Tooth Crown Research Articles

Do onlays and crowns offer similar outcomes to posterior teeth with mesial-occlusal-distal preparations? A systematic review.

Teeth prepared for mesial-occlusal-distal (MOD) restorations have a significant risk of cusp fracture. Crowns and onlays can provide cusp coverage to reinforce posterior teeth at risk. Onlays are often more conservative of tooth structure which may be an advantage for teeth with large MOD preparations. It remains uncertain how onlays and crowns compare for posterior teeth with MOD tooth structure loss. The purpose of this systematic review was to compare the resistance to fracture, success rate, survival rate, and failure rate of teeth with MOD preparations restored with onlays or crowns. An electronic search queried Medline (PubMed), Embase (Ovid), Scopus, the Cochrane Library, and grey literature (OpenGrey) from database inception through April 29, 2023. After eliminating duplicates and irrelevant records, 32 manuscripts were assessed. Only three publications met the criteria for inclusion. Most exclusions were due to poor reporting of restorative design and the amount of tooth structure remaining, or due to combining various restorative designs. Due to the limited sample size and high heterogeneity, no meta-analysis was conducted. One study observed a better outcome for onlays and two observed no difference. All three studies reported the mode of failure for crowns as more catastrophic whereas teeth with onlays could be salvaged. Onlays may be an advantageous alternative to crowns for teeth with MOD preparations, but the level of evidence is insufficient to draw meaningful conclusions. Current evidence is insufficient to determine whether onlays or crowns are providing a different outcome when used to restore posterior teeth with MOD tooth structure loss. However, the fracture of teeth with MOD tooth structure loss restored with onlays appears to be less catastrophic than when restored with crowns.

Effect of N-Acetylcysteine on initial Carious Enamel Lesions in primary teeth: an In-vitro study

BackgroundDental caries initiates with non-cavitated enamel lesions as the first stage. The cariogenic potential of N-Acetylcysteine (NAC) may be due to its usage frequency and form. This study aimed to evaluate the impact of exposure time of NAC on initial enamel caries-like lesions in primary teeth by assessing the morphological alteration using a scanning electron microscope (SEM) and mineral content using energy dispersive x-ray spectroscopy (EDX).MethodsForty primary incisor teeth were randomly divided into 4 groups S, S1, S2, and S3 (10 specimens/group). Teeth crowns were cut from their roots and inserted into an acrylic mold with its buccal surface directed upward. Centrally isolated enamel window (2 × 2 mm) on the tooth was done. Ten specimens were selected to evaluate normal enamel while the remaining thirty specimens were immersed in demineralizing solution for 96 h to produce enamel caries-like lesions. PH cycling was performed by immersing each tooth sample in 20 mL of demineralizing solution for 3 h then, preserved for the remaining day hours in 10 ml of artificial saliva interspersed with treatments applications with 10 ml NAC for 10 min twice a day for one- or three-months different treatment modalities. Thermocycling was done for all specimens then they were subjected to SEM and EDX analysis. ANOVA and Bonferroni post hoc tests were utilized in data analysis.ResultsIn teeth treated by NAC for 3 months (group-S3), SEM images showed severe loss of enamel architecture with large NAC deposits detected. A meaningful difference was observed among different groups concerning calcium, phosphorus, fluoride, ca/P ratio, carbon, nitrogen, and oxygen contents (P < 0.05).ConclusionNAC had a detrimental impact on enamel caries-like lesions in human primary teeth.

A tooth crown morphology framework for interpreting the diversity of primate dentitions.

Variation in tooth crown morphology plays a crucial role in species diagnoses, phylogenetic inference, and the reconstruction of the evolutionary history of the primate clade. While a growing number of studies have identified developmental mechanisms linked to tooth size and cusp patterning in mammalian crown morphology, it is unclear (1) to what degree these are applicable across primates and (2) which additional developmental mechanisms should be recognized as playing important roles in odontogenesis. From detailed observations of lower molar enamel-dentine junction morphology from taxa representing the major primate clades, we outline multiple phylogenetic and developmental components responsible for crown patterning, and formulate a tooth crown morphology framework for the holistic interpretation of primate crown morphology. We suggest that adopting this framework is crucial for the characterization of tooth morphology in studies of dental development, discrete trait analysis, and systematics.

A preliminary analysis of dental microstructure in Hamipterus (Pterosauria, Pterodactyloidea).

The toothed members of Pterosauria display an extremely wide range of tooth morphologies that supported a variety of feeding habits. Histological studies on the teeth of different pterosaur clades are potentially valuable in understanding the development of their tooth diversity. In this study, we used histological sections and scanning electron microscopy to describe and interpret the tooth microstructure of Hamipterus (Pterodactyloidea). Our analysis is based on seven teeth of Hamipterus (six isolated and one from a skull) from the Lower Cretaceous collected in Hami, China. Our results show that the enamel on the tooth crown is thin (~25 μm) in Hamipterus and covers only approximately half of the tooth crown. This thin enamel of the Hamipterus tooth makes it vulnerable and often becomes damaged during taphonomic and diagenetic processes. The radicular pulp inside the conical-shaped root shows a spindle space with a small foramen at the bottom, while the coronal pulp shows a small tunnel (100-140 μm in diameter). We estimate that the small teeth of Hamipterus likely took approximately 80 days to form. Furthermore, the tooth has Andresen lines, which represent 7-15 days period. For stable articulation of the tooth in the alveolus, the thick cellular cementum is concentrated on the lingual side of the root. The acellular cementum (~40 μm thick) layer runs from the root to the partial tooth crown.

Influence of a Metal Artifact Reduction Filter on the Diagnostic Accuracy of Complete and Incomplete Vertical Root Fractures

IntroductionThis study aimed to assess the influence of the e-vol DX BAR filter on the diagnostic accuracy of complete and incomplete vertical root fractures (VRFs). MethodsTwenty single-rooted teeth were selected. The tooth crowns were removed, and the root canals were prepared up to a 40/.06 instrument (ProTaper Next). Each specimen was scanned in a Prexion 3D cone-beam computed tomography (CBCT) device, in a dry human skull, in 4 different situations: no root canal filling, gutta-percha, fiberglass post, and metal post. The specimens were fractured in a universal testing machine by using a customized wedge. Each specimen was reinspected to confirm the presence of incomplete VRFs. Another set of CBCT scans was performed. Then, the fractures were completed in the universal testing machine, the teeth were reinspected, and the CBCT images were acquired again. Images were assessed by using the e-Vol DX software system, with the BAR filter and with the original images, for the diagnosis of VRFs. Statistical analysis was performed by using the DeLong and McNemar tests for the comparison of the area under the receiver operating characteristic curves (AUC), accuracy, sensitivity, and specificity values. ResultsThe use of the BAR filter did not improve the diagnostic values of AUC, accuracy, sensitivity, and specificity in both fracture patterns (P > .05). Incomplete VRFs presented significantly lower AUC, accuracy, and sensitivity compared with complete VRFs (P < .0001). ConclusionsThe BAR filter did not improve the diagnostic accuracy of VRFs. The intracanal materials also did not influence the diagnosis. Incomplete VRFs were highly associated with a decrease in sensitivity.

Is the traditional placement of stainless steel crowns in primary teeth more painful than the non-preparation Hall technique?

Is the anxiety level and pain experience in young children the same for the traditional method of stainless crowns placement that might require local anesthetic and excavation of decay compared to the Hall technique that requires no preparation and no anesthetic injections? A randomized controlled study of 2 groups (43 and 54) children 4-8 years old with proximal decay in primary first molars. Each child had one tooth restored with the Hall technique (HT) and the second tooth received a conventional stainless crown (CT) (with or without local anesthesia, as needed) and all crowns were cemented with a GIC resin type cement less than a month of each other. The order of the placement was reversed with the allocation randomly concealed. A visual Wong-Baker Pain Scale with six cartoon faces was used to record pain levels. Data were analyzed using SPSS (version 25). After computing univariate descriptive statistics, differences among proportions were examined using cross-tabulations and χ2 tests (α = 0.05). Analysis of variance was conducted for parametric analysis, and the Wilcoxon signed-rank test was used for within-group, and the Mann-Whitney U-test was used for between-group, nonparametric analysis. The pain scores did not differ by treatment type. The majority of children (58.3%) reported low procedural pain for both treatments leaving 47.7% reporting moderate to high procedural pain. Using local anesthetic with CT did not change the results. The pain scores were similar for both procedures. HT has been recommended as less traumatic and but this might not be true for all children.

Evaluation of Bioactive Glass Treatment for Dentin Hypersensitivity: A Systematic Review.

The aim of this systematic review is to compare home and office desensitizers containing bioactive glass with control groups in randomized controlled trials (RCT) conducted between 2018 and 2022. According to PRISMA guidelines, three electronic databases (Scopus, PubMed, and Cochrane Library) were searched for published scientific articles in October 2022. RCT with adult participants with dentin hypersensitivity (DH) diagnosed by evaporative, mechanical, or thermal stimulation, with a follow-up period and quantified pain assessment were included in the study. Studies that reported DH due to tooth restoration, crown preparation, bleaching, or periodontal surgery or used bioactive glass-ceramics were excluded. The quality of the studies was assessed using version 2 of the Cochrane Risk-of-Bias Tool for randomized studies (RoB 2 tool). Articles that were duplicative or unrelated to this study were excluded. Nine articles were selected for full-text evaluation, whereas two articles were rejected. The remaining seven reports were included in this review. The calcium sodium phosphosilicate group (CSPS) was not significantly different from the positive control groups. Compared with the control groups, fluoro calcium phosphosilicate (FCPS) may be the most effective long-term treatment option. In terms of DH symptom reduction, the FCPS group performed better than the CSPS group. CSPS at a concentration of 5-15% and FCPS at a concentration of 5% are effective in treating DH in adult participants.

Evaluation of video teaching on resident competency for all-ceramic crown tooth preparation.

This study aimed to analyze the impact of live video instruction using digital evaluation of residents' performance in full ceramic crown preparation. Digital evaluation using CEREC computer-aided design/computer-assisted manufacturing (CAD/CAM) 5.1.3 software was conducted of preparation on a typodont for all-ceramic crowns of mandibular first molars (MFMs) with a radial shoulder finish line, carried out by 30 residents. Each participant prepared two MFMs: group A prepared the right side without live video instruction, and group B prepared the left side after instruction. All prepared teeth were scanned by Dentsply Sirona chairside CAD/CAM system with Omnicom to assess the inter-occlusal space, undercut, the finish line of the preparation, and surface texture. The data were analyzed using Pearson Chi-square, Wilcoxon signed-rank test, and paired t-test. P-values less than 0.05 were considered to be statistically significant in all tests. Based on the Pearson Chi-square test, there were significant differences between the two groups in terms of inter-occlusal space on the buccal and lingual surface of the prepared tooth, in the presence of rough surfaces before and after the preparation, and difference in the type of finish line. The Wilcoxon signed-rank test revealed a significant difference in convergence angle buccolingually and the remaining height of the prepared teeth before and after the video instruction. The use of educational live video instruction can be helpful to residents in learning the principles of tooth preparation.

Incidence and Management of Tooth Root Fracture in Mandibular Fracture Line - A Retrospective Study.

In cases of trauma, the most common fractures of the facial region are the nasal bone fractures followed by mandibular fractures. About 60% of mandible fractures are associated with teeth in the fracture line; however conversely, the dentulous mandible has a higher susceptibility of fracture in any impact. Whenever a tooth is involved in the fracture line, it is not unlikely that the tooth root fracture will be associated with it. The prognosis and treatment of such a tooth persistent in a fracture line depends upon the level of tooth root fracture. This retrospective study was conducted in the Department of Oral and Maxillofacial Surgery in a Meerut hospital. The eligibility criteria were based on the cases involving fracture line passing through the teeth bearing area of mandible. Total of 56 cases of mandibular fracture treated from January 2021 till December 2022 by open reduction and fixation were included in the study. A total of 56 patients (66 fracture lines) with mandibular fractures were selected, out of which 18 (32%) patients had fracture of the root of the tooth in the fracture line. Third molar root fracture were present in 12 cases (66.6%), first premolars in 4 cases (22.2%), and first molars in 2 cases (11.1%). There were 14 multi rooted teeth (77.7%) and 4 single rooted teeth (22.2%) involvement. All the multi rooted teeth fracture were treated by extraction during open reduction and fracture fixation. The single rooted teeth were successfully treated by endodontic treatment postoperatively. The fracture line passing through the dentate segment may fracture the tooth crown and/or root or propagate through the socket without any injury to the root. Root fracture at cervical and middle third is constantly exposed to oral fluids. The affected tooth may be mobile and lose vitality. Teeth in the line of fracture must be removed when they preclude the correct reduction of the segments or if they represent a risk for infection. If the tooth or root does not cause any hindrance during reduction or it is not infected, the tooth can be salvaged by endodontic therapy. The incidence of root fracture was seen in 32% of cases. Fracture of the third molar roots was the single largest group (66.6%). No root fracture was observed in the anterior segment.

Pterosaur teeth from the Lower Cretaceous (Valanginian) Cliff End Bone Bed, Wadhurst Clay Formation, Wealden Supergroup of southern England, and their possible affinities

Until now there have been no formal descriptions of pterosaur remains from the Cliff End Bone Bed of the Lower Cretaceous (Valanginian), Wadhurst Clay Formation, Wealden Supergroup, of south-east England. This horizon yields abundant vertebrate material representing both aquatic and terrestrial taxa and recent examination of a large collection of vertebrate remains obtained by a private collector has led to the discovery of two isolated pterosaur teeth, both referable to the same taxon. Tooth crown morphology differs from that of teeth informally reported from the Wadhurst Clay Formation and attributed to ornithocheirids in being triangular in lingual and labial view, labiolingually compressed with well-defined carinae on the mesial and distal margins and with a low basal cingulum. Their possible affinities are discussed, and they are tentatively, but with some uncertainty, attributed to an istiodactylid. If this attribution is correct, they represent the earliest record of Istiodactylidae to date.

Variation of Tooth Crown Size in Cleft Lip and Palate Patients.

This study aims to compare the mesiodistal (MD) and buccolingual (BL) tooth crown size (TCS) of adult patients with cleft lip and palate (CL/P) and patients without CL/P. The sample of this study consisted of 146 adult patients, of both genders, of which 73 were included in the case group (with CL/P) and 73 were included in the control group (without CL/P). Data regarding gender and age and cleft type were collected. In addition, dental models were evaluated to obtain the TCS in the maximum distance of the MD and BL dimensions of all erupted permanent teeth (except third molars). The results were submitted to statistical analysis with a significance level of 0.05. In the upper arch, the central incisors (CI) were smaller in the case group for the MD and BL dimensions (p < 0.05). The lateral incisors (LI) and canine (C) were smaller only in the BL width (p < 0.05) and the second molars (SM), were smaller only in the MD dimensions. In the lower arch, there were significant differences only in the BL width between groups, the CI and LI presented smaller measurements in CL/P patients, while the left first molar (FM) and right first premolar (FPM) were larger (p < 0.05) than in patients without CL/P. Patients with CL/P have different sizes in certain teeth compared to patients without CL/P. Cleft lip and palate patients usually present important dental anomalies; thereby, the knowledge about trends in tooth size variations in CL/P patients can aid in dental and orthodontic treatment planning to obtain a stable, functional, and esthetic occlusion.

Epidemiologic assessment of dental health in the military exposed to toxic chemicals

Relevance. Destruction of toxic chemicals is impregnated with hazardous working conditions. In this regard, health monitoring in such workers is subject to more stringent requirements. Occupation-related difficulties in dental care availability cause faster dental health deterioration in the military. This adds relevance to finding and developing modern, rational and effective therapy and prevention measures tailored to specific working conditions the sites of toxic waste destruction.The objective is to evaluate the prevalence and structure of dental diseases and oral cavity disorders in the military exposed to toxic chemicals.Methods. A total of 178 male and female contracted military aged 27-50 years were examined within general medical examination required for admission to work with toxic chemicals. Standard dental methods were used during the examination: interview, visual, physical, and instrumental examinations. Examination data were fed into individual military medical records (form No. 2), as well as into earlier record forms.Results and discussion. Examined patients showed high prevalence of dental diseases (99.4 %), in particular, diseases of dental hard tissues and complicated dental caries. No less than half of the examined (54.5 %) required orthopedic dental treatment. More than 80 % of the examined revealed poor oral hygiene.Conclusion. Considering the high demand (90 %) for sanitation among the military, causing the 25% level of complicated f caries, with average tooth crown destruction score of 0.9 and absence of a staff dentist due to the small size of military units, it is deemed reasonable to involve specialists based on a prior agreed schedule and ensure compliance with developed methods and recommendations.

Comparing the effect of animal and plant-based yogurt extracts on enamel demineralization: an in vitro study.

Yogurt, due to its rich casein phosphopeptide (CPP) content could promote remineralization of enamel. Contrary to the age-old usage of animal milk based yogurt, vegan dairy products are gaining momentum due to multiple reasons. Considering this change, the aim of the present study was to assess the in vitro effect of animal and plant-based yogurt extracts on demineralization of enamel. Enamel windows were prepared on the crowns of sixty premolar teeth using nail paint. Teeth were divided into four groups of fifteen each and were treated with distilled water, demineralizing agent, solution with a mixture of demineralizing agent and yogurt supernatants, respectively for 96 hrs. Quantitative analysis was done using EDXRF (baseline and postexperimental calcium and phosphorus content). Additionally, confocal microscopic analysis was performed to assess the extent of demineralization. The animal-based yogurt (Group III) had the highest post experimental calcium value (mean±SD=81.15±5.02) and positive percentage of change in calcium level (15%; P=0.007) among the groups. This was followed by plant-based yogurt (Group IV) (mean calcium= 76.18±5.12; positive percentage change =8.11%; P=0.003). Animal based yogurt could provide higher protection against enamel demineralization when compared to plant-based yogurt.

New evidence for the antiquity of Desmostylus (Desmostylia) from the Skooner Gulch Formation of California.

Desmostylus is an extinct marine mammal genus that belongs to Desmostylia, a clade of extinct herbivorous mammals. While desmostylian remains are widely reported from Paleogene and Neogene marine strata of the North Pacific Rim, occurrences of the genus Desmostylus are almost entirely limited to middle Miocene strata, with only a few early Miocene records from Japan. Here we report a Desmostylus tooth from the earliest Miocene (Aquitanian) Skooner Gulch Formation in northern California, USA. This specimen exhibits cuspules around the crown, a primitive trait of the subfamily Desmostylidae, as seen in more basal branching desmostylid taxa such as Cornwallius and Ounalashkastylus, but with a high tooth crown and thickened enamel. The specimen is also diagnostically different from all other desmostylid genera, such as Cornwallius, and Ounalashklastylus. The Aquitanian age of the Skooner Gulch Formation implies that the distinctive tooth morphology of Desmostylus has persisted, largely unchanged, for more than 15 million years and that desmostylids possibly originated in western North America.

EFFECTIVENESS OF BLENDED TEACHING METHOD IN TOOTH CARVING APPLIED IN PRECLINICAL COURSE OF DENTAL EDUCATION DURING THE COVID-19 PANDEMIC

Background: The knowledge of dental morphology is essential in every aspects of dental medicine. Tooth carving is useful for development of the manual skills and has positive influence on students performance in clinical practice. In the extraordinary situation caused by the COVID-19 pandemic we needed to use innovative blended models in teaching of dental morphology. Te Aim of the research was to perform comparative analysis of the teeth carved by students in preclinical courses in prosthetic dental medicine, tutored in two methods – conventional and blended, applied in the circumstances of the COVID-19 pandemic. Methodology: Detailed evaluation of 381 carved teeth was done according to strictly defined criteria. Results: The analysis of work of students tutored through blended method demonstrates good level of the skills for reproduction of dental morphology. The approximal and masticatory surfaces of the tooth crown and the teeth roots of premolars and molars were reproduced in better quality by the students in the course with blended tuition. The differences in realization of the criteria are in range of 5%. Statistical significance was established only in re-creation of the masticatory surfaces of molars (p&lt; 0.05). Conclusion:The blended model of tuition can be considered as effective educational model for tooth carving in courses of pre-clinics of prosthetic dental medicine. It would be purposeful for this practice to be combined with traditional educational methods in order to improve the tuition quality.

Kissing molars class III detected at a young age

BackgroundKissing molars (KMs) is defined as a state in which the apex of two impacted molars face opposite directions and the occlusal surfaces touch each other and the crown is in one follicle. Class III KMs have been reported previously; however, reports on class III KMs in young people (< 18 years of age) are limited.Case presentationHere, we present the case of KMs class III confirmed at an early age, supported by a review of the literature. The patient was a 16-year-old female and experienced discomfort in the left molar of the lower jaw and visited in our department. We diagnosed KMs based on an impacted teeth on the buccal side, near the lower jaw wisdom teeth, and a cyst-like low-density area observed around the crown of both teeth, as revealed by computed tomography. We decide to extract the tooth and enucleate the cyst under local anesthesia as the patient experienced discomfort due to occlusion. Furthermore, the cyst-like structure removal and tooth extraction including tooth root were necessary as the patient had KM class III, possibly inducing complicated malocclusion. Although no previous reports recommended timing for KMs tooth extraction, we propose that extraction at an early stage is important regardless of age especially in class III cases.ConclusionsWe report a case of KM class III detected at an early age.

КЛИНИЧЕСКИЙ СЛУЧАЙ: ХИРУРГИЧЕСКАЯ РЕАБИЛИТАЦИЯ ПАЦИЕНТА ПОСЛЕ ВЗРЫВА ЭЛЕКТРОННОЙ СИГАРЕТЫ

We have carried out the rehabilitation of a patient after a traumatic injury to the maxillofacial region resulting from the explosion of an electronic cigarette. The patient was treated in the Department of Maxillofacial Surgery of the Republican Children's Clinical Hospital in Ufa. A 16-year-old boy was delivered by an ambulance to the emergency department of the Republican Children's Clinical Hospital in Ufa 30 minutes after the injury. The child was hospitalized in the department of maxillofacial surgery. At stage I, primary surgical treatment was performed, reposition of the free-lying fragment of the upper jaw in the frontal section and fixation of the mucosa of the alveolar process of the upper jaw in the region of 1.3 and 2.4 teeth with vicryl 2.0. The mucosa was mobilized along the transitional fold of the upper jaw in the anterior region, placed in the region of the defect in the upper jaw, and sutured with a 5-0 Vicryl thread. After 6 months, the patient enters the II stage of surgical treatment. The cortical plates were placed in the area of the defect and fixed with titanium screws. After another 6 months, the child enters the III stage of surgical treatment - the removal of titanium screws, the installation of dental implants. Stage IV. Installation of temporary crowns of teeth. &#x0D; As a result of smoking a vape, a teenager received severe traumatic stress. Stage IV of complex surgical treatment was carried out. There are stages of implant prosthetics, which is quite expensive for the patient, since this treatment is not included in the List of State Guarantees. Undoubtedly, vape smoking is a very cost-effective procedure, and very harmful to health in general.

Stelladens mysteriosus: A Strange New Mosasaurid (Squamata) from the Maastrichtian (Late Cretaceous) of Morocco

Mosasaurids, a clade of specialized marine squamates, saw a major adaptive radiation in the Late Cretaceous, evolving a wide range of body sizes, shapes, and specialized tooth morphologies. The most diverse known mosasaurid faunas come from the late Maastrichtian phosphates of Morocco. Here, we report an unusual new mosasaurid, Stelladens mysteriosus, based on a partial jaw and associated tooth crowns from lower Couche III phosphatic deposits at Sidi Chennane, Oulad Abdoun Basin, Morocco. Stelladens is characterized by short, triangular tooth crowns with a series of strong, elaborate, and serrated ridges on the lingual surface of the tooth, functioning as accessory carinae. Morphology of the teeth and associated jaw fragment suggest affinities with Mosasaurinae. No close analogues to the unique tooth morphology of Stelladens are known, either extant or extinct. It may have had an unusual and highly specialized diet, a specialized prey-capture strategy, or both. The diversity of mosasaurid teeth is much higher than that of plesiosaurs, ichthyosaurs, or extant marine mammals, and likely reflects both the ecological diversity of mosasaurids and complex developmental mechanisms responsible for tooth formation in mosasaurines. Mosasaurid diversity continued to increase up to the Cretaceous–Paleogene boundary.

EXPERIMENTAL SUBSTANTIATION OF THE USE OF THERAPEUTIC PROPHYLACTIC PASTE FOR PREVENTION OF COMPLICATIONS DURING ODONTOPREPARATION OF VITAL TEETH

Increased tooth sensitivity after preparation for nonremovable orthopedic structures is a common problem in orthopedic dentistry. In many cases, it can contribute to morphofunctional changes in the hard tissues of the tooth and lead to various complications, with pulpitis and periodontitis being the most common. This article presents the results of a study of rat blood serum after experimental tooth trauma. An analysis of pulp inflammation markers was conducted, which demonstrated that the proposed therapeutic complex significantly reduces inflammatory reactions in the tooth pulp, increases nonspecific resistance and antioxidant status of the pulp in animals following odontopreparation. The aim of our study. Experimental justification for the use of a complex of hyaluronic acid, bioflavonoids, and minerals to enhance the effectiveness of preventing complications after dental preparation for non-removable orthopedic structures. Investigate changes in pulp inflammation markers in the blood serum of experimental animals during dental preparation. Study the effect of the proposed complex on biochemical indicators in the blood serum of experimental animals. Materials and methods. The study was conducted on 48 sexually mature male Wistar rats weighing 220-270 g and aged 6-7 months. The animals were divided into 3 groups. The duration of the experiment was 21 days, after which the rats were euthanized under thiopental anesthesia (20 mg/kg) by bloodletting from the heart. Blood was collected to obtain serum. Serum catalase activity, alkaline phosphatase ALP, α2-macroglobulin, and alanine aminotransferase (ALT) were determined. Results of the study and their discussion. The study of alkaline phosphatase and alanine aminotransferase activity in the intact groups taken for analysis on the 7th and 21st day showed that these indicators were within the normal range and corresponded to data in the blood of rats presented in the literature sources. Conclusions. During the preparation of tooth crowns in experimental animals, pronounced inflammatory reactions develop in the traumatized pulp, which occur against the background of activation of the processes of oxidative stress (OS) with a characteristic phase course, accompanied by a significant increase in the concentration of inflammation markers in the blood serum. The proposed therapeutic and prophylactic complex effectively prevents established disturbances in the biochemical parameters of the blood serum of laboratory animals and is effective in preventing and preventing inflammatory processes in the pulp.

On the first Baryonychinae (Theropoda, Spinosauridae) teeth from South America.

We report the first occurrence in South America of spinosaurid specimens belonging to the clade Baryonychinae. The material comprises three tooth crowns recovered from the Lower Cretaceous (Berriasian-Valanginian) of the Feliz Deserto Formation, State of Sergipe, northeast Brazil. The three specimens have the typical conidont condition, displaying a fluted morphology, veined enamel texture and carinae extending to the cervix region, conditions similar to those shared among spinosaurid theropods. Furthermore, a notable feature is the presence of a serrated carinae composed of 6-7 diminutive denticles per millimetre, a key feature shared by baryonychine spinosaurids. Phylogenetic and multivariate analyses performed on dentition-based and crown-based datasets of theropod taxa confirm the relationship of the three tooth crowns described here with the well-supported spinosaurid clade. Our results retrieve the taxa which comprise the "classically" baryonychine clade as individual branches within a polytomy which includes the three tooth crowns and a subclade of spinosaurines (Spinosaurus + Angaturama/Irritator). Additionally, the discriminant and cluster analyses suggest that the materials are more similar to Suchomimus than to Baryonyx morphometrically, but clearly bearing similarities with baryonychines (sharing a similar morphospace). These new findings paleogeographically expand the occurrence of this clade to western Gondwana, and comprise one of the oldest spinosaurid records worldwide, which brings implications on hypotheses for the emergence and evolution of the clade. Furthermore, these new records indicate the presence of more than one spinosaurid taxon in the Lower Cretaceous deltaic paleoenvironment of the Feliz Deserto Formation.