Impact of optical fiber-based photo-activation on dental composite polymerization.

OBJECTIVES: The study aimed to introduce a novel two-step optical fiber-based photo-activation of dental resin-based composites (RBCs) for reducing polymerization shrinkage stress (PSS). METHODS: Proposed protocol design - in the first step, two flexible plastic optical fibers connected to a dental light curing unit (LCU), were used as light guides inserted into the filling to initiate low-irradiance polymerization from within; in the second step, fibers were extracted and remaining voids were filled with RBC, followed by conventional high-irradiance curing to finalize polymerization. Three bulk-fill RBCs were tested (Beautifil-Bulk Restorative, Filtek Bulk-fill Posterior, Tetric PowerFill) using tooth cavity models. Three non-invasive examination techniques were employed: Digital Holographic Interferometry, Infrared Thermography, and Raman spectroscopy for monitoring model deformation, RBC temperature change, and degree of conversion (DC), respectively. A control group (for each examined RBC) underwent conventional photo-activation. RESULTS: The experimental protocol significantly reduced model deformation by 15 - 35 %, accompanied by an 18 - 54 % reduction in RBC temperature change, emphasizing the impact of thermal shrinkage on PSS. Real-time measurements of deformation and temperature provided indirect insights into reaction dynamics and illuminated potential mechanisms underlying PSS reduction. After a 24-hour dark-storage period, DC outcomes comparable to conventional curing were observed, affirming the clinical applicability of the method. CONCLUSIONS: Protocol involving the use of two 1.5 mm fibers in the first step (300 mW/cm2 x 10 s), followed by a second conventional curing step (1000 mW/cm2 x 10 s), is recommended to achieve the desired PSS reduction, while maintaining adequate DC and ensuring efficient clinical application. CLINICAL SIGNIFICANCE: Obtained PSS reduction offers promise in potentially improving the performance of composite restorations. Additionally, leveraging the flexibility of optical fibers improves light guide approach for restorations on posterior teeth. Meanwhile, implementation in clinical practice is easily achievable by coupling the fibers with commercial dental LCUs using the provided plastic adapter.

Stresses in Premolars Restored Using Different Post-and-Core and Crown Materials: An FEA Study.

PURPOSE: The aim of the present study was to investigate the influence of three post-and-core systems and two crown materials on stresses in restored premolars using Finite Element Analysis (FEA). MATERIALS AND METHODS: A maxillary second premolar 3D model was created in SolidWorks 2014 (Dassault Systémés). Severe loss of tooth structure was simulated with six restorative options: 1) glass-fiber-reinforced composite post and composite core (GFRC)+CAD/CAM leucite-reinforced glass-ceramic crown (LRC); 2) carbon-fiberreinforced composite post and composite core (CFRC)+LRC; 3) metal cast post-and-core (MPC)+LRC 4) GFRC+CAD/CAM composite resin crown (CC); 5) CFRC+CC; 6) MPC+CC. Three-point occlusal loading (150N) was simulated and von Misses and maximum principal stresses calculated. RESULTS: Although maximum von Mises stresses in the crown and dentin were similar across groups (137.9-139.2MPa crown; 17.2-19.6 dentin), there were important differences in stress distribution in dentin. Only in MPC+CC group the maximum stresses were on the bottom of the post preparation cavity. Stress values within the posts were: CFRC(4.8MPa)>GFRC(6.7MPa)>MPC(10.3MPa). CC-restored models presented higher von Mises stresses within the post-and-core compared to the LRC groups. Maximum principal stresses were lower compared to von Mises stresses, following the same trend, and were distributed similarly in all the groups. CONCLUSIONS: Both GFRC and CFRC showed favourable stresses distribution in the dentin and restorative materials, while MPC increased stresses in core, post and post cement. The more rigid crown material seems to transmit less stresses to the underlying core and crown cement compared to CC.

Finite element and in vitro study on biomechanical behavior of endodontically treated premolars restored with direct or indirect composite restorations.

Objectives of the study were to investigate biomechanical properties of severely compromised premolars restored with composite restorations using finite element analysis (FEA), and in vitro fracture resistance test. A 3-D model of an endodontically treated premolar was created in Solidworks. Different composite restorations were modelled (direct restoration-DR; endo-crown-EC; post, core, and crown-C) with two different supporting tissues: periodontal ligament/alveolar bone (B), and polymethyl methacrylate (PMMA). Models were two-point axially loaded occlusally (850 N). Von Mises stresses and strains were calculated. The same groups were further tested for static fracture resistance in vitro (n = 5, 6.0 mm-diameter ball indenter, vertical load). Fracture resistance data were statistically analyzed (p < 0.050). The highest stresses and strains in all FEA models were observed on occlusal and vestibular cervical surfaces, corresponding to fracture propagation demonstrated in vitro. C showed the lowest stress in dentin, while EC showed lower stresses and strains in crown cement. B models demonstrated larger high stress areas in the root than PMMA models. No significant differences in fracture resistance (N) were observed between groups (DR: 747.7 ± 164.0, EC: 867.3 ± 108.1, C: 866.9 ± 126.3; p = 0.307). More conservative restorations seem a feasible alternative for endodontically treated premolars to conventional post-core-crown.

Micromechanical imaging of dentin with Brillouin microscopy.

The structure of teeth can be altered by diet, age or diseases such as caries and sclerosis. It is very important to characterize their mechanical properties to predict and understand tooth decay, design restorative dental procedures, and investigate their tribological behavior. However, existing imaging techniques are not well suited to investigating the micromechanics of teeth, in particular at tissue interfaces. Here, we describe a microscope based on Brillouin light scattering (BLS) developed to probe the spectrum of the light scattered from tooth tissues, from which the mechanical properties (sound velocity, viscosity) can be inferred with a priori knowledge of the refractive index. BLS is an inelastic process that uses the scattering of light by acoustic waves in the GHz range. Our microscope thus reveals the mechanical properties at the micrometer scale without contact with the sample. BLS signals show significant differences between sound tissues and pathological lesions, and can be used to precisely delineate carious dentin. We also show maps of the sagittal and transversal planes of sound tubular dentin that reveal its anisotropic microstructure at 1 µm resolution. Our observations indicate that the collagen-based matrix of dentine is the main load-bearing structure, which can be considered as a fiber-reinforced composite. In the vicinity of polymeric tooth-filling materials, we observed the infiltration of the adhesive complex into the opened tubules of sound dentine. The ability to probe the quality of this interfacial layer could lead to innovative designs of biomaterials used for dental restorations in contemporary adhesive dentistry, with possible direct repercussions on decision-making during clinical work. STATEMENT OF SIGNIFICANCE: Mechanical properties of teeth can be altered by diet, age or diseases. Yet existing imaging modalities cannot reveal the micromechanics of the tooth. Here we developed a new type of microscope that uses the scattering of a laser light by naturally-occurring acoustic waves to probe mechanical changes in tooth tissues at a sub-micrometer scale without contact to the sample. We observe significant mechanical differences between healthy tissues and pathological lesions. The contrast in mechanical properties also reveals the microstructure of the polymer-dentin interfaces. We believe that this new development of laser spectroscopy is very important because it should lead to innovative designs of biomaterials used for dental restoration, and allow delineating precisely destructed dentin for minimally-invasive strategies.

Characterization of spatial patterns of dental restorative nanocomposites.

The aim of this study was to provide important insights into the effects of four different dental polishing protocols (one single-step and one multi-step either followed or not by diamond paste polishing) on the 3D surface morphology of two representative dental resin-based nanocomposites (a nanofilled and a nanohybrid composite) by means of digital image analysis and processing techniques. The 3D surface morphology was investigated by atomic force microscopy. Segmentation, statistics of height distributions (described by statistical parameters, according to ISO 25178-2: 2012) and Minkowski functionals were applied to the images to characterize the spatial patterns of analyzed samples at micrometer scale. The nanofilled composite had significantly lower values of height parameters in comparison with nanohybrid one. Multi-step polishing protocol generated a statistically significant smoother finish for both tested materials, than one-step polishing protocol, even when it was followed by diamond paste polishing. Diamond paste polishing generated a statistically significant smoother surface of tested samples. This suite of surface analysis tools is important in the research and manufacture of these dental resin-based nanocomposites, where material surfaces have a key role in the functionality of objects.

Influence of the restorative procedure factors on stress values in premolar with MOD cavity: a finite element study.

In order to investigate the influence of cusp reduction, cavity isthmus width, and restorative material on stress values in premolar with mesio-occlusal-distal (MOD) cavity, numerical simulations were done on three-dimensional (3D) models of a maxillary second premolar designed using computerized tomography (CT) scan images. The use of four restorative materials (direct resin composite, direct resin composite with resin-modified glass-ionomer cement as the base, indirect resin composite, ceramic), three cavity preparation designs (without cusp coverage, 2-mm palatal cusp coverage, 2-mm palatal and buccal cusp coverage), and two cavity isthmus widths (1/2 and 2/3 intercuspal width) were simulated. After applying a static load of 200 N on the occlusal surface of the tooth, von Mises stresses in the enamel, dentin, and restoration were calculated using finite element analysis (FEA). Stress values in the enamel were primarily influenced by cavity preparation design, while restorative material showed higher contribution in dentin. The lowest stress values were obtained in models with cusp coverage and indirect restorations. Cavity isthmus width had minimal influence on stress values in tooth structures. None of the investigated factors determined stress values in the restoration. In conclusion, the use of ceramic restoration covering both palatal and buccal cusp provided the most favourable stress distribution of premolars with MOD cavity. Graphical abstract ᅟ.

Influence of restorative procedures on endodontically treated premolars: Finite element analysis of a CT-scan based three-dimensional model.

An endodontically treated tooth with mesial-occlusal-distal (MOD) cavity is often restored with composite resin. Palatal and buccal cusp reduction (MODP, MODPB), and/or fiber-reinforced composite posts (P), are used in an attempt to improve the longevity of the restoration. The aim of this study was to determine the effects of these procedures on von Mises stress values and distribution in dental tissues and restorative materials using finite element analysis. Based on CT scans of an extracted second upper premolar, six 3D endodontically treated tooth models (MOD, MODP, MODPB, MOD+P, MODP+P, MODPB+P) were created. Each model was subjected to a summary force of 150 N on the occlusal surface simulating the normal biting pattern and maximal von Mises stresses were calculated. MODP seems to reduce von Mises stress values in dental tissues and P seems to transfer some of the stresses from dental tissues to the composite filling.

Influence of the artificial saliva storage on 3-D surface texture characteristics of contemporary dental nanocomposites.

The aim of this study was to analyse the influence of the artificial saliva on a three-dimensional (3-D) surface texture of contemporary dental composites. The representatives of four composites types were tested: nanofilled (Filtek Ultimate Body, FUB), nanohybrid (Filtek Z550, FZ550), microfilled (Gradia Direct, GD) and microhybrid (Filtek Z250, FZ250). The specimens were polymerised and polished by the multistep protocol (SuperSnap, Shofu). Their surface was examined, before and after 3 weeks' exposure to artificial saliva storage. The surface texture was analysed using the atomic force microscope (AFM). The obtained images were processed to calculate the areal autocorrelation function (AACF), anisotropy ratio Str (texture aspect ratio), and structure function (SF). The log-log plots of SF were used to calculate fractal properties, such as fractal dimension D, and pseudo-topothesy K. The analysis showed changes in surface anisotropy ratio Str values, which became higher, whereas the Sq roughness (root-mean-square) reduced after the artificial saliva storage. All the samples exhibited bifractal structure before the saliva treatment, but only half of them remained bifractal afterwards (GD, FZ250), whereas the other half turned into a monofractal (FUB, FZ550). The cube-count fractal dimension Dcc was found to be material- and treatment-insensitive.

THE ROLE OF NUTRITION IN CARIES PREVENTION AND MAINTENANCE OF ORAL HEALTH DURING PREGNANCY.

INTRODUCTION: Pregnancy may pose an increased risk for the development of caries and other oral health problems. Continuous screening of oral health status, implementing appropriate preventive measures (particularly oral hygiene, healthy diet plans and education) is of paramount importance not only for oral health but also for the general health status of the future mother and her offspring. EFFECTS OF FOOD ON CARIES DEVELOPMENT: Caries prevention through healthy diet implicates the reduction in frequency and amount of intake of cariogenic food, above all ofrefined carbohydrates, i.e. sugars and sweets. Foods known to have caries-prophylactic effects should predominate in healthy diet plans. They mainly include solid foods, which have mechanical effects on teeth cleaning, as well as foods providing sufficient amounts of vitamins (A, C, D) and a variety of elements and compounds (calcium, phosphates, fluorides) favoring the preservation and remineralization of tooth structures. EDUCATION OF PREGNANT WOMEN ON HEALHY DEIT: In accomplishing these goals, education and direct positive communication between the educator and the pregnant woman play a crucial role. Educative approach is always individual and determined by the patient's specific cultural and socioeconomic features and status, as well as her habits, motivation and willingness to accept relevant recommendations. Accomplishing the aforementioned goals requires the appropriate organization and professional competence within the preventive dental service and its close cooperation with the relevant medical institutions and social support in the framework of public health protection. CONCLUSION: Preserving of oral health during pregnancy is predominantly influenced by the following factors: 1) healthy diet, 2) oral hygiene, 3) patients' education, 4) regular control of oral health, 5) appropriate organization of dental services and 6) community engagement.

Technical quality of root fillings performed by undergraduate students: a radiographic study.

AIM: The aim of this study was to evaluate the radiographic technical quality of endodontic treatment performed by undergraduate students at the School of Dentistry, Faculty of Medicine, University of Novi Sad, Serbia. MATERIALS AND METHODS: Electronic records of 220 patients treated by final-year undergraduate students during the school year 2011/2012 were examined, and the final sample consisted of 212 patients, 322 teeth, and 565 root canals. The criteria for overall radiographic adequacy of root canal fillings were defined as the presence of adequate length and density and absence of iatrogenic errors (ledge, fractured instrument, untreated canal, and apical transportation). Chi-square test was used to determine statistical significance between different parameters. RESULTS: Adequate root canal fillings were found in 74.22% of the teeth. The percentage of root fillings with adequate length and density was 89.73% and 92.6%, respectively. Fractured instruments and ledges were present in 16 root canals (2.8%), while the presence of missed canal and apical transportation was observed in 2 cases, each (0.3%). CONCLUSIONS: Overall, the technical quality of root canal fillings performed by undergraduate students was satisfactory.

Determination of surface roughness and topography of dental resin-based nanocomposites using AFM analysis.

The aim of this study was to determine surface roughness and topography of polished dental resin-based nanocomposites. Four representative dental resin-based nanocomposites were tested in the study: two nanohybrids (Filtek Z550 and Tetric EvoCeram) and two nanofilled (Filtek Ultimate Body and Filtek Ultimate Translucent); and two reference materials: one microfilled (Gradia Direct) and one microhybrid (Filtek Z250). Polymerized cylindrical specimens (4 mm x 2 mm) were polished with multi-step polishing system- Super Snap. Immediately after the polishing, topography of each specimen was examined by Veeco di CP-II Atomic Force Microscope. Specimen's surface has been scanned in 6 points in contact mode with CONT20A-CP tips. 1 Hz scan rate and 256 × 256 resolution were used to obtain topography on a 90 µm × 90 µm scanning area. Measured topography data were processed by Image Processing and Data Analysis v2.1.15 software. Following parameters were compared among specimens: average roughness and maximum peak-to-valley distance. All of the tested materials had similar average surface roughness after finishing and polishing procedure. The lowest values occurred in the material Filtek Ultimate Body, and the highest in the Filtek Z550. When interpreting maximum peak-to-valley distance the larger differences in values (up to 100%) occurred in Filtek Z550, Filtek Z250 and Filtek Ultimate Body, which is a result of the deep polishing channels and tracks. Type, size, distribution of fillers and filler loading in tested materials, didn't influence average roughness values, but had an impact on maximum peak-to-valley distance values.

Influence of cavity design preparation on stress values in maxillary premolar: a finite element analysis.

AIM: To analyze the influence of cavity design preparation on stress values in three-dimensional (3D) solid model of maxillary premolar restored with resin composite. METHODS: 3D solid model of maxillary second premolar was designed using computed-tomography (CT) data. Based on a factorial experiment, 9 different mesio-occlusal-distal (MOD) cavity designs were simulated, with three cavity wall thicknesses (1.5 mm, 2.25 mm, 3.0 mm), and three cusp reduction procedures (without cusp reduction, 2.0 mm palatal cusp reduction, 2.0 mm palatal and buccal cusp reduction). All MOD cavities were simulated with direct resin composite restoration (Gradia Direct Posterior, GC, Japan). Finite element analysis (FEA) was used to calculate von Mises stress values. RESULTS: The von Mises stresses in enamel, dentin, and resin composite were 79.3-233.6 MPa, 26.0-32.9 MPa, and 180.2-252.2 MPa, respectively. Considering the influence of cavity design parameters, cuspal reduction (92.97%) and cavity wall thickness (3.06%) significantly (P<0.05) determined the magnitude of stress values in enamel. The influence of cavity design parameters on stress values in dentin and resin composite was not significant. When stresses for enamel, dentine, and resin composite were considered all together, palatal cusp coverage was revealed as an optimal option. Cavity wall thickness did not show a significant effect on stress values. CONCLUSION: Based on numerical simulations, a palatal cusp reduction could be suggested for revealing lower stress values in dental tissues and restorative material. This type of cavity design should contribute to better biomechanical behavior of tooth-restoration complex, consequently providing the long-lasting clinical results.

Modulated photoactivation of composite restoration: measurement of cuspal movement using holographic interferometry.

The purpose of this research was to investigate the influence of modulated photoactivation on cuspal movement. Eight class II MOD composite restorations were analyzed under various photoactivation protocols in a real-time manner using holographic interferometry. During the first photoactivation protocol, the composite restoration was illuminated for 200 s continuously. In the second protocol, the polymerization lamp was first turned on for 5 s, then turned off for 120 s, and again turned on for a final 195 s. In both protocols, radiant exposure was the same. A significant decrease (p < 0.05) in cuspal deflection was found for two-step irradiation (average value of total cuspal deflection was 5.03 ± 0.62 µm) compared to continuous irradiation (average value of total cuspal deflection was 5.95 ± 0.65 µm). The two-step photoactivation protocol was found preferable, since it resulted in a significantly lower cuspal deflection (11% lower, compared to the continuous illumination).

Holographic detection of a tooth structure deformation after dental filling polymerization.

An experimental technique to reveal the effects of dental polymer contraction is established to choose the most appropriate polymerization technique. Tooth deformation following a dental filling polymerization is analyzed using double-exposure holographic interferometry. A caries-free, extracted human molar is mounted in dental gypsum and different cavity preparations and fillings are made on the same tooth. Dental composite fillings are polymerized by an LED light source especially designed for this purpose. Holographic interferograms are made for occlusal (class I), occlusomesial (class II), and mesioocclusodistal (class II MOD) cavities and fillings. Maximum intercuspal deformation ranges from 2 microm for the class I cavity to 14 mum for the MOD class cavity. A finite element method (FEM) is used to calculate von Mises stress on a simplified tooth model, based on experimental results. The stress varies between 50 and 100 MPa, depending on the cavity type.

[Current trends in dental practice].

INTRODUCTION: This paper reviews recent trends in basic dental disciplines and advantages of new clinical procedures over conventional. PROSTHETIC RECONSTRUCTION OF DEPULPED TEETH: Post and core restoration is one of the most common treatment modalities applied when the remaining coronal tooth structure is not sufficient to provide the necessary retention form for restoration. Nowadays, the restoration of endodontically treated teeth is based on the use of materials with a modulus of elasticity similar to that of dentin. A NEW CONCEPT OF LIGHT INDUCED POLYMERIZATION OF ESTHETIC MATERIALS IN DENTISTRY: Polymerization contraction stress of resin based composite during light-activation process may be reduced by various illumination schemes. Successful curing depends on the calculated energy density values (spatial irradiance x irradiation period - J/cm2) rather than on light irradiance levels (mW/cm2). THE ASSOCIATION BETWEEN PERIODONTAL DISEASE AND GENERAL HEALTH: It is well documented that various systemic diseases have a profound effect on periodontal tissues. Recently, it has been speculated that periodontal disease may influence systemic health and represent the risk factor for cardiovascular diseases or adverse pregnancy outcomes. COMPUTER SYSTEMS FOR AUTOMATIC LANDMARK DETECTION: Computer systems, which will automatically identify relevant skeletal and soft tissue roentgencephalometric landmarks, will represent a great improvement in the field of orthodontic diagnosis. By using the Active Appearance Model, it is possible to identify most of roentgencephalometric bony landmarks with an average error well below 2 mm. CURRENT TRENDS IN CARIES TREATMENT: Chemomechanical caries removal was introduced as an alternative to conventional mechanical procedures. Its advantages are: selective removal of carious tissue, absence of pain, reduced need for local anesthesia and less potentially negative effects on the dental pulp. CONCLUSION: The introduction of the surgical operating microscope, microsurgical instruments, ultrasonic retrotips for root-end cavity preparation and new root-end filling materials opened a new era in periapical surgery, even on multi-rooted teeth, often called endodontic microsurgery.

Real-time measurement of internal stress of dental tissue using holography.

We describe a real-time holographic technique used to observe dental contraction due to photo-polymerization of dental filling during LED lamp illumination. An off-axis setup was used, with wet in-situ processing of the holographic plate, and consequent recording of interference fringes using CCD camera. Finite elements method was used to calculate internal stress of dental tissue, corresponding to experimentally measured deformation. A technique enables selection of preferred illumination method with reduced polymerization contraction. As a consequence, durability of dental filling might be significantly improved.

[Light induced polymerization of resin composite restorative materials]. / Svetlosno idukovana polimerizacija kompozitnih materijala.

INTRODUCTION: Dimensional stability of polymer-based dental materials is compromised by polymerization reaction of the monomer. The conversion into a polymer is accompanied by a closer packing of molecules, which leads to volume reduction called curing contraction or polymerization shrinkage. Curing contraction may break the adhesion between the adhesive system and hard tooth tissues forming microgaps which may result in marginal deterioration, recurrent caries and pulp injury. POLYMERIZATION SHRINKAGE OF RESIN-BASED RESTORATIVE DENTAL MATERIALS: Polymerization of the organic phase (nonomer molecules) of resin-based dental materials causes shrinkage. The space occupied by filler particles is not associated with polymerization shrinkage. However, high filler loading within certain limits, can contribute to a lesser curing contraction. POLYMERIZATION SHRINKAGE STRESS AND STRESS REDUCTION POSSIBILITIES: Polymerization shrinkage stress of polymer-based dental resins can be controlled in various ways. The adhesive bond in tooth-restoration interface guides the contraction forces to cavity walls. If leakage occurs, complications like secondary caries and pulpal irritation may jeopardize the longevity of a restoration. Stress relieve can be obtained by modifications of the monomer and photoinitiator, or by specially designed tooth preparation and application of bases and liners of low modulus of elasticity. The polymerization contraction can be compensated by water absorption due to oral cavity surrounding. The newest approach to stress relief is based on modulation of polymerization initiation. CONCLUSION: This work deals with polymerization contraction and how to achieve leak-proof restoration. Restorative techniques that may reduce the negative effect of polymerization shrinkage stress need further research in order to confirm up-to-date findings.

[Effect of smoking on resorption of residual alveolar ridges in complete denture wearers]. / Uticaj pusenja na resorpciju rezidualnog alveolarnog grebena kod nosilaca totalnih zubnih proteza.

INTRODUCTION: Based on literature data it is obvious that there is a connection between smoking and periodontal diseases. Alveolar bone loss increases with smoking. Tobacco smoking affects the proportion of subgingival bacterial flora by influencing oxidoreduction potential of dental plaque and thus making conditions for development of anaerobic bacteria. According to some researchers, smoking affects the mineral component of bone tissue. Orthopantomograms show higher level of alveolar bone loss in smokers than in nonsmokers with the same level of oral hygiene. The aim of this study was to establish if smoking affects alveolar bone loss in complete denture wearers. MATERIAL AND METHODS: Our clinical investigation included 60 patients of both sexes (30 smokers and 30 nonsmokers) all complete dentures wearers. All patients met study criteria: jaw relation and smokers who smoke over 20 cigarettes per day. All subjects were interviewed, and after that orthopantomograms were made. They were used to calculate the degree of alveolar bone loss. RESULTS: The examined subjects were approximately of the same age. Mean age of smokers was 59.9 and nonsmokers 61.8. It was established that differences regarding resorption in men were not significant. The degree of resorption in women smokers and women non-smokers was different, but differences were not significant. DISCUSSION: It has been proven that the number of cigarettes smoked per day is very important. It is considered that the risk of oral epithelial dysplasia increases when smoking more than 20 cigarettes per day. Considering our results regarding resorption of edentulous alveolar ridge in smokers and nonsmokers, we concluded that there were no significant differences. There are opinions in literature that smoking is not an etiological factor in resorption, but there are some opinions that smoking is connected with the degree of resorption in periodontium. The analyses of resorptive changes in edentuolous smokers were done only around implants and it was estimated that smoking has more influence than other clinical risk factors. CONCLUSION: On the bases of our research we may conclude that smoking does not directly affect the degree of resorption of edentulous alveolar ridge with complete denture wearers.