Risk factors for endosseous dental implant failure

Failures of endosseous dental implants are rare and tend to cluster in patients with common profiles or risk factors. Clinical trials indicate that factors related to implant devices, anatomy, occlusion,systemic health or exposures, microbial biofilm, host immuno-inflammatory responses, and genetics may increase the risk for im-plant complications or loss. In general, factors associated with the patient appear more critical in determining risk for implant failure than those associated with the implant itself. Several risk factors can be modified. For example, the patient can modify smoking and the clinician can modify implant selection, site preparation,and loading strategy. In identifying these factors and making appropriate interventions, clinicians can enhance success rates while improving oral function, esthetics, and patient well-being.     

Erythema multiforme: a review and contrast from Stevens-Johnson syndrome/toxic epidermal necrolysis

Erythema multiforme and Stevens-Johnson syndrome/toxic epidermal necrolysis are separate diseases. Recent evidence suggests that they have different etiologies and require different treatments. This article provides an overview of the two conditions with emphasis on the differences between them. An outline of the diagnosis and management of the diseases is included.     

The effect of a sodium lauryl sulfate-free dentifrice on patients with recurrent oral ulceration

OBJECTIVE: Sodium lauryl sulphate (SLS) is the most commonly used detergent in dentifrices. Recent reports have suggested that it may exacerbate conditions with compromised epithelial integrity. The aim of this study was to compare the effect of an SLS-free dentifrice and an SLS-containing dentifrice on recurrent oral ulceration (ROU). DESIGN: A double-blind crossover clinical trial was carried out during which subjects used an SLS dentifrice for 8 weeks and an SLS-free dentifrice for 8 weeks. Each phase was preceded by a 2-week washout period. SETTING: A UK dental teaching hospital. SUBJECTS AND METHODS: Forty-seven subjects completed the trial. They were all in the age range 10-62 years, had regularly recurrent oral ulceration reporting at least one to two ulcers per month and had normal levels of vitamin B12, ferritin and folate. MAIN OUTCOME MEASURES: The trial phases were compared for the following ulcer parameters--number of ulcer days, total pain scores, number of ulcer episodes, and number of ulcers. Additional parameters compared were the number of ulcers per episode, ulcer duration, total pain per episode and ulcer size. RESULTS: None of the ulcer parameters measured was significantly affected by the use of the SLS-free dentifrice as compared with the SLS dentifrice. CONCLUSION: SLS-free dentifrice had no significant effect on ulcer pattern in the ROU study group.     

A comparison between in vivo radiographic working length determination and measurement after extraction

The purpose of this study was to compare the difference between the in vivo working length established by viewing a periapical radiograph and the in vitro measurement from the file tip to the apical foramen of the extracted tooth. Twenty-six canals from teeth that had been treatment planned for extraction were accessed under rubber dam isolation. The coronal portion of each canal was flared using Gates Glidden drills, and a K-type file was inserted down the canal until an electronic apex locator indicated that the file had reached the apex. A size 20 K-type file was locked into place with glass ionomer cement at this position. A radiograph was exposed and the tooth was extracted. Each tooth was viewed using a videomicroscope at 30x original magnification, and the distance from the file tip to the most coronal aspect of the major foramen was measured. Six examiners viewed each radiograph and assessed the working length of each canal. Chi(2) analysis of the data revealed a significant difference (p < 0.01) between the estimation of working lengths and the microscopic measurements. The examiners overestimated the distance between the file tip and the apical foramen of the tooth when the file was placed short, and underestimated the distance when the file was placed long. In conclusion, when the file is short it is actually closer to the apical foramen than it appears radiographically; when it is long it is actually longer than it appears radiographically.     

Immunocytochemical examination of immune cells in periapical granulomata and odontogenic cysts

Monoclonal antibodies (mAbs) were used to determine the presence and distribution of immune cells including lymphocytes, macrophages and Langerhans cells, in normal periodontal ligament, periapical granulomata, periapical cysts and dental developmental cysts. Isolated T-lymphocytes, but not B-lymphocytes, were detected in specimens of non-inflamed periodontal ligament. Increased numbers of T and B lymphocytes were found in all of the lesions examined. Monocytes/macrophages were associated with most periapical granulomata, dental developmental cysts and all periapical cysts. Langerhans cells, intraepithelial lymphocytes, and monocytes/macrophages were not detected in the rests of Malassez but were found in some epithelia within periapical granulomata and in most epithelial linings of odontogenic cysts. Increased numbers of immune cells were seen around proliferative epithelia and adjacent to the epithelial linings of cysts. Epithelium, particularly that of odontogenic cysts, showed positive reactions for HLA-Dr, lysozyme and for α-1 antitrypsin. The presence of immune cells in periapical granulomata and odontogenic cysts, suggests that cell-mediated and humoral immunoreactions occur in these lesions and may be associated with the epithelial proliferation within the periapical lesions.     

Indomethacin or flurbiprofen treatment of periodontitis in beagles: Comparison of effect on bone loss

The effect of two non-steroidal anti-inflammatory drugs, indomethacin and flurbiprofen, on the progression of periodontal disease was studied in 16 beagle dogs over a 12-month period. Standardized radiographs were used to measure the rate of bone loss. Following a 6-month pretreatment baseline period, 5 dogs were dosed daily with 1.0 mg/kg indomethacin, 5 dogs were dosed daily with 0.02 mg/kg flurbiprofen, and 6 dogs were dosed with empty gelatin capsules for a 6-month period. In the untreated control dogs, the rate of bone loss in the treatment period significantly increased from baseline. In contrast, the rate of bone loss significantly decreased from baseline in the flurbiprofen-treated dogs. In the indomethacin-treated dogs, rate of bone loss in the treatment period was not significantly different from baseline. The data indicate that both flurbiprofen and indomethacin inhibit alveolar bone loss in beagles compared to untreated controls. The data also indicate that with the dosages employed flurbiprofen is overall more effective.     

A custom mandibular distraction device for the rat

In the last several years, the rat model has been used as a reliable means of studying distraction osteogenesis (DO). This model has several benefits, including lower cost, the availability of molecular reagents for the rat, and the ability to perform a large number of operations in a short time. We have recently developed an external device that is custom-made for the rat mandible and secured at the mandibular ramus. The device consists of a Leone (Florence, Italy) jackscrew distraction assembly (0.2 mm per one-quarter turn), 2 Luhr L-shaped 0.8-mm five-hole microplates, and four 0.8-mm x 3-mm microscrews (Stryker-Leibinger Corp., Kalamazoo, MI) for fixation. Additionally, there is a methylmethacrylate block that is placed on the lingual surface of the angle of the mandible to support the posterior screws. Sterile surgical technique was used, and the same two surgeons performed all operations. To date, we have operated on 153 Sprague-Dawley rats. The procedure has been well tolerated by the animals. We had 17 postoperative deaths (11% mortality), largely as a result of anesthetic complications. There were no wound infections or dehiscence. A mandible fracture was noted in 6 rats (4%), which occurred at the time of device placement. There were no device dislodgments. Postmortem examination showed the device to be well positioned in all rats, with good callous formation at the distraction site. The rats surpassed their preoperative weight after an average of 9.2 days. These results compare favorably with those of other models currently in use. We have developed a device that is currently being used in the study of DO in the rat mandible. Our device is small in size, does not require wide undermining for its placement, and has had a low incidence of device dislodgment or infection. This model has shown great reproducibility and thus should be effective in its application for the histologic and biochemical investigation of DO in the rat.     

Dental materials: 1974 literature review part II

This paper, which is presented in two parts, reviews the work on dental materials published in 1974. Included in Part I were sections on amalgam, casting alloys, denture base polymers, composite filling materials, soft lining materials, fissure sealants, impression materials, dental ceramics and model and die materials. A review of the literature relating to cements, dental implants and dental biomechanics is presented in Part II.