Preben Hörsted-Bindslev

Marginal adaptation of a low-shrinkage silorane-based composite: 1-year randomized clinical trial

The aim of the present study was to examine the marginal adaptation of a new low-shrinkage silorane-based composite material (Filtek™ Silorane, 3M-Espe) by comparing it with a methacrylate-based composite material (CeramX™, Dentsply DeTrey). In particular, we wanted to test the hypothesis that reduced polymerization shrinkage would improve the marginal adaptation. Seventy-two patients participated in the study. A total of 158 restorations were placed in 80 premolars and 78 molars. Only Class II restorations were included, and each patient could contribute with more than one tooth. The restorations were scored at baseline and after one year. While statistical comparison of marginal adaptation at follow-up indicated better performance of CeramX™ both occlusally and approximally (p = 0.01 and p < 0.01), the low kappa value (32%) reflects the difficulty to assess marginal adaptation clinically. The reduction in polymerization shrinkage demonstrated in the laboratory was not clinically significant in the present study.

Randomized clinical trial of root-end resection followed by root-end filling with mineral trioxide aggregate or smoothing of the orthograde gutta-percha root filling – 1-year follow-up

AIM To compare healing after root-end resection with a root-end filling of mineral trioxide aggregate (MTA) or smoothing of the orthograde gutta-percha (GP) root filling. METHODOLOGY Forty-four patients (consisting of 52 teeth with periapical infection), average age of 54.6 years (range 30-77) participated in a randomized clinical trial (RCT) comparing the MTA and GP treatment methods. Radiographs produced 1-week and 12 months post-operatively were compared after blinding for treatment method, and healing was assessed as complete, incomplete, uncertain, or unsatisfactory. RESULTS Six teeth were not available for the 12-month follow-up: three teeth (GP) had been re-operated because of pain and two teeth (one GP, one MTA) had been extracted because of root fracture (these five teeth were classified as failures). One patient (GP) was not available for recall. In the GP group, seven teeth (28%) showed complete healing, six teeth (24%) incomplete healing, six teeth (24%) uncertain healing and two teeth (8%) unsatisfactory healing after 1 year. In the MTA group, 22 teeth (85%) showed complete healing, three teeth (12%) incomplete healing, and none were scored as uncertain or unsatisfactory healing after 1 year. The difference in healing between the GP and the MTA groups was significant (P < 0.001). CONCLUSIONS The results from this RCT emphasize the importance of placing a root-end filling after root-end resection. Teeth treated with MTA had significantly better healing (96%) than teeth treated by smoothing of the orthograde GP root filling only (52%).

Endodontic photoactivated disinfection using a conventional light source: an in vitro and ex vivo study.

OBJECTIVE The antimicrobial effect of photoactivated disinfection (PAD) using toluidine blue and an LED lamp was tested on endodontic pathogens in planktonic suspension and after inoculation into extracted teeth. Irradiation time was limited to 30 seconds. STUDY DESIGN The effect of PAD on planktonic suspensions of Escherichia coli, Candida albicans, Enterococcus faecalis, Fusobacterium nucleatum, and Streptococcus intermedius was analyzed using Poisson regression. Moreover, cultures of S. intermedius were inoculated into prepared root canals of extracted molars. The effect of PAD performed immediately after inoculation or after overnight bacterial incubation was determined by a 2-sample t test. RESULTS Photoactivated disinfection yielded significant reductions (P < .001) in the viable counts of all organisms in planktonic suspension. The PAD treatment of S. intermedius in root canals yielded a mean log10 reduction of 2.60 (P < .001) immediately after inoculation and of 1.38 (P < .001) after overnight incubation. CONCLUSION Photoactivated disinfection using a conventional light source strongly reduces the number of viable endodontic pathogens in planktonic suspension and in root canals.

Fluoride release from alternative restorative materials

Numerous laboratory studies have been performed to evaluate the fluoride releasing capacity of different restorative materials. The studies have comprised release of fluoride, uptake of fluoride in the dental hard tissues and the inhibitory effect on demineralization. The present paper discusses the results from and the clinical relevance of the laboratory studies especially as regards the glass ionomer materials and resin composites.

Two-year evaluation of class II resin-modified glass ionomer cement/composite open sandwich and composite restorations.

Abstract Restorations made of a combination of resin modified glass ionomer cement (RMGIC) and composite resin (CR) – open sandwich fillings – have been recommended for use in proximal boxes of molar cavities. The aim of this study was to compare the clinical behaviour over time of RMGIC/CR sandwich restorations versus CR restorations in Class II molar cavities. During a period of 2 years, a total of 220 restorations were placed in 118 patients by one operator (VV). A random block allocation was used to allocate cavities to one of the two restorative techniques. Bitewing radiographs and photographs were taken at baseline and at annual recall appointments. At present, a total of 210 restorations have been evaluated after 1 year and 141 restorations after 2 years. All restorations were evaluated using a modification of USPHS criteria. A total of three RMGIC/CR and two CR restorations (2.8%) were rated as failures caused by endodontic complications or major fractures. Twenty-eight teeth were reported to have postoperative sensitivity at the baseline evaluation 1 week following placement. Nine RMGIC/CR (8.5%) and four CR (4.9%) restorations with minor fractures were rated Charlie but were still acceptable. Bitewing radiographs revealed progression of carious lesions in proximal surfaces of originally intact or restored teeth adjacent to five (5.9%) RMGIC/CR restorations and eight (10.9%) CR restorations. No statistically significant differences between the two types of restoration were observed with respect to marginal adaptation, discoloration and caries progression. However, a higher number of large CR fillings exhibited postoperative sensitivity at baseline compared to moderate CR or extensive and moderate RMGIC/CR restorations.

Shade Guide Optimization—A Novel Shade Arrangement Principle for both Ceramic and Composite Shade Guides When Identifying Composite Test Objects

STATEMENT OF PROBLEM The most widely used shade guide for composite materials is made of ceramic and arranged according to a non-proven method. There is a need for a composite shade guide using a scientifically based arrangement principle. PURPOSE To compare the shade tab arrangement of the Vitapan Classical shade guide and an individually made composite shade guide using both the originally proposed arrangement principle and arranged according to ΔE2000 values with hue group division. MATERIALS AND METHODS An individual composite shade guide made from Filtek Supreme XT body colors was compared to the Vitapan Classical shade guide. Twenty-five students matched color samples made from Filtek Supreme XT body colors using the two shade guides arranged after the two proposed principles--four shade guides in total. Age, sequence, gender, time, and number of correct matches were recorded. RESULTS The proposed visually optimal composite shade guide was both fastest and had the highest number of correct matches. Gender was significantly associated with time used for color sampling but not regarding the number of correct shade matches. CONCLUSIONS A composite shade guide is superior compared to the ceramic Vitapan Classical guide when using composite test objects. A rearrangement of the shade guide according to hue, subdivided according to ΔE2000, significantly reduces the time needed to take a color sample and increases the number of correct shade matches. CLINICAL SIGNIFICANCE Total color difference in relation to the lightest tab with hue group division is recommended as a possible and universally applicable mode of tab arrangement in dental color standards. Moreover, a shade guide made of the composite materials itself is to be preferred as both a faster and more accurate method of determining color.