Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence and countermeasures of the color effect of restorations Ⅱ.Expression and delivery of color message

进行个别前牙或前牙列部分修复时,医师不仅要注意颜色设计的问题,最终还需要将邻近修复体的天然牙颜色精确复制于修复体上.色彩的复制包括色彩的定位、色彩的表达、色彩的再现3个步骤.     

Influence of different combinations of CAD-CAM crown and customized abutment materials on the force absorption capacity in implant supported restorations – In vitro study

ObjectivesTo evaluate the force absorption capacity of implant supported restorations utilizing different CAD-CAM materials for the fabrication of crowns and customized abutments.Methods80 titanium inserts were scanned to design customized abutments and crowns. The specimens were divided into four groups (n = 20/material): (Z): zirconia, (P): PEEK, (V): VITA Enamic, and (E): IPS e.max. Each group was subdivided into two subgroups according to customized abutment material: (Z) zirconia, and (P) for PEEK. For the assessment of force absorption, all specimens were loaded in a universal testing machine, applied loads curves were collected from the machine’s software, and resulting loads curves were collected from forcemeter below the assembly. The slopes of all curves were analyzed using Two-way multivariate analysis of variance with pairwise comparisons using Tukey Post Hoc test (p < 0.05).ResultsThe curve progression of the applied and resulting forces varied among the investigated materials for each specimen. For zirconia abutments, ZZ showed the highest slope values of the applied and resulting force curves, followed by EZ, VZ, and PZ demonstrating statistically significant differences (P < .001). As for PEEK abutments, ZP and EP showed the least slope values, followed by PP then VP demonstrating statistically significant differences (P < .001). For Zirconia and e.max crowns, using PEEK abutments significantly increased slope loss. As for PEEK and Vita Enamic crowns changing abutment material did not significantly affect slope loss.SignificanceCombining rigid crown materials with less rigid abutments might enhance their force absorption capacity. However, with less rigid crown materials a stiff substructure might be mandatory to preserve their force absorption behavior.     

Clinical efficacy of resin-based direct posterior restorations and glass-ionomer restorations – An updated meta-analysis of clinical outcome parameters

ObjectiveThe present review is an update of a systematic review that has been published in 2012. Meanwhile, many new clinical trials on resin composites had been published. New materials such as bulk fill resin composites and new glass-ionomer (GIC) based materials had been introduced. The focus of this review was to evaluate the longevity in relation to the material class and adhesive class, while adjusting for a possible study bias effect.Material and methodsThe database PUBMED/SCOPUS were searched for clinical trials on posterior resin composites. The inclusion criteria were: (1) studies published between 2000 and 2019, (2) prospective clinical trial with at least 2 years of observation; (2) minimal number of restorations at last recall = 20; (3) report on drop-out rate; (4) report of operative technique and used materials; (5) utilisation of Ryge, modified Ryge or FDI evaluation criteria. The bias of each study was assessed by two independent reviewers using Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. For the statistical analysis, linear mixed models fitted on the individual data recorded along time have been used with random effects to account for study, patients and experiment effects. P-values smaller than 0.05 were considered significant.ResultsOf the 423 clinical trials, 62 studies (including 110 experiments) met the inclusion criteria. Material class was divided according to the composite filler in microhybrid (39 experiments/2807 restorations), nanohybrid (24 experiments/1254 restorations), and hybrid (22 experiments/1255 restorations). So-called bulk fill materials were treated as a separate category (9 experiments/506 restorations) as were the GIC (11 experiments/2121 restorations) and the compomer materials (5 experiments/238 restorations). Only one study (1.6%) had low risk of bias, 42 (67.7%) were assessed to have unclear risk of bias and 19 (30.6%) had a high risk of bias. In 52.3% of the studies Class II and Class I restorations had been placed. After 10 years, the survival rate for resin composite restorations dropped to about 85–90% with no significant difference between hybrid, microhybrid and nao-hybrid resin materials. The main reasons for restoration replacement were bulk fractures and wear, which accounted for a about 70% of replacements. Caries at the restorative margins accounted for about 20% of the replacements, and retention loss, inacceptable colour match or marginal integrity, endodontic treatment or cusp fracture for about 10% of the replacements of the resin composite restorations. For compomer and GIC restorations the mean overall survival rate was about 80% after 6 years. For GIC, the main reasons for failure were substantial loss of anatomical contour along with loss of proximal contacts and retention loss. Mainly fractures reduced the longevity of compomers restorations. Also, there was no statistically significant difference between hybrid, micro-hybrid, nano-hybrid and bulk fill resin composites with regard to colour match, surface texture, material fractures, and anatomical form.Conclusions:Posterior resin composite restorations that were placed with the enamel etch technique showed the best overall performance; the longevity was not significantly influenced by the filler type or viscosity of resin composite material. With regard to colour match, surface texture and anatomical form, nanohybrid resins were not significantly superior to hybrid or microhybrid resin composites. Compomer and GIC restorations demonstrated considerable shortcomings and had a significant shorter longevity.     

Shades of a color. Illusion or reality?

Attaining the highest clinical level in esthetic and cosmetic dentistry necessitates the development of artistic skills; of balancing illusion with reality. The shade of a tooth is a combination of color and light and varies in different light conditions. Understanding the differences in color shades is the basis to creating illusions. Understanding light and color, and the reality of illusions, allows the clinician to design and sculpt a smile, to modify a flawed display artistically so that patients may perceive it as natural and more attractive, and to design laminates and veneers, class III, class IV, and cervical cavities.     

In vitro evaluation of marginal and internal adaptation after occlusal stressing of indirect class II composite restorations with different resinous bases and interface treatments. “Post-fatigue adaptation of indirect composite restorations”

The present study evaluated the influence of different composite bases and surface treatments on marginal and internal adaptation of class II indirect composite restorations, after simulated occlusal loading. Thirty-two class II inlay cavities were prepared on human third molars, with margins located in cementum. A 1-mm composite base extending up to the cervical margins was applied on all dentin surfaces in the experimental groups; impressions were made and composite inlays fabricated. The following experimental conditions were tested: no liner (control group), flowable composite treated with soft air abrasion (experiment 1), flowable composite sandblasted (experiment 2) and restorative composite sandblasted (experiment 3). All specimens were submitted to 1,000,000 cycles with a 100-N eccentric load. Tooth-restoration margins were analysed semi-quantitatively by scanning electron microscopy before and after loading; internal adaptation was also evaluated after test completion. The percentage of perfect adaptation in enamel was 79.5% to 92.7% before loading and 73.3% to 81.9% after loading. Perfect adaptation to dentin was reduced before loading (54.8% to 77.6%) and after loading (41.9% to 63%), but no difference was found among groups for pre- and post-loading conditions. No debonding occurred between the base and composite luting. A significant, negative influence of cyclic loading was observed. The results of the present study support the use of flowable or restorative composites as base/liner underneath large class II restorations. Soft air abrasion represents a potential alternative to airborne particle abrasion for treating cavities before cementation. The application of a composite base underneath indirect composite restorations represents a feasible non-invasive alternative to surgical crown lengthening to relocate cavity margins from an intra-crevicular to supra-gingival position.     

Expression levels of the receptor activator of NF-κB ligand and osteoprotegerin and the number of gram-negative bacteria in symptomatic and asymptomatic periapical lesions

ObjectiveThe study aimed to verify the potential correlation between the detected amount of gram-negative bacteria and the radiographic sizes of the lesions in patients with symptomatic and asymptomatic apical periodontitis. Furthermore, to evaluate whether the expression of receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) and the RANKL/OPG ratio are differentially regulated in both groups.DesignTwenty patients with periapical lesions were divided into two groups: symptomatic (SYM) n = 10 and asymptomatic (ASYM) n = 10. After periapical surgery, the lesions were collected and processed for histological examination, and immunohistochemistry. The percentage of RANKL- and OPG-immunopositive areas relative to the total area of the microscopic field was calculated. For gram staining, the number of gram-negative cells per microscopic field was assessed. The radiographs of each patient were processed and measured. The Student’s t-test and the Pearson correlation coefficient were performed.ResultsThe SYM group showed a significantly higher number of gram-negative cells (p = 0.007) when compared to the ASYM group. A higher number of gram-negative bacteria occurred more frequently in larger periapical lesions and the SYM group (p = 0.03). The expression for RANKL and OPG and the RANKL/OPG ratio were not significantly different between the groups. There was a significant positive correlation between the number of bacteria and OPG levels in the SYM group (p = 0.01).ConclusionThe number of bacteria seems to influence the symptoms and the radiographic size of a periapical lesion. Gram-negative bacteria may play an important role in OPG activity in the SYM group.     

Clinical evaluation of chemomechanical and mechanical caries removal: status of the restorations at 3, 6, 9 and 12 months

In this study, the clinical efficacy of Carisolv™ system and the hand excavation method in the removal of occlusal dentine caries of primary molar teeth was evaluated. Both Carisolv system and hand excavation method were applied for the removal of caries on different teeth of the same children. After the removal of the caries, Dyract AP materials were used to restore the teeth. The clinical follow-up was made every 3 months within a year. The clinical evaluations of restorations were carried out in accordance with US Public Health Service (USPHS) criteria. To determine whether there was any statistical difference between the groups, chi-square analysis was used. During both excavation methods, pain occurrence and the need for anesthesia and the time spent were all recorded. The time spent for the removal of caries in Carisolv system and in hand excavation method was 9.03±4.14 min (mean±SD) and 7.34±3.41 min (mean±SD), respectively (P>0.05). At the end of 1 year, differences between Carisolv and hand excavation groups in terms of marginal adaptation and secondary caries were found to be statistically insignificant (P>0.05). During the removal of caries, certain children complained about pain both in Carisolv system and hand excavation method (7.1 and 35.7%, respectively). As a result, it can be argued that Carisolv system is effective in the removal of caries and causes minimum level pain occurrence. Compared to hand excavation, Carisolv system seems to be a promising restorative approach to remove occlusal caries in primary molar teeth. Studies of longer duration are needed to confirm these findings.     

In vitro evaluation of the polishing effect and optical properties of monolithic zirconia

Statement of problem

The relationship between surface roughness and the optical characteristics of zirconia prostheses may be affected by the type of shaded block.

FDI World Dental Federation: clinical criteria for the evaluation of direct and indirect restorations—update and clinical examples

In 2007, new clinical criteria were approved by the FDI World Dental Federation and simultaneously published in three dental journals. The criteria were categorized into three groups: esthetic parameters (four criteria), functional parameters (six criteria) and biological parameters (six criteria). Each criterion can be expressed with five scores, three for acceptable and two for non-acceptable (one for reparable and one for replacement). The criteria have been used in several clinical studies since 2007, and the resulting experience in their application has led to a requirement to modify some of the criteria and scores. The two major alterations involve staining and approximal contacts. As staining of the margins and the surface has different causes, both phenomena do not appear simultaneously. Thus, staining has been differentiated into marginal staining and surface staining. The approximal contact now appears under the name “approximal anatomic form” as the approximal contour is a specific, often non-esthetic issue that cannot be integrated into the criterion “esthetic anatomical form”. In 2008, a web-based training and calibration tool called e-calib () was made available. Clinical investigators and other research workers can train and calibrate themselves interactively by assessing clinical cases of posterior restorations which are presented as high-quality pictures. Currently, about 300 clinical cases are included in the database which is regularly updated. Training for eight of the 16 clinical criteria is available in the program: “Surface lustre”; “Staining (surface, margins)”; “Color match and translucency”; Esthetic anatomical form”; “Fracture of material and retention”; “Marginal adaptation”; “Recurrence of caries, erosion, abfraction”; and “Tooth integrity (enamel cracks, tooth fractures)”. Typical clinical cases are presented for each of these eight criteria and their corresponding five scores.     

Clinical application of narrow Br?nemark System implants for single-tooth restorations.

Replacing small, single incisors with implants can be esthetically challenging and difficult because of the limited amount of bone. In this investigation, 3.0-mm-diameter implants were used to support 30 single maxillary and mandibular incisors in 21 patients. The implants have been in function for 3 to 7 years, and 29 are still stable. Only 2 complications in the mandibular incisor region have occurred; 1 implant fractured (after 5 years of function) and 1 prosthesis was replaced. The overall success rate is 96.7%. The favorable results and esthetic appearance achieved suggest that replacing small incisors where light occlusal forces are present with narrower implants is a feasible treatment option.