THE PROSTHODONTIC TREATMENT OF THE MANDIBLE EDENTULOUSNESS. CLINICAL CASE

The article presents a clinical case of the prosthodontic treatment of the mandible edentulousness. Edentulousness is a widespread pathology that depends on the social and economic situation in the country, the demographic situation, the level of dental care and prevention organization. The current worldwide trend of population aging leads to an increase in the number of the elderly, and this number is expected to increase in the future. According to the WHO, today about 600 million people are people over 60, and this number will have doubled by 2030 and will constitute 2 billion in 2050 mostly in developed countries. The situation in Ukraine is not better. Functional and aesthetic rehabilitation of patients with edentulousness requires a comprehensive approach to the prosthodontic treatment planning. Complete removable laminar dentures on the mandible have a number of disadvantages. Insufficient fixation, stabilization, diction problems, aesthetic problems, decreased self-esteem of the patient are among the key ones. Modern protocols of the prosthodontic treatment require the manufacture of dental prostheses based on intraosseous dental implants. Complete dentures based on intraosseous dental implants have a number of advantages over the fixed dentures. Compensation for deficient bone support of the facial soft tissues occurs by means of the basis. Patients’ possibility to remove a secondary restoration by themselves lead to proper hygiene of the oral cavity and peri-implant area in particular. The clinical research conducted by S. Wolfart (2016) showed the possibility of fixed/removable dental prosthesis fixation in 14-31 days (early loading) after the surgical stage of implantation provided that 4-6 intraosseous dental implants were installed. The maximum mobilization of the patient to comply with the recommendations and prescriptions is the main task considering the limited postoperative period before the dental prosthesis fixation. Our publication describes the treatment of a patient born in 1967, who was diagnosed with a mandible complete absence of teeth. Diagnosis, examination and treatment were performed on the basis of the Department of Dentistry Postgraduate Education of Ivano-Frankivsk National Medical University. The described prosthodontic treatment plan involves the manufacture of a complete denture with bar system based on four intraosseous dental implants according to the early loading protocol in a patient with primary treatment of mandible edentulousness. The choice of treatment plan was based on the results of past medical history, the patient’s disease, basic and additional methods of examination, analysis of individual indications and contraindications and readiness for the selected treatment plan. This treatment protocol has its advantages over the protocol of manufacturing a fixed prosthesis based on intraosseous dental implants such as a higher level of proprioceptive sensations, increased level of hygiene, lower complexity of clinical and laboratory stages, affordability. The term of clinical and laboratory stages of manufacturing (from the surgical stage of implant treatment to the fixation of the dental prosthesis) constituted 16 days. Additional opportunities for success in clinical and laboratory stages of treatment, the accuracy of manufacture and minimization of complications in the future were created as a result of the combination of digital and analog treatment methods in dental prosthesis manufacturing.

Immediate Vs. Early Loading of Bone Level Tapered Dental Implants with Hydrophilic Surface in Fully Edentulous Maxilla:Clinical and Patient-Centered Outcomes

ABSTRACT The aim was to: (i) compare changes among primary and secondary implant stability between immediate and early loaded implants in edentulous maxilla, (ii) evaluate oral health related quality of life (OHRQoL) and (iii) determine patient satisfaction with 6-implant supported fixed full-arch dentures. A prospective, randomized controlled clinical trial was conducted on 24 edentulous maxilla patients. The BLT SLActive® implants in 12 patients were immediately loaded with temporary restorations while12 patients did not receive temporary restorations. Definitive (final) dentures were delivered to all patients after 6 weeks. Stability of the implants were assessed by Insertion Torque (IT) and Resonance Frequency Analysis (RFA). Oral Health Impact Profile-19 ( OHIP-19) questionnaire was used to evaluate OHRQoL and a Visual Analogue Scale (VAS) for patient satisfaction. The IT value of implants assigned for immediate and early loading group was 27.17±9.55Ncm and 25.01±11.06Ncm, respectively. Changes in implant stability from baseline to week 6 were similar in both groups when measured by Penguin ® (p=0.881) and Ostell ® (p= 0.828). Patients in the immediate load group reported significantly lower OHIP physical pain scores (p=0.016), OHIP psychological disability score (p=0.046) and significantly higher VAS function score (p=0.009) and VAS aesthetics score (p=0.009). Implant loading protocols don’t have a significant effect on the change in implant stability 6 weeks after implantation, however, immediate loading significantly improves OHRQoL and satisfaction of patients with maxillary edentulism treated by fixed full-arch dentures. Future trials will determine the role of immediate loading protocol in clinical scenarios with various amounts of available jaw bone using different numbers of implants to retain a fixed prosthetic restoration in the edentulous maxilla.

Immediate load implants: systematic review of the major technical and patient comfort approaches

Introduction: The first implant follow-up studies constituted the scientific foundation of modern implantology. Early loading was identified as a critical factor and, therefore, several waiting times were tried until the establishment of a period of at least three months for the mandible and five to six months for the maxilla. Therefore, implant with immediate load (ILI) was defined as “installation of a prosthetic element over an implant, without OI having occurred”. Objective: To demonstrate, through a systematic review, the clinical success rates of the immediate loading technique, present the indication criteria, and the follow-up of the procedures. Methods: This study followed the PRISMA model. Clinical studies were selected, involving retrospective, prospective and randomized studies. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. The bibliographic search was performed using online databases PubMed, Scopus, Web of Science, and Google Scholar. Results and Conclusion: A total of 135 articles were found involving immediate loading implants. A total of 78 articles were evaluated in full and 35 were included and evaluated in the present study. The analysis of the literature obtained showed that the success rates with the ILI technique are compatible with those of the late loading, as long as certain guidelines are followed, which were divided into factors related to the patient, surgical technique, implant, prosthesis, and to aesthetics. The high success rate is a consequence of correct surgical and prosthetic planning, harmony between the implant system, patient, and dentist.

Implant Treatment by Guided Surgery Supporting Overdentures in Edentulous Mandible Patients

Introduction: This study aimed to show the clinical outcomes of implants inserted by guided surgery supporting mandibular overdentures in edentulous patients. Patients and methods: Mandibular edentulous patients were diagnosed with an oral examination, cone-beam computerized tomography, and diagnostic casts for intermaxillary relations and treated with overdentures over two implants by guided surgery. After flapless surgery, implants were early loaded with an overdenture at 6 weeks. Results and discussion: Fourteen patients (nine females and five males) were treated with 28 implants. Four patients (28.6%) had a previous history of periodontitis. Five patients (35.7%) were smokers. Nine patients (64.3%) suffered from systemic diseases (i.e., diabetes, cardiovascular diseases). The clinical follow-up of the study was 44.7 ± 31.4 months. Clinical outcomes showed a global success of 100% of implants. Fourteen overdentures were placed in the patients over the implants. Mean marginal bone loss was 1.25 mm ± 0.95 mm. Four patients (28.6%) showed some kind of mechanical prosthodontic complications. Six implants (21.4%) were associated with peri-implantitis. Conclusions: This study indicates that treatment of mandibular edentulous patients with overdentures by guided surgery and early loading of implants placed appears to be a successful implant protocol.

Strains Comparisons of Unbound Base/Subbase Layer Using Three Elasto-Plastic Models under Repeated Loads

The constitutive model is the crucial part for the finite element analyses. To study the elasto-plastic properties of unbound granular materials (UGMs) under repeated vehicular loads, an elasto-plastic constitutive model called revised spatially mobilized plane (SMP) was proposed and validated. In this study, the revised SMP model was used for the plastic strain analyses of a typical three-layer pavement structure. To make comparisons, the Mohr-Coulomb and Druck-Prager models were employed for the numerical computation. The results show that plastic tensile and compressive strains in the horizontal and vertical directions appear on the top surface of UGM using the revised SMP model, but no plastic strains are produced by the Mohr-Coulomb and Druck-Prager models. The distribution of plastic strains in the revised SMP model had a good relationship with the actual loading areas under the vehicular loading, which related to the rutting. With the Mohr-Coulomb and Druck-Prage models, a great plastic strain was produced during the first several loading cycles and hardly increased in the following loading cycles, while the plastic strain in the revised SMP model presented an obvious increasing tendency with increased loading cycles. The predicted permanent deformations of the revised SMP, Mohr-Coulomb and Druck-Prage models were 0.557 mm, 0.78 mm and 0.155 mm, respectively. Our work reveals that the Mohr-Coulomb model may over-predict and Druck-Prage model may under-predict the rutting of pavement in early loading stage and the results proved that the revised SMP model had advantages in the description of the plastic strain of UMG under repeated loads.

The influence of laser-microgrooved implant and abutment surfaces on mean crestal bone levels and peri-implant soft tissue healing: a 3-year longitudinal randomized controlled clinical trial

Purpose The study aimed to compare clinical and radiographic parameters of peri-implant site of laser-microgrooved implants with either laser-microgrooved or regular machined prosthetic abutment post 3 years of early loading. Method Twenty edentulous sites of systemically and periodontally healthy individuals were allocated into two groups in this prospective, two-armed, randomized double-blinded clinical trial in 1:1 ratio, wherein each site received laser-microgrooved implants with either laser-microgrooved or machined prosthetic abutments. Outcome measures included full-mouth plaque (FMPS%) and bleeding score (FMBS%), site-specific plaque (SPS%) and bleeding score (SBS%), peri-implant sulcus depth (PISD mm), and mean crestal bone loss (MCBL mm) evaluated at baseline (6 weeks), 1 and 3 years post-early loading. Mean and standard deviation of all parameters were estimated, between groups and at different time points using independent and paired t-test, respectively, Normality was checked using Kolmogorov–Smirnov test and Shapiro–Wilk test, P value ≤ 0.05 was considered as statistically significant. Results Three-year follow-up of test group showed statistically significant reduction in SPS, SBS, PISD (P value ≤ 0.001). The MCBL reduced from 1.93 mm to 0.61 mm (P value ≤ 0.001); in other words, a bone gain of 0.15 mm was obtained in the test group. Conclusion Within the limitations of the present study, laser-microgrooved implants loaded with laser-microgrooved prosthetic abutments showed superior results clinically and radiographically when compared to loading with machined abutments.

Immediate Implants with Early Loading Accompanying Autogenous Bone Grafting in a Maxilla with Periodontal Destruction: A Case Report

In the case of multiple hopeless teeth and severe bone loss, a conventional healing protocol of 3–4 months has been recommended to prevent the possibility of infection or unpredictable resorption of grafted bone during consolidation of the extraction socket. The use of a provisional denture is inevitable in the case of delayed implant placement, which is a common risk factor for wound dehiscence after a bone graft. Although autogenous bone is still the gold standard for bone grafting because of its excellent biocompatibility and osteogenic potential, there has been controversy in the unpredictable resorption of autogenous bone grafting. We present a case of successful maxillary rehabilitation without the use of provisional dentures by immediate implant placement, with early loading accompanying an extensive autogenous bone graft.

Experimental investigation of sludge dewatering for single- and double-drainage conditions with a vacuum negative pressure load at the bottom

The moisture content of municipal sludge is relatively high, which increases the cost of sludge transportation and treatment. To reduce the volume of the sludge, sludge dewatering is needed. This paper proposes the theory of sludge dewatering and facilitates efficient and economical technology of sludge dewatering. Sludge dewatering tests were carried out by using homemade rapid sludge dewatering devices. There were two groups of tests with single- and double-drainage conditions, and all test runs were loaded with a negative vacuum pressure at the bottom. During the experiments, the vacuum degree and the pore water pressure in the sludge were monitored in real time. After the experiments, the data were compared and analyzed. At the initial stage, the sludge dewatering extent and the sludge dewatering velocity for double-drainage conditions were much higher than those for single-drainage conditions. The vacuum occurring for single-drainage conditions lagged behind that for double-drainage conditions in the sludge. The value of vacuum degree for single-drainage conditions was lower than that for double-drainage conditions, and the vacuum attenuation for single-drainage conditions was considerable. The excess pore water pressure for double-drainage conditions dissipated faster than that for single-drainage conditions in the sludge. The pore water pressure for single-drainage conditions at the top and middle of the sludge layer first increased and then decreased in the early loading stage, resembling the Mandel effect. Overall, with a vacuum negative pressure load at the bottom, the sludge dewatering efficiency for double-drainage conditions was much higher than that for single-drainage conditions. This study provides an experimental and theoretical basis for engineering applications in the sludge treatment industry.

MODIFICATION OF CEMENTITIOUS MATRIX OF RAPID-HARDENING HIGH-PERFORMANCE CONCRETES

The paper presents the results of research concerning the peculiarities of modern High Performance Concretes based on cementitious systems "Portland cement – active mineral additives – micro fillers – superplasticizers – accelerators of hardening". Physico-chemical regularities of structure formation of super plasticized cementitious systems are established. It is shown that the formation of secondary fine ettringite due to the interaction of active alumina with calcium hydroxide and gypsum in the non-clinker part of the binder because of the effect of "self-reinforcement" compensates for shrinkage and increases the strength of the cementitious system. The modification of the cementitious matrix makes it possible to obtain Rapid Hardening High Performance Concretes that provide early loading and turnover of the formwork of monolithic constructions.