1,721,018 research outputs found
The "index technique" in worn dentition: a new and conservative approach.
No full textThe development and reliability of ad- hesive resin composite systems have offered clinicians a further option for the management of tooth-surface loss. Patients with minimum, moderate, and severe hard tissue wear can be treated based on the application of minimally in- vasive adhesive composite restorations for posterior and anterior worn dentition. This article presents the “index tech- nique”, a new and very conservative ap- proach to the management of worn den- tition. The technique allows for a purely additive treatment without sacrificing healthy hard tooth tissue. It follows the principles of bioeconomics (maximum conservation of healthy tissue) and the reinforcing of residual dental structure. Depending on the severity of enamel
and dentin wear, the number of caries, and the size of existing restorations, dif- ferent treatment options can be applied to each tooth: direct and indirect partial restorations, or full crowns. It is essential to diagnose and treat tooth-surface loss in order to properly restore biomechan- ics, function, and esthetics by means of adhesive restorations. This article proposes that the index technique is a fast and conservative approach for the planning and management of a full- mouth adhesive treatment in all cases of worn dentition. The technique is based on stamping composite directly on the tooth surface by means of a transpar- ent index created from the full-mouth wax-up following an initially planned increase in occlusal vertical dimension (OVD)
Comparison of posterior indirect adhesive restorations (PIAR) with different preparation designs according to the adhesthetics classification. Part 1: Effects on the fracture resistance
No full textAim: To investigate whether: 1) in the adhesive era, a full-crown restoration in a molar tooth is more resistant compared with an overlay-type restoration; b) a posterior indirect adhesive restoration (PIAR) is similar to a sound tooth from a mechanical point of view.
Materials and methods: Seventy extracted molars were divided into five groups (1. Butt Joint; 2. Full Bevel; 3. Shoulder; 4. Full Crown; 5. Sound Tooth (control); N = 14) and prepared with four different PIAR overlay design types (according to an adhesthetics classification). Seven expert dentists performed all the preparation and cementation phases with codified protocols. A CAD/CAM workflow was used to realize the 56 monolithic lithium disilicate restorations. The samples were tested with thermomechanical aging (margin quality data will be given in Part 2 of this article series), and the resistance to fracture was then tested and analyzed.
Results and conclusions: In terms of fracture resistance in a situation of overload and within the limitations of the present study, it is possible to conclude that the Full Bevel group showed higher fracture strength than all the other groups. All PIAR restorations performed equally or better than the natural control tooth in the Sound Tooth group. The Full Crown group did not perform better than partial overlay PIAR. The fracture types were limited to the crown in 50% or more of the samples; the rest involved the cervical part of the root. The preparation design that involved the root the least was the Full Crown group (14%)
Post-orthodontic recontouring using the Injection Resin Technique.
No full textAim: to present a versatile, rapid and effective technique for post-orthodontic recontouring of lateral upper incisors using flowable composite and a PVS matrix.
Methods: a 15-years old female patient presented at the end of the orthodontic treatment with microdontia of the lateral upper incisors. The integrity of the enamel suggested a minimally invasive adhesive technique with a “no prep” approach and the “Injection Resin Technique” was chosen. Alginate impressions of both arches were recorded for the realization of the diagno- stic wax-up. A clear PVS impression material was used to replicate the wax-up, thus obtaining a clear matrix and two small openings were made to allow insertion of the composite tip.The unprepared teeth were submitted to the adhesive protocol, the clear matrix was positioned and an A2-shade flowable resin composite was injected in a controlled manner, taking care to avoid bubbles formation. The resin was light-cured through the PVS matrix for 2 minutes, then without it for 2 more minutes. Composite excesses were removed using a #12 scalpel blade and the restorations were finished and polished.
Results: one week after treatment, the patient was called back for a subsequent polishing session and was extremely satisfied with the treatment.
Conclusion: sst and minimally invasive solution to complete the aesthetic result of the orthodontic treatment
Nanoleakage and marginal quality of direct composite veneering system for cervical fillings.
Full text linkAim of this study was to evaluate the marginal adaptation and nanoleakage in class V bonded restorations before and after thermo- mechanical loading using Componeer Class V (CCV) compared to con- ventional composites. The null-hypothesis tested was that marginal adap- tation and nanoleakage of CCV was not significantly different compared to conventional composites before and after thermo-mechanical loading. Standardized Class V cavities (width 2.0mm, length 3.0mm, depth 1.5mm) were created in 40 human premolars and molars at the cement- enamel junction. Cavity dimensions were standardized using a digital caliper. Teeth were divided in four groups (N=10): Group 1 One- coat- Bond-Self-etching bonding agent with Synergy-D6+CCV (Coltene); Group 2 One- coat-Bond-Self-etching bonding agent Synergy-D6- flow+CCV (Coltene), Group 3 Scotchbond Universal adhesive system with Filtek-Supreme-XTE (3M ESPE); (Group 4) Scotchbond Universal adhesive system with Filtek-Supreme-XTE-flow (3M ESPE). Restorations were placed according to manufacturers’ instructions. Marginal quality was analyzed under a SEM using epoxy resin replicas before and after thermo-mechanical loading (240,000 mechanical cycles x 50N with a frequency of 1HZ and 7800 thermo-cycles between 5° and 55C° with chewing simulator CS4-Mechatronik). Data were statistically analyzed by two-way ANOVA and Tukey’s post-hoc test (α=0.05).Specimens were then processed to investigate nanoleakage expression under SEM.
The null hypothesis was partially accepted since no significant statistical differences were found in marginal adaptation with CCV compared to mar- gins obtained with conventional composite both before and after thermo- mechanical cycling (p>0.05). Conversely the nanoleakage analysis showed only significant differences between group 1 and group 4 (p<0.05).
The marginal quality of class V cavities restored with CCV was similar to conventional composite restorations, both before and after thermo- mechanical cycling. Nanoleakage expression was dependent on the restor- ative material type. Further clinical research is essential to confirm that composite shells for direct veneering can be a valid restorative procedure
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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