Short-Term Results of IPS-Empress Inlays and Onlays

Purpose A leucite-reinforced, glass-ceramic material was recently introduced for clinical use. In this clinical trial, IPS-Empress inlays and onlays were evaluated using the modified United States Public Health Service (USPHS) criteria. Materials and Methods The teeth of 36 patients were restored with 105 posterior inlays and 25 onlays, fabricated by an indirect technique. After etching the restorations with hydrofluoric acid, they were silanized and luted using composite cements. The restorations were evaluated visually, clinically with a mirror and probe, and by bitewing radiographs and clinical photographs, using modified USPHS criteria. Restorations having neither charlie nor delta criteria were defined as successful, and their survival rate was calculated according to Kaplan-Meier analysis. Results The mean observation period for the 130 restorations was 23.4 ± 6.1 months. After 2 years, 127 restorations were successful with an estimated survival rate of 97.5%. Three restorations failed because of fractures. The esthetic results were excellent. Conclusions The initial clinical results of this esthetic restorative material are encouraging. However, because of fatigue phenomena for all ceramic materials, a longer observation period is needed to provide a definitive prognosis of the long-term clinical behavior.     

Approximal caries increment in two cohorts of schoolchildren after discontinuation of a professional flossing program with chlorhexidine gel

We have in two earlier studies evaluated the effect of professional flossing with chlorhexidine (CHX) gel treatment, in 4- to 7-year-old preschool children and in 12- to 15-year-old teenagers. The mean caries reduction after 3 years was around 40% compared to placebo gel or no gel treatment. The aim of the present investigation was to follow up these two clinical studies. The preschool children were followed up to the age of 16 years and the teenager group to the age of 19. Of the total number of original children, 71 and 80% were available at the age of 16 and 19 years, respectively. At the 9-year follow-up, when the children were 16 years old, the former CHX group had still significantly lower mean DFS than the control group (p < 0.05). The differences in caries increment occurred between 7 and 12 years of age, whereas the number of new caries lesions during the next 4 years were almost the same in the three groups. At the 4-year follow-up, when the teenagers were 19 years old, DFS was 6.9 in the former CHX group compared to 10.4 in the control group (p < 0.05). The main conclusion of these two follow-up studies after 9 and 4 years, respectively, is that caries reductions obtained at the end of professional flossing with a 1% CHX gel were maintained.     

Study on the necessity for cross-section imaging of the posterior mandible for treatment planning of standard cases in implant dentistry

OBJECTIVE: To investigate whether cross-section imaging influences the planning and therapy of standard implant cases in the posterior mandible. MATERIAL AND METHODS: In a prospective study conducted over 16 months, the planned treatment (standard implant therapy without bone augmentation procedures in the premolar and molar regions of the mandible) was compared with the postoperative result in 50 randomly selected patients. Clinical examinations and panoramic radiographs were performed pre- and postoperatively, whereas cross-sectional tomography was performed only preoperatively. RESULTS: The vertical magnification factor in the panoramic radiographs was very constant pre- and postoperatively with 1 : 1.27 and in the spiral tomograms with 1 : 1.52. In 11 of 77 implant sites, the mandibular canal could not be evaluated in the spiral tomograms. The additional information from cross-sectional spiral tomography did not influence the original planning in 74 of 77 (96.1%) implant sites. Based on the postoperative panoramic radiograph, the average distance from the tip of the implants to the mandibular canal was 3.04+/-2.06 mm. In two cases (2.6%), transient postoperative altered tactile sensation of the mental nerve was found. CONCLUSION: The information from preoperative cross-sectional spiral tomography has minor impact on treatment planning in standard implant cases in mandibular premolar and molar regions. The clinical examination provides sufficient information for selecting implant diameter and the panoramic radiograph provides sufficient information for implant length selection.     

Extraoral subcondylar ramus osteotomy for correction of mandibular prognathism: The surgical technique and complications

1178 patients with mandibular prognathism and/or asymmetry, in some cases combined with maxillary retrognathism, were treated by extraoral horizontal or oblique ramus osteotomy during the period from 1939 to 1989. The described percutaneous retromandibular approach is a simple, rapid and reliable technique which can usually be performed under local anaesthesia. Very few complications, particularly neurological, were observed. These aspects justify consideration of this technique when indications for a simple, straight set-back procedure of the mandible exist, and there is no tendency to bite-opening. However, the method demands intermaxillary fixation for 6-9 weeks postoperatively.     

Have the causes of maxillofacial fractures changed over the last 16 years in Finland? An epidemiological study of 725 fractures

Abstract –  A retrospective study was undertaken to assess causes of maxillofacial fractures in Helsinki in 1981 and 1997. Hospital records of 725 patients were analyzed according to several factors including age, sex, cause of fracture and time of the injury. The time intervals between the accident and hospital examination were also evaluated. Number of maxillofacial fractures was 318 in 1981 and 407 in 1997 (27.9% increase) and most patients were men. The male to female ratio was 2.8:1 in 1981, 3:1 in 1997. In 1981, most affected patients were in the age group of 31–40 years (33.2% of men, 28.9% of women). Sixteen years later the most affected age group was 41–50 years (23.3% of men, 30.4% of women). Assault was the cause of the injury in 42% of patients followed by traffic accidents (26%) and fall (17%). During the study period violence had become more severe in nature. Kicking as the cause of maxillofacial fracture increased by 7.3% and use of a weapon by 5.7% between the years studied. Bicycle accidents increased by 19.3% but motor vehicle accidents decreased by 31.6% between the years. Falls, and bicycle and pedestrian accidents were the causes that accounted for most of the increase in maxillofacial fracture. In 1997, maxillofacial fractures were slightly more common from June to August and from Friday to Sunday than at other times (45.2 and 50%, respectively).     

A survey of deans: trends, challenges, and mentoring in prosthodontics. Part 2.

PURPOSE: This study consists of two parts. Part 1, a survey of program directors, was conducted to examine current trends in advanced education in prosthodontics in the United States. Part 2 reports on the findings of a survey distributed to the deans of US dental schools to evaluate their observations of trends in prosthodontic education. MATERIALS AND METHODS: A national, electronic survey of 55 dental school deans was distributed by e-mail to evaluate an interest in specialty training, an interest in specialization in prosthodontics, faculty shortages, programs to address faculty shortages, predoctoral curriculum in prosthodontics, opinions regarding dental specialties, and the administrative position of prosthodontics within the schools. RESULTS: Of the 55 deans, 44 deans responded, an 80% response rate. Only five deans reported a decrease in the number of students seeking specialty training after dental school. The remaining 39 deans reported a large increase, slight increase, or no change in those seeking specialty training. In 29.6% of the deans' responses, an increased interest in prosthodontics was reported, whereas 16 deans reported no change in the level of interest. One or more open faculty positions in prosthodontics existed at 29 dental schools, and 28 schools offered at least one incentive or a variety of incentives to recruit faculty. The respondents to the deans' survey revealed predoctoral student exposure to prosthodontists was high, and exposure to postgraduate prosthodontics students was low. A survey of internal school programs that might have an impact on an increased interest in prosthodontics revealed the presence of a predoctoral mentoring program for prosthodontics in 80% of the institutions. The clinical curriculum included treatment of a variety of cases, including complex cases as defined by a diagnostic classification system. The response to whether dental specialties should be combined or remain individual provided some interesting data. Only 40.9% of the deans responded that prosthodontics was a separate department. CONCLUSION: Dental school deans reported an increased interest in specialty training. Predoctoral student exposure to prosthodontics was high due to the nature of their clinical experience and due to the exposure to full-time prosthodontics faculty. Many dental schools have programs, such as mentoring and new technology, which might have an impact on predoctoral students' increased interest in prosthodontics.     

Evaluation of accuracy of computer-aided intraoperative positioning of endosseous oral implants in the edentulous mandible

The overall accuracy of a novel surgical computer-aided navigation system for placement of endosseous implants was evaluated. Five dry cadaver mandibles were scanned using high resolution computed tomography (HRCT). The position of four interforaminal dental implants was planned on the computer screen and transferred to the cadaver mandibles using VISIT, a surgical navigation software developed at the Vienna General Hospital. The specimens were HRCT-scanned again to compare the position of the implants with the preoperative plan on reformatted slices after matching of the pre- and postoperative data sets using the mutual information technique. The overall accuracy was 0.96 +/- 0.72 mm (range 0.0-3.5 mm). No perforation of the mandibular cortex or damage to the mandibular canal occurred. We conclude that computer-aided implant surgery can reach a level of accuracy where further clinical developments are feasible.