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Biomedical subjects

A Carrassi

Publications and source records attributed to A Carrassi.

At least 37 records · Page 2Linked to original sources
PubMed1997

Local antimicrobial therapy of oral mucositis in paediatric patients undergoing bone marrow transplantation.

The present investigation has examined the clinical benefits of tobramycin, polymyxin E and amphotericin therapy in the management of oral mucositis in children undergoing chemotherapy prior to bone marrow transplantation. Tobramycin, polymyxin E, and amphotericin reduced the degree of oral mucositis more than conventional therapy of diphenhydramine, Maalox, and local analgesic. While there was a statistically significant fall in the severity of the mucositis with tobramycin, polymyxin E and amphotericin, this was unlikely to be of practical benefit.

Adolescent↗
PubMed1997

The effect of surface roughness on early in vivo plaque colonization on titanium.

THE STUDY ASSESSES IN VIVO the surface roughness necessary to reduce plaque colonization on titanium after 24 hours. Three groups of 16 titanium disks were assigned to 3 different polishing groups (A, B, and C). The roughness was evaluated with a laser profilometer and the morphology with a scanning electron microscope (SEM). Eight volunteers were enrolled and two stents were applied in the mandibular posterior region of each. Each stent supported 3 disks, one per group. The volunteers suspended oral hygiene for 24 hours, after which the stents were removed; one was processed for evaluation of the adherent biomass and the other for SEM study. On each specimen a global area of 100 x 125 microns was examined with SEM. The area was composed of five 20 x 25 microns randomly selected fields. For each field the density of bacteria and the morphotypes were recorded. The data quoted for the global area are cumulative of those observed in the 20 x 25 microns fields. Group A had a significantly smoother surface than groups B and C. The adherent microbial biomass determination and SEM evaluation revealed that group A contained less bacteria than the roughest group. The bacterial population was composed of cocci in group A, and of cocci and short and long rods in groups B and C. We conclude that a titanium surface with Ra < or = 0.088 microns and Rz < or = 1.027 microns strongly inhibits accumulation and maturation of plaque at the 24-hour time period and that such smoothness can be achieved in transgingival and healing implant components.

Analysis of Variance↗
PubMed1996

Prevalence of oral lesions in inflammatory bowel disease.

OBJECTIVE: To obtain precise data on the prevalence of oral lesions in inflammatory bowel disease (IBD). METHODS: Oral lesions were carefully sought in a consecutive series of 198 Italian IBD outpatients, 77 with Crohn's disease (CD) and 121 with ulcerative colitis (UC); 89 subjects with functional intestinal motility disorders served as controls. RESULTS: The oral lesions detected were angular cheilitis (in 7.8% of CD patients, 5% of UC patients, and 0% of controls (p < 0.05, patients vs controls), lichen (6.5, 5.8, and 3.3%, respectively, p = not significant), aphthous ulcers (5.2, 5.8, and 5.6%, respectively, p = not significant), candidiasis (5.2, 0.8, and 0%, respectively, p < 0.05, CD patients vs controls), benign tumors (5.2, 0, and 7.8%, respectively, p < 0.05, patients vs controls), leukoplakia (5.2, 11, and 3.3%, respectively, p = not significant), and, less frequently, glossitis and herpes labialis. No specific CD oral lesions were observed in this series. No correlation was found between clinical disease activity and frequency of oral lesions. CONCLUSIONS: Aphthous ulcers are not common in IBD patients. Oral candidiasis is more frequent in CD than UC patients and controls.

Adolescent↗
PubMed1996

[Hepatitis C and dentistry. Review of the literature].

In 1988 the RNA virus responsible for the majority of cases of parenteral non A, non B hepatitis (NANBH) was isolated and designated Hepatitis C Virus (HCV). Since then, the sequence of the genome of the virus has been defined and at least 10 different types identified. Clinical studies indicate that the majority of patients who acquire HCV develop chronic hepatic disease, in particular chronic active hepatitis or cirrhosis and some of them will develop hepatocellular carcinoma. Currently, there is no effective anti-HCV therapy and no passive or active immunization protocol for HCV. Epidemiological studies indicate that HCV infection is relatively well confined to specific patient populations, in particular injecting drug users and recipients of blood and blood products. Nevertheless as HCV infection is transmitted mainly parenterally it must be regarded as a potential hazard for dental health care staff. This article reviews current knowledge concerning HCV infection with particular attention to those issues relevant to the dentists in Italy including the dental management of the HCV infected patient and the risk of HCV cross-infection in the dental environment.

Female↗
PubMed1995

Ultrastructure of hypersensitive and non-sensitive dentine. A study on replica models.

Patients with cervical dentine exposures do not always complain of dentine hypersensitivity. The identification of morphological features connected to symptoms is important for both prevention and management of dentine hypersensitivity. The aim of the study was to determine the relationship between the dentine ultrastructure and clinical symptoms in patients with cervical dentine exposures. Replica models for a total of 28 teeth (from 10 patients) with cervical non caroius lesions and dentine exposures were obtained before and after acid etching. The replica models were studied blindly in the scanning electron microscope (SEM). 12 of these were classified clinically as hypersensitive and 16 as non-sensitive. Because of the morphological heterogeneity of all specimens, a grid was used to isolate smaller, more homogeneous areas. 120 (75 non-sensitive and 45 hypersensitive areas) grid areas randomly selected from the 28 dentine surfaces were analyzed. The presence and morphology (amorphous or crystalline) of smear layers and the density and diameter of dentine tubules were recorded. The chi 2 test was used for statistical analysis. In unetched specimens, the surfaces classified as non-sensitive were frequently coated by an amorphous smear layer (88.0%) and occasionally by a crystalline smear layer (2.7%). Only a few and narrow tubules were observed (9.3%). On the other hand, the unetched specimens of the hypersensitive dentine exhibited less frequently (31.3%) an amorphous smear layer. The presence of crystalline smear layer (33.3%), many and wider patent tubules and, sometimes, loss of intertubular dentine manifested as grooves between tubules, were observed (35.6%). The differences were significant (p < .001). In hypersensitive dentine, the acid etching always removed the smear layer whereas removal in non-sensitive dentine was partial or absent. These morphological findings underline the rôle of smear layer in reducing permeability of dentine in patients with dentine sensitivity.

Acid Etching, Dental↗
PubMed1992

Prevention of local relapses and new localisations of oral leukoplakias with the synthetic retinoid fenretinide (4-HPR). Preliminary results.

This paper analyses preliminary results of a randomised chemoprevention trial in patients surgically treated for oral leukoplakia started in 1988 at the Istituto Nazionale Tumori of Milan with the synthetic retinoid N-(4-hydroxyphenyl)-retinamide (4-HPR). To date 115 patients have been randomised, after surgical excision of oral leukoplakia, to receive 200 mg 4-HPR daily for 52 weeks versus no intervention. 80 patients completed the 1-year intervention, 41 in the control group and 39 in the 4-HPR group. During this period 12 local relapses or new lesions occurred in the control group and three in the 4-HPR group. Only 5 patients interrupted the intervention because of toxicity. No impaired dark adaptation was observed. It is concluded that 4-HPR is well tolerated and seems efficacious in preventing relapses and new localisations during the treatment period. This promising trend needs further confirmation.

Adult↗
PubMed1991

[An assessment of the proliferative activity in oral lichen planus].

The author's aim was to evaluate the cell proliferation of oral lichen planus, by an in vitro labelling technique using tritiated thymidine (TLI). For this purpose six patients with oral lichen planus and six control volunteers with oral mucosa clinically sound were studied. The cell kinetic parameter was investigated by counting cells from autoradiographs on histological sections of the biopsies. Significant differences were found between the basal TLI of the two group (p = 0.002) but no between the epithelial TLI (Wilcoxon test).

Biopsy↗
PubMed1990

[Study of cellular kinetics in oral leukoplakia].

The Authors aim was to study the Labeling Indices (LI) of 12 subjects with oral leukoplakia, using an in vitro labeling technique with tritiated thymidine (Silvestrini-Kit, Ribbon spa, Milan). Twelve volunteers of our Dental Clinic were enrolled in this study as a control group. The kinetic parameter was investigated by counting cells from autoradiographs on histological selections of the biopsies. By a Wilcoxon test, significant differences were found between the LI of the two groups: p = 0.00003. Finally, a comparison has also been made between LI of these lesions and the LI of oral squamous cell carcinomas.

Adult↗
PubMed1990

A new method of bacterial identification using gold immunolabelling and scanning electron microscopy.

This study sought to develop an immunolabelling technique to identify specific bacteria by scanning electron microscopy. Bacterial suspensions were prepared of Actinobacillus actinomycetemcomitans, Porphyromonas (Bacteroides) gingivalis and mixtures of these species with other genera of common oral microorganisms. This method was also used to examine subgingival plaques from 6 subjects with chronic adult periodontitis. Sample preparation consisted of prefixation of the bacterial suspensions with 0.2% glutaraldehyde, incubation with species-specific rabbit antisera and goat anti-rabbit IgG conjugated with colloidal gold particles, postfixation in 2% glutaraldehyde and dehydration in ethanol. Finally, the samples were dried, coated with evaporated carbon and examined by scanning electron microscopy. Pure cultures and artificial mixtures of A. actinomycetemcomitans and Bact. gingivalis were specifically labelled by gold probes as demonstrated by both secondary and back-scattered imaging. These species were also evident in samples of subgingival plaque. The findings indicate that this new technique can be used to identify specific microorganisms both in plaque samples and on the root surface of extracted teeth.

Actinobacillus↗
PubMed1990

Identification of Actinobacillus actinomycetemcomitans by gold immunolabeling and scanning electron microscopy.

Recent evidence suggests that dental plaque is not a homogeneous bacterial mass but, on the contrary, specific bacterial morphotypes and species may be preferentially located within certain microenvironments. The aim of the present study was to develop combined gold immunolabeling and scanning electron microscopic (SEM) techniques for the identification of periodontal pathogens in subgingival dental plaque and on the root surfaces of extracted teeth. Suspensions of pure A. actinomycetemcomitans cultures or suspensions of A. actinomycetemcomitans mixed together with other oral bacteria were prepared, labeled with goat anti-rabbit IgG conjugated with 5 nm or 40 nm colloidal gold particles, and observed by SEM using both secondary and back-scattered imaging. Scanning electron microscopy demonstrated that the A. actinomycetemcomitans bacterial cell surface was specifically labelled. There was no cross-reaction with any of the other bacterial morphotypes. Only the labeled A. actinomycetemcomitans were visible in mixtures examined by back-scattered imaging scanning electron microscopy. The combined techniques of gold immunolabeling and SEM may, therefore, be useful in identifying A. actinomycetemcomitans in subgingival plaque samples and on the root surfaces of extracted teeth as well as in studies of bacterial ecology in dental plaque, in general.

Actinobacillus↗
PubMed1989

Impacted molars.

Explore the source record for details and available documents.

Humans↗
PubMed1989

Early plaque colonization on human cementum.

We have described the morphology of developing plaque on cementum in an in vivo human model. Slabs of cementum obtained from sound teeth, rendered anorganic with 5% sodium hypochlorite, were glued to orthodontic brackets and positioned on the upper canines, premolars and molars in 8 volunteers. The brackets were removed after 2, 4, 8, 24 h and processed for scanning electron microscopy (SEM). Within 2 h, a thin pellicle covered the cementum surface, with few micro-organisms detectable. At 4 and 8 h, coccoid plaques were present. Filaments inserted perpendicularly to the plaque surface were seen at 24 h. The results indicate that early bacterial colonization of human cementum is a selective process, mediated by an organic pellicle and mainly involves cocci.

Bacteria↗
PubMed1989

Periodontitis in a patient with chronic neutropenia.

The aim of this investigation was to obtain information about the composition and the morphology of the microorganisms that inhabit the root surface of a patient with chronic neutropenia and severe and progressive periodontitis. In addition, gingival biopsies were studied by both scanning and transmission electron microscopy (SEM and TEM) to look for bacteria within the gingiva. Dark field microscopy (DFM) revealed 50% spirochetes, 30% motile rods, and 20% coccoid forms. Fourteen extracted teeth studied by SEM showed that the distribution of different bacterial morphotypes varies along the root surface and spirochetes are the prevailing bacteria on the most apically located plaque. TEM analyses of gingival tissue revealed no bacterial invasion within the gingiva. This study suggests that spirochetes may play an important role in the etiology of periodontitis associated with chronic neutropenia. In spite of neutropenic status, there was no bacterial invasion into the gingiva, suggesting that host reaction to dental plaque has not been abolished in this condition.

Adult↗
PubMed1989

[Amount of mineralized tissue removed by root planing].

The Author's aim was to determine the amount of mineralized tissues removed during root planing conducted by means of a curette, using a profilometer. Records were kept at time 0 and after 4 cycles of 5 strokes each. Mean values of final records show that the average of tissue removal, expressed in microns, was greater than the mean thickness of cementum in the instrumented areas.

Dental Cementum↗
PubMed1989

[Precancerous oral lesions. Diagnostic and therapeutic protocol].

The NRC (National Research Council) task force on head and neck cancer issued this document to help clinicians involved in diagnosing and treating precancerous oral diseases. Chapter 1 includes definition, epidemiology, risk factors (alcohol, smoking, poor oral hygiene), WHO classification, clinical picture of leukoplakias, erythroplasia, lichen planus, as well as their natural history. Chapter 2 points out the clinical signs to be looked for in order to make a proper diagnosis and discusses biopsy techniques. Chapter 3 deals with therapeutic procedures (surgical technique and medical treatment), while Chapter 4 concerns follow-up according to the clinical and histological diagnosis. Finally, some statistical forms are enclosed: Form 1 consists of information regarding educational qualifications, occupation, alcohol consumption, smoking and dietary habits; Form 2 consists of information about previous diseases and the history of the present disease; Form 3 records the signs and symptoms observed for the precancerous lesion; Form 4 records treatment modalities; Form 5 records patient follow-up.

Humans↗