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Biomedical subjects

N J Shepherd

Publications and source records attributed to N J Shepherd.

At least 19 recordsLinked to original sources
PubMed2003

The polycyclic aromatic hydrocarbon composition of mussels (Mytilus edulis) from Scottish coastal waters.

Blue mussels (Mytilus edulis) were collected from coastal areas and voes in Shetland and Orkney during March and April 1998 and from various coastal locations around mainland Scotland and from the Islands during October and December 1999. The polycyclic aromatic hydrocarbon concentration and composition (2- to 6-ring parent and branched) were determined for all samples. Additional analysis, including sensory assessment and the determination of n-alkanes and geochemical biomarkers, was also undertaken on the Shetland and Orkney mussels collected in 1998. Mussels from Shetland and Orkney exhibited a wide range of total PAH concentration (14.7 to 7,177 ng g(-1) wet weight). Those mussels collected in 1999 exhibited a narrower concentration range. The lowest value (mussels from Loch Kentra) was 8.4 ng g(-1) wet weight while the maximum concentration was 344.1 ng g(-1) wet weight and was determined in mussels from Granton East in the Firth of Forth. The PAH concentration ratios in mussels from Dury Voe (Grunna), Long Hope and Kirkwall Bay were consistent with a predominately petrogenic source for these contaminants. This was supported by both the sensory assessment and the n-alkane and triterpane profiles. Comparisons of the PAH concentrations in mussels with sediments collected from the same locations around Shetland and Orkney showed that in areas of high sediment PAH concentration the bioavailability of these contaminants was limited.

Animals↗
PubMed1999

Topical antiseptic agent after large loop excision of the transformation zone: results of a randomised controlled trial.

One hundred patients undergoing large loop excision of the transformation zone (LLETZ) were randomised to receive postoperative local treatment with sultrin (sulphathiazole 3.42%, sulphacetamide 2.86%, sulphabenzamide 3.7%) pessaries: one pessary twice daily for 5 days, or no treatment. Outcome measures included duration and severity of vaginal bleeding, discharge, pelvic pain, need for oral antibiotic therapy and unplanned hospital admission. There was no significant difference in the severity of symptoms in the treatment and control groups for bleeding, discharge or pain, averaged over the study period. Postoperative morbidity following LLETZ was frequent but mild. Use of prophylactic antiseptic agents is not recommended.

Clinical Trial↗
PubMed1999

A simple prosthetic approach using cement-retained implant prosthesis after surgical treatment of ameloblastoma.

Ameloblastoma is an odontogenic tumor of epithelial origin that manifests itself in the maxillofacial area with marked deformity. After removal of the tumor, prosthetic reconstruction may be challenging because of extensive tissue loss, which necessitates careful treatment planning. We describe a case in which a patient lost considerable supporting tissue after excision of the tumor. The mandible was grafted with autogenous corticocancellous bone harvested from the left anterior iliac crest in a delayed manner. After healing, six implants were placed. After second-stage surgery, a new method was used to reduce thickness of the soft tissue around the implants. A cement-retained nine-unit fixed partial denture was fabricated in three clinical visits. The patient has been monitored for 5 years with no complications despite the use of cement to retain the prosthesis and the unfavorable crown-to-root ratio.

Ameloblastoma↗
PubMed1998

Affordable implant prosthetics using a screwless implant system.

Many dentists have been reluctant to place dental implants because they have found that most implants are costly and time-consuming to place and have long-term maintenance problems. Most of these problems are caused by using screws to connect the abutment to the implant, the crown to the abutment or both. The use of a screwless implant system and conventional prosthetics, the author contends, can make implant dentistry affordable, versatile and easy to incorporate into all general dental practices.

Cost-Benefit Analysis↗
PubMed1996

A general dentist's guide to proper dental implant placement from an oral surgeon's perspective.

This article is designed to help the general or restorative dentist more accurately predict proper implant placement by using palatal stents for the maxilla and lingual stents for the mandible, as well as parallel pin guides and vacupress stents, which help ensure both precise location and angulation. Because these stents and pin guides are easily used during surgery, the restorative dentist can prescribe with accuracy the exact position where the implants should be placed. To further the predictability of implant placement, especially in the anterior maxilla, an abutment can actually be placed into the pilot hole in the bone and checked with a vacupress stent before making the implant socket.

Acrylic Resins↗
PubMed1995

Angulation assessment of anterior single tooth root form implants: technical note.

A technique is presented to evaluate the angulation and position of an anterior single tooth root form implant by means of a surgical template, a pilot osteotomy, and an abutment guide. The space available for the restorative materials can be assessed and the angulation modified, if necessary, to improve the esthetic potential. If the angulation is satisfactory and sufficient room is available for the prosthesis, the surgeon can continue with implant placement at the initial site.

Cuspid↗
PubMed1978

Denture stabilization with peralveolar tubing.

Mock dentures were stabilized in six monkeys by means of polyethylene tubings passed through surgically created buccolingual peralveolar channels. Macroscopic, radiographic, and microscopic examinations demonstrated that the dentures were stabilized and the tubings well tolerated throughout the 120-day study period.

Alveolar Process↗