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Vol 26, No 4 (2022)

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Experimental and Theoretical Investigation

Comparative evaluation of the accuracy of the dental arch display using modern intraoral three-dimensional scanners

Borodina I.D., Grigoryants L.S., Gadzhiev M.A., Apresyan S.S., Batov R.V., Stepanov A.G., Apresyan S.V.


BACKGROUND: At present, modern dentists used dental intraoral three-dimensional (3D) scanners routinely in their daily work. Obtaining an optical 3D image of the teeth and dentition helps avoid errors at the stage of obtaining traditional silicone impressions and significantly reduces the level of discomfort during dental procedures. Intraoral scanner systems are commercially available today. Despite their advantages over traditional silicone impressions, the accuracy of the optical impressions obtained during total and subtotal prosthetics on the upper and lower jaw are still questionable.

AIM: This study aimed to evaluate the accuracy of scanning models of the patient’s dentition obtained using intraoral scanners and to determine the currently available models of digital devices that are optimal in terms of price and quality.

MATERIAL AND METHODS: The reference scan (master model) was an optical image of the reference model of the upper jaw of a patient with a full dentition made by additive 3D-printing technology obtained using a laboratory scanner. To level out the shrinkage errors of photopolymerization materials, the resulting model was scanned on the same day using intraoral scanners selected for the study. The obtained scan results were compared with the reference scan of the control group. Based on the measurements made at reference points, the average error value relative to the master model and its precision were calculated for each scanner. In addition to the average values, the error parameters of the scanners in the frontal and chewing sections were calculated, as well as the arc error, which was equal to the difference in the values of the discrepancy at the reference points at which the maximum and minimum values were obtained. The cost and availability of scanners on the domestic market, under the sanctions policy of foreign countries, were also considered.

RESULTS: The CEREC Primescan AC scanner showed the best accuracy according to the results of model discrepancies. It has an average error of 13.72±7.34. The arc error was 18.8 microns, and the discrepancies in the frontal area and chewing area were 18 and 6.8 microns, respectively. 3Shape Trios 3 scanner has the closest accuracy, with an average error of 16.28±5.94 microns. The error value of Aoralscan 3 was 42.08±18.34 microns, its arc accuracy was 65 microns, and the discrepancies in the frontal and chewing areas were 33 and 55.1 microns, respectively. Emerald S Mode C had an average error of 35.84±22.29 microns, which was higher than that of Medit i500 and Aoralscan 3; however, Aoralscan 3 showed better precision (18.34 microns versus 22.29 microns). According to the comparison results of the models in the MeshLab program, CEREC Primescan AC showed the smallest median of distances (18 microns). The TRIOS 3 and Emerald S Mode C differed from the standard by an average of 29 microns, and Aoralscan 3 scanners had of 33 microns and Medit i500 had 41 microns.

CONCLUSION: The precision of Aoralscan 3 scanner, which is the best among its analogs in the price category, makes it the most affordable scanner for dental surgical, orthodontic, and orthopedic fields. CEREC Primescan AC is the leader of the premium scanners involved in the study and available in the dental market.

Russian Journal of Dentistry. 2022;26(4):287-297
pages 287-297 views

Axial displacement of the suprastructures at the conical implant — abutment interface

Guskov A.V., Mishin D.N., Kalinovskiy S.I., Ilyasov V.V.


BACKGROUND: The inconsistency of the congruence of the surface of the implant–abutment interface leads to the impaired communication of the implant shaft with the oral cavity, breakdown of the structure, including the implant, and changes in the occlusal relationships because of axial displacement.

AIM: This study aimed to investigate the degree of axial displacement of abutments made relative to implants and analogs. Specific tasks were as follows: (1) to make various abutments for implants with a conical connection obtained from MIS, (2) to study the value of axial displacement of abutments of each type relative to the implant with load modeling, and (3) to examine the value of the axial displacement of abutments of each type relative to the analog of the implant from the tightening force of the screw.

MATERIALS AND METHODS: Axial displacements were tested using implants and analogs of MIS implants with conical joints. Original and non-original abutments were chosen as suprastructures. The original abutment was presented by CS-CPK62. Abutments for the conical connection C1 were made by milling, laser sintering, and casting according to burned models. The fastening of implant analogs and implants was made in a block of plaster of the 4th class. The study was conducted in a simulation complex we have developed, which creates a cyclic load within 30 kg. The study was divided into two stages. In the first stage, axial displacements on analogs from the force of screw tightening were examined. Abutments were attached with various forces: 7 Ncm (tightening force with a simple screwdriver), 15 Ncm, and 30 Ncm. After each screw tightening, vertical measurements were made with a micrometer. In the second stage, axial displacements on implants under load in the original simulation complex were assessed. The screw was tightened with a force of 30 Ncm, as recommended by the manufacturer, and load simulation was performed. Measurements were made both before and after the load simulation.

RESULTS: The original abutments and those made by milling showed the greatest deviation (0.056 mm and 0.066 mm, respectively), and abutments obtained by casting had deviations of 0.047 mm. The smallest deviation was found in the abutment made by laser sintering (0.032 mm). The values obtained in the second stage were as follows. Original abutments and abutments obtained by milling showed the smallest axial displacement when modeling the load (0.00167 mm each). Moreover, the abutments obtained by casting and laser melting showed significant displacements (0.007 mm and 0.004 mm, respectively).

CONCLUSIONS: A pattern was revealed: the smoother the surface of the conical parts, the stronger the axial displacement on the analog implants in the range of 7–30 Ncm, whereas an uneven surface gives the smallest axial displacement, and fixation according to the protocol provided resistance to chewing loads on the implants in the original and milled abutments. The use of a platform with a conical system to create high-precision orthopedic structures has certain limitations because an error in the height of the restoration is created in laboratory conditions. The use of non-original suprastructures leads to the accumulation of errors. Thus, it is necessary to further evaluate conical systems from other manufacturers and improve the accuracy of restorations based on dental implants.

Russian Journal of Dentistry. 2022;26(4):299-308
pages 299-308 views

Clinical Investigation

A clinical example of dystopia and retention of tooth 2.8 in the maxillary sinus

Andriadze E.O., Shapiro I.E., Sipkin A.M.


BACKGROUND: Patients commonly present with anomalies of tooth formation and teething because of the urgency of this problem.

AIM: This study aimed to improve the effectiveness of the diagnosis and treatment of patients with third molars located in the maxillary sinus cavity.

MATERIALS AND METHODS: To increase the level of effectiveness of the diagnosis and treatment of patients with deep retention and third molar dystopia, this study discusses an integrated approach to the timely diagnosis and treatment of such patients and prevention of postoperative complications.

RESULTS: The strategies in the treatment of patients with anomalies in the eruption of the third molars were determined, and the need for cone-beam computed tomography during diagnosis and subsequent treatment was explained. The factors that contribute to the reduction of postoperative complications were also determined.

CONCLUSIONS: This clinical case shows the need for preoperative preparation and treatment of patients with third molars located in the maxillary sinus in a hospital setting for better postoperative management.

Russian Journal of Dentistry. 2022;26(4):309-315
pages 309-315 views

Peculiarities of emotional status in patients with epilepsy during dental operations

Bazikyan E.A., Matsepuro A.A., Vlasov P.N., Chunikhin A.A.


BACKGROUND: Epilepsy is one of the most common neurological diseases. At the dental appointment of patients with epilepsy, there are always concerns about the occurrence of sudden unpredictable conditions, in particular, epileptic seizures.

AIM: The aim of the study was to study the emotional status of patients with epilepsy during dental surgical interventions.

MATERIALS AND METHODS: The study involved 164 patients, of which 105 patients with epilepsy (study group) and 59 patients constituted the control group without somatic and mental illnesses. The study group included 14 pharmacoresistant patients and 91 patients in the phase of drug remission. The tests were used to reveal the psychoemotional state of the patients before the surgical dental intervention.

RESULTS: In the group of drug-resistant patients, there was an increased level of anxiety and in two cases even a depressive state that required the appointment of psychoactive drugs. The group in medication remission did not differ significantly from the control group in terms of psychoemotional state.

CONCLUSIONS: Based on the data obtained, patients with epilepsy from the pharmacoresistant group are recommended to provide anesthesia during dental surgical interventions.

Russian Journal of Dentistry. 2022;26(4):317-321
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Dynamics of indicators of the proteinase-inhibitory system of the body in destructive forms of chronic apical periodontitis during treatment

Demyanenko S.A., Morozova M.N., Kharchenko V.Z., Tofan Y.V., Aliyev L.L., Duryagina L.K., Degtyareva L.A., Dubrovina-Parus T.A.


BACKGROUND: Destructive forms of chronic apical periodontitis (CAP) remain one of the most difficult problems not only in dentistry and endodontics but also in medicine. In addition to the progressive local process in the alveolar process of the jaw, they are a source of autoinfection and auto-intoxication, causing or exacerbating pathologies in other organs.

AIM: This study aimed to analyze the dynamics of the activity of nonspecific proteinases and their inhibitors in patients with destructive forms of CAP when performing a standard endodontic treatment.

MATERIALS AND METHODS: Some indicators of the proteinase-inhibitory system of the oral fluid and blood plasma were studied in 28 somatically healthy patients aged 25–55 years with destructive forms of CAP in multi-root teeth. The canals were treated according to the protocol of the European Society of Endodontics. After instrumental and medical treatments of the root canal, it was dried and temporarily sealed with calcium hydroxide-based preparation. The tooth was closed with temporary fillers for 10–14 days.

RESULTS: The comparative analysis of the indicators of the proteinase-inhibitory system showed that destructive forms of CAP and rehabilitation of the pathological focus, to a greater or lesser extent, affect its condition.

CONCLUSIONS: Changes in the parameters of the proteinase-inhibitory system in the development of CAP during endodontic treatment were observed both locally (oral fluid) and systemically (blood plasma).

Russian Journal of Dentistry. 2022;26(4):323-329
pages 323-329 views

Psychological state of patients during adaptation to removable dentures and methods of optimization

Kerimkhanov K.A., Iordanishvili A.K.


BACKGROUND: Optimized use of removable dental prosthesis and enhancement of the adaptation period to such orthopedic substituting dental constructions in the oral cavity are the actual aims of practical stomatology.

AIM: This study aimed to estimate the psychological state of patients in the process of adaptation to removable dental prostheses and to assess the influence of dental prosthesis fixation on the optimization of adaptation for them.

MATERIALS AND METHODS: In the case of psychosensory–anatomical–functional maladaptation syndrome, the psychological states of 35 people with partial and 38 with complete tooth loss before and during the adaptation period of their dental rehabilitation for removable acrylic dentures were assessed. The study groups were divided into two subgroups, depending on the method used to improve the fixation of dentures.

RESULTS: During the initial examination, all study patients with partial or complete tooth loss had impaired adaptability to these conditions, mainly due to anatomical and functional disorders of the masticatory apparatus. During the adaptation period, an improvement in the psychological status of the patients was noted, especially in those who used the cream for fixation of dentures for domestic production.

CONCLUSION: During their adaptation to the removable partial and full dentures, patients are recommended to use the prescribed cream to improve their fixation and thereby allow the reduction of painful symptoms from the prosthetic bed tissues and significantly improve the psychological status of the patients during the adaptation period.

Russian Journal of Dentistry. 2022;26(4):331-336
pages 331-336 views

Cone-beam computed tomography evaluation of the possibility of fabrication of screw-retained implant crowns on maxillary central incisors

Merzhoeva K.M., Murashov M.A., Voronov I.A.


BACKGROUND: Immediate implant placement to the fresh socket of the extracted tooth, with immediate loading, is well documented. Dental roots in proximity to the vestibular plate require thorough attention from clinicians. Implants placed close to the vestibular plate often lead to its resorption and gingival recession. Therefore, dental surgeons place implants 2–3 mm away from the vestibular plate. In turn, prosthodontists plan implant placement so that the screw channel is not on the vestibular surface, which is most significant in the aesthetic area. However, this is not always possible, and there is a conflict between implant placement with proper primary stability and its simultaneous loading with a screw-retained crown.

AIM: To conduct radiological assessment of the ideal implant placement for a screw-retained crown.

MATERIALS AND METHODS: A total of 120 cone-beam computed tomography (CBCT; 3 groups of 40 people with different root positions) were analyzed. In each group, the possibility of extracting tooth 1.1 and inserting an implant was evaluated in compliance with the protocol for immediate implantation and the possibility to have the screw shaft of the artificial crown on the palatal surface.

RESULTS: Group C was defined as the most favorable for immediate implant placement with a screw-retained crown. The least favorable was group N. In total, the screw channel in 40% of the cases was located palatally, 26.6% to the incisal edge, and 33.3% on the vestibular surface.

CONCLUSIONS: Careful analysis of CBCT when planning implant-supported restoration in the aesthetic area is an integral part of the treatment. A team approach is required from surgeons and prosthodontists when planning. In a larger percentage of cases, implant-supported prosthetics in the maxillary central incisors involve the use of alternative solutions for the restoration of screw-retained crowns.

Russian Journal of Dentistry. 2022;26(4):337-344
pages 337-344 views

Role of motivation in successful orthodontic treatment in teenagers

Soldatova L.N., Sachyan Y.V., Prokhorova V.V.


BACKGROUND: Orthodontic treatment is a long-term and responsible therapy that affects the quality of life of a patient at any age. Adolescence is the most suitable for eliminating dentition and jaw anomalies and one of the most difficult from the point of view of psychology. To achieve quick and successful treatment results, the orthodontist should establish a trusting contact with the patient, consider age-related behavioral characteristics, and know and apply modern methods of orthodontic treatment and psychological methods.

AIM: This study aimed to evaluate the role of motivation in successful orthodontic treatment in teenagers.

MATERIAL AND METHODS: Fifty-one patients participated in the experiment (28 girls and 23 boys; age, 12–16 years), who were undergoing orthodontic treatment with removable and non-removable equipment. The first group was composed of patients with a positive dynamic, fixed type of treatment, and good hygiene, and was responsible for wearing extra equipment. Patients with positive treatment results were those who understood their orthodontic problems, were willing to receive treatment, and were able to choose their equipment for the treatment. The second group consisted of patients who were receiving the prescribed treatment, and the equipment was chosen either by the parents or their orthodontist. In these cases, patients’ dental hygiene worsened because of missing appointments and non-adherence to the recommendations of the orthodontist for the use of the extra equipment. These patients also felt uncomfortable communicating socially because of their orthodontics.

RESULTS: The success of orthodontic treatment for adolescents depends on their voluntariness in making decisions to start treatment, emotional readiness for it, and trusting relationships between the parents, patient, and doctor. Thus, considering the preferences of teenagers when choosing medical equipment is necessary so that they could receive a more detailed explanation of the need for timely orthodontic treatment, which will increase their motivation.

CONCLUSIONS: The patient’s progress was followed throughout their treatment. To reach optimal results and cooperation with the patient, the orthodontist has to consider the patient’s willingness to begin treatment, understand the different procedures, and allow them to choose their equipment while taking into account their age and psychological maturity. These procedures do not only increase the success of orthodontic treatment but also prevent unwanted results and positively influence the psychoemotional status of the teenager.

Russian Journal of Dentistry. 2022;26(4):345-353
pages 345-353 views

Memory pages

The Patriarch of maxillofacial traumatology (on the 100th anniversary of Professor V.A. Malyshev, Colonel of Medical Service)

Iordanishvili A.K.


The prominent place in the cohort of famous Russian dentists of XX century belongs to the participant of Great Patriotic War 1941–1945, Doctor of Medicine, Professor, colonel of medical service Vasily Alekseevich Malyshev (1922–2006), whose 100-year anniversary is celebrated by Russian stomatological community in 2022.

AIM: To present scientific, clinical, pedagogical and social activity of prominent maxillofacial surgeon Doctor of Medicine, Professor, colonel of medical service V.A. Malyshev, as well as his merits before the Motherland.

To present the role of V.A. Malyshev in formation and development of the military stomatology, maxillofacial surgery and traumatology in Russia on the basis of analysis of the national literature, life and professional activity as well as scientific labors of the doctor of medical sciences, professor, colonel of the medical service.

Scientific works of V.A. Malyshev are mainly devoted to the research of issues of clinic, diagnostics, treatment of fractures of the lower jaw and prevention of traumatism. Having become the master of maxillofacial traumatology, he has significantly improved the diagnostics of maxillofacial injuries and introduced in everyday clinical practice a great number of original methods and effective ways of treatment of the indicated pathology. His scientific and practical developments and suggestions regarding the treatment of patients with maxillofacial region injuries have been widely spread in our country, implemented in practice of many medical preventive institutions and included in many textbooks, manuals and teaching aids used in Russian higher educational institutions. His method of treatment of chronic fractures of mandibular articular process by means of its replantation with following osteosynthesis, which was developed in our country and abroad, gained recognition not only in our country but also abroad.

V.A. Malyshev was one of the oldest military dentists of Russia, a brilliant teacher, an excellent scientist and clinician. His name was well known to the stomatological community of the USSR, and since 1991 in Russia and the former Soviet Union. His work for 50 years was connected with the department of maxillofacial surgery and dentistry of Military Medical Academy named after S.M. Kirov. In 1975–1988 V.A. Malyshev as an off-duty chief dentist did a lot to improve the organization and provision of dental care to the servicemen and sailors.

Russian Journal of Dentistry. 2022;26(4):355-361
pages 355-361 views

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