Blood flow changes using a 3D xenogeneic collagen matrix or a subepithelial connective tissue graft for root coverage procedures: a pilot study.

BACKGROUND: The study investigated the early healing process following the treatment of single Miller class I and II recessions with a 3D xenogeneic collagen matrix (CMX) or connective tissue graft (CTG). METHODS: This pilot investigation was designed as a single-center randomized controlled parallel trial. A total of eight subjects (four per group) were treated with either CMX or CTG in the anterior maxilla. Vascular flow changes were assessed by laser Doppler flowmetry (LDF) before and after surgery and at days 1, 2, 3, 7, 14, and 30 while clinical evaluations took place at baseline and at days 60 and 180. Pain intensity perception was evaluated by the short-form McGill pain questionnaire (SF-MPQ), at days 1 and 14. RESULTS: The vascular flow fluctuated similarly in both groups pre- and post-operatively, but the CTG exhibited a more homogeneous pattern as opposed to CMX that showed a second phase of increased blood flow at 14 days. Clinically, the CTG led to greater change in mean root coverage and keratinized tissue gain but CMX was associated with lower early pain intensity scores. CONCLUSIONS: Within the limits of the study, the vascular flow alterations during the early healing of both graft types followed a similar pattern. The CMX was associated with a second peak of increased blood flow. CLINICAL RELEVANCE: The vascular flow changes after the application of CMX for single tooth recession root coverage did not show major differences from those observed after the use of a CTG. A trend for better clinical performance in terms of root coverage and keratinized tissue gain was noted for the CTG, but the initial patient morbidity was less for CMX

Keramik in der Zahnerhaltung - unter dem Aspekt der CAD/CAM Technik

Die Anwendung von Keramik in der zahnerhaltenden Therapie ist seit 1862 in Form von gebrannten Porzellaninlays bekannt. „CAD/CAM“ (Computer Aided Design/Computer Aided Machining) bezeichnet die moderne, computerunterstützte Fertigung. Das erste CAD/CAM-Keramikinlay wurde am 19. September 1985 und die ersten CAD/-CAM Veneers im September 1986 an der Universität Zürich bei Patienten eingesetzt. Adhäsive CAD/CAM-Keramikinlays und -Veneers haben sich seither in Langzeitstudien bewährt

Accuracy testing of a new intraoral 3D camera

Surveying intraoral structures by optical means has reached the stage where it is being discussed as a serious clinical alternative to conventional impression taking. Ease of handling and, more importantly, accuracy are important criteria for the clinical suitability of these systems. This article presents a new intraoral camera for the Cerec procedure. It reports on a study investigating the accuracy of this camera and its potential clinical indications. Single-tooth and quadrant images were taken with the camera and the results compared to those obtained with a reference scanner and with the previous 3D camera model. Differences were analyzed by superimposing the data records. Accuracy was higher with the new camera than with the previous model, reaching up to 19 microm in single-tooth images. Quadrant images can also be taken with sufficient accuracy (ca 35 microm) and are simple to perform in clinical practice, thanks to built-in shake detection in automatic capture mode

Clinical performance of chairside CAD/CAM feldspathic ceramic posterior shoulder crowns and endocrowns up to 12 years

In 55 patients, 25 endocrowns (test) and 40 shoulder crowns (control) were produced chairside in a private practice using the Cerec 3 (CAD/CAM) method and Vita Mark II feldspathic ceramic. The crowns were examined at baseline and after up to 12 years using modified USPHS criteria. The survival estimate was assessed by Kaplan-Meier analysis. The 12 years survival estimate of the shoulder crowns was 95% on molars and 94.7% on premolars. Endocrowns showed 90.5% survival on molars and 75% on premolars. Statistically, the differences between the survival estimates were not significant (P > 0.05). The longevity of Vita Mark II Cerec 3 shoulder crowns on molars and premolars, as well as of endocrowns on molars, proved to be--for private practice--a very acceptable result, while the premolar endocrowns tended to show a higher risk for failure

Strength of CAD/CAM-generated esthetic ceramic molar implant crowns

PURPOSE: One-visit in-office CAD/CAM fabrication of esthetic ceramic crowns as a superstructure for posterior implants is quite new. The aim of the study was to evaluate the strength of esthetic ceramic CAD/CAM crowns with varied occlusal thickness and seated with adhesive and nonadhesive cements on titanium and zirconia abutments. MATERIALS AND METHODS: Esthetic ceramic CAD/CAM-generated molar crowns (n = 15 per group) with occlusal thicknesses of 0.5 mm and 1.5 mm were seated on titanium (1) and zirconia (2) abutments: noncemented (a) and with nonadhesive cement (b) or 2 adhesive resin-based cements (c) and (d). In addition, 15 molar crowns with 5.5-mm occlusal thickness were seated on short zirconia abutments (3) using cements (c) and (d). All crowns had the identical occlusal morphology and were loaded with a crosshead speed of 0.5 mm/min until fracture. Load data were analyzed using 2-way ANOVA, the Scheffé test, and Weibull probability of failure analysis. RESULTS: Fracture loads of 1.5-mm occlusal thickness crowns (a, b, c, d) were higher (P < .001) than those of 0.5-mm crowns (except for group ld). Occlusal 5.5-mm crowns on short zirconia abutments had similar (2c) or less (2d) strength than the respective 1.5-mm crowns. Nonadhesive crowns (1b, 2b) were weaker (P < .001) than adhesive crowns (1c, 1d, 2c, 2d). Fracture loads of 0.5- and 1.5-mm crowns were significantly higher on titanium than on zirconia abutments with both cements. Adhesive cement d generally showed higher fracture loads than c on both titanium and zirconia. CONCLUSION: Esthetic ceramic CAD/CAM molar implant crowns gained high strength with adhesive cements on both titanium and zirconia implant abutments compared to nonadhesive cementation

Flexural strength of Cerec 2 machined and jointed InCeram-Alumina and InCeram-Zirconia bars

OBJECTIVE. The flexural strength of Cerec 2 InCeram-Alumina and InCeram-Zirconia bars is evaluated. The focus of the in vitro study is to identify a jointing procedure for InCeram which may be used for producing full-ceramic fixed-partial-denture frameworks. METHODS. Six groups (n=15) of machined and jointed InCeram-Alumina (T1-T5) and InCeram-Zirconia (T6) bars (3x4x13mm(3)), respectively, were examined using a 3-point-bending test. InCeram-Alumina joint-free controls were: machined (C1), slip cast (C2, C3) and cut from the block (C4) bars. Machined joint-free InCeram-Zirconia bars were used as controls (C5). InCeram-Alumina slip was used for jointing T1-T5 and InCeram-Zirconia slip for bars T6. Bars were jointed in groups T1 and T2 using butt joint (S1), in T3 and T4 oblique (S2, S3) and in T5 and T6 rounded (S4) joint shapes. RESULTS. Two-way analysis of variance showed significant differences between materials (p0.05) were found between machined/jointed InCeram-Zirconia (475 (54) MPa, T6), joint-free InCeram-Alumina slip cast (498 (125) MPa, C2) and joint-free InCeram-Alumina machined bars (511 (59) MPa, C1). SIGNIFICANCE. Compared to conventional slip cast InCeram-Alumina the flexural strength of machined/jointed InCeram-Zirconia appears to be adequate for fixed-partial-denture frameworks

Clinical and scanning electron microscopic evaluation of fiber-reinforced inlay fixed partial dentures: preliminary results after one year.

STATEMENT OF PROBLEM: Restorative dentistry searches for nonmetal reinforcement of esthetic fixed partial dentures (FPDs). PURPOSE: This clinical study evaluated conservative fiber-reinforced composite FPDs bonded to inlay abutments. MATERIAL AND METHODS: Twenty fiber-reinforced composite inlay FPDs were made for 15 patients. Restorations were manufactured with the Targis Vectris glass-fiber-reinforced composite system and a simplified laboratory technique. The 20 bonded inlay FPDs were examined clinically and by SEM after 1 year. RESULTS: All 20 FPDs were intact at the 1-year examination. There were no signs of fracture, surface defects, or excessive wear with SEM. SEM marginal analysis exhibited 91.6% +/- 5% excellent margins at the tooth-luting composite interface and 86. 1% +/- 8% excellent margins at luting composite/restoration interface. CONCLUSION: On the basis of the results of this descriptive study, bonded glass-fiber-reinforced composite inlay FPDs were considered clinically successful at the 1-year examination

Intraoral scanning systems - a current overview

There is no doubt today about the possibilities and potential of digital impression-taking with the aid of intraoral optical impression systems, and the past few years have seen a considerable increase in the range of optical intraoral scanners available on the market. On the strength of numerous innovations and a wider range of indications in orthodontics and implantology, intraoral scanning systems appear to be a highly promising development for the future. Digital impression-taking with intraoral scanners has already shown itself in some respects to be clearly superior to conventional impression- taking. Particularly worthy of mention is the versatile integration of digital impressions into diagnostic and treatment concepts to provide a customizable healthcare solution for the patient. It remains exciting to look forward to future developments that will allow us to observe digital impression-taking--as with other digital applications already established in everyday life--becoming firmly established in the routine of dentistry and dental technology. This article presents an overview of the benefits and limitations of digital impression-taking using intraoral scanning systems, and includes a summary of all the relevant intraoral scanners available on the market at present