Georgi Iliev

Dr. Georgi Iliev

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Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2016 in Balkan Journal of Dental Medicine
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Journal Article
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GIGeorgi Iliev
Georgi Iliev
Nowadays in the aesthetic dentistry concepts, techniques, and materials which aim is to establish new smiles with minimally invasive approaches and maximum natural effect on the restorations and in the same time to restore the mastication and phonetics for a better quality of life are used. However, the patient's demands and the level of information has driven the profession to a certain questioning respecting the treatment customization especially those related to treatment planning according to the individual psychological characteristics of each patient, that if ignored, may lead to esthetically dissatisfaction, even though all the esthetic rules which tend to establish standards were incorporated. The purpose of this article is to show that besides the esthetic rules established throughout the time, the emotional expression of the treatment, represented by the shapes and lines constituent of a smile, should also be taken into consideration during the treatment planning. Softwares for personalized smile design could be powerful tool for planning such new smile designs.

1 March 2020
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Journal Article
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GIGeorgi Iliev
Georgi Iliev
GRGiuseppe Romeo
Giuseppe Romeo

29 November 2024 in Applied Sciences
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Journal Article
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GIGeorgi Iliev
Georgi Iliev
RVRadosveta Vasileva
Radosveta Vasileva
DKDimitar Kirov
Dimitar Kirov
EDElitsa Deliverska
Elitsa Deliverska
JNJanet Kirilova Nikolova
Janet Kirilova Nikolova
Contemporary indirect restorative materials vary in their physical and mechanical properties, necessitating additional research. This investigation aims to compare the mechanical properties (such as fatigue and compressive strength) of indirect dental restorative materials. In an in vitro study, the mechanical behaviour of monolithic onlay restorations made from a lithium disilicate glass–ceramic (Group A), a ceramic-infiltrated composite (Group B), a polymer-based composite resin (Group C), and zirconia (Group D), bonded to a prepared tooth model, was evaluated after ageing and mechanical cycling. The average value of compressive strength (stage of cracking) in each group was as follows: Group A, 871 N; Group B, 728 N; Group C, 2655 N; and Group D, 2005 N. Moreover, the results of the compressive strength test (stage of destruction) in each group were as follows: Group A, 2516.5 N; Group B, 2266 N; Group C, 5670 N; and Group D, 3543 N. An analysis of variance (ANOVA) followed by Tukey’s (HSD) post hoc test was conducted to assess pairwise comparisons among group means. Statistical analysis revealed significant differences between Groups C and D and the others, highlighting the potential of these materials in clinical applications. Based on the average values, it can be concluded that the 3D-printed ceramic-infiltrated composite onlays exhibited the highest compressive resistance values among the materials evaluated. The lithium disilicate glass–ceramic and the ceramic-infiltrated composite are brittle materials, which should be considered when covering teeth with high occlusal stress.

6 January 2026 in Dentistry Journal
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Journal Article
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GIGeorgi Iliev
Georgi Iliev
Lucian Toma CiocanLucian Toma Ciocan
Lucian Toma Ciocan
VVVlad Gabriel Vasilescu
Vlad Gabriel Vasilescu
GVGaudentiu SOLUTIONS SRL - Gaudentiu Varzaru
Gaudentiu SOLUTIONS SRL - Gaudentiu Varzaru
Florin MiculescuFlorin Miculescu
Florin Miculescu
SPSilviu Mirel Pițuru
Silviu Mirel Pițuru
Background/Objectives: The clinical application of CAD/CAM restorative materials continues to evolve due to increasing demand for aesthetic, durable, and minimally invasive indirect restorations. Hybrid nanoceramics, such as Grandio disc (VOCO GmbH, Cuxhaven, Germany), are increasingly used in indirect restorative dentistry due to their favourable combination of mechanical strength, polishability, wear resistance, and bonding potential. One challenge associated with adhesive protocols for CAD/CAM materials lies in achieving durable bonds with resin cements. Extensive post-polymerization during fabrication reduces the number of unreacted monomers available for chemical interaction, thereby limiting the effectiveness of traditional adhesive strategies and necessitating specific surface conditioning approaches. This study aimed to evaluate, in a preliminary, non-inferential manner, the influence of several combined conditioning protocols on surface micromorphology, elemental composition, and descriptive SBS trends of a CAD/CAM hybrid nanoceramic. This work was designed as a preliminary pilot feasibility study. Due to the limited number of specimens (two discs per protocol, each providing two independent enamel bonding measurements), all bond strength outcomes were interpreted descriptively, without inferential statistical testing. This in vitro study investigated the effects of various surface conditioning protocols on the adhesive performance of CAD/CAM hybrid nanoceramics (Grandio disc, VOCO GmbH, Cuxhaven, Germany) to dental enamel. Hydrofluoric acid (HF) etching was performed to improve adhesion to indirect resin-based materials using two commercially available gels: 9.5% Porcelain Etchant (Bisco, Inc., Schaumburg, IL, USA) and 4.5% IPS Ceramic Etching Gel (Ivoclar Vivadent, Schaan, Liechtenstein), in combination with airborne-particle abrasion (APA), silanization, and universal adhesive application. HF may selectively dissolve the inorganic phase, while APA increases surface texture and micromechanical retention. However, existing literature reports inconsistent results regarding the optimal conditioning method for hybrid composites and nanoceramics, and the relationship between micromorphology, elemental surface changes, and adhesion remains insufficiently clarified. Methods: A total of ten composite specimens were subjected to five conditioning protocols combining airborne-particle abrasion with varying hydrofluoric acid (HF) concentrations and etching times. Bonding was performed using a dual-cure resin cement (BiFix QM) and evaluated by shear bond strength (SBS) testing. Surface morphology was examined through environmental scanning electron microscopy (ESEM), and elemental composition was analyzed via energy-dispersive X-ray spectroscopy (EDS). Results: indicated that dual treatment with HF and sandblasting showed descriptively higher SBS, with values ranging from 5.01 to 6.14 MPa, compared to 1.85 MPa in the sandblasting-only group. ESEM revealed that higher HF concentrations (10%) created more porous and irregular surfaces, while EDS indicated an increased fluorine presence trend and silicon reduction, indicating deeper chemical activation. However, extending HF exposure beyond 20 s did not further improve bonding, suggesting the importance of protocol optimization. Conclusions: The preliminary observations suggest a synergistic effect of mechanical and chemical conditioning on hybrid ceramic adhesion, but values should be interpreted qualitatively due to the pilot nature of the study. Manufacturer-recommended air abrasion alone may provide limited adhesion under high-stress conditions, although this requires confirmation in studies with larger sample sizes and ageing simulations. Future studies should address long-term durability and extend the comparison to other hybrid CAD/CAM materials and to other etching protocols.

19 July 2020 in Clinical Case Reports
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KCKrasimir Ivanov Chapanov
Krasimir Ivanov Chapanov
GIGeorgi Iliev
Georgi Iliev
SKStoyan Torezov Kazakov
Stoyan Torezov Kazakov
This case report describes an alternative approach for the planning of immediate implant placement and provisionalization, which uses a new online dental software that predicts the esthetic outcome.

16 May 2023 in Applied Sciences
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Journal Article
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GIGeorgi Iliev
Georgi Iliev
DFDimitar Filtchev
Dimitar Filtchev
BTBranka Trifkovic
Branka Trifkovic
DJDanimir Jevremović
Danimir Jevremović
ZPZhanina Pavlova
Zhanina Pavlova
Daniela StoevaDaniela Stoeva
Daniela Stoeva
Background: Appropriate abutment selection according to the individual specificities of each patient is a leading factor in achieving high aesthetic results. Standardized titanium abutments are the most widely used due to their easy use and low cost. It is considered that customized abutments can eliminate many of the complications seen with factory abutments in prosthetic treatment. The purpose of this study is to evaluate whether customized abutments have better mechanical behavior in laboratory settings than standard ones. The null hypothesis is that customized abutments have better resistance to cyclic load and compression than factory abutments. Methods: The study model includes thirty implant suprastructure samples, fabricated digitally, divided into three groups according to the type of implant abutment and the used material: Group A (control group) comprised monolithic implant crowns made of zirconium dioxide and a titanium base; Group B (test group) comprised monolithic implant crowns made of zirconia implant crowns and a customized titanium alloy abutment; and Group C (test group) comprised monolithic implant crowns made of lithium disilicate and a customized titanium alloy abutment. The samples were subjected to dynamic load in a computer-controlled 2-axis machine that simulated masticatory movements, Chewing Simulator CS-4 (SD-Mechatronik, Westerham, Germany), for 250,000 cycles at a frequency of 2 Hz. The samples were then subjected to compressive strength testing in an Instron M 1185 universal testing machine. A metal steel disc was used as an antagonist, exerting pressure at a rate of 2 mm/min at room temperature on each sample. After conducting the laboratory tests, the samples were examined by an experienced expert under a Carl Zeiss microscope (Carl Zeiss Microscopy GmbH, Jena, Germany). Results: All samples were found to have passed the fatigue test in the masticatory simulator without any of the listed complications. The average value of the compressive strength at which the structures in each group fracture is as follows: Group A, 5669.2; Group B, 3126.5; and Group C, 1850.6. Based on the average values, it can be concluded that the combination of materials used in Group A has the greatest resistance. Conclusion: The weak link in the prosthetic complex consisting of a crown and abutment seems to be the crown. No abutment failure was found regardless of the type. However, monolithic zirconia crowns over standard titanium abutments withstand higher mechanical forces compared with zirconia and lithium disilicate crowns over customized ones. Detailed studies in clinical settings may provide more in-depth information on this issue.