The use of orthodontic aligners has increased significantly due to their convenience and esthetic advantages. However, understanding their microbiological behavior and cytotoxicity is essential. This study aimed to evaluate the metabolic activity (MA) and proliferation of different bacterial strains—assessed through colony-forming unit (CFU) counts—as well as the cytotoxicity of three widely used aligner systems: Spark, Invisalign, and Smile. Wettability and surface free energy (both dispersive and polar components) were determined using the sessile drop technique. The bacterial strains Streptococcus oralis, Actinomyces viscosus, Streptococcus gordonii, Enterococcus faecalis, and Porphyromonas gingivalis were cultured, and their behavior on the aligner surfaces was assessed under simulated oral cavity conditions in both aerobic and anaerobic environments using a bioreactor. Cytocompatibility was evaluated with HFF-1 human fibroblasts. Distinct strain-specific behaviors were observed. For Spark aligners, the contact angle was 70.5°, Invisalign 80.6°, and Smile 91.2°, and the surface free energy was 60.8, 66.7, and 74. 2 mJ/m², respectively, highlighting the high polar component of the Spark aligner of 31.9 mJ/m² compared to 19.3 and 20.2 mJ/m² for Invisalign and Smile, respectively. The Spark aligner exhibited the lowest metabolic activity for Streptococcus oralis (23.1%), Actinomyces viscosus (43.2%), Porphyromonas gingivalis (17.7%), and biofilm formation (2.4%), likely due to its higher hydrophilicity. The Smile aligner showed the lowest metabolic activity for Streptococcus gordonii (23.6%) and Enterococcus faecalis (51.1%), attributed to its low polar surface free energy component. CFU counts were minimal for all aligners and bacterial strains, including biofilm. All aligners demonstrated cytocompatibility above 70% (Spark: 71.0%, Invisalign: 75.7%, and Smile: 75.6%). These findings highlight the importance of considering aligner material properties in clinical practice and underscore the need for proper oral hygiene and aligner maintenance.

The ectopic eruption of the maxillary first permanent molar (EEM) is a local alteration of dental eruption with a multifactorial aetiology. The aims of our study were to determine the prevalence of the EEM in children and to analyse whether there is a relationship between EEM and dento-skeletal characteristics. A total of 322 children were analysed with the Ricketts cephalometric study and descriptive and analytical statistical analysis was carried out. The prevalence of EEM was 8.7%, with no statistically significant differences regarding gender or location, but a higher prevalence in the 7-year-old age group (18.8%) and bilateral EEM was more prevalent than unilateral EEM (p < 0.05). The most frequent findings were a shortened anterior cranial base, a retroposition of the maxilla and a distal position of the upper permanent first molar in relation to the pterygoid vertical in children with EEM. No statistically significant differences were found regarding the cephalometric parameters except a decreased palatal plane in the bilateral EEM group and a distal upper incisor position in the EEM group (p < 0.05). In conclusion, the prevalence of the EEM was 8.7%, more frequently bilateral, and significantly in seven-year-old patients. Children with bilateral EEM have decreased palatal plane values and a more posterior position of the upper incisor.

Background and Objectives: Addressing deep carious lesions poses significant challenges in daily dental practice due to the inherent complexity of their treatment. Traditionally, complete removal of carious tissues has been the norm, potentially leading to pulp tissue exposure and subsequent pulpitis. In contemporary dentistry, there is a growing preference for minimally invasive techniques, such as selective removal, offering a more conservative approach with enhanced predictability and success rates. Materials and Methods: Our study commenced with a comprehensive systematic review. After that, we performed a meta-analysis focused exclusively on randomized controlled trials involving permanent dentition. Our investigation incorporated seven selected articles, which scrutinized success rates and the incidence of pulp exposure in minimally invasive techniques (MIT) versus conventional techniques (CT). Statistical analysis employed U Mann–Whitney and Wilcoxon tests to interpret the results. Results: Although the difference did not reach statistical significance, MIT demonstrated marginally superior success rates compared to CT. Furthermore, MIT exhibited a lower percentage of pulp exposure when contrasted with CT. However, due to the limited sample size, statistical significance for this difference could not be established. Conclusions: Minimally invasive techniques for caries removal emerge as a conservative and promising approach to safeguard pulp tissues in comparison to conventional techniques. The need for additional randomized controlled trials is emphasized to unequivocally establish the superior success rates of these procedures over their conventional counterparts.

Background/Objectives: Preclinical training in pediatric dentistry is traditionally performed on acrylic primary teeth or natural extracted teeth in phantoms or dental manikins. With technological advancements, virtual simulation has become increasingly common, enhancing the development of cognitive and motor skills in dental students while complementing traditional methods. Specific objectives included assessing whether preclinical theoretical knowledge impacts motor skill scores, comparing the quality of dental preparations on acrylic teeth versus those performed using virtual simulation (Simodont^®) and evaluating students’ perceptions of Simodont^® use. Methods: An observational, descriptive, cross-sectional study was conducted. Students first completed a theoretical knowledge survey on dental preparations, class II caries, and pulpotomies. They then performed dental preparations on both acrylic primary teeth and the Simodont^® simulator, with their work assessed by a pediatric dentistry professor. Finally, students completed a perception survey regarding their experience. Results: The introduction of the Simodont^® was positively received. Theoretical knowledge prior to preclinical exercises did not significantly influence practice scores. Average scores for preparations on acrylic teeth (class II: 2.57; pulpotomy: 3.60) were higher than those achieved using Simodont^® (class II: 1.97; pulpotomy: 2.92). Conclusions: Dental preparation scores were higher on acrylic teeth compared to the virtual simulation. While students reported a positive experience with Simodont^®, they expressed a preference for traditional learning methods involving acrylic teeth on phantoms or dental manikins.

The aim of this study was to evaluate the comfort of children and adolescents with conventional full-arch dental impression methods compared to two intraoral scanners (iTero^TM and Primescan^TM). Methods: A monocentric, analytical, controlled crossover study was designed to compare conventional impression and digital impression with two intraoral scanners (iTero^TM and Primescan^TM) in children and teenagers. Patient comfort was evaluated using a 100 mm VAS scale adapted to Spanish and for children. A descriptive and analytical statistical method was conducted with a confidence level of 95% (p ≤ 0.05) and asymptotic or bilateral significance. Results: A total of 51 subjects were enrolled in the study (mean age = 12.35 years). Although the group of 10–14-year-olds was the most numerous, gender was equally distributed among the age groups. None of the variables on the VAS scale showed differences between the gender categories (p > 0.05). There were differences (p < 0.05) with respect to the age categories, as the middle adolescent group showed the worst general perception and total comfort during the conventional impression. Statistically significant differences were found between all VAS scale items and the three impression methods (p < 0.05). Conclusions: The digital impression technique is superior in terms of total comfort to the conventional alginate impression in children and adolescents.

Background: Dentinogenesis imperfecta type I (DGI-I) is a hereditary alteration of dentin associated with osteogenesis imperfecta (OI). Aim: To describe and study the morphological characteristics of DGI-I with scanning electron microscopy (SEM). Material and methods: Twenty-five teeth from 17 individuals diagnosed with OI and 30 control samples were studied with SEM at the level of the enamel, dentin–enamel junction (DEJ) and four levels of the dentin, studying its relationship with clinical–radiographic alterations. The variables were analysed using Fisher’s exact test, with a confidence level of 95% and asymptotic significance. Results: OI teeth showed alterations in the prismatic structure in 56%, interruption of the union in the enamel and dentin in 64% and alterations in the tubular structure in all of the cases. There is a relationship between the severity of OI and the morphological alteration of the dentin in the superficial (p = 0.019) and pulpar dentin (p 0.004) regions. Conclusions: Morphological alterations of the tooth structure are found in OI samples in the enamel, DEJ and dentin in all teeth regardless of the presence of clinical–radiographic alterations. Dentin structural anomalies and clinical dental alterations were observed more frequently in samples from subjects with a more severe phenotype of OI.