Biomedical subjects
J W Frame
Publications and source records attributed to J W Frame.
Implant supported overdentures--the Birmingham experience.
OBJECTIVES: The use of an implant retained overdenture with magnets offers a simple treatment approach to the problem of instability of the complete denture. Advantages with magnets include a simplified clinical technique and reduced lateral stresses on the abutments. This paper reports on a long-term study undertaken at Wordsley Hospital and Birmingham Dental teaching hospital in the West Midlands. METHODS: Twenty-one patients received implant-retained overdentures with magnets over a 5-year period. The average age of the patients was 63 years (range 44-83 years). Seventy-eight Astra (Astra Tech AB, Mölndal, Sweden) implants were placed: 17 patients had four, two had three and two had two implants placed. RESULTS: During the 5-year study, 11 implants were lost, one from infection, and the remaining 10 were lost because of a failure of osseointegration. This equates to an 86% success rate which increases to 97% when implants shorter than 1 cm are discounted. Over this period, the average number of dentures constructed per patient was 2.3. The main reason for denture replacement was a loss of function of the magnets. When the steel casing around the magnets was breached, then corrosion resulted. The life expectancy of the magnets over the 5-year period was 77 weeks (+/-50 weeks). One denture was replaced due to problems of instability. Patient satisfaction with the treatment remains high, and all patients can now wear dentures satisfactorily. CONCLUSIONS: The use of a magnet retained overdenture offers a simple reconstructive approach to complete denture instability. Methods are currently being investigated to improve the clinical function and durability of the magnets. The success rate with the implants remains good after 5 years in function.
In vivo surface analysis of titanium and stainless steel miniplates and screws.
This study was undertaken to characterize the surfaces of Champy titanium and stainless steel miniplates and screws that had been used to stabilize fractures of the mandible in an animal model. Miniplates and screws were retrieved at 4, 12, and 24 weeks after surgery. Low-vacuum scanning electron microscopy (SEM) of autoclaved unused (control) and test miniplates from the same production batches was undertaken. Energy-dispersive X-ray (EDX) analysis was used to identify compositional variations of the miniplate surface, and Vickers hardness testing was performed. At autopsy, clinical healing of all fractures was noted. SEM analysis indicated no perceptible difference in the surface characteristics of the miniplates at all time intervals. Aluminium and silicon deposits were identified by EDX analysis over the flat surfaces. There was extensive damage to some screw heads. It is concluded that there were no significant changes in the surface characteristics of miniplates retrieved up to 24 weeks after implantation in comparison with controls. Damage to the screws during insertion due to softness of the materials may render their removal difficult. There was no evidence to support the routine removal of titanium or stainless steel miniplates because of surface corrosion up to 6 months after implantation.
Surgical management of premalignant lesions of the oral cavity with the CO2 laser.
The management of patients with premalignant and malignant lesions of the oral cavity can present problems. The potentially invasive nature of premalignant lesions together with their large extent influences the treatment. The common modalities of treatment of these lesions are surgical excision, cryotherapy, electrosurgery and radiotherapy. Recently, CO2 laser surgery has become available. Less pain, little bleeding, minimal post-operative edema, reduced risk of infection, and low recurrence rates were advantages observed following CO2 laser surgery in the mouth when compared to other modalities of treatment. Healing following CO2 laser surgery progressed well with little postoperative scarring and re-epithelialization was complete after 4-6 weeks. The newly formed epithelium appeared normal and was soft on palpation.
Second year general professional training for dentists: the West Midlands regional scheme one year on.
the West Midlands regional scheme offers new dental graduates the opportunity to undertake a 2-year period of general professional training prior to embarking on their chosen career pathway. Ideally experience should be gained in primary and secondary care. This paper describes the second year of the West Midlands scheme introduced a year ago, which combines house officer and general practice experience.
Subperiosteal behaviour of alginate and cellulose wound dressing materials.
A histological comparison was undertaken of the tissue response to a new sodium calcium alginate material (Kaltostat) and an oxidized regenerated cellulose wound dressing (Surgicel) when implanted between bone and periosteum in the jaws at intervals of up to 24 wk. Both biomaterials caused a foreign body reaction, persisting up to 12 wk after surgery. New bone formation occurred along the surface of the mandible in some specimens, but was not apparently related to the implants. It was concluded that the implantation of Kaltostat or Surgicel between bone and periosteum in the jaws caused a delay in wound healing, and had no effect on bone induction.
Mast cells in laser and surgical wounds.
Precooling of tissues was investigated as a possible means of reducing thermal damage during CO2 laser surgery of the oral mucosa. The changes in mast cells in scalpel, and in non-cooled and precooled (tissue temperature lowered to approximately 10 degrees C) CO2 laser wounds were studied. Standard wounds five mm in length were created with the CO2 laser or scalpel on the dorsum of the tongues of 32 Sprague-Dawley rats under general anesthesia with fentanyl/fluanisone and midazolam. Animals were killed with excess anesthetic immediately or six hours after surgery, their tongues were removed, trimmed, fixed in neutral formalin and processed to paraffin wax. Acid (pH 1.4) toluidine blue stained sections were used to count normal and degranulated mast cells in five fields (0.1 mm2) located at defined positions immediately adjacent to the wound site. At both 0 and 6 hours normal mast cell numbers were significantly different between treatment groups (P<0.045; ANOVA) with mean numbers highest in scalpel wounds and lowest in uncooled laser wounds. Similarly, at 0 time, there were significant differences in degranulated mast cells between treatment groups (P=0.004; ANOVA) but highest numbers were detected in uncooled laser wounds and lowest in scalpel wounds. There were no significant differences in degranulated mast cell counts at six hours although there was a similar distribution in numbers between groups. Total numbers of mast cells (normal + degranulated) did not differ between treatment groups. These results demonstrated that i) laser wounds are associated with greater levels of mast cell degranulation than scalpel wounds and ii) precooling of tissues prior to laser treatment decreases the level of mast cell degranulation. It is concluded that tissue damage in CO2 laser surgery may be reduced by precooling of tissue.
The development and evaluation of management training for general dental practitioners.
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Second year vocational training in the West Midlands region.
January 1994 saw the start of a pilot second year VT scheme in the West Midlands combining house officer/GDP associateship experience as an integral part of general postgraduate training in dentistry. The scheme is funded by a grant from the W.M. Board of Postgraduate Medical and Dental Education. The availability of such a course in each region would be beneficial for those dentists who wish to experience hospital practice following their mandatory vocational training.
Alginate fiber dressing for oral mucosal wounds.
The aim of this study was to evaluate the effect on hemostasis and wound healing of a proprietary alginate fiber dressing when applied to a wound of the buccal mucosa of approximately 2 mm depth. The study showed a significant reduction in the number of residual bleeding points in shallow wounds when the alginate fiber dressing was applied for 5 minutes as compared with the use of non-alginate-impregnated surgical gauze. There was no significant difference in the rate of epithelial repair of the test and control sites nor in the area of the resulting mucosal scar. In addition, there was no significant difference in the numbers of tissue components in the submucosa. It is concluded that the alginate fiber dressing material evaluated in this study may be effective as a hemostatic mucosal dressing in shallow wounds, but it does not accelerate mucosal wound healing.
Participatory continuing dental education.
The significance of continuing education for the development of a professional person is indisputable. There is evidence that participatory continuing education is the most effective form for this activity to take in relation to dentists and clinical practice. Working Group 15, appointed by the FDI Commission, specifically studied this form of continuing education by use of a questionnaire to 26 representative national dental associations. The majority of countries surveyed have at least some education of this sort although it forms only a small proportion overall. Little evaluation seems to take place to measure the subsequent value to the practitioners attending. The results of the information gathered are discussed and recommendations are made.
An audit of CO2 laser surgery in the mouth.
The use of the carbon dioxide laser to perform surgical procedures in the oral cavity has been described the last few years. This study involved the clinical audit of 83 patients who had undergone laser surgery in the oral cavity during 1985 to 1990 in Birmingham, England. The diagnosis of the 83 lesions treated were benign, premalignant or malignant. The most common sites of the lesions were the floor of the mouth/ventral surface of the tongue and other parts of the tongue, followed by upper alveolus and/or palate, angle of the mouth and/or cheeks, lower alveolus, and lips. The results showed that the use of the carbon dioxide laser in treating oral soft-tissue pathology presented advantages over conventional techniques. Although trismus, numbness and early signs of infection were observed after surgery, local discomfort and pain were the most common complaints after laser surgery. The carbon dioxide laser does not offer any enhanced cure-rate for oral pathology, but rather it is a precise means of removing soft tissue lesions in selected patients with little upset afterwards.
Magnet retained overdentures using the Astra dental implant system.
The Astra Implant System (AIS) is a biologically sound and simple way of providing stability for the complete lower denture where anatomical changes have made retention, stability and comfort difficult to achieve. An ongoing clinical study has been undertaken where 20 patients have been provided with magnet retained overdentures using this implant system. This represented a total of 70 implants placed. Seven implants were removed from four patients (three at exposure, one infection). The remaining implants have been followed up for 12 to 25 months and are considered to have achieved successful osseointegration. All the patients in the study are successfully wearing a lower denture retained by magnets. The overall success rate for the implants placed is 90% but if implants less than 9 mm in length are excluded from the results then the success rate is 97.7%.
Tissue response to a haemostatic alginate wound dressing in tooth extraction sockets.
Kaltostat is a new haemostatic wound dressing composed of non-woven sodium calcium alginate fibres, and was originally developed to cover exposed wounds of the skin. A histopathological study was undertaken to determine the tissue response to Kaltostat in healing tooth sockets, to obtain a comparison with oxidised regenerated cellulose (Surgicel). Tooth sockets filled with blood clot acted as controls. The results showed that both biomaterials delayed wound healing in the early phase (1-4 weeks), giving rise to foreign body reactions. At 12 weeks there was little difference between the control sockets and the sockets containing the test materials, although remnants of retained dressing materials were identified. Healing of the tooth sockets was complete at 24 weeks.
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Assessment of thermal damage in precooled CO2 laser wounds using biological markers.
Precooling of the tissues was investigated as a possible means of reducing the thermal damage during CO2 laser surgery of the oral mucosa. Standard wounds 5 mm long were created with the CO2 laser, with and without precooling, or the scalpel on the dorsum of tongues. Tissue damage was evaluated by studying changes in mast cells and in the activity of lactate (LDH) and succinate (SDH) dehydrogenase. Cooled unoperated tongues acted as controls. The area of thermal damage, indicated by loss of SDH activity, was significantly smaller in precooled tissues (p < 0.001). Although a similar pattern was detected using LDH, the difference was not significant. At both 0 and 6 h normal mast cell numbers were significantly different between groups (p < 0.02). Furthermore, at 0 time, there were significant differences in the numbers of degranulated mast cells between surgical treatment groups (p = 0.001), although not at 6 h. Total numbers of mast cells (normal and degranulated) did not differ between treatment groups or between 0 and 6 h sampling times. Positive significant correlations were observed between the cross-sectional areas and widths of non-reactive succinate and lactate dehydrogenase and the number of degranulated mast cells around the laser wounds. Analysis of the data demonstrated that (i) uncooled laser wounds but not precooled laser wounds were associated significantly with greater levels of immediate mast cell degranulation than scalpel wounds (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)
West Midlands regional training scheme for orthodontics in dental practice.
The need for continuing education in orthodontics is recognised by many practitioners and the demand for post-graduate courses is high. The limitations of such courses, particularly the short technique type, are recognised and within the West Midlands the value of a longer term clinical attachment has been emphasised. The West Midlands has a well established orthodontic consultant service with fifteen NHS and one honorary consultant; the specialist practitioner service is small by national standards. All of the orthodontic consultants have long supported the clinical assistant post as a valuable vehicle for practitioners' continuing education. Building on the example given by the consultants in the four Thames Regions, a structured, centralised academic programme has been developed to enhance the clinical training given during these two year posts.
The management of oral premalignant lesions.
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