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Biomedical subjects

Lucio Montebugnoli

Publications and source records attributed to Lucio Montebugnoli.

11 recordsLinked to original sources
PubMed2006

Merkel cells in the oral mucosa.

Ninety-eight consecutive surgical biopsies of oral mucosa from 96 patients were evaluated immunohistochemically with an anti-cytokeratin 20 (CK 20) anti-body to evidence Merkel cells (MC). Fifteen cases, showing the highest number of MC, were additionally studied with chromogranin A, S-100 protein, neuro filaments, epithelial membrane antigen, and double immunostaining for CK 20 and Ki67 antibodies to evaluate MC proliferation. Electron microscopy was performed in 2 cases. MC were observed in 58 cases. The highest number of MC was found in the gingival, buccal, and palate mucosa, especially in chronically damaged oral mucosa (lichen and chronic aspecific inflammation) as well as in the mucosa overlying tumors rather than in normal or acute inflammation. MC were not observed in dysplastic or neoplastic epithelium. MC showed evidence of proliferation, as demonstrated by Ki67 positivity, in 3 cases. In conclusion, MC appear to play a role in the reparative processes of oral mucosa.

Adolescent↗
PubMed2005

Molecular detection of Treponema denticola and Porphyromonas gingivalis in carotid and aortic atheromatous plaques by FISH: report of two cases.

Treponema denticola and Porphyromonas gingivalis have been identified in atheromatous plaques of two patients suffering from atherosclerosis by PCR and fluorescence in situ hybridization (FISH). The use of the FISH technique suggested that these periodontopathic micro-organisms might be metabolically active within the wall of arteries, under the atherosclerotic lesion.

Aged↗
PubMed2005

Treponema denticola infection is not a cause of false positive Treponema pallidum serology.

It has long been assumed that parodontal disease can be a cause of false positive results in syphilis serology, but so far there are no definitive data supporting this hypothesis. In this study we tested 250 serum samples obtained from blood donors. All of them were negative when routinely screened for antibodies against Treponema pallidum. Then, all these samples were tested by immunoenzymatic (ELISA) and Western Blot (WB) assays to investigate reactivities against T. denticola. Thirteen samples showed a strong positivity when tested by both methods. When tested by WB against T. pallidum no sample met the positivity criteria. Nevertheless, bands with molecolar weights of about 30-35 KDa (endoflagellar core antigens) were recognized. All the 13 subjects serologically T. denticola positive underwent oral clinical and radiological observation: all showed a very poor parodontal status (CPSS > 103). Eleven crevicular fluid samples out of the total of 13 patients were T. denticola positive by Real Time PCR carried out using a LightCycler system. In this study we demonstrated that the presence of T. denticola in the crevicular fluid samples obtained from patients with a severe periodontal status and/or a positive serology against T. denticola is not a cause of false positive results in syphilis serology.

Antibodies, Bacterial↗
PubMed2005

Failure of anti-retraction valves and the procedure for between patient flushing: a rationale for chemical control of dental unit waterline contamination.

PURPOSE: To evaluate the efficacy of anti-retraction valves; and to compare between-patient flushing with water and with using a chemical treatment to control patient-to-patient contamination through dental unit waterlines (DUWL). METHODS: For the first aim, nine new antiretraction valves from three different manufacturers were utilized. Each valve was installed along the water line connecting the high-speed handpiece to the dental unit. The handpieces were made to run and stop in a container filled with a solution of about 7 log10/mL of Bacillus subtilis spores (used as a marker) and retraction of spores was measured. Subsequently, all nine valves were installed in dental units in use in private offices, and all tests repeated after 15, 30 and 60 working days. For the second aim, the efficacy of mechanical flushing (30 seconds for each instrument) was compared with that of mechanical flushing in combination with pressurized air and of a between-patient disinfecting procedure (2 minutes contact with TAED and persalt utilizing an "autosteril" system). Before each test (10 tests for each procedure), known concentrations of Pseudomonas aeruginosa (ATCC 27853) suspension (4 to 7 log10cfu/mL) was loaded in the DUWL and let sit for 20 minutes. RESULTS: In the anti-retraction valve experiment, at baseline only one anti-retraction valve showed a failure in opposing fluid retraction. After 15 days, three valves, after 30 days, six valves, and after 60 days, eight valves showed failure. In the flushing experiment, a highly significant linear correlation (r =.9178) was found between values before and after mechanical flushing. Post flush log10cfu/mL values showed the removal of about only 1 log10cfu/mL of the microorganisms (only about 10% in absolute counts). On the other hand, no cfu/mL was detected in waterlines after the "autosteril" disinfecting cycles.

Colony Count, Microbial↗
PubMed2004

Appearance of the root canal walls after preparation with NiTi rotary instruments: a comparative SEM investigation.

The aim of this study was to evaluate, in vitro, with scanning electron microscope (SEM), the appearance of root canal walls shaped by three different rotary NiTi techniques and one conventional manual technique in human extracted teeth. Four different instruments were used: K3, Hero 642, RaCe and K-file. Each sample was irrigated with 5 ml of 5% NaOCl and 5 ml of 3% H2O2 and EDTA, Rc-Prep (1 ml). Each sample was prepared for SEM observation and analyzed in the coronal, middle and apical third, comparing its aspect with a predefined scale of four different parameters: presence of smear layer, pulpal debris, inorganic debris and surface profile. The apical third showed significantly more pulpal and inorganic debris, smear layer and a high number of surface profile irregularities. No significant difference was found at the coronal, middle and apical thirds between manual and rotary techniques for inorganic debris, smear layer and surface profile. Much pulpal debris were found in the apical third for K3 and RaCe compared with Hero 642 and K-file. In conclusion, mechanical rotary techniques with NiTi instruments produced quite similar results compared with a conventional manual technique using K-files. The present study demonstrated that dentin and pulpal debris, the morphology of smear layer and surface profile were only partially influenced by the type of endodontic instruments. The apical third was the anatomical area with greater amount of debris and smear layer.

Analysis of Variance↗
PubMed2004

Heart rate variability: a sensitive parameter for detecting abnormal cardiocirculatory changes during a stressful dental procedure.

BACKGROUND: The authors conducted a study to evaluate the sensitivity of heart rate variability, or HRV, in quantifying the cardiocirculatory reaction to dental stress compared with other clinical parameters more frequently used in clinical practice. METHODS: Twenty-five healthy subjects (15 men and 10 women aged 19 through 73 years) who underwent dental extractions were enrolled in the study. The authors measured systolic blood pressure, or SBP; diastolic blood pressure, or DBP; heart rate, or HR; and HRV at baseline, immediately after local anesthetic was administered, during the dental extraction and five minutes after the dental extraction. Time domain measures of HRV were based on interbeat intervals and were obtained by using standard deviations of the R-R intervals, which were calculated during a five-minute period in a continuous electrocardiographic record. RESULTS: Analysis of variance for repeated measures showed no time-related difference between the four study periods with regard to SBP and DBP. However, HR values were significantly different in three of the four periods, and HRV values were significantly different in all four testing periods. Furthermore, HRV values exhibited greater variability in the maximum changes recorded during dental extractions compared with HR values (0 to 80 milliseconds versus 0 to 31 beats/minute, respectively). CONCLUSIONS: HRV is a highly sensitive parameter for quantifying the sympathetic drive to the heart during a cardiovascular reaction to a dental operation. CLINICAL IMPLICATIONS: Clinicians may find that HRV evaluation is useful in monitoring patients with heart disease to detect early signs of cardiac impairment related to local, high sympathetic activity and to prevent cardiovascular emergencies.

Adult↗
PubMed2003

Permeability and morphology of dentin after erosion induced by acidic drinks.

BACKGROUND: The aims of this study were to evaluate 1) the alterations of dentin permeability after single exposure of dentin to several acidic soft drinks with different acid composition; 2) the effectiveness of smear layer on dentin surface to prevent erosion of sound dentin; and 3) the role of brushing procedures. METHODS: Dentin discs from human third molars were prepared. Each disc was treated with 0.5 M neutral EDTA for 5 minutes to remove the smear layer and to calculate the maximum fluid flow rate for each disc (to which an arbitrary value of 100% was assigned) using a pressure apparatus working at 1.0 psi. An homogeneous thin smear layer was then recreated with an abrasive paper under water. The following acidic drinks were applied for 5 minutes onto dentin surface: cola drink (phosphoric acid), orange fruit juice (ascorbic + citric acid), white wine (tartaric acid), vinegar (acetic acid), and mucolytic syrup (benzoic and tartaric acid). Each sample was then brushed for 3 minutes. Finally, each sample was brushed with a toothpaste and, as the final step, etched with phosphoric acid for 1 minute. Permeability was measured after each step. RESULTS: All acidic drinks were able to statistically increase dentin permeability and to open dentinal tubules by removing the smear layer. CONCLUSIONS: The study demonstrated that acidic drinks increased dentin permeability by removing and dissolving the smear layer and smear plugs. The erosion of peritubular dentin and smear plug removal is the main agent responsible for the increase in dentin permeability and probably for clinical dentin hypersensitivity. Brushing procedures reduced dentin permeability, creating a new fine and thin smear layer. Toothpaste may play a protective role in preventing complete smear layer removal and reducing dentin hypersensitivity by producing a new artificial smear layer and deposit inside tubules. The use and the abuse of acidic drinks may damage dentin and increase the risk for dentin hypersensitivity.

Acids↗
PubMed2002

Effectiveness of metronidazole gel on cyclosporine-induced gingival overgrowth in heart transplant patients.

To evaluate the efficacy of metronidazole on cyclosporine-induced gingival overgrowth (GO), a prospective intra-subject double-blind longitudinal study was performed on six heart transplant patients with GO. All patients underwent scaling and root planing before any treatment. Metronidazole gel (Elyzol, Cabon) was then applied in two of the four anterior hemi-sextants of each subject, following a balanced random pre-programmed list, with a placebo gel being applied to the remaining two hemi-sextants. Plaque index (PI), bleeding on probing (BP) and probing depth (PD) were recorded for all teeth of the four anterior hemi-sextants before and at 1, 2, 3, and 4 months after gel application. A general linear model was fitted and ANOVA for repeated measurements with split-plot design and Chi-square analysis were used for statistical analysis. PD significantly decreased after 1 month following both treatments. Analogous results were obtained as regards PI and BP. No statistically significant difference was detected between results obtained with metronidazole and placebo. However, PD in the group of teeth treated with placebo significantly increased after 4 months, while PD values obtained from teeth treated with metronidazole remained statistically unchanged with respect to the 1st month. In conclusion, short-term results suggest that metronidazole and placebo are equally effective in reducing periodontal parameters and GO when associated with scaling and root planing. Long-term results, however, showed greater efficacy of metronidazole with respect to placebo in controlling cyclosporine-induced GO.

Analysis of Variance↗
PubMed2002

A new chemical formulation for control of dental unit water line contamination: An 'in vitro' and clinical 'study'

BACKGROUND: Water delivered by dental units during routine dental practice is highly contaminated. The aim of this study is to evaluate the efficacy of a new chemical solution flushed through Dental Unit Water Lines (DUWL) for the control of contamination inside dental units. MATERIALS AND METHODS: Six old dental units equipped with a device designed to automatically flush disinfecting solutions through the water system (Castellini Autosteril) were selected. Water samples from DUWL effluents were collected in each dental unit for 10 randomly selected days, before and after a 5 minute DUWL disinfecting cycle with TetraAcetylEthileneDiamine (TAED) and persalt (Ster4spray produced by Farmec spa, and distributed by Castellini spa). Water samples were plated in R2A Agar and cultured at room temperature for 7 days, and the total number of heterotrophic microorganisms counted and expressed in Log10 CFU/mL A general linear model was fitted and multiple regression ANOVA for repeated measures was used for the statistical analysis. RESULTS: The mean contamination in DUWL effluent at baseline was 5.45 &#PlusMinus; 0.35 CFU/mL (range 4.79 to 5.93 CFU/mL). When water samples were tested "in vitro" against the chemical, no growth of heterotrophic bacteria was detected after a 5 minute contact in any of the water samples tested. After undergoing a 5 minute disinfecting cycle with the chemical, DUWL mean contamination in water effluents was 2.01 &#PlusMinus; 0.32 CFU/mL (range 1.30 to 2.74 CFU/mL) (significant difference with respect to baseline). CONCLUSIONS: An inbetween patient disinfecting procedure consisting of flushing DUWL with TAED and persalt equivalent to 0.26% peracetic acid could be useful in routine dental practice for cross-contamination control.

Journal Article↗
PubMed2002

Circulatory dynamics during dental extractions in normal, cardiac and transplant patients.

BACKGROUND: The authors conducted a study to evaluate the relationship between the circulatory dynamics of patients with heart disease and these patients' cardiac status when undergoing dental extractions. METHODS: Subjects with minimal heart disease, or MHD; with severe heart disease, or SHD; or who received a heart transplant, or TRAN; as well as control, or NOR, subjects were enrolled in the study. The authors recorded subjects' systolic blood pressure, or SBP; diastolic blood pressure, or DBP; and heart rate, or HR, while they were under basal conditions and during postanesthesia and dental extraction periods. The authors estimated a general linear model and performed analysis of variance. RESULTS: Under basal conditions, MHD subjects did not show significantly different mean blood pressure values compared with NOR subjects but did show slightly significantly higher mean HR values. Mean DBP and HR values were significantly higher in SHD and TRAN subjects than in MHD and NOR subjects, while SBP values in SHD subjects were significantly lower than those in MHD, TRAN and NOR subjects. During dental extraction sessions, SBP, DBP and HR mean values increased significantly compared with basal conditions and post-anesthesia periods in MHD and NOR subjects. SHD and TRAN subjects showed no significant time-dependent variation during dental extraction sessions in any circulatory parameter. CONCLUSIONS: MHD subjects had cardiovascular responses to stress similar to those of NOR subjects, while SHD and TRAN subjects had similar slight and dulled cardiac responses. CLINICAL IMPLICATIONS: Patients with SHD may not be able to adapt their cardiac performance to an emotional stress such as a dental appointment, while it seems to be easier for MHD and TRAN patients. Managing TRAN patients is relatively easier than managing SHD patients.

Adult↗