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.     

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.     

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).     

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.     

A IIIman protein is involved in the transport of glucose,mannose and fructose by oral streptococci

We show in this article that the transport of glucose, mannose and fructose by the phosphoenolpyruvate: mannose phosphotransferase system of oral streptococci requires the participation of a protein component that we have called III_man. This protein was purified from Streptococcus salivarius by chromatography on DEAE-cellulose, DEAE-TSK, hydroxyapatite, and Dyematrex Green A. The purified protein migrated as a 38,900 molecular weight protein on a sodium dodecyl sulfate polyacrylamide gel. However, electrophoretic analysis of phosphoproteins and Western blot experiments indicated the presence in membrane-free cellular extracts of S. salivarius of 2 different forms of III_man having molecular weights of 38,900 and 35,200. The presence of the high-molecular-weight form of III_man was observed by immunodiffusion. Western blot and phosphorylation by [³²]PEP in S. salivarius, Streptococcus mutans, Streptococcus sobrinus, and Streptococcus lactis but not in Streptococcus faecium, Staphylococcus aureus, Bacillus subtilis and Lactobacillus casei. Antibodies directed against the III_man of S. salivarius did not react with the III_man of Escherichia coli.     

Temporomandibular disorders—pain outside the head and face is rarely acknowledged in the chief complaint

Statement of problem. With diagnostic and therapeutic procedures being heavily influenced by the patient's chief complaint, the question arises whether this information alone represents a solid basis for clinical action. Purpose. The aim of this investigation was to assess the agreement between pain complaints and patient-generated paper-and-pencil drawings of the distribution of pain in patients suffering from temporomandibular disorders. Methods. The study included 140 adult female patients with temporomandibular disorders. Pain drawings served as a standard, against which the oral reports were compared. In 40 (29%) of the patients, pain was limited to the head and face; in the remaining subjects, it exceeded the boundaries of these regions. Nine potential pain sites were distinguished (head, face, neck, shoulders, arms, chest, abdomen, back, and legs). Whenever one of these regions was part of the drawing or the pain complaint, it was counted. Sensitivity, specificity, and kappa indices were computed for each site. Results. Patients with pain limited to the head and face showed a close correspondence between pain report and drawing. On the other hand, patients with temporomandibular disorders with concomitant pain sites outside the head and face frequently did not mention these additional pain locations. This was reflected in low sensitivities (minimum: 0.00; maximum: 0.48) and low kappa values (minimum: –0.02; maximum: 0.19). Conclusions. This study showed that the chief complaint frequently underestimates the real extent of pain involvement. (J Prosthet Dent 1997;78:592-5.)     

Tooth injury increases expression of the cold sensitive TRP channel TRPA1 in trigeminal neurons

Objective

Transient receptor potential (TRP) channels, a family of structurally related proteins have been implicated in the sensation of pain and hyperalgesia caused by exogenous and endogenous agonists, as well as touch, pH, and temperature. The objective of this study was to determine the effects of tooth injury on the expression of the cold sensitive channel TRPA1, in the trigeminal ganglion, the primary source of sensory and nociceptive innervation of teeth.

Design

We analyzed TRPA1 expression in a rodent model of tooth injury, by Western blot analyses of proteins extracted from trigeminal ganglia.

Results

We found that TRPA1 was selectively increased in trigeminal ganglia innervating injured teeth when compared to TRPA1 expression in trigeminal ganglia innervating healthy teeth.

Conclusions

Our results provide the first evidence of increased expression of a cold-sensitive TRP channel in trigeminal ganglia after pulp exposure, and are consistent with the possibility that increased expression and function of TRPA1 in trigeminal neurons contributes to hyperalgesia and allodynia following tooth injury.