Vertical distraction of the severely resorbed edentulous mandible: a clinical,histological and electron microscopic study of 10 treated cases

The aim of this study was to evaluate the clinical and histomorphological results of distraction of the severely resorbed edentulous mandible. In a group of 10 edentulous patients suffering from insufficient retention of their mandibular denture related to a severely resorbed mandible, the anterior segment was augmented as a preimplant surgical procedure using the nonvoluminous Groningen Distraction Device (GDD). Two months after the last day of distraction, a bone biopsy was taken with a trephine, both distraction screws were replaced by endosseous implants and the guide screw was removed. The biopsies were examined by means of light microscopy (LM) and transmission electron microscopy (TEM). Radiographical and histomorphological examination of the biopsies revealed the presence of two cortical zones, one at each end of the biopsies, a poorly mineralized, fibrous interzone in the middle of the distraction gap, and two zones of mineralization between the central fibrous and the peripheral cortical zones. Formation of lamellar bone parallel to the distraction vector was clearly visible in the mineralization zone as well as signs of remodelling at the borderline between the native cortical bone and the generate. Clinical examination showed in all patients that the anterior segment distracted from the mandible body was sufficiently enlarged to enable insertion of endosseous implants with a length of at least 12 mm. One implant was lost during the healing phase, but was successfully replaced thereafter. Implant retained overdentures were fabricated 3 months after implantation. All patients have good function 11.2 +/- 4.3 months after the end of treatment. From this study it is concluded that the GDD has proven to be a reliable tool for augmentation of the anterior segment of a severely resorbed edentulous mandible enabling osseointegration of endosseous load-bearing implants.     

Custom metal occlusal surfaces for acrylic resin denture teeth

A simple step-by-step procedure has been presented for the fabrication of custom metal occlusal surfaces for acrylic resin denture teeth. This technique works equally well with complete or removable partial dentures and provides the patient with a long-lasting prosthesis and minimal postinsertion problems due to occlusal changes and wear.     

Relation of Gothic arch apex to dentist-assisted centric relation

This method of fabrication of an immediate nasal prosthesis has distinct advantages which recommend its use. These are (1) the use of an RTV silicone rubber impression as the refractory cast cuts fabrication time to minutes rather than hours, as compared with other methods of fabricating a nasal prosthesis; (2) the RTV silicone is permanent and stable and provides an exact reproduction of the part to be excised; (3) the initial RTV silicone impression may be used during fabrication of the definitive prosthesis as the mold for production of a wax sculpting model; (4) PVC prostheses offer a unique advantage of being soft enough for trimming with scissors at the time of surgery and are flexible and tissue-compatible; and (5) psychological trauma is minimized and the patient is better prepared for a definitive prosthetic restoration.     

Tongue piercing as risk factor to periodontal health

Body piercing has grown in popularity among teenagers and young adults. Dating back to antiquity, piercing is a cultural practice used in ceremonial or religious rites; however, today, it is commonly exercised as a method of self-expression. Different complications and side effects are associated with intraoral piercing, including pain, swelling, infection, gingival trauma, chipped or fractured teeth, increased salivary flow, calculus buildup, and interference with speech and swallowing. We present a case report of periodontal treatment of traumatized gingival tissue caused by a tongue stud. The step-by-step periodontal surgical management of the case has been elaborated. The role of oral and dental health care professionals in managing the growing problem of tongue piercing as a periodontal risk factor has also been highlighted.     

Opinions of dental professionals from a large American insurance system on outcome of non-surgical root canal treatment

PURPOSE: To assess the opinions of dental professionals working within the Delta Dental insurance system regarding the predictability of initial endodontic treatment, expected long-term outcome and the importance of placing a coronal coverage after completion of treatment. METHODS: An eight-item questionnaire was distributed among participants attending a continuing education course. The questionnaire included four items on practice profile and demographics and four multiple-choice questions regarding participants' opinions on endodontic treatment outcome. RESULTS: 51% of participants responded that the expected retention rate of teeth 5-10 years after endodontic treatment was more than 90%. Sixty-eight percent of participants responded that the need for additional treatment was expected to occur within the first 3 years after initial endodontic treatment. 87% of participants responded that placing coronal coverage after completion of endodontic treatment was very important for long-term tooth retention. Ninety-three percent of participants responded that overall, endodontic treatment was a predictable procedure with long-term tooth retention rate. Statistically significant associations were found between (1) year of experience and expected rate of retention (P < 0.01); (2) participants' years of experience and their responses regarding the need for additional treatment (P < 0.05); and (3) their opinions that endodontic treatment was a predictable procedure with long-term tooth retention rate (P < 0.05).     

BOOK REVIEW

Book reviewed in this article:
The Health Robbers Edited by Stephen Barrett & Gilda Knight     

Susceptibility of a polycaprolactone-based root canal filling material to degradation. I. Alkaline hydrolysis

Polycaprolactone, a thermoplastic aliphatic polyester, is reportedly susceptible to both alkaline and enzymatic hydrolyzes. This screening study examined the susceptibility of Resilon, a polycaprolactone-based root filling composite, to alkaline hydrolysis. There were 15-mm diameter disks of Resilon and Obtura gutta-percha prepared by compressive molding and immersed in 20% sodium ethoxide for 20 or 60 min. Control disks were immersed in ethanol for 60 min. These disks were examined using field-emission scanning electron microscopy and energy dispersive X-ray analysis. For Resilon, the surface resinous component was hydrolyzed after 20 min of sodium ethoxide immersion, exposing the spherulitic polymer structure and subsurface glass and bismuth oxychloride fillers. More severe erosion occurred after 60 min of sodium ethoxide treatment. Gutta-percha was unaffected after immersion in sodium ethoxide. As Resilon is susceptible to alkaline hydrolysis, it is possible that enzymatic hydrolysis may occur. Biodegradation of Resilon by bacterial/salivary enzymes and endodontically relevant bacteria warrants further investigation.     

Salivary micelles: identification of complexes containing MG2, sIgA, lactoferrin, amylase, glycosylated proline-rich protein and lysozyme

Micelles represent macromolecular structures in saliva and the aim of this study was to identify salivary proteins that occur in these globular particles. Micelles were isolated from whole saliva (WS) collected from three individuals and analysed in different experiments. Samples were subjected to polyacrylamide gel electrophoreses, hydrolysed to determine their amino acid composition and total protein concentration, examined by scanning electron microscopy and examined on Western blots probed with a panel of antibodies directed against salivary proteins. On Coomassie Brilliant Blue stained gels, the banding pattern of whole saliva and micelles was similar but the intensity of bands was quite different. Amino acid analysis confirmed that the amino acid composition of micelles was distinct from that of whole saliva. Scanning electron microscopy showed that micelles exhibit a complex pattern consisting of individual particles or clusters of particles with different sizes and shapes. Micelles contain proteins with high (MG2 and secretory IgA), intermediate (lactoferrin, amylase and glycosylated proline-rich protein (PRP)) and low (lysozyme) molecular weight that were immuno-detected on blots probed with specific antibodies. Micelles represent particulate multicomponent structures in whole saliva that contain a subset of salivary proteins known to be important components of the innate immune system and are likely to play an important role in the maintenance of homeostasis in the oral environment.     

Extracellular matrix molecules in chronic obstructive sialadenitis: an immunocytochemical and Western blot investigation

The exact pathomechanism of inflammation progress and fibrosis in chronic sialadenitis is unknown. Connective tissue growth factor (CTGF), matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) have been implicated in the pathogenesis of various fibrotic conditions. These factors are thought to be essential in the regulation of extracellular matrix turnover and the development of tissue fibrosis. In the present study, the expression of CTGF, MMP-2, -3, -9, -13 and TIMP-3 was examined in chronic obstructive sialadenitis. Tissue samples of 13 patients with chronic sialadenitis of the submandibular gland associated with sialolithiasis and 4 normal tissue samples of the submandibular gland were analyzed immunohistochemically and by Western blot analysis. An intense CTGF immunoreactivity was observed in the ductal system of inflamed salivary glands, whereas in normal glands no reactivity or a very low CTGF immunoreactivity was present. Immunohistochemical studies revealed a low to strong reactivity of MMP-2, -3, -9, -13, and TIMP-3 in the ductal system, in acinar cells and in lymphomonocytic infiltrates in normal and inflamed tissues. The expression of MMP-2, -3, -9, -13, and TIMP-3 was confirmed by Western blotting in all cases. Over-expression of CTGF in chronic obstructive sialadenitis suggests that this factor may play a role in glandular fibrosis. However, the physiological role of MMP-2, -3, -9, -13, and TIMP-3 in normal glands, as well as their possible role in inflammation progress and fibrosis in chronic obstructive sialadenitis, remains to be elucidated.     

Survey of state funds available for rehabilitation of patients with cleft lip/palate

An effort was made to determine the amount of funds budgeted in each of the 50 U.S. states for total rehabilitation of patients with cleft lip and/or cleft palate. Questionnaires were sent following a pilot letter to the directors of each state Department of Health. Total funds per patient ranged from $17,442 for Delaware to a low of $426 for Wisconsin. Dental funds per patient ranged from $4,214 dollars for Wyoming to a low of $192 for New York.