A survey of the dissatisfied denture patient.

A small but important group of complete denture wearers find great difficulty in adjusting to, and wearing, dentures. In the past, efforts have been made to identify a factor or group of factors which typify these patients so that the clinician, having recognised the factors, might modify the management approach accordingly. Most research has concentrated on one form of investigation. In this study a wide range of tests was applied to complete denture wearers attending for treatment at Cardiff or Leeds Dental School, including an exhaustive interview and questionnaire, clinical examination and a personality assessment. In the majority of cases technical errors in denture construction accounted for the presenting complaint. It was not possible to identify a factor or group of factors common to those patients who had suffered chronic denture problems.

Glycosaminoglycans in peri-implant sulcus fluid from implants supporting fixed or removable prostheses.

Previous studies have indicated that examination of glycosaminoglycans (GAG) present in peri-implant sulcus fluid (PISF) may be a useful indicator of metabolic activity of the supporting bone. The GAG content in PISF from osseointegrated implants ad modum Brånemark in the maxilla was quantified and analysed. The study comprised 2 groups with 10 patients in each group. In one group the patients wore removable prostheses; in group 2 the patients wore fixed prostheses. The groups were matched for age, sex and function period of their prosthetic appliances. Clinical data were recorded, and the levels of the GAG hyaluronan (HA) and chondroitin-4-sulphate (C4S) were assessed using cellulose acetate electrophoresis and densitometric scanning of Alcian blue-stained strips against known GAG standards. PISF volumes and levels of C4S as potential bone marker showed no significant difference (both groups median 0.003 microgram). There was a somewhat higher median value for HA (0.015 microgram) in the group of patients with removable prostheses compared with the group with fixed prosthesis (HA = 0.008 micrograms) (NS). HA is known to be present in high amounts in gingival tissue. As both plaque index and gingival bleeding were more frequent in patients with removable prostheses, this may be the reason for the somewhat higher value for HA in this group of patients. The difference in biomechanical properties of fixed and removable prostheses on implants do not appear to be reflected in the bone responses as measured by GAG content in PISF.

A survey of complete denture prosthetics for the elderly, the handicapped and difficult patients.

A survey was carried out to establish information on the facilities and management of the elderly and the handicapped and to evaluate the treatment of the difficult edentulous patient in general dental practice. A postal questionnaire was sent to a total of 1090 dentists in three regions of England and Wales. There was a 50.4% response. Ninety-nine per cent of practitioners were able to treat the ambulant elderly, whereas only 72% offered treatment if the patient was wheelchair dependent. Ninety-six per cent of all respondents undertook domiciliary visits. All practitioners provided prosthetic treatment (complete and partial dentures) for the elderly, whereas fewer felt able to treat the physically and the mentally handicapped. There was less conservative and periodontal treatment provided than prosthetic treatment. A similar pattern was obtained in all three regions. Forty-seven per cent preferred to treat difficult complete denture patients privately, 44% under the NHS and 6% not at all. There were regional variations in the referral patterns of these difficult denture cases. The majority of respondents considered that there should be more opportunities for postgraduate education in prosthetic dentistry.

Levels of glycosaminoglycans in peri-implant sulcus fluid as a means of monitoring bone response to endosseous dental implants.

The presence of certain glycosaminoglycans in peri-implant sulcus fluid may be an effective means of monitoring changes in bone metabolic activity following initial loading of implant abutments. This study has investigated levels of chondroitin 4 sulphate and hyaluronan in peri-implant sulcus fluid from titanium osseointegrated implants following initial abutment placement and exposure to masticatory stresses. Abutments were placed after a 3-month osseointegration period post-initial surgical placement of the interosseous stage. 10 edentulous patients, each with 5 mandibular implants were reviewed at 2, 4, 6 and 8 days after abutment placement. Clinical details were assessed and recorded and sulcus fluid collected in microcapillary tubes for a 5-min period for each abutment. Levels of glycosaminoglycans were assessed using cellulose acetate electrophoresis and densitometric scanning of alcian blue stained strips against known glycosaminoglycan standards. Maximum levels of sulcus fluid (0.3-1.25 microliters/5 min) were evident at 4 days with a decrease towards 8 days. Levels of sulphated glycosaminoglycans were also maximal at 2-4 days (range 0.03 - 0.126 micrograms/5 min) and decreased at 6-8 days. Hyaluronan was detected within a similar range of values reaching maximal levels at 4 days and decreasing by 8 days. The results indicate that glycosaminoglycan levels of peri-implant sulcus fluid is an effective means of measuring and maintaining changes in bone metabolism. The absence of proteodermatan sulphate precludes soft tissues being a source of these markers.

Sieve cells in Phloem of a middle devonian progymnosperm.

Phloem tissue from a Middle Devonian member of the Aneurophytales (Progymnospermopsida) is described. This may be the oldest firm evidence of conducting elements of the phloem, extending our knowledge of this tissue back some 35 million years. The discovery indicates a close phylogenetic relation between progymnosperms and gymnosperms and provides a basis for investigating patterns of specialization in the phloem of these groups of plants.

Seed from the upper devonian.

We present evidence proving the existence of seeds in the Upper Devonian and extending the known age of seed plants from the Lower Carboniferous (Mississippian) into the Upper Devonian.