Microleakage of Diaket and amalgam in root-end cavities prepared using MicroMega sonic retro-prep tips

The in vitro sealing ability of the root-canal sealer Diaket when used as a root-end filling material was compared with that of amalgam using linear microleakage of Indian ink. Eight groups of 20 extracted teeth each were formed, plus 12 control teeth as follows: 1) root-end resection of 45° bevel, root-end cavity preparation with an 008 round bur, amalgam root-end filling; 2) 45° bevel, bur, Diaket; 3) 45° bevel, using a sonic retro-prep tip, amalgam; 4) 45° bevel, sonic, Diaket; 5) no bevel, bur, amalgam; 6) no bevel, bur, Diaket; 7) no bevel, sonic, amalgam; 8) no bevel, sonic, Diaket. Root-end cavity depths of 3 mm were prepared. Specimens were immersed in Indian ink for 2 weeks. The teeth were demineralized, rendered transparent and linear dye penetration recorded. Results showed that Diaket provided a superior seal to amalgam irrespective of the root-end preparation. The degree of bevel of the resected root-end did not influence leakage. Sonic instrumentation resulted in a larger root-end cavity than with burs.     

Osseointegrated implants for single tooth replacement in general practice: A 1-year report from a multicentre prospective study

The single tooth implant is a treatment option for the replacement of missing single teeth and in many cases is the treatment of choice. It is, however, an expensive treatment requiring a co-ordinated approach to the surgical and restorative aspects of treatment. In this study, a group of dentists in general and restorative dental practice and with no previous experience in implant surgery underwent an intensive training course in all aspects of implant treatment for single teeth. Using a system of simplified instrumentation with a strict adherence to protocol, the group installed and restored single tooth implants ad modum Brånemark in a wide range of clinical situations. At the one year follow-up period following crown insertion, the success rate of treatment compared favourably with results reported from centres using the specialist team approach to treatment. The results of this study indicate that further consideration should be given to the training of general dentists so that improved delivery of dental health care can be provided at a more economic level.     

Sub-gingival microflora in Macaca mulatta species of rhesus monkey

The Macaca mulatta species of rhesus monkey is one of several non-human primate (nhp) models for periodontal disease. This report presents the bacteriology of the gingival sulci in M. mulatta monkeys. Three sub-gingival sites (maxillary right central incisor, the disto-buccal of the mandibular left second molar and mesio-buccal of the mandibular right second molar) of 9 monkeys were evaluated clinically before scaling and 7 days after scaling. Plaque samples were obtained from sub-gingival sites before clinical examination and studied bacteriologically by dark field microscopy, selective and non-selective culture, and by primary phenotypic characterizations of culture isolates. Several gingival sites presented with mild gingival inflammation. Anaerobic and facultatively anaerobic bacteria were the predominant flora colonizing the gingival sulci. The major microbial groups were Haemophilus species (100% of sites; percentage of total anaerobic count (TAC); 21-51), Peptostreptococcus micros (89%, 7.5–29.5), Actinomyces sp. (85%, 7–27), Fusobacterium nucleatum (90%, 5–8), Actinobacillus actinomycetemcomitans (73%, 1.3–12), black-pigmented anaerobic rods ( BPAR ) (80%, 0.6–6.5) and oral streptococci (80%, 0.2–1.0). Microbial groups detected less often were Wolinella sp. (66%, 0–2.6), Capnocytophaga sp. (30%), Eikenella corrodens (4.7%, 0), Campylobacter sp. (28%, 0–0.1) and spirochetes (4.7%, 0–0.07). Seven days after gingival sites were scaled, the plaque score and indices for gingival inflammation declined significantly. The gingival flora after scaling were characterized by lower proportions of the Actinomyees sp., P. micros and BPAR; and increased proportions of the oral streptococci, relative to pre-scaling levels. The major microbial groups at scaled gingival sites were the Haemophilus sp., oral streptococci, F. nucleatum and A. actinomycetemcomitans. The mutual proportions of microbial groups varied non-significantly within gingival sites and between monkeys. In conclusion, the M. mulatta gingival sulci are colonized by microbial species that resemble putative pathogens of periodontal disease, and the composition and character of the gingival flora are similar to the gingival flora of other Old World monkey models.     

An epidemiologic survey of facial fractures and concomitant injuries

A 5-year review of facial fractures and concomitant injuries at a level 1 trauma center is presented. The anatomic location of the facial fractures, age and sex of the patients, cause of injury, and associated systems injuries are presented. The majority of facial fractures were found in males; the most prevalent age range was 16 to 30 years. Mandible fractures outranked zygomatic and maxillary fractures (6:2:1). Assaults and motor vehicle accidents were the most frequent causes of facial fractures, and lacerations followed by neurologic and orthopedic injury were the most frequently encountered concomitant injuries. Motor vehicle accidents were the most frequent cause of associated injury.     

Periodontal implications of orthodontic treatment in adults with reduced or normal periodontal tissues versus those of adolescents

This longitudinal study monitored periodontal status in 20 adults and 20 adolescents undergoing fixed orthodontic treatment. Ten adults had generalized periodontitis and received periodontal treatment, including periodontal surgery, before orthodontic treatment. They also received periodontal maintenance at 3-month intervals during orthodontic treatment. The other 10 adults had normal periodontal tissues. Neither these latter adults nor the adolescents received periodontal maintenance during orthodontic treatment. Periodontal status was determined (1) at six standard sites before fixed appliances were placed (baseline), (2) at 1, 3, 6, 9, 12, and 18 months after appliances had been placed, and (3) 1, 3, 6, and 12 months after appliances had been removed. At each of these visits, these sites were assessed for plaque index, gingival index, bleeding tendency, and pocket depth. Loss of attachment between baseline and 3 months after appliances were removed and tooth loss were also determined. Complete data were obtained for 15 adolescents and 14 adults. During orthodontic treatment the adolescent group showed significantly more (p less than 0.05) periodontal inflammation and supragingival plaque than the adults; after appliances were removed, this pattern was no longer statistically significant. For loss of attachment, there were no significant differences among adolescents, adults with normal periodontal tissues, or adults with reduced but healthy periodontal tissues who had undergone treatment for periodontal disease. For tooth loss, three nonstudy site teeth with pockets deeper than 6 mm and/or furcation involvements were lost because of periodontal abscesses in the adult group treated for periodontal disease.     

Arginolytic and ureolytic activities of pure cultures of human oral bacteria and their effects on the pH response of salivary sediment and dental plaque in vitro

Thirty-nine different microorganisms commonly found in supragingival plaque and salivary sediment were screened for their ability to raise the pH by producing base from arginine, lysylarginine and urea. Only Actinomyces naeslundii and Staphylococcus epidermidis showed significant pH-rise activity with all three compounds. Eleven bacteria demonstrated such activity with arginine and lysylarginine but not with urea. Only one, Actinomyces viscosus, produced a pH-rise with urea but not with the two arginine compounds. The remaining 26 bacteria showed little or no base-forming activity with any of the three test substrates. The ability of the different oral bacteria to produce base (especially from urea) was a less universal function than their ability to produce acid from fermentable carbohydrate. Substituting pure cultures of arginolytic or non-arginolytic bacteria for portions of the mixed bacterial populations of plaque or sediment in test incubations containing glucose and arginine altered their ability to produce pH-fall-pH-rise responses shaped like those of the Stephen curve in vivo. In general, addition of arginolytic bacteria made these in vitro pH responses less acidic, whereas addition of non-arginolytic bacteria made the responses more acidic. Because of the relatively high arginolytic activity of the plaque harvested in this study, the effect of adding non-arginolytic bacteria was more readily seen than the converse. Similar changes in levels of ureolytic microorganisms and incubation with glucose and urea had little effect on sediment or plaque being able to produce a pH-fall-pH-rise type of response. When increasing proportions of the mixed bacteria in salivary sediment were replaced with the highly cariogenic Lactobacillus casei or Streptococcus mutans, the pH minimum became slightly more acidic and then slightly more alkaline, whereas the pH-rise became progressively and significantly less. Thus arginolytic bacteria have a different and greater effect on shaping the pH response of plaque or sediment than ureolytic bacteria. A large change in the proportions of arginolytic or non-arginolytic microorganisms may be needed to make a plaque microflora potentially non-cariogenic or cariogenic, respectively.     

Xeroradiography in the diagnosis of nonradiopaque sialoliths

Sialolithiasis may be the most common disease of the salivary glands in patients more than 20 years of age. Approximately 19% of sialoliths occur in the parotid gland. Of these, only up to 71% can be successfully diagnosed radiographically. The remaining 29% provide a diagnostic dilemma. Xeroradiography, because of its tissue-edge enhancement, can distinguish tissue margins of different density more dramatically than can conventional imaging and is an invaluable aid in the diagnosis of nonradiopaque sialoliths.     

An epidemiologic study of the oral health status of high school students in New Jersey

This study was performed in order to record the prevalence of tooth decay in high school students in New Jersey. During the Spring of 1986, 3,556 students, aged 13 to 18 years, in 8 public high schools in 7 communities, participated in the study. The subjects were examined by 3 trained examiners with mirror, explorer, air syringe and overhead auxiliary light. A lesion was recorded as dental caries if there was a perceptible break in the enamel surface. Questionable incipient areas were not recorded as carious lesions. Mean DMFT was found to be 4.17 +/- 3.7 and mean DMFS was 7.02 +/- 7.4. Hispanic subjects had more decay (DMFT 4.98, DMFS 9.03) than black subjects (DMFT 4.13, DMFS 6.94) and white subjects (DMFT 3.53, DMFS 5.43). Females had more decay (DMFT 4.51, DMFS 7.67) than males (DMFT 3.79, DMFS 6.33). Hispanic and black subjects also had more untreated decay (24 and 22 percent decayed of the DMFT) compared with only 11% untreated decay in white subjects. Socioeconomic level was inversely related to caries activity; however, geographic location of the school within the state (north versus south) was not a factor.     

Transmission illumination of teeth. A system for operative dentistry procedures

In an in vitro trial, transillumination provided good, comfortable vision of an operating area both during cavity preparation and the insertion of adhesive restorative materials. Secondly, transillumination provided better differentiation of hard tissues and their condition than incident illumination; this was particularly noticeable in deciding on the presence of caries at the dentino-enamel junction. The most suitable colour was in the green range of the spectrum and a variable intensity control was desirable. With refinement, this system could facilitate operative dentistry particularly for difficult situations.