Open Access Online OnlyOriginal ArticlesDOI: 10.3238/dzz-int.2021.0019Seiten: 112, Sprache: Englisch
Introduction: The aim of this study was to evaluate whether hemostatic agents containing aluminum chloride affect the microtensile bond strength of a universal adhesive to dentin.
Materials and Methods: The occlusal enamel of 50 human molars was removed to expose a flat dentin surface. A universal adhesive was applied either in self-etch (SE) or etch & rinse mode (ER), or a contamination with a "hemostatic agent" (Astringent; ARP or Racegel; RAC) was performed prior to the adhesive application. In the control group (control; C), no contamination in SE and ER mode was performed. A composite build-up was placed onto the adhesively pre-treated surface and specimens were cut to obtain 80 microsticks per group. Half of the specimens were stored for 24 hours before the microtensile bond strength test was performed, the other half was tested after thermocycling (TC, 5,000 cycles). The fractured surfaces were evaluated using a light-optical microscope in order to analyze the failure pattern.
Results: In the SE-mode, dentin contamination with both hemostatic agents prior to universal adhesive application led to a significant decrease in bond strength, compared to the controls before (SE_ARP: 5.67 ± 7.64 MPa; SE_RAC: 5.08 ± 6.04 MPa vs. SE_C: 24.91 ± 12.06 MPa) and after TC (SE_ARP_TC: 2.38 ± 4.43 MPa; SE_RAC_TC: 4.01 ± 4.42 MPa vs. SE_C_TC 24.27 ± 10.67 MPa). Moreover, the SE-mode with prior contamination showed significantly lower bond strength values to dentin before (SE_ARP 5.67 ± 7.64 MPa vs. ER_ARP 20.90 ± 10.91 MPa and SE_RAC 5.08 ± 6.04 MPa vs. ER_RAC 25.62 ± 9.41 MPa) and after TC (SE_ARP_TC 2.38 ± 4.43 MPa vs. ER_ARP_TC 20.91 ± 11.21 MPa and SE_RAC_TC 4.01 ± 4.42 MPa vs. ER_RAC_TC 18.94 ± 9.54 MPa) compared to the ER-mode. In the ER-mode, only contamination with ARP led to a significantly lower bond strength compared to uncontaminated dentin before TC. The fracture analysis showed significant more adhesive fractures in the SE-mode than in the ER-mode.
Conclusion: Considering the limitations of this in-vitro study, the universal adhesive showed higher dentin bond strength when used in ER-mode after contamination with an aluminum chloride-based hemostatic agent.
Schlagwörter: dentin, hemostatic agent, microtensile bond strength, universal adhesive
Open Access Online OnlyClinical SnapshotsDOI: 10.3238/dzz-int.2021.0016Seiten: 143, Sprache: Englisch
In dentistry, silicate ceramics with varying amounts of glass are distinguished from oxide ceramics with little or no glass content. In an ideal glass, there are no crystalline structural elements like in ceramics. The higher and finer the arrangement of the crystalline structure, the less light can pass through the ceramic (Fig. 1); the opaquer it appears.
Schlagwörter: feldspathic ceramic, leucite ceramic, lithium disilicate, lithium silicate, methods, milling, pressing, printing, silicate ceramics, technological processing, zirconium
Open Access Online OnlyOriginal ArticlesDOI: 10.3238/dzz-int.2021.0017Seiten: 148, Sprache: Englisch
Introduction: Tooth surface loss (TSL) is etiologically the sum of cumulative, multifactorial events, which ultimately lead to irreversible loss of tooth structure. Tooth surface loss can be pathological depending on its extent and progression and it can necessitate that the dentist initiates individualized preventive or therapeutic measures in cooperation with the affected patient.
Methods: A literature search for various studies published on PubMed and in the S3 guideline Bruxism up to February 2020 was conducted as part of this narrative review. The studies were evaluated based on topic-related search terms and also a manual search through their respective reference lists was performed. Standard values for TSL were defined and different methods for recording findings were compared.
Results: A sound diagnosis and regular monitoring are mandatory treatment steps for the dentist when treating patients with TSL. Clinical examinations including the "Tooth Wear Index" or the "Tooth Wear Evaluation System" are available for this purpose; these help convey, depending on the index applied, the qualitative and/or quantitative loss of tooth substance. Based on the severity and extent of TSL, thorough consideration is needed for determining if a conservative or an interventional treatment is indicated. Conservative measures include protective splints, fluoridation, and regular monitoring; interventional measures constitute definitive restorations after an initial pre-restorative phase.
Conclusion: A systematic decision tree for the diagnosis and therapy of patients with non-cariogenic, vertical TSL was developed based on the current recommendations found in literature. It is intended to provide dental practitioners with a guideline for the diagnosis and treatment of patients with TSL in their everyday practice.
Schlagwörter: prosthetic rehabilitation, tooth surface loss (TSL), "Tooth Wear Evaluation System", "Tooth Wear Index"
Open Access Online OnlyOriginal ArticlesDOI: 10.3238/dzz-int.2021.0018Seiten: 158, Sprache: Englisch
Introduction: In orthopaedic wear of titanium components of endo-prosthesis is an increasing problem, especially in hip prosthesis. Inflammation and tissue degeneration make surgical revisions risky and unfavourable. As approximately one million dental implants are inserted every year in Germany alone, side-effects like multi-etiological periimplantitis become more fre-quent. This study is motivated by the need to prevent disturbance of osseo-integrative healing of implants after insertion due to phagocytosis of nano-particles. That may cause activation of prolonged tissue inflammation with subsequent higher risk of implant loss or activation of multi-etiological peri-implantitis.
Methods: Human donor bone of D1 quality (Os femoris) was cut in appropriate size and 6 Conelog implants (Camlog) of 3,8 mm diameter (3 implants with a microrough surface and 3 of machined surface) together with 6 Thommen implants of 4 mm diameter (3 implants with a microrough surface and 3 of machined surface) were inserted with a maximum torque of 20 Ncm. Afterwards the bone cavity was opened and investigated for titanium wear. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) was used to perform detection of nanoparticles. Statistical analysis was performed using ANOVA.
Results: The occurence of titanium was very limited. Therefore, the size of particles could not be measured. Overall 150 sites in 12 implants have been analyzed (average of 12.5 sitesper implant). In total, the measurements of 37 sites produced positive detection of small traces of titanium (0.016–0.364 wt.%). No differences have been found regarding the surface morphology or type of manufacturer. Remarkably there are differences in the sub-groups. There is a statistically significant difference between machined and microrough surfaces in Canelog implants (p = 0.0161). No difference has been found in machined and microrough Thommen implants (p = 0.696).
Summary and Conclusion: This unpretentious investigation actually shows that wear of titanium can occur in human bone simply due to implant insertion. Though wear is extremely limited in human donor bone and of little clinical relevance. Further long-term investigations regarding aspects of bio-tribocorrosion in dental implants are needed. The risk of prolonged inflammation during osseointegration is considered to be extremely low and therefore titanium implants are a safe and predictable therapeutic option.
Schlagwörter: bio-tribocorrosion, human donor bone, particles, titanium, wear
Open Access Online OnlyGuidelineDOI: 10.3238/dzz-int.2021.0020Seiten: 176, Sprache: Englisch
In 2013, the first version of the S3-guideline "Implant-prosthetic rehabilitation in the edentulous maxilla" was published. The professional society that released the guideline (Deutsche Gesellschaft für Implantologie e.V.) invited participants to attend a new guideline conference in September 2019. The results from this conference, where representatives from a total of 15 professional societies participated, have now been published in the form of a recent update. In preparation for the update, a systematic literature search in the relevant databases was repeated and the retrieved literature was assessed; this resulted in the inclusion of 11 additional studies. Exclusively titanium implants were examined. The superstructures were fixed (one-piece, screw-retained) or removable (mostly bar-retained). The key recommendations relating to the number of implants were checked and confirmed. In total, 14 new recommendations and statements were included; many of these are related to fixed restorations on 4 implants.
Schlagwörter: S3-Guideline, edentulous, implant-prosthetic rehabilitation, implant-supported, maxilla, number of implants
Open Access Online OnlyPosition PaperDOI: 10.3238/dzz-int.2021.0021Seiten: 182, Sprache: Englisch
Pain of endodontic origin usually requires dental intervention as soon as possible. In the ideal case, this should represent the first step of regular dental treatment afterward.
Full pulpotomy without root canal instrumentation is the first-line therapy for managing pain in symptomatic irreversible pulpitis. In exceptional cases, complete root canal preparation with the placement of intracanal dressings can be performed. Both treatment approaches reliably result in freedom from pain within 24 hours. In the case of symptomatic apical periodontitis, the mechanical root canal preparation up to a size that permits irrigation of the canals over their entire length is required. If orthograde access to the periradicular tissue appears impossible or very risky (e.g. root canal filled tooth with an intracanal post or instrument fragment), the administration of analgesics with additional long-term anesthesia may be indicated in order to enable causal treatment the following day with sufficient treatment time. For acute perira-dic-ular abscesses, the primary goal of pain management is to ensure the adequate drainage of pus. A simple incision without the trepanation of the affected tooth does not represent an adequate causal therapy. In exceptional circumstances, when the trepanation of the tooth is not possible, it should ensue promptly (ideally within 24 hours) after the incision.
In the management of endodontic pain, medication can be considered as an adjunct to, but not a substitute for, the causal therapy indicated in each case.
Schlagwörter: apical periodontitis, irreversible pulpitis, periradicular abscess, pulpotomy, trepanation