Carina Sonia Neagu

Background and Objectives: Conventional dental adhesives doped with magnetic nanoparticles (MNPs) hold the promise of preventing microleakages. However, esthetic concerns have motivated the quest for coatings capable of masking the dark color of MNPs. This study aims to quantify regional chromatic differences between teeth restored using dental adhesives with different MNP content. Materials and Methods: We prepared cavities in 42 artificial molars and 9 extracted teeth and divided them into 6 groups: Group 0 (G0), G1, and G2, comprising 14 artificial teeth each and G0e, G1e, and G2e, comprising 3 extracted teeth each. In G0 and G0e, we applied the commercial adhesive, in G1 and G1e we applied the adhesive loaded with MNPs with dual coating (SiO₂ followed by Ca(OH)₂), whereas in G2 and G2e we applied the adhesive doped with uncoated MNPs. For the statistical analysis of color differences, we employed Bland–Altman plots and the one-sample t-test. Results: G1 was similar to G0 in terms of color coordinate distribution, whereas G2 was different. Compared to G0, dental fillings from G1 had mean differences of (−0.56, 0.18, −0.07) in the CIELAB color coordinates (L*, a*, b*), respectively, whereas the mean differences between G2 and G0 were (−15.6, −3.5, −15.7). The CIEDE2000 color differences were 1.5 [1.3, 1.6] between G1 and G0 (mean [95% confidence interval]) and 17.0 [16.0, 18.0] between G2 and G0. Nevertheless, 24.4% of the point pairs compared exceeded the acceptability limit for color difference (1.8). Conclusions: Although the silica and calcium hydroxide coating is highly effective in alleviating the esthetic impact of MNP-laden dental adhesives, further research is warranted to reduce between-specimen variability.

Recent advancements in dental adhesive technology have demonstrated the significant benefits of incorporating magnetic nanoparticles (MNPs) into resin adhesives

Background and Objectives: Orthodontic auxiliaries create plaque-retentive niches that may amplify biofilm accumulation and inflame adjacent soft tissues. While cross-sectional comparisons suggest higher palatal burden beneath acrylic elements, less is known about real-world patterns accumulated across years of routine care. We retrospectively evaluated periodontal and palatal outcomes, and, in a microbiology sub-sample, site-specific colonization, across three device types: molar bands, Nance buttons, and removable acrylic plates. Methods: We reviewed 2022–2025 records from a university orthodontic service, including consecutive patients aged 18–30 years with documented pre-placement and 6-month follow-up indices. Groups were bands (n = 92), Nance (n = 78), acrylic (n = 76). Standardized charted measures were abstracted: Plaque Index (PI), Gingival Index (GI), bleeding on probing (BOP%), probing depth (PD), and palatal erythema grade (0–3). A laboratory sub-sample (n = 174 visits) had archived swabs cultured for total aerobic counts (log₁₀ CFU/cm²) at the device, adjacent enamel, and palatal mucosa; Streptococcus mutans burden was available from qPCR (log₁₀ copies/mL). Results: Baseline characteristics were similar, except for longer wear at follow-up in Nance (10.1 ± 4.0 months) vs. bands (8.7 ± 3.2) and acrylic (6.9 ± 3.0; p < 0.001). At 6 months, device type was associated with greater worsening of PI and GI (both p < 0.001) and with higher palatal erythema (bands 0.7 ± 0.5; Nance 1.6 ± 0.8; acrylic 1.9 ± 0.7; p < 0.001). Microbiologically, palatal mucosal colonization was lowest with bands (3.3 ± 0.5), higher with Nance (4.9 ± 0.6), and highest with acrylic (5.0 ± 0.7; p < 0.001); S. mutans mirrored this gradient (p < 0.001). Palatal CFU correlated with erythema (ρ = 0.6, p < 0.001) and ΔGI (ρ = 0.5, p < 0.001). In adjusted models, acrylic (OR 6.7, 95% CI 3.5–12.8) and Nance (OR 4.9, 2.5–9.3) independently predicted erythema ≥2; recent prophylaxis reduced odds (OR 0.6, 0.3–0.9). Conclusions: In this single-center cohort, palate-contacting designs were associated with higher palatal biomass and erythema than bands. These associations support device-tailored hygiene considerations and proactive palatal surveillance, particularly for acrylic components.

Background: Large periapical cyst-like lesions pose challenges for nonsurgical management. This study evaluated the clinical and radiological outcomes of conventional endodontic therapy alone versus endodontic therapy with decompression in treating such lesions. Methods: Ten patients with CBCT-confirmed periapical lesions >5 mm were randomly assigned to two groups. Group 1 received standard root canal treatment with calcium hydroxide; Group 2 received the same protocol plus decompression. Lesion dimensions were measured in three planes using CBCT at baseline, 12 months, and 24 months. Results: Both groups showed significant lesion size reduction over time. At 12 months, Group 2 had a significantly greater mean reduction (8.49 ± 5.09 mm) compared to Group 1 (4.36 ± 1.46 mm) (p = 0.008). At 24 months, both groups had comparable outcomes (Group 1: 1.12 ± 0.98 mm; Group 2: 2.41 ± 5.15 mm; p = 0.356), with most lesions nearly or fully resolved. Histopathology confirmed radicular cysts in decompressed cases. Conclusions: Conservative endodontic therapy is effective for large periapical lesions. Adjunctive decompression accelerates early healing, particularly in extensive cases, potentially reducing the need for surgical intervention. CBCT is valuable for monitoring healing.

Background and Objectives: Dental adhesives augmented with magnetic nanoparticles (MNPs) have been proposed to prevent microleakages. MNPs dispersed in a dental adhesive reduce the thickness of the adhesive layer applied in a magnetic field and enhance the bond strength by favoring the penetration of the adhesive into dentinal tubules. However, the restoration’s color has been found to be affected by the MNPs. This study tests the hypothesis that MNP coating can alleviate the esthetic impact of magnetic dental adhesives. Materials and Methods: We synthesized Fe₃O₄ MNPs with silica coating (MNPs-SiO₂), calcium-based coating (MNPs-Ca), and no coating. Their morphology was studied using transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Their chemical composition was assessed by energy-dispersive X-ray spectroscopy (EDX), and magnetic properties were measured using a vibrating sample magnetometer. FTIR spectroscopy was used to evaluate the polymerization of the MNP-laden adhesive. We prepared cavities in molar phantoms divided in four groups (n = 15 each) restored using the same adhesive with different MNP contents: Group 0 (G0)—no MNPs, G1—MNPs-SiO₂, G2—MNPs-Ca, and G3—uncoated MNPs. The restoration’s color was quantified in the CIELAB color space using a dental spectrophotometer. Results: MNPs-SiO₂ were globular, whereas MNPs-Ca had a cubic morphology. The SiO₂ layer was 73.1 nm ± 9.9 nm thick; the Ca(OH)₂ layer was 19.97 nm ± 2.27 nm thick. The saturation magnetization was 18.6 emu/g for MNPs-SiO₂, 1.0 emu/g for MNPs-Ca, and 65.7 emu/g for uncoated MNPs. MNPs had a marginal effect on the adhesive’s photopolymerization. The mean color difference between G0 and G2 was close to the 50:50% acceptability threshold, whereas the other groups were far apart from G0. The mean whiteness index of G2 did not differ significantly from that of G0; G1 deviated marginally from G0, whereas G3 differed significantly from G0. Conclusions: These results suggest that MNP coating can mitigate the influence of MNP-laden dental adhesives on the color of restorations.

The impression materials utilized today in dental medicine offer a good reproducibility and are easily accepted by patients. However, because they are polymer-based, they have issues regarding their dimensional stability. In this respect, the present work proposes a new type of dental impression, which is reinforced with rigid mouthguards. The aim of the study is to test the performances of such new impressions by comparing them to conventional ones—from this critical point of view, of the dimensional stability. Three types of polymeric materials were considered for both types of impressions: alginate, condensation silicone, and addition silicone. In order to obtain the new type of impressions, a manufacturing technique was developed, comprising the following phases: (i) conventional impressions were made; (ii) a plaster model was duplicated, and 15 rigid mouthguards were obtained; (iii) they were inserted in the impression technique, with each mouthguard positioned on the cast before the high-consistency material was inserted in the tray and the practitioner took the impression; (iv) the mouthguard remained in the tray and the low-viscosity material was inserted over the mouthguard; (v) the impression was positioned on the model, and after the material hardened, the mouthguard-reinforced impression was analyzed. In the evaluation of the dimensional stability, rigorous statistical analysis was essential to discern the performance differences between conventional and mouthguard-reinforced dental impressions. Statistical analyses employed non-parametric Mann–Whitney U tests because of the non-normal distribution of the data. They indicated a statistically significant improvement in the dimensional stability of addition silicone impressions when reinforced with mouthguards (p < 0.05), showcasing superior performance over conventional methods. Conversely, alginate and condensation silicone reinforced impressions did not exhibit the same level of stability improvement, suggesting the need for further optimization of these materials. In conclusion, from the three considered elastomers, addition silicone was found to be the prime candidate for high-precision dental impressions, with the potential to improve their quality from conventional impressions by utilizing the proposed reinforcing technique.

An important challenge in today’s dentistry is to create sturdy and aesthetic restorations. Dental research aims to create restorations with long-term durability and optical properties similar to healthy natural teeth. Recent works have shown that the magnetic handling of a dental adhesive doped with magnetic nanoparticles (MNPs) improves the adhesion between the composite and the dentin. This study presents the preparation of dental adhesives loaded with iron oxide (Fe₃O₄) NPs incorporated in SiO₂ shells, and their applications in the creation of dental veneers. Extracted incisors were prepared for veneering and divided in two groups: Group A was bonded with normal adhesive and Group B was bonded with the augmented adhesive, in the presence of a permanent magnet. The samples were analyzed using stereomicroscopy, optical coherence tomography (OCT), and scanning electron microscopy (SEM), the latter combined with energy dispersive analysis of X-rays (EDAX). All techniques enabled the visualization of the veneer-adhesive and adhesive-dentin interfaces: (i) stereomicroscopy demonstrated that the adhesive layer was thinner for Group B and revealed conglomerates of MNPs in the adhesive layer; (ii) OCT enabled a visualization of the marginal closure, as well as of defects in the two interfaces; (iii) SEM provided a high-resolution image of the adhesive layer, whereas EDAX furnished an elemental analysis of the augmented adhesive. In conclusion, under the action of an external magnetic field, MNPs can penetrate deeper into the demineralized structure of the tooth, reducing the thickness of the adhesive layer and, thereby, decreasing the probability of microleakage.