June 16, 2017
Patient satisfaction with removable denture renewal
Patient satisfaction 3 months after new denture insertion was associated with factors of satisfaction and quality related to the old prosthesis and the patient’s jaw type and sex, according to a study published online September 6, 2016, in Journal of Prosthodontics.
Researchers conducted the study to see whether patient satisfaction after denture removal was affected by factors related to the old prosthesis, jaw type, and reasons for requesting denture removal.
Researchers recruited 50 patients for the study. All patients sought treatment at the Department of Prosthetic Dentistry at the University Hospitals Leuven, Leuven, Belgium, to replace their existing removable dentures. They received 74 new dentures (54 complete and 20 partial), and 48 were placed in the maxillary arch and 26 in the mandibular arch. The study population was a roughly even male-female split with a mean age of about 68 years. Data were collected between August 2012 and May 2014.
Researchers focused on the following independent variables: why patients requested new dentures (fit, esthetics, wear, damage, recent extractions, and advice of dentist), satisfaction with the old prosthesis (general, retention, stability, comfort, pronunciation, chewing, and esthetics), and technical quality of the old prostheses as assessed by a dentist (stability, retention, border fit, wear, and esthetics).
Satisfaction was assessed before treatment and 3 months after prosthesis insertion by having patients fill out a questionnaire. To determine total satisfaction 3 months postinsertion, the researchers merged 6 satisfaction items measured after treatment. Change of total satisfaction 3 months postinsertion represented the comparison of old and new prostheses. Sex, age, and a cognitive screening test were included as confounding variables. The researchers conducted Mann-Whitney U tests and linear mixed model analyses.
Researchers found that all aspects of satisfaction significantly improved with new prostheses in maxillary and mandibular jaws. Multivariate analysis showed that total satisfaction 3 months postinsertion was higher for maxillary prostheses if the patient was more satisfied with the retention of the old prosthesis, and if the dentist assessed the esthetics of the old prosthesis as deficient. The change of total satisfaction 3 months postinsertion was higher and associated with lower satisfaction with both chewing and esthetic before the treatment. The outcomes variables evaluated in this study were not affected by the age and the cognitive status of the patient.
“These factors may help dentists predict therapeutics benefits when deciding on the need for denture replacement,” the researchers said. They cited small sample size, a limit of just 1 follow-up treatment, and uneven numbers of complete and partial dentures as limitations of their study.
Read the original article.
Consulting Editor: Luiz Meirelles DDS, MS, PhD
Director, Professional Products and Standards
ADA Science Institute
Comparing flowable and bulk fill resin-based composites
Restorative bulk-fill resin-based composites (RB-RBCs) show better marginal adaptation than flowable-fill RBC (FB-RBCs). Lower levels of polymerization shrinkage and polymerization shrinkage stress in RB-RBCs induce less polymerization shrinkage force at the margin, according to a study published online April 12, 2017, in Operative Dentistry.
Researchers conducted the study to compare the marginal adaptation of 2 FB-RBCs, 2 RB-RBCs, and 1 regular incremental-fill RBC in mesial-occlusal-distal (MOD) cavities in vitro. They also measured the influence of linear polymerization shrinkage, shrinkage force, flexural modulus, and bottom/top surface hardness ratio on the marginal adaptation.
Researchers used RBCs from 5 different manufacturers. They captured images under X100 magnification before and after thermomechanical loading and calculated the marginal adaptation. They also measured linear polymerization shrinkage, polymerization shrinkage stress flexural modulus, and other properties. Gaps, cracks in the enamel layer, and chipping of composite, enamel, or dentin were considered imperfect margins.
Researchers prepared a Class II MOD cavity in 40 extracted sound mandibular molars and filled and light cured 5 different RBCs from different manufacturers.
Lower levels of polymerization shrinkage and polymerization shrinkage stress were observed for RB-RBCs than for FB-RBCs and the control. In addition, better marginal adaptation was calculated for RB-RBCs than for FB-RBCs and the control, likely correlated to the reduced polymerization shrinkage at the margin of RB-RBCs. An important finding from this experiment highlights the lower flexural modulus of FB-RBCs, suggesting that when capped with RBCs, they may not provide effective support during normal function.
“In the preloading state, the influence of polymerization shrinkage and stress might be masked due to the tight bonding between the composites and the tooth,” the researchers noted. “But their influence might remain in the margin as residual stresses. After loading, their influences might be shown more evidently when the bonding between composites and teeth is weakened through the loading process.”
Read the original article.
You just seated another beautiful IPS e.max crown. The excess cement has been removed and now you start to cure the cement through the restoration in segments, starting with the proximal margins. Do you ever wonder how much light actually penetrates through the restoration and reaches the cement? Learn More.
Masking ability of monolithic and bilayer CAD-CAM ceramic structures
Monolithic veneers can mask C4-shaded backgrounds but do not mask metallic backgrounds. Bilayer structures show greater shade masking ability than monolithic structures. Those findings are from a study published online April 12, 2017, in Operative Dentistry.
Researchers designed the study to evaluate the masking ability and translucency of computer-aided design and computer-aided manufacturing ceramic structures (monolayer and bilayer) with different thicknesses. They tested the hypothesis that masking ability is influenced by the thickness, translucency, and layering of the ceramic structure.
Researchers evaluated disks of high translucency (HT) and low translucency (LT) lithium disilicate-based ceramic. Disks had 4 different thickness layers of veneer (0.7 millimeters, 1.0 mm, 1.5 mm, and 2.0 mm) and 3 levels of background color substrates (shade C4, coppery, and silvery). Researchers evaluated the disks as monolithic structures or combined with 0.5-mm–thick zirconia frameworks.
The masking ability and translucency were calculated based on CIE L*a*b* color coordinates measured with a spectrophotometer. The translucency parameter was calculated using color coordinates measured over standard white and black backgrounds. The masking ability was calculated by CIEDE2000 color difference metric (DE00) for each specimen measured over a tooth-colored substrate (shade A2) compared with 3 darker backgrounds (shade C4 and 2 metal substrates).
Researchers found that the presence of a 0.5-mm zirconia framework (bilayer) significantly increased the opacity compared with its monolayer counterparts. Even the thinner bilayers (0.7-mm veneer plus 0.5-mm zirconia) were more opaque than the thicker monolayers (2 mm). Within the HT and LT groups, a reduction in thickness resulted in an increase in translucency for monolayer and bilayer structures. The HT structures showed higher translucency values than LT structures with the same thickness regardless of the structural design (monolayer or bilayer).
The color variation over metallic backgrounds was always significantly higher than over the C4-simulated tooth substrate. For all substrates, within the same translucency and veneer thickness, monolayer groups had a lower masking ability than bilayer groups. Over C4-simulated tooth substrate, thinner bilayers (0.7-mm veneer plus 0.5-mm zirconia) had masking abilities similar to those of thicker monolayers (2 mm).
“A bilayer structure allows the preservation of tooth structure by using a thinner restoration,” the researchers noted, “yet offers a better esthetic appearance than a monolithic ceramic structure to mask dark substrates.”
Read the original article.
100% of 21 Clinician Reports evaluators stated they would incorporate SpeedCEM Plus cement into their practice and 100% rated it excellent or good and worthy of trial by colleagues. Learn More.
Get your patients ready for summer with a new, brighter smile
A great smile can brighten up any summer get-together or vacation for your patients. There’s no time like the present to give them the information they need to brighten their smiles. The comprehensive brochure, “Tooth Whitening for a Brighter Smile” will give your patients options for in-office whitening, whitening toothpastes, and home-use whiteners.
- The merits and side effects of each whitening option.
- Limitations of whitening.
- Warnings against too much whitening.
- Dramatic before-and-after photos.
The 6-page brochure is available in packs of 50 from the ADA Catalog. A sample can be viewed here. To order, call 1-800-947-4746 or go to ADAcatalog.org. The title is available personalized as well. Readers who use the code 17406E before July 7 can save 15 percent on all ADA Catalog products.
Do you struggle…
Tetric EvoFlow Bulk Fill is designed to provide dentin-like opacity helping to conceal staining and maximize esthetics. This self-leveling flowable can be placed in increments up to 4 mm and cured in just 10 seconds. Use Tetric EvoCeram Bulk Fill as a capping layer for enamel-like translucency and natural esthetics. Learn More.
JADA+ Specialty Scans and JADA+ Scans
JADA+ Specialty Scans and JADA+ Scans are quarterly newsletters updating dentists on the latest research in selected specialties and disciplines in dentistry. ADA Publishing and the consulting editors from the represented specialties and disciplines aggregate and summarize research from previously published materials, each item attributed to its publication of origin. JADA+ Scan specialties and disciplines include endodontics, oral pathology, orthodontics, pediatric dentistry, periodontics, prosthodontics, radiology, cosmetic/esthetic and osseointegration. The ADA has engaged the specialty organizations in these areas as well as its own Science Institute and Division of Legal Affairs to assist with these newsletters. View past issues here.
Editorial and Advertising Policies
Any statements of opinion or fact are those of the authors and do not necessarily reflect the views of the American Dental Association. Neither the ADA nor any of its subsidiaries have any financial interest in any products mentioned in this publication. Any reference to a product or service, whether in advertisements or otherwise, is not intended as an endorsement or as approval by the ADA or any of its affiliated organizations unless accompanied by an authorized statement that such approval or endorsement has been granted.
All matters pertaining to advertising should be addressed to the advertising sales manager, Sales and Marketing Department, American Dental Association, Publishing Division, 211 E. Chicago Ave., Chicago, Ill 60611, 1-312-440-2740, fax 1-312-440-2550. All advertising appearing in ADA publications must comply with official published standards of the American Dental Association, a copy of which is available on request.