Reaction of PPh and [(p-ClC H )N ][BF ] affords [(p-ClC H )N(PPh )N(PPh )][BF ] 1, while reaction with (Ph PCH ) gave [(p-ClC H )(NPh PCH ) )][BF ] 2. These species confirm the Lewis acidity of [(p-ClC H )N (PR )][BF ] cations at N. In contrast, use of bulky phosphines afford the species [ArN (PR )][BF ] (R=tBu 3, Mes 4). Compound 3 undergoes one electron reduction to give the stable radical [(p-ClC H )N (PtBu )] 5. Combination of 3 and PtBu acts as an FLP to effect (SPh) cleavage, generating [PhSPtBu ] and the radical [ArN (PR )] . Collectively, these data affirm the ability of the cations [ArN (PR )] to behave as one or two electron acceptors.

Reaction of PPh3 and [(p‐ClC6H4)N2][BF4] affords [(p‐ClC6H4)N(PPh3)N(PPh3)][BF4] 1, while reaction with (Ph2PCH2)2 gave [(p‐ClC6H4)(NPh2PCH2)2)][BF4] 2. These species confirm the Lewis acidity of [(p‐ClC6H4)N2(PR3)][BF4] cations at N. In contrast, use of bulky phosphines afford the species [ArN2(PR3)][BF4] (R=tBu 3, Mes 4). Compound 3 undergoes one electron reduction to give the stable radical [(p‐ClC6H4)N2(PtBu3)]. 5. Combination of 3 and PtBu3 acts as an FLP to effect (SPh)2 cleavage, generating [PhSPtBu3]+ and the radical [ArN2(PR3)].. Collectively, these data affirm the ability of the cations [ArN2(PR3)]+ to behave as one or two electron acceptors.

The significant advancement of molecular biology has revolutionized medicine and provided important technologies to further clinical research development. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) are DNA sequences derived from bacteriophages which have previously infected the bacterial species. The CRISPR–Cas system plays a key role in bacterial defense by detecting and destroying DNA fragments during subsequent bacteriophage invasions. The Cas9 enzyme recognizes and cleaves new invading CRISPR‐complementary DNA sequences. Researchers have taken advantage of this biological device to manipulate microbes’ genes and develop novel therapeutics to tackle systemic disease. In this review, we discuss the potential of utilizing CRISPR–Cas systems in the periodontal field to develop personalized periodontal care. We summarize promising attempts to bring this technology to the clinical setting. Finally, we provide insights regarding future developments to best utilize the CRISPR–Cas systems to advance precision periodontics. Although further research is imperative to evaluate the safety and potential of using CRISPR–Cas to develop precision periodontics approaches, few studies showed promising data to support the investment into this important technology in the dental sector. CRISPR–Cas9 can be a useful tool to create knockouts in vitro and in vivo as a screening tool to identify cellular pathways involved in the pathogenesis of periodontitis. Alternative CRISPR systems such as CRISPRa, CRISPRi, and Cas13 can be used to modify the transcriptome and gene expression of genes involved in periodontitis progression. CRISPR systems such as Cas3 can be used to target the periodontal biofilm and to develop new strategies to reduce or eliminate periodontal pathogens. Currently, the utility of CRISPR–Cas applications in clinical settings is limited. Through this review, we hope to foster further discussion in the periodontal research and clinical communities with respect to the potential clinical application of novel, CRISPR–Cas based, therapeutics for periodontitis.

Introduction: This study was conducted to assess the microleakage in Er:YAG laser-ablated and bur-prepared root and coronal dentin cavities using self-etch and total-etch adhesive systems. Methods: Sixty extracted caries-free human third molars were sectioned for dentin exposure. Then, two standard class V cavities were prepared in the root and coronal dentin of each tooth and allocated to one of the following conditioning groups randomly (n=12/Group): G1: Diamond bur for cavity preparation and single bond (BESB) etch-and-rinse adhesive for bonding, G2: Er:YAG laser (160 mJ, 20 Hz, 29.88 J/cm2 ) and SB (LESB), G3: Er:YAG laser and SB without acid etching (LSB), G4: Diamond bur and Clearfil SE Bond (BCSE) self-etch system, and G5: Er:YAG laser and Clearfil SE Bond (LCSE). The cavities were filled with Z100 composite resin. Dye penetration was assessed after thermocycling. Data analysis was done by Kruskal–Wallis and Mann–Whitney U tests. Statistical significance was set at P<0.05. Results: The results showed there were no statistically significant differences in microleakage between the two preparation methods (bur and laser) or the bonding agents applied (P>0.05). Regardless of the cavity preparation method, dye penetration was significantly higher in coronal dentin than in root dentin (P<0.05). Conclusion: The Er:YAG laser had the same efficacy as the conventional method for cavity preparation, and microleakage did not depend on the bonding agent. Microleakage was significantly higher in coronal restorations than in root restorations.