RESUMO
The placement of orthodontic appliances into the oral area can lead to infection, inflammatory and gingival collapse. Using an antimicrobial and anti-inflammatory material in the matrix of orthodontic appliance may help to reduce these issues. This study aimed to assess the release pattern, the antimicrobial action and the flexural strength of self-cured acrylic resins after adding different weight percentages of curcumin nanoparticles (nanocurcumin). In this in-vitro study, 60 acrylic resin samples were divided into five groups (n = 12) based on the weight percentage of curcumin nanoparticles added to the acrylic powder (0 for control, 0.5, 1, 2.5, and 5%). Then, the dissolution apparatus was used for the release assessment of nanocurcumin form the resins. For antimicrobial action assessment, the disk diffusion method was used and a three-point bending test was performed with a speed of 5 mm/min to determine the flexural strength. Data were analyzed using one-way analysis of variance (ANOVA) and Post-Hoc Tukey tests (with p < 0.05 as significant level). The microscopic images showed the homogeny distribution of nanocuricumin in self-cured acrylic resins in varied concentrations. The release pattern showed a two-step release pattern for all concentrations of nanocurcumin. The one-way ANOVA outcomes indicated that adding curcumin nanoparticles to self-cured resin increased the diameter of the inhibition zones for the groups against Streptococcus mutans (S. mutans) significantly (p < 0.0001). Additionally, as the weight percentage of curcumin nanoparticles increased, the flexural strength decreased (p < 0.0001). However, all strength values were higher than the standard value (50 MPa). No significant difference was detected between the control group and the group with 0.5 percent (p = 0.57). Considering the proper release pattern and the potent antimicrobial activity of curcumin nanoparticles, then the preparing self-cured resins containing curcumin nanoparticles can be beneficial for antimicrobial aims without damaging the flexural strength to use in orthodontic removable applications.
RESUMO
Introduction: Phototherapy with a light-emitting diode (LED) is used in medicine due to its potential bio-stimulatory effects on the human body. However, controversy still exists regarding the efficacy of low-level laser therapy (LLLT) and phototherapy with LED. This in vivo study aimed to quantitatively and qualitatively assess the newly formed bone following LED phototherapy of the human maxillary sinuses. Methods: This randomized clinical trial (concurrent parallel) was conducted on 44 patients in two groups (n=22) at the Implant Department of Tehran University of Medical Sciences. Randomization was done by a random sequence generator program. The inclusion criteria were absence of chronic sinusitis and chronic bone marrow conditions, no history of surgery at the site, absence of diabetes mellitus, no history of chemotherapy or radiotherapy, maxillary premolar edentulism, and signing informed consent forms. Group A underwent LED phototherapy with 620 ± 2 nm wavelength for 20 minutes daily for a total of 21 days after sinus lift surgery. Group B served as the control group and did not receive phototherapy. After 6 months, the grafted sites were re-opened for implant placement, and bone biopsy samples were obtained using a trephine bur. The samples were stained with hematoxylin and eosin and inspected under a light microscope. The results were statistically analyzed using the Mann-Whitney U test. Both the surgeon and pathologist were blinded to the group allocation of patients. Results: Forty tissue specimens were analyzed. Insignificant differences existed between the two groups in terms of the degree of inflammation, bone quality, and maturity of collagen. Histological analyses revealed no significant difference in the mineralized areas of bone between the two groups (P >0.05). Conclusion: The results indicated that LED phototherapy cannot significantly enhance osteogenesis after sinus lift surgery. No side effects were observed in the experimental group.
