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Life (Basel, Switzerland) Jan 2023Presbyopia can be defined as the refractive state of the eye in which, due to a physiological decrease in the ability to accommodate, it is not possible to sustain... (Review)
Review
Presbyopia can be defined as the refractive state of the eye in which, due to a physiological decrease in the ability to accommodate, it is not possible to sustain vision without fatigue in a prolonged manner, along with difficulty focusing near vision. It is estimated that its prevalence in 2030 will be approximately 2.1 billion people. Corneal inlays are an alternative in the correction of presbyopia. They are implanted beneath a laser-assisted in situ keratomileusis (LASIK) flap or in a pocket in the center of the cornea of the non-dominant eye. The purpose of this review is to provide information about intraoperative and postoperative KAMRA inlay complications in the available scientific literature. A search was conducted on PubMed, Web of Science, and Scopus with the following search strategy: ("KAMRA inlay" OR "KAMRA" OR "corneal inlay pinhole" OR "pinhole effect intracorneal" OR "SAICI" OR "small aperture intracorneal inlay") AND ("complication" OR "explantation" OR "explanted" OR "retired"). The bibliography consulted shows that the insertion of a KAMRA inlay is an effective procedure that improves near vision with a slight decrease in distance vision. However, postoperative complications such as corneal fibrosis, epithelial iron deposits, and stromal haze are described.
PubMed: 36836669
DOI: 10.3390/life13020312 -
Journal of International Society of... 2022The aim of this study was to assess and compare the coronal microleakage of e-Temp (DiaDent, Korea), intermediate restorative material (IRM) (Dentsply, Sirona), and...
AIM
The aim of this study was to assess and compare the coronal microleakage of e-Temp (DiaDent, Korea), intermediate restorative material (IRM) (Dentsply, Sirona), and Systemp Inlay (Ivoclar Vivadent, Germany) temporary restorative materials used to seal the class I cavity preparations.
MATERIALS AND METHODS
In this experimental study, three temporary restorative materials were assessed for microleakage. A standardized class I access cavities (2 mm × 4 mm) were prepared in 30 freshly extracted intact human premolar teeth. Teeth were then divided randomly into three groups consisting of 10 samples each. Teeth were restored with e-Temp ( = 10), IRM ( = 10), and Systemp Inlay ( = 10), temporary restorations, and subjected to thermocycling 5000 times in a cold bath followed by a temperature of 55°C with a dwell time of 30 seconds. Teeth were painted with two layers of nail polish except for 1 mm around the restoration margin, soaked in 1% methylene blue dye solution (pH 7.4), and kept for 24 h. Sticky wax was used to seal the apical foramina. All the teeth were sectioned mesiodistally, and the specimens were examined for the amount of dye penetration (microleakage) through the restoration using Digital Microscope under 50× magnification. Data were analyzed using descriptive statistics, Mann-Whitney , and Kruskal-Wallis tests.
RESULTS
e-Temp showed 1 (10%) specimen with dye penetration up to 1 mm (Score 1). The specimens restored with IRM showed a 1 (10%) and 9 (90%) of scores for 1 and 3 dye penetration. However, 2 (20%) teeth restored with Systemp Inlay showed a dye penetration up to 3 mm or more (Score 3). A comparison of mean microleakage values of e-Temp (0.03 ± 0.10), IRM (2.69 ± 0.77), and Systemp Inlay (0.78 ± 1.64) showed a statistically significant difference ( < 0.001). IRM specimens showed significantly higher microleakage values than e-Temp and Systemp Inlay specimens ( < 0.05).
CONCLUSION
All the temporary restorative materials tested in this experiment showed a certain extent of microleakage. The temporary restorative material e-Temp showed the least microleakage values followed by Systemp Inlay and IRM.
PubMed: 36777014
DOI: 10.4103/jispcd.JISPCD_183_21 -
Journal of Prosthodontic Research Oct 2023To evaluate the influence of retainer design and ceramic materials on the durability of minimally invasive cantilever resin-bonded fixed dental prostheses (RBFDPs) after...
PURPOSE
To evaluate the influence of retainer design and ceramic materials on the durability of minimally invasive cantilever resin-bonded fixed dental prostheses (RBFDPs) after artificial aging.
METHODS
One hundred caries-free human mandibular molars were prepared as abutments for all-ceramic cantilevered fixed dental prostheses using the following retainer designs: One wing (OW), Two wings (TW), Inlay ring (IR), Lingual coverage (LC), and Occlusal coverage (OC). Two ceramic materials were used: monolithic high translucent zirconia(z) and zirconia-reinforced lithium disilicate (ZLS) (n=10). All restorations were adhesively bonded with resin cement. The thermocycling of the specimens were performed between 5°C and 55°C for 10,000 cycles and then exposed to 240.000 cycles of dynamic loading on a chewing simulator. All surviving specimens were loaded onto the pontic until failure using a universal testing machine.
RESULTS
The mean failure load ranged from 124.00 to 627.00 N for the zirconia groups and from 133.30 to 230.00 N for the ZLS groups. Regarding the materials, a significantly higher failure load was recorded in the zirconia groups than in the ZLS groups (P<0.001), except for OW (P=0.748). Regarding the retainer designs, a significant different failure load was recorded between the different designs except for IR and LC in the zirconia groups, IR and OC, OW and TW, and TW and LC in the ZLS groups (P<0.001).
CONCLUSIONS
Zirconia IR, LC, and OC can be used as cantilever RBFDP in the premolar region. The fracture resistance of the ZLS design was below the normal bite force and should not be recommended as the first option.
PubMed: 36775338
DOI: 10.2186/jpr.JPR_D_22_00226 -
Polymers Jan 2023The aim of this study is to compare the marginal seal and tensile bond strength (TBS) of prostheses fixed to enamel-dentin using different adhesive systems....
The aim of this study is to compare the marginal seal and tensile bond strength (TBS) of prostheses fixed to enamel-dentin using different adhesive systems. Resin-composite inlays directly fabricated from Class V cavities of extracted human molars/premolars and mini-dumbbell-shaped specimens of bonded enamel-dentin were prepared for microleakage and tensile tests, respectively. Four adhesive systems were used: primerless-wet (1-1 etching for 10-, 30-, or 60-s, and 4-META/MMA-TBB), primer-moist (All-Bond2 + Duolink or Single-Bond2 + RelyX ARC), self-etch (AQ-Bond + Metafil FLO), and dry (Super-Bond C&B) bonding. Dye penetration distance and TBS data were recorded. Failure modes and characteristics of the tooth-resin interface were examined on the fractured specimens. All specimens in 10-, 30-, and 60-s etching primerless-wet, Super-Bond, and AQ-Bond had a microleakage-free tooth-resin interface. Primer-moist groups showed microleakage at the cementum/dentin-resin margin/interface. Significantly higher TBSs (p < 0.05) were recorded in primer-less-wet and Super-Bond groups with the consistent hybridized biopolymer layer after the chemical challenge and mixed failure in tooth structure, luting-resin, and at the PMMA-rod interface. There was no correlation between microleakage and TBS data (p = −0.148). A 1−3 µm hybrid layer created in the 10−60 s primerless-wet technique, producing complete micro-seal and higher tensile strength than enamel and cured 4-META/MMA-TBB, may enhance clinical performances like Super-Bond C&B, the sustainable luting resin.
PubMed: 36679164
DOI: 10.3390/polym15020283 -
International Journal of Computer... Aug 2023For computer-aided planning of facial bony surgery, the creation of high-resolution 3D-models of the bones by segmenting volume imaging data is a labor-intensive step,...
PURPOSE
For computer-aided planning of facial bony surgery, the creation of high-resolution 3D-models of the bones by segmenting volume imaging data is a labor-intensive step, especially as metal dental inlays or implants cause severe artifacts that reduce the quality of the computer-tomographic imaging data. This study provides a method to segment accurate, artifact-free 3D surface models of mandibles from CT data using convolutional neural networks.
METHODS
The presented approach cascades two independently trained 3D-U-Nets to perform accurate segmentations of the mandible bone from full resolution CT images. The networks are trained in different settings using three different loss functions and a data augmentation pipeline. Training and evaluation datasets consist of manually segmented CT images from 307 dentate and edentulous individuals, partly with heavy imaging artifacts. The accuracy of the models is measured using overlap-based, surface-based and anatomical-curvature-based metrics.
RESULTS
Our approach produces high-resolution segmentations of the mandibles, coping with severe imaging artifacts in the CT imaging data. The use of the two-stepped approach yields highly significant improvements to the prediction accuracies. The best models achieve a Dice coefficient of 94.824% and an average surface distance of 0.31 mm on our test dataset.
CONCLUSION
The use of two cascaded U-Net allows high-resolution predictions for small regions of interest in the imaging data. The proposed method is fast and allows a user-independent image segmentation, producing objective and repeatable results that can be used in automated surgical planning procedures.
Topics: Humans; Image Processing, Computer-Assisted; Neural Networks, Computer; Tomography, X-Ray Computed; Mandible; Artifacts
PubMed: 36637748
DOI: 10.1007/s11548-022-02830-w -
Dental Materials Journal Jan 2023This review describes the development of ultra-high translucent zirconia (referred to as UHTZ) using new manufacturing technology and its characterization results. The... (Review)
Review
This review describes the development of ultra-high translucent zirconia (referred to as UHTZ) using new manufacturing technology and its characterization results. The development of UHTZ was primarily due to the adoption of two basic manufacturing technologies, "Cyclic CIP" and "Plus Y Technology". This manufacturing technology could provide stable processing characteristics, which improves chipping resistance during milling. Furthermore, the enlargement factor (processing coefficient) for UHTZ is smaller than those for conventional products. In general, the higher the light transmittance, the lower the flexural strength. Despite its extremely high translucency, the most significant feature of UTHZ is that its flexural strength is comparable to that of 5Y. Furthermore, UHTZ has higher chemical durability and uniform microstructure, which results in less wear on the opposing teeth and superior discoloration resistance. Therefore, UHTZ is a new option for inlay, onlay, and laminate veneer applications, where lithium disilicate glass ceramics has been widely used.
Topics: Materials Testing; Dental Porcelain; Ceramics; Zirconium; Flexural Strength; Surface Properties
PubMed: 36631076
DOI: 10.4012/dmj.2022-243 -
Clinical Oral Investigations Jun 2023To assess the impact of the age of resin-based composite (RBC) restorations used for deep margin elevation (DME) on the marginal quality and fracture resistance of...
OBJECTIVES
To assess the impact of the age of resin-based composite (RBC) restorations used for deep margin elevation (DME) on the marginal quality and fracture resistance of inlays.
MATERIALS AND METHODS
Permanent human molars with direct RBC restorations, involving the mesial, occlusal, and distal surface (MOD), were allocated to four groups (each n = 12). Half of the teeth underwent thermomechanical loading including 240,000 occlusal load cycles and 534 thermal cycles (TML, 5 °C/55 °C; 49 N, 1.7 Hz). With RBC left in one proximal box as DME, all teeth received MOD inlays, made from lithium disilicate (LDS) or a polymer-infiltrated ceramic network material (PICN). The restored teeth underwent TML including 1.2 million occlusal cyclic loadings and 2673 thermal cycles. The marginal quality was assessed at baseline and after both runs of TML. Load-to-fracture tests were performed. The statistical analysis comprised multiple linear regressions (α = 0.05).
RESULTS
Simulated aging of RBC restorations had no significant effect on the marginal quality at the interface between the RBC and the tooth and the RBC and the inlay (p ≥ 0.247). Across time points, higher percentages of non-continuous margin were observed between the inlay and the tooth than between the tooth and the RBC (p ≤ 0.039). The age of the DME did not significantly affect the fracture resistance (p ≥ 0.052).
CONCLUSIONS
Artificial aging of RBC restorations used for DME had no detrimental effect on the marginal quality and fracture resistance of LDS and PICN inlays.
CLINICAL RELEVANCE
This laboratory study suggests that-in select cases-intact, direct RBC restorations not placed immediately before the delivery of an indirect restoration may be used for DME.
Topics: Humans; Aged; Inlays; Composite Resins; Dental Materials; Dental Porcelain; Ceramics; Computer-Aided Design; Materials Testing; Dental Stress Analysis
PubMed: 36622446
DOI: 10.1007/s00784-022-04841-y -
European Journal of Dentistry Oct 2023This article compares and evaluates the marginal and internal fitness and three-dimensional (3D) accuracy of class II inlays fabricated using Tescera (TS) resin,...
OBJECTIVE
This article compares and evaluates the marginal and internal fitness and three-dimensional (3D) accuracy of class II inlays fabricated using Tescera (TS) resin, milling of hybrid and zirconia blocks, and 3D printing with NextDent C&B.
MATERIALS AND METHODS
Fifty-two mesio-occlusal inlays were fabricated using conventional method with TS, milling of Lava Ultimate (LU), milling of Zolid Fx multilayer (ZR), and 3D printing ( = 13 each). The marginal and internal fitness were evaluated at six points in the mesio-distal section of a replica under a digital microscope (160× magnification), and the accuracy was evaluated using 3D software. Analyses were conducted using -test, one-way analysis of variance (ANOVA) and two-way ANOVA, while Duncan's multiple range test was used for post hoc analyses ( = 0.05).
RESULTS
The marginal and internal fitness of the 3D and ZR were significantly superior to that of the TS and LU. For LU, ZR, and 3D, a significant discrepancy between the marginal gap and internal gap was observed ( < 0.05). On evaluating accuracy, trueness was significantly higher in ZR than in TS and LU; precision was significantly higher in 3D and ZR than in TS and LU ( < 0.05).
CONCLUSION
The marginal and internal fitness and the accuracy of TS, ZR, and 3D were within the clinically acceptable range. The marginal and internal fitness and accuracy of 3D were better than those of TS and LU, which are commonly used in dentistry. There is immense potential for using 3D-printed inlays in routine clinical practice.
PubMed: 36599450
DOI: 10.1055/s-0042-1758796 -
BMC Oral Health Dec 2022Evaluating the effect of different surface treatment methods on the micro-tensile bond strength (µTBS) of two different resin-matrix computer-aided...
BACKGROUND
Evaluating the effect of different surface treatment methods on the micro-tensile bond strength (µTBS) of two different resin-matrix computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics (RMCs).
METHODS
A standardized inlay preparations were performed on 100 intact maxillary premolars. According to the type of the restorative material, the teeth were randomly divided into two equally sized groups (n = 50): (polymer-infiltrated ceramic (Vita Enamic) and resin-based composites (Lava Ultimate)). The inlays were fabricated using CAD/CAM technology. In each group, the specimens were randomly assigned to five subgroups (n = 10) according to the surface treatment method: group 1 used was the control group (no surface treatment); group 2, was treated with air abrasion with 50 μm AlO (A) and universal adhesive (UA); group 3, was treated with air abrasion with 50 μm AlO (A) and silane coupling agent (S); group 4, was treated with hydrofluoric acid (HF) and universal adhesive (UA) and group 5, was treated with Hydrofluoric acid (HF) + silane coupling agent (S). The inlays were then cemented to their respective preparations using dual-cure self-adhesive resin cement (RelyX U200, 3 M ESPE) according to the manufacturer's instructions. The µTBS test was conducted in all groups, and stereomicroscope and scanning electron microscope were used to inspect the failure mode. The data were statistically analyzed using a two-way analysis of variance (ANOVA) and Tukey's post-hoc multiple comparison tests at a significance level of p < 0.05.
RESULTS
Surface treatments significantly increased the µTBS of the materials compared to the control group (p < 0.05). For CAD/CAM RBCs, the µTBS value highest in group 2 whereas, for PICN, the µTBS value was highest in group 3. Cohesive failure of CAD/CAM restorative material was the most predominant mode of failure in all treated groups, whereas adhesive failure at restoration-cement interface was the most predominant failure mode in the control group.
CONCLUSION
Surface treatments increase the µTBS of resin-matrix CAD/CAM ceramics to tooth structure. Air abrasion followed by universal adhesive and hydrofluoric acid followed by silane application appears to be the best strategies for optimizing the bond strength of CAD/CAM RBCs and PICN respectively.
Topics: Humans; Air Abrasion, Dental; Ceramics; Computer-Aided Design; Dental Bonding; Dental Materials; Dentin; Hydrofluoric Acid; Materials Testing; Resin Cements; Silanes; Surface Properties; Bicuspid
PubMed: 36564766
DOI: 10.1186/s12903-022-02674-5 -
BMC Medical Education Dec 2022To investigate the effect of virtual simulation systems on the teaching of inlay experiments and to guide the experimental teaching of tooth preparation. (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
To investigate the effect of virtual simulation systems on the teaching of inlay experiments and to guide the experimental teaching of tooth preparation.
METHODS
Participants in their second semester of the junior year were selected to carry out the unified teaching and evaluation of dental preparation theory. The age varied from 18 to 22 years (19.96 ± 0.70) and the participants were randomly divided into four groups (n = 19) with a similar male-to-female ratio following CONSORT guidelines, including a jaw simulation model training group (Group J), a virtual simulation system training group (Group V), a jaw model training first followed by a virtual system training group (Group J-V), and a virtual system followed by a jaw model training group (Group V-J). The inlay tooth preparation assessment was performed on the extracted teeth. The data were analysed according to the assessment scores by a senior clinician. The subjective feelings of the students towards the system were evaluated using questionnaires.
RESULTS
The second theoretical scores of Group V-J (63.5 ± 2.89) and Group J-V (60.5 ± 3.25) were higher than those of Group V (57.5 ± 3.13) and Group J (58.0 ± 3.67). The experimental scores of Groups J-V and V-J (62.79 ± 2.84; 64.00 ± 2.85) were higher than those of Groups V and J (56.05 ± 3.39; 55.74 ± 2.53). The questionnaire survey illustrated that most students preferred the digital virtual simulation system (perfect assessment: 91.3%, accuracy: 82.6%, satisfaction: 52.2%).
CONCLUSION
Virtual simulation training can facilitate the teaching effect of tooth preparation in inlay experiments, and the teaching mode of Group V-J was the best. Therefore, this teaching mode is to be popularised.
Topics: Male; Female; Humans; Adolescent; Young Adult; Adult; Educational Measurement; Simulation Training; Computer Simulation; User-Computer Interface; Teaching
PubMed: 36471301
DOI: 10.1186/s12909-022-03930-6