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Biomedical subjects

M Midda

Publications and source records attributed to M Midda.

At least 19 recordsLinked to original sources
PubMed1994

A laboratory investigation of the bactericidal effect of a NdYAG laser.

Laser irradiation produces bactericidal effects which may be of use in dentistry. The aims of this study were to investigate the effect of pulsed NdYAG laser irradiation on bacteria in a laboratory model, in the presence and absence of a black dye, Suomi ink. The experiments were carried out in small capillary tubes containing a measured volume of Enterococcus faecalis broth culture. This model simulated the number of organisms that could be expected to occur in an infected root canal. Laser irradiation was delivered from a NdYAG laser via a 320-microns fibre. Powers of 0.3 to 3.0 W were used for 20 to 60 s. Controls received no irradiation. The effect of the black dye was investigated by the addition of a fixed volume to the culture before lasering. The treatments were evaluated for bactericidal effect by comparing the number of viable bacteria remaining in the irradiated and the control specimens. At energy doses of 54 J and above, without black dye, a reduction of 10,000-fold or greater occurred. A similar reduction was achieved at energies above 25 J when black dye was added. These results indicate the energy levels which should be investigated to assess the potential role of the NdYAG laser in endodontics.

Colony Count, Microbial↗
PubMed1993

The periodontal abscess--a case report.

Determining the causative factors of dental abscesses continues to tax the diagnostic skills of clinicians. A case is discussed of an unusually presenting chronic periodontal abscess involving the bifurcation of the upper left first premolar.

Bicuspid↗
PubMed1992

NdYAG laser treatment of dentinal hypersensitivity.

Eighteen per cent of all patients have some degree of sensitivity and a range of therapies has been devised to alleviate this condition. An electronic monitoring machine was constructed which allowed for air stream, directed at a patient's tooth, to be started by the clinician and halted by the patient when the sensation of pain in the tooth became too unpleasant to tolerate. The time for which the patient could tolerate the air flow was electronically measured in units of 1/50th second. By measuring the patient's reaction time on each visit and correcting the readings obtained for 'tooth pain time' using these figures, a quantitative measure of sensitivity change is achieved. Using this system, a clinical trial has been conducted to test the efficacy of the NdYAG dental laser. The 30 patients treated had an average tooth pain time initially of 1.2 seconds. Following laser treatment patients were recalled at 3, 7 and 14 days. At the 2-week review, this figure had increased to 7.8 seconds, which was found to be statistically significant. Control (unlased) teeth demonstrated an average improvement of only 1.7 seconds (not statistically significant). Patients' subjective assessment of sensitivity pain on a 0-10 scale averaged 8.0 before treatment. This reduced to 3.7 after treatment. Treatment of this condition can thus be performed easily and painlessly with a predictable response and considerable patient satisfaction.

Adult↗
PubMed1992

Update on periodontology: 3. Initial preparation.

Over the last two decades there have been many changes in the basic concepts of periodontology, which have had profound effects on clinical practice. The aim of this series is to highlight the main areas of change to assist the busy GDP in staying up-to-date. Part 1 discussed current concepts in the histopathology of periodontal disease and part 2 looked at the problems of diagnosis. Part 3 will now examine the central role of plaque control in periodontics.

Dental Plaque↗
PubMed1992

Lasers in periodontics.

Clinical lasers are of two types. Soft lasers are essentially an aid to healing, with relatively few rigorous studies available to support their use. Surgical hard lasers, however, can cut both hard and soft tissues, replacing the scalpel and drill in many areas. After initial experiments with the ruby laser, most clinicians have been using argon, carbon dioxide, and now Nd:YAG systems. The first dental laser based on a Nd:YAG engine provides handpieces of similar size to conventional instrumentation, and being fed by a fibre-optic "cable," has the flexibility for intra-oral use that the carbon dioxide lasers, widely used in oral surgery, lack. Furthermore, extensive clinical investigation has demonstrated their safety in clinical practice, and the fact that procedures can usually be performed without a local anaesthetic is obviously seen as an advantage by patients. Sterilizing as it cuts, the Nd:YAG laser promises to find uses not only in caries removal and soft tissue surgery but also in periodontics and endodontics.

Dentin Sensitivity↗
PubMed1992

The use of lasers in periodontology.

Clinical lasers are of two types: "soft" and "hard" lasers. Soft lasers are claimed to aid healing and to reduce inflammation and pain. However, few rigorous studies are available to support their use. Surgical hard lasers can cut both hard and soft tissues, and newer varieties can transmit their energy via flexible fiberoptic cables. Many procedures can be performed without local analgesia, and because lasers sterilize as they cut, in spite of current controversies, they promise to find uses in all disciplines of dentistry, including periodontics.

Aluminum↗
PubMed1991

Lasers in dentistry.

Clinical lasers are of two types; soft lasers are essentially an aid to healing with relatively few rigorous studies available to support their use. Surgical hard lasers, however, can cut both hard and soft tissues and replace the scalpel and drill in many areas. From initial experiments with the ruby laser most clinicians are using Argon, CO2 and now NdYAG systems. The first dental laser based on a NdYAG engine provides handpieces of similar size to conventional instrumentation and, being fed by a fibre-optic 'cable', has the flexibility for intra-oral use that the CO2 lasers, widely used in oral surgery, lack. Furthermore, extensive clinical investigation has demonstrated their safety in clinical practice and the fact that procedures can usually be performed without a local anaesthetic is obviously seen as a considerable advantage by patients. Sterilising as it cuts, the NdYAG laser promises to find uses not only in caries removal and soft tissue surgery, but also in endodontics and gingival curettage.

Dental Instruments↗
PubMed1991

MHC antigen expression in human oral squamous carcinoma cell lines.

This study quantified the constitutive and interferon-gamma (IFN-gamma) stimulated expression of MHC class I (HLA-ABC and beta 2 microglobulin) and class II antigens (HLA-DR, -DP, -DQ) on normal and malignant oral keratinocytes using radioimmunoassay and immunocytochemical techniques. Normal keratinocytes and three of four malignant cell lines (H103, H157, H314) expressed MHC class I antigens constitutively; IFN-gamma increased MHC class I expression with significant changes in normals, H157 and H314. Normal keratinocytes expressed significantly more constitutive MHC class I antigens than H103 and H157 and significantly more IFN-gamma stimulated MHC class I antigens than H103, H157 and H314. MHC class II antigens predominantly were not expressed constitutively on normals, H103 and H157 but, in H314, HLA-DR, -DP and -DQ antigens were demonstrated on 35, 11 and 5 per cent of cells, respectively, and resulted in a non-coordinated pattern of expression (HLA-DR greater than -DP = -DQ). IFN-gamma induced HLA-DR on normals, H103 and H157, whilst HLA-DP and -DQ remained undetectable. In H314, IFN-gamma enhanced HLA-DR, -DP and -DQ (significant increase of HLA-DQ) but the interrelationship between these antigens was maintained (HLA-DR greater than -DP = -DQ). Normal keratinocytes expressed significantly more IFN-gamma stimulated HLA-DR than H103 and H157 but significantly less HLA-DR than H314 under similar experimental conditions. One oral malignant cell line (H191) did not express MHC class I and MHC class II antigens either constitutively or in response to IFN-gamma. The results demonstrate aberrant patterns of MHC expression (absence, enhanced, diminished) in the different malignant oral keratinocyte cell lines.

Carcinoma, Squamous Cell↗
PubMed1991

The influence of puberty on spirochetal numbers assessed by dark field microscopy: a pilot study.

There seems to be a difference in the susceptibility, prevalence and severity of periodontal disease between children and adults. These differences could be due to; composition of plaque, host response or tissue alterations occurring with age. One of the micro-organisms suspected to play a role in the initiation of periodontal disease is the spirochete. A quick and simple way to observe spirochetes is via dark-field microscopy. The present study sample subgingival plaque from the crevices of 6 prepubertal and 6 postpubertal children and observed it under darkfield microscopy. The technique did not involve dispersion. The results showed a higher percentage of spirochetes for the postpubertal group (15.19% in the prepubertal and 21.62% in the postpubertal) but statistical analysis failed to show any significant difference. The small size of the sample, the variety in the technique and the clinical measurements influence the result.

Adolescent↗
PubMed1991

Update on periodontology: 1. Current concepts in the histopathology of periodontal disease.

Over the last two decades there have been many changes in the basic concepts of periodontology, which have had profound effects on clinical practice. The aim of this series is to highlight the main areas of change and to assist the busy general practitioner in staying up-to-date. The first article deals with the current understanding of the histopathogenesis of gingivitis and periodontitis.

Humans↗
PubMed1990

Adult linear immunoglobulin A disease manifesting as desquamative gingivitis.

Desquamative gingivitis is a manifestation of various dermatoses, particularly lichen planus and mucous membrane pemphigoid. A rare example of adult linear immunoglobulin A disease manifesting as desquamative gingivitis is presented. Although the initial clinical features were typical of desquamative gingivitis, the persistence of ulceration after dental extractions was unusual, and the management of the oral lesions proved difficult. The clinical, immunopathologic, and therapeutic aspects of linear immunoglobulin A dermatoses are reviewed.

Aged↗
PubMed1990

Guided tissue regeneration: an overview.

In recent years a new technique in periodontal surgery, known as guided tissue regeneration, has been developed in Scandinavia and the USA. After raising a flap and debriding the root surface, an inert membrane is placed between the flap and the underlying tissues. This allows the periodontal ligament to regain some of the connective tissue attachment lost during the disease process, something which has been unobtainable until now. The purpose of this paper is to review the area of periodontal reattachment and to introduce the new technique of guided tissue regeneration.

Connective Tissue↗
PubMed1989

An inverted upper lateral incisor.

A case is presented of an inverted upper lateral incisor in an 11-year-old patient. It is believed that involvement of this tooth is previously unreported.

Child↗