The results of the application of an advanced algorithm of direct prosthetics based on dental implants with a personalized approach

Summary. Partial adentia is a topical issue in modern dentistry. Rational use of dental implants (DI) with direct prosthetics (DP) on installed implants at partial adentia is a modern and quick answer to this question. But still there is a number of unresolved issues in the method of direct prosthetics on DI. The most relevant of these is how to use modern CAD/CAE/CAM technologies to personalize the eruption profile of natural teeth while maintaining the height of periimplantative bone tissue (BT) and the volume of surrounding soft tissues. Purpouse: to improve the quality of stomatological treatment of patients at the stages of dental implantation by applying an improved algorithm of direct prosthetics on dental implants on the basis of scientific justification of rational use of personalized prosthetic constructions and prosthetic elements, as well as pharmacological support of such interventions. Materials and methods of research. The clinical study included 80 patients – 63 patients were included in the main cohort (had dentition defects and/or required tooth extraction) who were randomized into three groups (I–III), according to the applied treatment; 17 patients were included in the additional cohort (group IV – without dentition defects) who’s clinical and laboratory parameters were within the physiological norm. According to the above distribution of patients of the main cohort by study groups (groups I-III), each patient received the following treatment measures according to the study plan. Patients in group I (21 patients) used an improved direct prosthetics (DP) algorithm on DI with screw fixation of prosthetic structures from the level of the implant platform, and patients in group II (21 patients) – from the level of mesostructure of multi-unit abutment with the manufacture of individualized hybrid and/or crowns using CAD/CAE/CAMtechnologies. Prevention of inflammation and pain in patients of groups I–II was carried out by prescribing a complex of pharmacological support, which contained – the drug nimesulide, a complex drug bromelain, trypsin, in combination with drug rutoside threehydrate, and the drug trometamol dexketoprofen. Patients in group III (21 patients) used the conventional protocol of DP on DI with screw fixation of prosthetic structures from the level of the DI platform with the use of standard prosthetic elements and structures of artificial crowns made by traditional laboratory methods, while preventing inflammation and pain in patients of this group was carried out by prescribing a complex of pharmacological support, contained of the drug meloxicam, a complex drug of bromelain, trypsin, in combination with the drugrutoside threehydrate, as well as the drug ibuprofen. Clinical, functional and radiological studies, followed by statistical analysis of the results were provided for the patients of groups I–IV. Results. Prescription of the proposed pharmacological support complex at the stage of direct prosthetics in dental patients of groups I and II allowed to prevent pro-inflammatory resorption of BT due to surgical trauma of bone and soft tissues in the area of dental implantation, minimize loss of marginal BT around DI. Patients of groups I and II achieved a significant (p < 0.05, compared with group III) increase in the coefficient of stability of the implant (CSI) starting from the 20th day (group I – 65.37±1.12 units and group II – 64.93±0.75 units) in contrast to the delayed increase of this coefficient in group III (63.18±0.72 units), in which this indicator began to increase only from the 30th day. As a result, the loss of the height of the marginal BT after 12 months (1.11±0.03 mm) in group III was significantly (p < 0.05) higher than in groups I and II. Structural features of standard abutments, and the lack of ability to reproduce the anatomical features of the natural eruption profile of prosthetic structures made manually in traditional way contributed to a significant increase in the rate of loss of marginal BT (1.20±0.04 mm) in 24 months in patients of group III in contrast to patients of groups I and II. Instead, the minimal loss of marginal BT height throughout the study period was observed in group II which used an improved algorithm of DP on DI with screw fixation of prosthetic structures from the mesostructure of multi-unit abutment with the manufacture of individualized hybrid crowns with the help of CAD/CAE/CAM-technologies. The use of multi-unit abutments allowed to seal the access to the DI shaft and to carry out all subsequent stages of prosthetics at a level higher than the DI shaft. In particular, in group II of the study absence of infection with oral fluid in the DI shaft during the stages of prosthetics, minimization of trauma to the marginal bone, periosteum and soft tissues around the DI during impression obtaining, fixation of temporary and permanent structures of dental prostheses, as well as the author's algorithm of reproduction of a natural profile of eruption allowed to maintain a significantly higher (p < 0.05) volume of BT around the DI after 12 and 24 months in comparison with group I where titanium platforms and personalized constructions of abutments and profiles of eruption of dental prostheses were used and group III, where standard abutments from the level of DI shaft and traditional constructions of dental prostheses were used. The results of remote clinical trials have demonstrated the high efficiency of the proposed complex of treatment measures and the rationality of its components according to the algorithm in patients of groups I and II compared to traditional approaches in patients of group III. The loss of periimplantative soft tissue height after 12 and 24 months of DI was significantly lower (p < 0.05) in patients of groups I and II, compared with group III. In group II after 12 and 24 months the loss of soft tissues around DI was significantly lower (p < 0.05) compared with group I. Conclusions. Prescription of the proposed pharmacological support complex at the stage of dental implantation and direct prosthetics on DI, contained of the drug nimesulide, complex drug bromelain, trypsin in combination with the drug rutoside threehydrate and trometamol allowed to prevent inflammation-induced resorption of BT in areas of surgical trauma of bone and soft tissues, helped to minimize the loss of marginal BT height around the DI. In patients of groups I and II, that received the proposed complex of pharmacological support, the loss of BT in the first 6 months after the intervention was significantly smaller (p < 0,05) (group I – 0,15 ± 0,04 mm, group II 0,10 ± 0,02 mm), and KSI credibly (p < ) bigger in contrast to patients of group III (loss of BT 0.66 ± 0.03 mm, KSI 79.06 ± 0.54 units) in whom pharmacological support contained meloxicam and ibuprofen, the action of which was insufficient for full prevention of trauma and inflammation for induced local resorption of the marginal bones around the installed DI, and as a consequence of the predominance of BT resorption processes over its formation. According to the results of remote (after 12 and 24 months) clinical and radiological examinations in patients of groups I and II who used identical in composition to author's complex of pharmacological support and developed personalized protocol of direct prosthetics on DIfound significant differences in bone and soft tissue loss around DI between these groups. It is proved that the use of personalized protocol of direct prosthetics on dental implants from the level of mesostructures of multi-unit abutments in patients of group II prevented multiple injuries of the marginal bone, periosteum and mucous tunic around the DI during routine prosthetic manipulations. As a result, in group II were found significantly lower (p<0.05) rates of bone and soft tissue loss around DI after 12 and 24 months after dental implantation and direct prosthetics in comparison with group I. The proposed author's protocol of direct prosthetics on dental implants using modern CAD/CAE/CAM technologies allowed reproducing natural eruption profile in personalized way. When used in patients of group II from the level of multi-unit abutments after 24 months significantly better (p<0.05) results were obtained in maintaining the height of periimplantative bone tissue and the volume of surrounding soft tissues compared to traditional prosthetic methods used in patients of group III. Key words: direct prosthetics, dental implantation, personalized approach, CAD/CAE/CAM-technologies, multi-unit abutment.