Biomedical subjects

M N Mandikos

Publications and source records attributed to M N Mandikos.

5 recordsLinked to original sources

PubMed2001

A comparison of the wear resistance and hardness of indirect composite resins.

STATEMENT OF PROBLEM: Various new, second-generation indirect composites have been developed with claimed advantages over existing tooth-colored restorative materials. To date, little independent research has been published on these materials, and the properties specified in the advertising materials are largely derived from in-house or contracted testing. PURPOSE: Four second-generation indirect composites (Artglass, belleGlass, Sculpture, and Targis) were tested for wear resistance and hardness against 2 control materials with well-documented clinical application. Human enamel was also tested for comparison. MATERIAL AND METHODS: Twelve specimens of each material were fabricated according to the manufacturers' directions and subjected to accelerated wear in a 3-body abrasion, toothbrushing apparatus. Vickers hardness was measured for each of the tested materials, and energy dispersive x-ray (EDX) spectroscopy was performed to determine the elemental composition of the composite fillers. The statistical tests used for wear and hardness were the Kruskal-Wallis 1-way ANOVA test with Mann-Whitney tests and 1-way ANOVA with multiple comparisons (Tukey HSD). The Pearson correlation coefficient was used to determine the existence of a relationship between the hardness of the materials and the degree to which they had worn. The level of statistical significance chosen was alpha=.05. RESULTS: The control material Concept was superior to the other composites in wear resistance and hardness and had the lowest surface roughness. Significant relationships were observed between depth of wear and hardness and between depth of wear and average surface roughness. Enamel specimens were harder and more wear resistant than any of the composites. EDX spectroscopy revealed that the elemental composition of the fillers of the 4 new composites was almost identical, as was the composition of the 2 control composites. CONCLUSION: The differences in wear, hardness, and average surface roughness may have been due to differences in the chemistry or method of polymerization of the composites. Further research in this area should be encouraged. It was also apparent that the filler present in the tested composites did not exactly fit the manufacturers' descriptions.

Acrylic Resins↗

PubMed1998

Construction faults, age, gender, and relative medical health: factors associated with complaints in complete denture patients.

STATEMENT OF PROBLEM: Many practitioners will experience a situation, whereby a patient with newly fabricated complete dentures continues to experience difficulty in adapting to them. This can lead to a protracted period of discouraging "adjustment appointments" that may not result in the eventual resolution of the problem. Therefore it is often concluded that there is some patient factor, either age, gender, medical, or psychologic status that is hindering the success of treatment. PURPOSE: This study examined a group of 100 patients who experienced ongoing difficulties with their new complete dentures, to determine possible underlying causes. MATERIAL AND METHODS: A retrospective study was conducted with information derived from patient records. All patients were treated by the same prosthodontist after having been referred specifically for their denture problems. Information regarding patient age, gender, medical and psychological histories, and information pertaining to the dentures at the time of presentation was derived from patient records. RESULTS: Statistical analysis comparing age, gender, and medical and psychologic status with the number or type of patient complaint failed to show any significant relationships. Significant relationships were observed when denture design faults or the condition of a patient's mucosa were compared with patient complaints. CONCLUSIONS: This study suggests that in most instances, complete denture patients present with complaints only when there is a real design fault or a tissue problem.

Adaptation, Physiological↗

PubMed1998

Polyvinyl siloxane impression materials: an update on clinical use.

Polyvinyl siloxane impression materials have applications in a variety of indirect procedures in prosthodontics and restorative dentistry. Favourable handling properties, good patient acceptance and excellent physical properties have resulted in their popularity in today's practice. In this review, the chemistry and important physical properties of polyvinyl siloxanes are summarized, and recent clinical questions of improved hydrophilics, tray adhesives, disinfection, and glove-induced polymerization inhibition are addressed.

Adhesives↗

PubMed1995

A denture swallowed. Case report.

Swallowing and aspiration of dental foreign objects is often reported in the literature. Swallowing seems to be more common than aspiration, and is observed most often in the elderly. Too often the size and configuration of these objects compounds their impaction and removal. A 67-year-old man swallowed a unilateral removable partial denture which became lodged in his mid-oesophagus. The denture was located by radiographic examination of his chest and removal by a rigid oesophagoscopy was performed under general anaesthetic.

Aged↗

PubMed1995

The use of a dynamic opening device in the treatment of radiation induced trismus.

A commonly observed sequela of radiation therapy for malignancy of the head and neck is trismus. Patients may experience a marked restriction of jaw opening and overall mobility, which is of great concern and lessens the quality of life. A 66 year old edentulous man experiencing radiation therapy induced trismus was treated with a dynamic opening device to improve his opening and range of movement, before new maxillary and mandibular complete dentures were constructed for him.

Aged↗