This in vitro study compared the shear bond strength (SBS) and antibacterial efficacy of an orthodontic adhesive containing either cinnamon or titanium dioxide (TiO₂) nanoparticles (NPs). A total sample of 120 freshly extracted teeth was randomly divided into three groups, according to the type of NPs incorporated into adhesive for metallic orthodontic brackets’ bonding: group 1—conventional orthodontic adhesive (TXT) as a control; group 2—conventional orthodontic adhesive mixed with TiO₂ NPs (TXT + TNP); and group 3—conventional orthodontic adhesive mixed with cinnamon NPs (TXT + CNP). The SBS and adhesive remnant index (ARI) scores were evaluated and compared between the groups. The antibacterial efficacy against Streptococcus mutans for all the groups was assessed via a disc agar diffusion test. Data comparisons among groups were performed by ANOVA followed by Bonferroni post hoc test. Antibacterial efficacy comparison between the experimental groups was performed via an independent t-test. The significance level for all the tests was set at p ≤ 0.05. The highest mean SBS values (10.11 ± 1.88 MPa) were in the TXT control group followed by TXT + TNP (9.40 ± 1.78 MPa), and the lowest SBS was in the TXT + CNP (8.99 ± 1.77 MPa) group. The mean SBS among the experimental groups was non-significant (p = 0.241). Antibacterial effects significantly increased (p ≤ 0.05) in both experimental groups. However, TXT + TNP revealed a significantly higher antibacterial effect (p = 0.021) than TXT + CNP. In conclusion, incorporating cinnamon or TiO₂ NPs into an orthodontic adhesive improves its antibacterial effects without compromising the bond strength for clinical purposes.

This in vitro study assessed the effect of different primers on the shear bond strength (SBS) and adhesive remnant index (ARI) of orthodontic brackets bonded to reinforced polyetheretherketone (PEEK) substrate. A total of 40 specimens were randomly distributed to two groups based on the primer used for orthodontic bonding: group 1 (control)—Transbond XT adhesive with Visio.link primer and group 2 (test)—orthodontic adhesive (Transbond XT) with traditional orthodontic primer. After bonding, specimens were thermocycled followed by SBS testing and ARI scoring of debonded specimens. Data were analyzed using the unpaired independent t-test and the Chi-square test. Group 1 specimens showed significantly higher SBS values (21.38 ± 1.48 MPa) compared to group 2 specimens (18.63 ± 1.29 MPa) (p < 0.0001). Adhesive remnant index scores showed no significant variations in bond failure modes and distributions between groups. The SBS obtained by the tested primers exceeded the clinically recommended value. Consequently, there is a comparable clinical application for both tested primers in orthodontic bonding, especially the traditional orthodontic primer, where the availability of Visio.link in clinical practice is not ensured.

Aim of the study: To evaluate the vertical dimension change through the amount of molar intrusion after using modified vertical holding appliance (VHA) versus miniscrew. Subjects and methods: A sample of thirty six patients (32 females and 4 males) that presented with extruded upper molars and/or anterior open bite with age ranged from 17.6-26.4 years Group (1) VHA with mini screw (VHAMS) 12 patients (11 females and 1 male) , Group (2) molar intrusion with miniscrew only 12 patients (11 females and 1 male) , and Group (3) VHA without miniscrew 12 patients (10 females and 2 males), Lateral cephalometric X-ray view were taken before intrusion (T1), six months after the application of upper molar intrusive mechanics (T2) and six months after comprehensive orthodontic treatment (T3). Results: Significant increase in SNB, overbite in groups 1and 2, while there was a significant decrease in the angle of convexity, SN-MP, FMPA, LAFH, overjet, and open bite in groups 1 and 2, indicating improvement of the open bite and facial profile. Conclusion: Vertical Holding Appliances (VHA) and miniscrew-assisted intrusion can be effective in treating open bites or over-erupted maxillary molars. However, miniscrew-assisted intrusion often offers better control and predictability, leading to superior outcomes, particularly in cases of severe open bites.