A detailed report on the measures taken in the Department of Conservative Dentistry and Periodontology in Munich at the beginning of the COVID-19 outbreak.

OBJECTIVES: The corona disease (COVID-19) is developing into one of the greatest challenges for healthcare professionals around the world. In this article, we report the detailed actions taken in the Department of Conservative Dentistry and Periodontology, University Hospital, Ludwig-Maximilians-University (LMU), Munich, Germany, during the early phase of the COVID-19 pandemic. MATERIAL AND METHODS: After a joint on-site inspection of the dental clinic with the Department of Clinical Microbiology and Hospital Hygiene, existing clinical and hygiene protocols were adapted for COVID-19 patients. RESULTS: A comprehensive summary of the preparation of the facilities as well as pre- treatment, treatment and posttreatment protocols are described and arising problems are being discussed. CONCLUSIONS: The importance of rigorous hygiene and treatment protocols as well as a sufficient supply of PPE for dental offices and hospitals is highlighted. The measures reported may be subject to change due to the dynamics of the pandemic. CLINICAL RELEVANCE: The modes of transmission of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (e.g., droplets, aerosols, and fomites) can pose a risk for dental healthcare professionals and patients alike. The presented measures may guide dental faculties and dental practices during the early stage of the COVID-19 crisis.

Fabricating fiber-reinforced composite posts.

Endodontic posts do not increase the strength of the remaining tooth structure in endodontically treated teeth. On the contrary, depending on the post design employed (tapered versus parallel-sided), the root can be weakened relative to the amount of tooth removed during preparation. In many cases, if there has been a high degree of damage to the clinical crown, conservative preparation for an anatomic tapered (biomimetic) post with the incorporation of a ferrule on solid tooth structure is necessary to protect the reaming root structure as well as for the long-term retention of the composite resin core and the definitive restoration. Adhesively luted endodontic posts reinforced with glass or quartz fiber lead to better homogeneous tension distribution when loaded than rigid metal or zirconium oxide ceramic posts. Fiber-reinforced posts also possess advantageous optical properties over metal or metal oxide post systems. The clinician should realize that there are admittedly substantial differences in the mechanical loading capacity of the different fiber-reinforced endodontic posts and should be aware of such differences in order to research and select a suitable post system for use.

[Placement of composites in the masticatory load-bearing posterior region (in German)]. / Platzierung von Kompositen im kaulasttragenden Seitenzahnbereich.

Direct composite restorations are placed in the cavities in the posterior region using an incremental layering technique. Numerous different layering concepts are described in the literature. However, only those procedures that can be easily and reliably applied in routine clinical treatment have become established in daily practice. This article is intended to provide a clinically oriented overview of the most common layering procedures for the direct restoration of posterior defects with plastic composite materials.

Longevity of lithium disilicate indirect restorations in posterior teeth prepared by undergraduate students: A retrospective study up to 8.5 years.

OBJECTIVES: To analyze retrospectively the clinical performance and survival of lithium disilicate inlays, partial crowns and crowns placed by undergraduate students. METHODS: 250 lithium disilicate posterior restorations (IPS™Emax Press) were evaluated. Mean service time was 6.6 years (79 months) with a maximum observation time of 8.5 years (102 months). Clinical performance was assessed using FDI Criteria. Descriptive statistics were used to display the distribution of the criteria. Success and survival of the restorations were calculated with the Kaplan Meier method. A Cox regression analysis was performed to detect influencing parameters for the survival or the success of the restorations. RESULTS: Survival and success rates of lithium disilicate indirect restorations were calculated at 6.6 years with 96.3 % and 93.8 %, respectively. After 8.5 years the survival rate was calculated with 94 % and the success rate with 83.8 %. 10 out of 250 restorations (4%) failed, while the main reasons for failure were fracture of material, debonding/loss of restoration, endodontic complications as well as recurrence of caries. A Cox regression analysis failed to show a correlation between restoration failure and the experience level of the students, an existing root canal treatment, type of tooth, bruxism or the use of rubber dam. CONCLUSIONS: Lithium disilicate indirect posterior restorations demonstrate a high success and survival rate after a mean service of 6.6 years when placed by undergraduate students with different levels of experience. Co-factors influencing the survival or success rate of these restorations could not be identified. CLINICAL SIGNIFICANCE: Lithium disilicate restorations show a good clinical performance up to 8.5 years when prepared by undergraduate students.

Corrigendum: A 3-year controlled randomized clinical study on the performance of two glass-ionomer cements in Class II cavities of permanent teeth.

OBJECTIVE: To compare the clinical performance of two glass-ionomer cements in combination with two light-cured coatings in Class II cavities. METHOD AND MATERIALS: In total, 43 Equia Fil/Equia Coat and 42 Fuji IX GP Fast/Fuji Coat LC restorations were placed, in 34 patients. Only Class II cavities with two- or three-surface restorations were included. The clinical performance was evaluated at baseline, after 1, 2, and 3 years using the FDI criteria. For the statistical analysis, Fisher exact test, Wilcoxon signed-rank test and Mann-Whitney U test were applied. The success and survival of the restorations were calculated with the Kaplan-Meier method and a log-rank test was used to detect significant differences between the tested materials. RESULTS: At the 3-year recall, no significant differences could be detected between the two glass-ionomer cements for any of the evaluated criteria (Mann-Whitney U test, P > .05). When comparing the baseline with the recall data at 3 years for each material separately, significant changes could be observed in both materials for the criteria "surface luster," "fracture of material and retention," and "approximal anatomical form" (Wilcoxon signed-rank test, P < .05). Additionally, the Equia Fil restorations showed a notable change for the criteria "marginal adaptation" (Wilcoxon signed-rank test, P = .039). At the 3-year follow up, the Equia Fil and the Fuji IX GP Fast restorations exhibited an overall survival rate of 89.3% and 88.0%, respectively. Three fillings in each group failed. CONCLUSION: The two glass-ionomer cements tested performed similarly in Class II cavities in adult patients, with a moderate failure rate after 3 years. (Original article published in Quintessence Int 2019;50:592-602; doi: 10.3290/j.qi.a42692).

A 3-year controlled randomized clinical study on the performance of two glass-ionomer cements in Class II cavities of permanent teeth.

OBJECTIVE: To compare the clinical performance of two glass-ionomer cements in combination with two light-cured coatings in Class II cavities. METHOD AND MATERIALS: In total, 43 Equia Fil/Equia Coat and 42 Fuji IX GP Fast/Fuji Coat LC restorations were placed, in 34 patients. Only Class II cavities with two- or three-surface restorations were included. The clinical performance was evaluated at baseline, after 1, 2, and 3 years using the FDI criteria. For the statistical analysis, Fisher exact test, Wilcoxon signed-rank test and Mann-Whitney U test were applied. The success and survival of the restorations were calculated with the Kaplan-Meier method and a log-rank test was used to detect significant differences between the tested materials. RESULTS: At the 3-year recall, no significant differences could be detected between the two glass-ionomer cements for any of the evaluated criteria (Mann-Whitney U test, P > .05). When comparing the baseline with the recall data at 3 years for each material separately, significant changes could be observed in both materials for the criteria "surface luster," "fracture of material and retention," and "approximal anatomical form" (Wilcoxon signed-rank test, P < .05). Additionally, the Equia Fil restorations showed a notable change for the criteria "marginal adaptation" (Wilcoxon signed-rank test, P = .039). At the 3-year follow up, the Equia Fil and the Fuji IX GP Fast restorations exhibited an overall survival rate of 86.21% and 84.0%, respectively. CONCLUSION: The two glass-ionomer cements tested performed similarly in Class II cavities in adult patients, with a moderate to high failure rate after 3 years.

Microleakage of XP Bond in Class II cavities after artificial aging.

PURPOSE: To determine the microleakage of etch and rinse adhesives. MATERIALS AND METHODS: Standardized Class II cavities were cut in 40 human molars with one proximal box limited within enamel and one proximal box extending into dentin. Teeth were assigned randomly to 5 groups (n = 8) and restored with incrementally placed composite restorations. Five combinations were tested: G1 = XP Bond + Ceram X Mono, G2 = Syntac Classic + Tetric EvoCeram, G3 = Scotchbond 1 XT + Z250, G4 = P&B NT + Ceram X mono, G5 = Optibond Solo Plus + CeramX Mono. After finishing and polishing, teeth were stored for 48 h in water at 37 degrees C before being subjected to artificial aging by thermal stress (5/55 degrees C, 2000x, 30 s) and mechanical loading (50 N, 50,000x). Teeth were isolated with nail varnish and immersed in 5% methylene blue for 1 h. After sectioning, specimens were evaluated for leakage (ordinal scale: 0 to 4) at enamel and dentin margins under a stereomicroscope. Results were analyzed using the Kruskal-Wallis H-test and Mann-Whitney U-test (p < 0.05). RESULTS: Statistical analysis showed significant differences among the groups in both enamel and dentin. Mean ranks (H-test) were: enamel: G2 (64.44) < G1 (66.69) < G4 (74.88) < G3 (98.25) and G5 (98.25); dentin: G3 (65.53) < G1 (74.42) < G4 (81.09) < G2 (81.84) < G5 (99.61). CONCLUSION: Microleakage of XP Bond is at the same level as or even better than other etch-and-rinse adhesives.

Temporäre Anhebung der Vertikaldimension mit Komposit in einem vereinfachten direkten Spritzgussverfahren.

The comprehensive dental rehabilitation of complex prosthetic cases is often associated with increasing occlusal vertical dimension and transferring horizontal mandibular position in centric relation. The newly defined position of the mandibula should be functionally and esthetically evaluated for a longer time period before irreversible measures are performed. This case report discusses in detail a time-saving and economic direct method for increasing occlusal vertical dimension with long-term provisional composite restorations using a simplified injection molding technique and illustrates the complete intraoral and laboratory workflow.

[Temporary increase of occlusal vertical dimension with direct composite using a simplified injection molding technique. Prearrangement for subsequent lab-made restorations]. / Temporäre Anhebung der Vertikaldimension mit Komposit in einem vereinfachten direkten Spritzgussverfahren. Vorbereitungsmassnahme für nachfolgende laborfertige Restaurationen.

The comprehensive dental rehabilitation of complex prosthetic cases is often associated with increasing occlusal vertical dimension and transferring horizontal mandibular position in centric relation. The newly defined position of the mandibula should be functionally and esthetically evaluated for a longer time period before irreversible measures are performed. This case report discusses in detail a time-saving and economic direct method for increasing occlusal vertical dimension with long-term provisional composite restorations using a simplified injection molding technique and illustrates the complete intraoral and laboratory workflow.

4-year clinical performance and survival analysis of Class I and II compomer restorations in permanent teeth.

PURPOSE: To evaluate the 4-year clinical performance of the compomer Hytac in Class I and II cavities of permanent posterior teeth. METHODS: 53 compomer restorations were placed using the self-conditioning adhesive Hytac OSB (total bonding) without additional phosphoric acid-etching according to manufacturer's instructions. Restorations were rated (modified USPHS criteria) at baseline, after 6, 12, 18, 36 and 48 months in relation to tooth type (molar, premolar), size and class of cavities, isolation type (rubber dam, cotton rolls) and use of a calcium hydroxide liner. After 4 years, 39 restorations (73.6%) were available for examination. Statistical analysis was performed using Kaplan-Meier survival analysis with the logrank test and Fisher's exact test for the failure analysis. RESULTS: After 4 years, the success rate was 84.6%, six restorations failed (15.4%). The average annual failure rate was therefore 3.85%. Loss of marginal integrity was the main cause of restoration failure. The probability that a restoration would remain clinically acceptable after 4 years was calculated to be 89% (Kaplan-Meier). No significant performance differences could be found between any of the restoration groups.

[Bulk-fill-composites. Modern application technique of direct composites for posterior teeth]. / Bulk Fill-Komposite. Neuartige Einsatztechnik von Kompositen im Seitenzahnberich.

Direct composite restorations in the posterior dentition have become an indispensable element of modern dentistry. The performance of these restoration, even in the masticatory load-bearing posterior region, has been conclusively proven in many clinical studies. This procedure is usually carreid out in an elaborate layering technique. This time-consuming procedure requires an economically sensible fee, corresponding to the effort involved. Aside from the possibilies that highly aesthetic composites offer in the application of polychromatic multiple-layer techniques, there is also a great market demand for the most simple and quick and therefore economical composite-based materials for posterior teeth. These products are offered in the category of bulk-fill composite.