Automated image registration of cerebral digital subtraction angiography.

PURPOSE: Our aim is to automatically align digital subtraction angiography (DSA) series, recorded before and after endovascular thrombectomy. Such alignment may enable quantification of procedural success. METHODS: Firstly, we examine the inherent limitations for image registration, caused by the projective characteristics of DSA imaging, in a representative set of image pairs from thrombectomy procedures. Secondly, we develop and assess various image registration methods (SIFT, ORB). We assess these methods using manually annotated point correspondences for thrombectomy image pairs. RESULTS: Linear transformations that account for scale differences are effective in aligning DSA sequences. Two anatomical landmarks can be reliably identified for registration using a U-net. Point-based registration using SIFT and ORB proves to be most effective for DSA registration and are applicable to recordings for all patient sub-types. Image-based techniques are less effective and did not refine the results of the best point-based registration method. CONCLUSION: We developed and assessed an automated image registration approach for cerebral DSA sequences, recorded before and after endovascular thrombectomy. Accurate results were obtained for approximately 85% of our image pairs.

Antiplaque and antigingivitis effectiveness of a hexetidine mouthwash.

OBJECTIVE: To assess the antiplaque/antigingivitis efficacy of a hexetidine-containing mouthwash. METHODS: This examiner-blind, parallel group, controlled clinical study examined the effectiveness of a hexetidine (0.1%) mouthwash both in inhibiting the development of supragingival plaque and in reducing gingivitis. One hundred and thirty-four adult subjects completed the 2-week experimental gingivitis model study. Following baseline examinations, which included plaque index, modified gingival index and gingival bleeding index, subjects received a full dental prophylaxis. Subjects were randomly assigned to one of three mouthwashes (hexetidine 0.1%, chlorhexidine 0.12% (positive control) or a 5% hydroalcohol negative control) and commenced three times daily supervised rinsing as their sole method of oral hygiene. All indices were rescored after 2 weeks. RESULTS: Compared to the negative control group, the hexetidine group demonstrated a statistically significant inhibition and reduction of supragingival plaque and gingival inflammation with reductions of 6.3%, 33.5% and 56% for gingivitis, plaque and gingival bleeding, respectively. The results of the chlorhexidine group were used to validate the study. CONCLUSION: The study confirms the efficacy of a hexetidine rinse in reducing supragingival plaque and gingival inflammation.

Comparative efficacy of an antiseptic mouthrinse and an antiplaque/antigingivitis dentifrice. A six-month clinical trial.

BACKGROUND: The efficacy of an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic, Pfizer) and an antiplaque/antigingivitis dentifrice (Colgate Total, Colgate-Palmolive) has been demonstrated in numerous double-blind clinical studies. This study was conducted to determine their comparative efficacy. METHODS: Three hundred sixteen subjects with mild-to-moderate gingival inflammation and plaque received a dental prophylaxis and began their randomly assigned brushing and rinsing regimen in an unsupervised setting. Subjects brushed for one minute and rinsed with 20 milliliters for 30 seconds twice daily for six months. The three groups were L (control toothpaste/Listerine rinse), T (Colgate Total toothpaste/control rinse) and P (control toothpaste/control rinse). RESULTS: Subjects in the L and T groups demonstrated statistically significantly lower (P < .001) Modified Gingival Index, or MGI; Bleeding Index, or BI; and Plaque Index, or PI, at both three and six months than subjects in the P group. The magnitude of reduction for the L group was 22.9 percent, 70 percent and 56.1 percent, respectively, and for the T group, 20.8 percent, 58 percent and 22.1 percent, respectively. Subjects in the L group were not different from subjects in the T group in regard to visual signs of gingivitis (MGI), but were more effective (P < .001) than subjects in the T group in experiencing reduced BI and PI. No product-related adverse events were reported. CONCLUSION: Although the Listerine Antiseptic and Colgate Total antiplaque/antigingivitis products produced similar, clinically significant reductions in gingivitis (as measured by MGI and BI), Listerine, when used in conjunction with a fluoride dentifrice and usual oral hygiene, provided a greater benefit in reducing plaque. CLINICAL IMPLICATIONS: When considering an antiplaque/antigingivitis product to recommend to patients, clinicians should consider Listerine Antiseptic, in conjunction with usual oral hygiene, if more rigorous plaque control is desired.

Effect of an essential oil-containing antiseptic mouthrinse on plaque and salivary Streptococcus mutans levels.

BACKGROUND: Clinical studies in which antimicrobial mouthrinses were shown to have significant antiplaque activity most frequently have used gingivitis as the clinically relevant endpoint. However, there is evidence to suggest that mouthrinses containing active agents effective against Streptococcus mutans, such as chlorhexidine, may also have a role in inhibiting dental caries. This clinical study was conducted to determine the effect of 2x-daily rinsing with an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic) on levels of recoverable S. mutans and total streptococci in supragingival interproximal plaque and in saliva. Additionally, a follow-up in vitro study is reported which determined whether a differential susceptibility to the antiseptic mouthrinse exists among different strains of streptococci. METHOD: Following baseline saliva and plaque sampling for quantification of recoverable S. mutans and total streptococci, 29 qualifying subjects were randomly assigned either the essential oil mouthrinse or a sterile water control. They rinsed with 20 ml for 30s 2 x daily for 11 days and once on the 12th day, in addition to their usual oral hygiene procedures. On day 12, saliva and plaque samples were again collected and microbiological quantification performed. The procedures were repeated with the alternate rinse after a 1-week washout period. RESULTS: The essential oil mouthrinse produced respective reductions of 69.9% and 75.4% in total recoverable streptococci and in S. mutans in plaque, and corresponding reductions of 50.8% and 39.2% in saliva. The in vitro study revealed that streptococci from the mutans group were more susceptible to the bactericidal activity of the essential oil mouthrinse than streptococci from the mitis group. CONCLUSIONS: As antimicrobial mouthrinses are most frequently recommended to patients whose mechanical oral hygiene procedures are not adequate for the control of supragingival plaque and gingivitis, this study provides an additional rationale for the inclusion of the essential-oil mouthrinse as an adjunct to daily oral hygiene procedures.

Clinical effectiveness of essential oil-containing dentifrices in controlling oral malodor.

PURPOSE: To assess the efficacy of two essential oil-containing dentifrices in the reduction of human intrinsic oral malodor ("morning bad breath"). MATERIALS AND METHODS: Two clinical trials were conducted which used observer-blind, negative control, parallel designs. To insure a homogeneous test population with similar oral odor characteristics, subjects followed instructions that included toothbrushing with a standard ADA-accepted fluoride dentifrice the night before. On odor evaluation days, subjects refrained from all oral hygiene procedures and from eating or drinking any food or beverage or smoking prior to and during the odor evaluations. Eighty healthy adult subjects in the first trial and 90 in the second trial with qualifying baseline levels of oral malodor participated. Odor ratings of each subject's breath were made by 4-5 trained judges using a nine point hedonic scale, i.e., 1 = most pleasant, 5 = neutral, 9 = most unpleasant. Qualifying subjects were randomly assigned one of two essential oil dentifrices or a negative control dentifrice. Subjects brushed with their assigned dentifrice for 60 s, rinsed with 20 ml of water for 10 s, and received post-treatment hedonic odor ratings at 30, 60, 90, 120, 180, and 240 min. Data were analyzed using an ANCOVA to adjust for baseline scores. RESULTS: The essential oil dentifrices were significantly more effective (P < or = 0.033) than the control in reducing intrinsic oral malodor from 90 to 120 min.

Effect of an essential oil-containing dentifrice on dental plaque microbial composition.

PURPOSE: To determine the effect of 6 months use of an essential oil-containing (EO) antiplaque/antigingivitis fluoride dentifrice on the balance of the oral microbial flora and on the emergence of resistant microbial forms by analysis of dental plaque and saliva. MATERIALS AND METHODS: The dentifrice essential oils consisted of a fixed combination of thymol, menthol, methyl salicylate, and eucalyptol. An identical fluoride-containing dentifrice without the essential oils served as the control. A subgroup of 66 subjects from a clinical trial population of 321 was randomly selected for characterization of their dental plaque microflora. Saliva was also cultured to monitor for the emergence of opportunistic pathogens. Supragingival plaque and saliva were harvested at baseline, after which subjects received a dental prophylaxis. Subjects were sampled again after 3 and 6 months of product use prior to clinical examination. Plaque was characterized for microbial content by phase contrast microscopy for recognizable cellular morphotypes and by cultivation on nonselective and selective culture media. Determination of the minimum inhibitory concentrations of the test agent against selected Actinomyces and Veillonella isolated bacterial species was conducted at all time points to monitor for the potential development of bacterial resistance. RESULTS: There were no statistically significant differences between the microbial flora obtained from subjects using the essential oil-containing dentifrice and the vehicle control for all parameters and time periods except for the percentage of spirochetes at 6 months and for percentage of "other" microorganisms at 3 months. The EO group exhibited a lower adjusted mean for both parameters. Additionally, there was no evidence of the development of bacterial resistance to the antimicrobial activity of the essential oils or the emergence of opportunistic pathogens.

In vivo antimicrobial activity of an essential oil-containing mouthrinse on interproximal plaque bacteria.

This study determined the in vivo interproximal bactericidal efficacy of an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic) following toothbrushing. Thirty-four generally healthy adults, aged 23-64 years, completed this evaluator-blind, randomized, controlled, crossover designed study. Subjects rinsed for 30 seconds with 20 ml of either the essential oil rinse or a negative control rinse. Five minutes later, interproximal plaque was collected using paper points, and recoverable bacterial counts were quantified using both end point dilution and spectrophotometric methods. The results from the end point dilution demonstrated a statistically significant (p < 0.001) 43.8% reduction in recoverable plaque bacteria from interproximal spaces following rinsing with the essential oil mouthrinse. This study suggests that the clinical effectiveness of the essential oil mouthrinse against plaque and gingivitis may be attributable to the rapid kill and plaque permeabilizing properties of the formulation.

Effects of sublethal exposure to an antiseptic mouthrinse on representative plaque bacteria.

Although the mechanism responsible for the clinical antiplaque efficacy of oral antiseptics is generally considered to be primarily one of bactericidal activity, it has been suggested that oral antiseptics may have additional effects on bacteria exposed to sublethal levels. Studies reported herein, investigated the effects of sublethal levels of an essential oil-containing antiseptic mouthrinse (Listerine Antiseptic, Warner-Lambert Co., Morris Plains, NJ) on selected activities of representative plaque microorganisms using in vitro models. These studies demonstrated that sublethal exposure to the tested oral antiseptic can have significant effects in reducing intergeneric coaggregation, increasing bacterial generation time, and extracting endotoxin from Gram-negative bacteria. These in vitro activities can be correlated with features of plaque formation and pathogenicity seen in vivo; however, additional studies will be necessary to confirm that these mechanisms are, in fact, operative clinically.

Antiseptic mouthrinse-induced microbial cell surface alterations.

This study determined the effect of an essential oil-containing mouthrinse, Listerine Antiseptic, on microbial cell surface morphology using scanning electron microscopy. Twenty-four hour cultures of C. albicans, A. viscosus, S. sanguis, F. nucleatum, and A. actinomycetemcomitans were harvested and washed in buffer. Triplicate samples were overlaid on poly-L-lysine coated coverslips, immersed in either Listerine or buffer for 30 seconds, fixed in glutaraldehyde followed by post-fixing in 1% osmium tetroxide, dehydrated, and embedded in Peldri II. Exposure of the microorganisms to Listerine Antiseptic for 30 seconds resulted in distinct morphological alterations of cell surfaces suggestive of loss of cell surface integrity. The extent of alteration varied among the structurally different species; cell surface roughening was mild in S. sanguis but extensive in the other microorganisms which developed distinct surface blebs and other abnormalities after the 30-second exposure. These results suggest that a brief exposure to Listerine produces significant morphological changes which may be associated with cell death and may help explain the alteration of surface-associated activities demonstrated in previous studies.

Reduction of viable bacteria in dental aerosols by preprocedural rinsing with an antiseptic mouthrinse.

Two double-blind controlled clinical studies were conducted to determine the efficacy of preprocedural rinsing with Cool Mint Listerine Antiseptic mouthrinse on the level of viable bacteria recovered from dental aerosols when generated immediately after and 40 minutes after rinsing. Eighteen healthy subjects participated in each study. In the first study, following a 24-hour no-oral-hygiene period, subjects received a 10-minute ultrasonic scaling of a randomly chosen half mouth, rinsed with either Cool Mint Listerine or a control, and received an ultrasonic scaling of the remaining half mouth. During each scaling period, aerosolized bacteria were collected on a sterile filter using a modified air-sampling device. The filters were overlaid on culture media, incubated aerobically, and colonies were counted. The second study followed the same basic design except that ultrasonic scaling was done for 5 minutes, and the post-rinsing sampling was performed following a 40-minute simulated dental treatment period. Rinsing with Cool Mint Listerine resulted in a 92.1% reduction in viable bacteria in aerosols generated immediately after rinsing and a 91.3% reduction in aerosols generated 40 minutes after rinsing. These reductions were significantly greater than control (P = 0.0001). These studies suggest that preprocedural rinsing with Cool Mint Listerine Antiseptic may potentially reduce the risk of cross contamination in the dental operatory.

Endotoxin levels in periodontally healthy and diseased sites: correlation with levels of gram-negative bacteria.

This study investigated the correlation between endotoxin levels and the percentage of Gram-negative bacteria in healthy sites and in periodontitis sites. Twelve healthy adults participated. Each subject provided 3 periodontitis sites with 5 to 8 mm probing depths that bled on gentle probing and 3 healthy sites with sulcus depths of 1 to 3 mm that did not bleed. Clinical examinations and sterile paper point sampling of all study sites were conducted on days 0, 7, and 14, and site-specific endotoxin levels and percentage of Gram-negative bacteria were determined. There were significant differences in both endotoxin levels and percentage Gram-negative bacteria between healthy and periodontitis sites across all 3 sampling periods, but no difference across sampling periods in the healthy sites and the periodontitis sites, respectively. Correlation coefficients revealed a high degree of correlation between site-specific endotoxin levels and percentage of Gram-negative organisms. Using a sample dilution of 1 x 10(4), endotoxin levels differentiated healthy from periodontitis sites with a specificity of approximately 91% and a sensitivity of approximately 90%.

Clinical and laboratory characterization of early onset periodontitis.

Clinical and laboratory data were compared in 72 patients with localized periodontitis (LP) and 103 patients with generalized periodontitis (GP). Significantly more LP than GP cases had decreased neutrophil chemotaxis (CTX), and were seropositive for Actinobacillus actinomycetemcomitans (Aa). Significantly, more GP cases were seropositive for Bacteroides gingivalis (Bg). All clinical indices were similar on affected teeth in LP and GP, but the attachment loss was greater on clinically unaffected teeth in GP when compared with LP. LP cases with CTX defects had a significantly lower mean age, were more often seropositive for Aa antibodies, and were more often female than LP patients with normal CTX. Significantly more GP cases with CTX defects were seropositive for Aa antibody. GP patients with normal CTX had a higher plaque index on both affected and unaffected teeth than did GP patients with a CTX defect. Our data suggest that chemotaxis and/or specific bacteria may be contributory, but not always necessary, factors in these disorders. The overlap in clinical and laboratory profiles of LP and GP continues to cloud the distinction of these early onset forms of periodontitis.

A comparison of the reactivity of Eubacterium species with localized and serum immunoglobulins from rapidly progressive and adult periodontitis patients.

Immunoglobulins in sera and in supernatant fluids of explant cultures of diseased gingival tissues from 20 rapidly progressive and 20 adult periodontitis sites were tested by an ELISA assay for reactivity with typed strains of Eubacterium alactolyticum, E. brachy, E. limosum and E. nodatum. Immunoglobulins present in tissue culture fluids from both rapidly progressive and adult periodontitis samples reactive with E. brachy and E. nodatum were significantly greater (P less than 0.05) than those reactive with E. alactolyticum or E. limosum. The titers to E. brachy in tissue culture fluids from adult periodontitis were significantly greater (P less than 0.05) than those from rapidly progressive periodontitis; there was no difference in titers to the other three species. The only significant difference in serum titers was that sera from patients with rapidly progressive periodontitis had significantly greater reactivity to E. alactolyticum than did sera from adult periodontitis patients. These data indicate that immunoglobulins in the sera of rapidly progressive and adult periodontitis patients do not necessarily reflect the reactivity of localized immunoglobulins present in the diseased gingival tissue explant culture fluids from these patients.

Accelerated healing of carbon dioxide laser burns in rats treated with composite polyurethane dressings.

Healing time, infection rate, and residual scar formation were compared in carbon dioxide laser burns in rats treated in four ways: Spandra composite dressing, OpSite composite dressing, Petrolatum Gauze (USP), and no treatment. There were no infections and no differences in scar formation among the treatment groups. The mean healing times were ten days for the polyurethane dressings (Spandra and OpSite), 13 days for Petrolatum Gauze, and 16 days for the untreated group. Spandra was easier to apply and handle than OpSite. These findings suggest that synthetic gas-permeable dressings promote healing after cutaneous carbon dioxide laser surgery more effectively than conventional treatments of ointment-impregnated gauze or leaving the wound exposed to the air.

Effect of periodontal therapy on specific antibody responses to suspected periodontopathogens.

The effects of clinically successful periodontal therapy were studied in juvenile periodontitis (JP) and rapidly progressive periodontitis (RP) patients and compared with periodontally healthy subjects (HS). Serum samples were obtained in 35 HS prior to the study and in 12 of these subjects 3-4 years later. Serum samples were obtained from 50 JP patients initially, 9 subjects immediately following surgical therapy and 29 of these subjects 3-4 years later. RP patients provided 46 initial serum samples, 9 following therapy and 27 samples 3-4 years later. Antibody levels were determined utilizing a standardized enzyme-linked immunosorbent assay with Bacteroides gingivalis, B. ochracea, Fusobacterium nucleatum and Actinobacillus actinomycetemcomitans serving as antigens. The JP patients showed an initial rise in antibody levels immediately following therapy followed by a significant decrease in antibody levels 3 to 4 years later. The RP patients did not show an early change in antibody levels but by 3 to 4 years post-therapy, antibody levels had significantly decreased. However, during this study, the antibody levels of JP and RP patients remained significantly higher when compared with HS patients.

A clinical, demographic and microbiologic study of ANUG patients in an urban dental school.

35 ANUG patients were examined and compared clinically and demographically. Plaque removed from ulcerated sites in 20 patients was cultured using quantitative anaerobic procedures and examined by electron and darkfield microscopy. Patients were classified as having ANUG when presenting with ulceration and necrosis of interproximal papillae, pain and bleeding. The clinical symptoms of fetid odor, pseudomembrane formation, lymphadenopathy and elevated body temperature were present in 97%, 85%, 61% and 39% of the ANUG patients, respectively. 83% of the patients were smokers. The ANUG patients demonstrated a lower average age (24 years) than the general clinic population (32 years). There was a slightly higher % of male (54%) than female (46%) and the % of Caucasian (51%) and black (49%) ANUG patients were almost equal. Cultural studies revealed that gram-negative rods were the predominant cultivable micro-organisms present in the plaque, representing 78.2% of the total recoverable count. Of these, nearly half were strict anaerobes with Bacteroides gingivalis and Fusobacterium nucleatum accounting for 7.8% and 3.4%, respectively. Anaerobic and facultative gram-positive cocci (15.5%), gram-negative cocci (3.5%) and gram-positive rods (2.8%) were also isolated. Microscopic analysis of the morphologic composition of plaque revealed that rods (43%) constituted the greatest % of the total microorganisms observed followed by spirochetes (30%) and cocci (27%). 8 distinct types of spirochetal periplasmic flagellar arrangement were observed by electron microscopy, the "2-4-2" periplasmic flagellar arrangement being most numerous.

Systemic antibody response of clinically characterized patients with antigens of Eubacterium brachy initially and following periodontal therapy.

Eubacterium brachy, a gram-positive anaerobic rod, has been implicated by cultural studies to be associated with the microflora of periodontal diseases. Serum samples from 184 clinically characterized patients were evaluated in a standardized enzyme-linked immunosorbent assay (ELISA) for reactivity to E. brachy antigens. Sera from clinically healthy subjects (HS) served as controls. Sera from rapidly progressive periodontitis (RP) patients demonstrated significantly greater reactivity by ELISA than did HS when reactivity with E. brachy antigens was determined (P less than 0.05). Juvenile periodontitis (JP) and adult periodontitis (AP) patients did not differ in reactivity by ELISA from HS (P greater than 0.05). Three to 4 years following successful periodontal therapy, reactivity was not significantly altered in any patient group (P greater than 0.05). The possible significance of these findings and the importance of an extracellular antigen of E. brachy in the immunopathology of periodontal diseases are discussed.