal bacteria discriminate between Alzheimer’s disease patients and normal subjects

The associations of inflammation/immune responses with clinical presentations of Alzheimers disease (AD) remain unclear. We hypothesized that TNF-alpha and elevated antibodies to periodontal bacteria would be greater in AD compared to normal controls (NL) and their combination would aid clinical diagnosis of AD. Plasma TNF-alpha and antibodies against periodontal bacteria were elevated in AD patients compared with NL and independently associated with AD. The number of positive IgG to periodontal bacteria incremented the TNF-alpha classification of clinical AD and NL. This study shows that TNF-alpha and elevated numbers of antibodies against periodontal bacteria associate with AD and contribute to the AD diagnosis.

Periodontal status of adult patients treated with fixed buccal appliances and removable aligners over one year of active orthodontic therapy

OBJECTIVE To compare the periodontal status of adults treated with fixed buccal orthodontic appliances vs removable orthodontic aligners over 1 year of active therapy. MATERIALS AND METHODS The study population consisted of 42 subjects; 22 treated with fixed buccal orthodontic appliances and 20 treated with removable aligners. Clinical indices recorded included: plaque index (PI), gingival index (GI), bleeding on probing (BOP), and probing pocket depth (PPD). Plaque samples were assessed for hydrolysis of N-benzoyl-DL-arginine-naphthylamide (BANA test). Indices and BANA scores were recorded before treatment and at 6 weeks, 6 months, and 12 months after initiation of orthodontic therapy. RESULTS After 6 weeks, only mean PPD was greater in the fixed buccal orthodontic appliance group. However, after 6 months, the fixed buccal orthodontic appliance group had significantly greater mean PI, PPD, and GI scores and was 5.739 times more likely to have a higher BANA score. After 12 months, the fixed buccal orthodontic appliance group continued to have greater mean PI, GI, and PPD, while a trend was noted for higher BANA scores and BOP. CONCLUSIONS These results suggest treatment with fixed buccal orthodontic appliances is associated with decreased periodontal status and increased levels of periodontopathic bacteria when compared to treatment with removable aligners over the 12-month study duration.

A Comparison of the Apical Seals Achieved Using Retrograde Amalgam Fillings and the Nd:YAG Laser

The purpose of this in vitro study was to compare the apical seals achieved using retrograde amalgam fillings or the Nd:YAG laser. Freshly extracted teeth were randomly separated into groups that would have their apices treated either with a Nd:YAG laser or retrograde amalgam. After instrumentation and obturation, bacterial reservoirs were prepared in the coronal portion of canals. Teeth to receive retrofillings had their apices prepared and amalgams placed. Teeth to be lasered had no apical preparations. Teeth and culture media were then sterilized by irradiation. Streptococcus salivarius was deposited in the opened bacterial reservoirs. At intervals, culture media with an indicator in culture chambers was observed for color change. Specimens that demonstrated color change were cultured for S. salivarius. Under the conditions of this in vitro study, no statistically significant difference was found in bacterial leakage between the laser-treated group and the retrograde amalgam group.

Competent Antigen-Binding Fragments (Fab) from Secretory Immunoglobulin A Using Streptococcus sanguis Immunoglobulin A Protease

Immunoglobulin A (IgA) protease, a family of bacterial enzymes, cleaves human IgA1 at a single bond generating distinct Fab and Fc fragments. Purified secretory IgA with known specificity for Streptococcus mutans NCTC 10449 (serotype c) was hydrolyzed with IgA protease prepared from Streptococcus sanguis ATCC 10556. The isolated Fab fragments retained their initial activity by specifically binding to antigen and by deterring the sucrose-dependent adherence of S. mutans to glass indicating that the antigen-binding fragments behave as immunologically competent elements.

Antibacterial activity of As-annealed TiO2 nanotubes doped with Ag nanoparticles against periodontal pathogens

It is important to develop functional transmucosal implant surfaces that reduce the number of initially adhering bacteria and they need to be modified to improve the anti-bacterial performance. Commercially pure Ti sheets were anodized in an electrolyte containing ethylene glycol, distilled water and ammonium fluoride at room temperature to produce TiO2 nanotubes. These structures were then annealed at 450°C to transform them to anatase. As-annealed TiO2 nanotubes were then treated in an electrolyte containing 80.7 g/L NiSO4 ·7H2O, 41 g/L MgSO4 ·7H2O, 45 g/L H3BO3, and 1.44 g/L Ag2SO4 at 20°C by the application of 9 V AC voltage for doping them with silver. As-annealed TiO2 nanotubes and as-annealed Ag doped TiO2 nanotubes were evaluated by SEM, FESEM, and XRD. Antibacterial activity was assessed by determining the adherence of A. actinomycetemcomitans, T. forsythia, and C. rectus to the surface of the nanotubes. Bacterial morphology was examined using an SEM. As-annealed Ag doped TiO2 nanotubes revealed intense peak of Ag. Bacterial death against the as-annealed Ag doped TiO2 nanotubes were detected against A. actinomycetemcomitans, T. forsythia, and C. rectus indicating antibacterial efficacy.

Experimental antibacterial and mineralizing calcium phosphate-based treatment for dentin surfaces

Objectives: This study aimed to determine the efficacy of experimental calcium phosphate-based solutions (sCaP) containing fluoride (F), with and without zinc (Zn) ions on reducing susceptibility to acid dissolution and Streptococcus mutans (S. mutans) colonization of dentin surfaces. Methods: Dentin sections were treated with double distilled water (control) and with sCaP solutions differing in pH and in F− and/or Zn2+ ion concentrations. Solutions A (pH 7); B, C, and D (pH 5.5); solution C, twice Zn2+ and F− ion concentration compared to B; solution D is similar to C but without Zn2+. The dentin surfaces were characterized using scanning electron microscopy (SEM), x-ray diffraction, and Fourier Transform Infrared spectroscopy. Dissolution was determined in acidic buffer. Bacterial (S. mutans) attachment and growth were evaluated using SEM and Bioquant. Statistical analyses applied analysis of variance (ANOVA) and Duncan’s multiple Range test. Results: Compared to control, dentin surfaces treated with sCaP solutions showed: (a) occluded dentin tubules; (b)reduced susceptibility to acid dissolution; and (c) Zn2+ ions were more effective than F− ions in inhibiting bacterial colonization. Significance: Acidic sCaP containing both F and Zn ions have mineralizing, acid resistance, and antibacterial effects and may be potentially useful as a strategy against dentin caries formation and progression.

Destructive periodontal diseases in minority populations.

Disparities in the prevalence and severity of destructive periodontal diseases have been reported for American minority populations and have raised the following questions. Are differences in destructive periodontal disease prevalence and severity due to genetic or other confounding variables associated with ethnicity race? Do risk factors for destructive periodontal diseases differ among American minority populations or differ from the population at large? Answers to these questions will have profound impact on the direction of future research and the allocation of resources to address disparities in destructive periodontal diseases in American minority populations. Risk assessment studies that examined a set of clinical, demographic, immunologic, and microbiologic parameters of Asian Americans, African Americans, and Hispanic Americans resident in the greater New York City region suggest that occupational status, monitored as a surrogate variable for socioeconomic status, may be a more robust risk factor than ethnicity/race for destructive periodontal diseases in these populations.

Effectiveness of a professional formula disinfectant for irreversible hydrocolloid

In this study, the effectiveness of Professional Lysol (PL) disinfectant in both its spray and solution forms was evaluated as a surface disinfectant for irreversible hydrocolloid (IH) impressions. Sixteen impressions of a typodont were made with IH, immersed in a microbial broth, and then rinsed in running tap water. The impressions were then treated as follows: four were immersed in PL for 2.5 minutes; four were sprayed by PL and stored for 10 minutes; four were immersed in 2% glutaraldehyde for 10 minutes; four were untreated. Pretest plates showed an average of 421 colonies per plate (c/p). The glutaraldehyde group showed 0.00 c/p. The PL spray group showed 1.75 c/p. The PL immersion group showed 19.00 c/p and showed evidence of surface deterioration in the IH. The untreated group showed 426.25 c/p.

Photocatalytical Antibacterial Activity of Mixed-Phase TiO2 Nanocomposite Thin Films against Aggregatibacter actinomycetemcomitans.

Mixed-phase TiO2 nanocomposite thin films consisting of anatase and rutile prepared on commercially pure Ti sheets via the electrochemical anodization and annealing treatments were investigated in terms of their photocatalytic activity for antibacterial use around dental implants. The resulting films were characterized by scanning electron microscopy (SEM), and X-ray diffraction (XRD). The topology was assessed by White Light Optical Profiling (WLOP) in the Vertical Scanning Interferometer (VSI) mode. Representative height descriptive parameters of roughness R a and R z were calculated. The photocatalytic activity of the resulting TiO2 films was evaluated by the photodegradation of Rhodamine B (RhB) dye solution. The antibacterial ability of the photocatalyst was examined by  Aggregatibacter actinomycetemcomitans suspensions in a colony-forming assay. XRD showed that anatase/rutile mixed-phase TiO2 thin films were predominantly in anatase and rutile that were 54.6 wt% and 41.9 wt%, respectively. Craters (2–5 µm) and protruding hills (10–50 µm) on Ti substrates were produced after electrochemical anodization with higher R a and R z surface roughness values. Anatase/rutile mixed-phase TiO2 thin films showed 26% photocatalytic decolorization toward RhB dye solution. The number of colonizing bacteria on anatase/rutile mixed-phase TiO2 thin films was decreased significantly in vitro. The photocatalyst was effective against A. actinomycetemcomitans colonization.

Bacterial contamination in reversible hydrocolloid conditioning units

Four hydrocolloid conditioning units were randomly tested for bacterial contamination. All were contaminated beyond the United States Armys acceptable limit of potability. The predominant bacteria were identified. A discussion of clinical significance and proposals for aseptic technique are presented.