Introduction: There are different possibilities of orthodontic planning for cases with congenital absence of maxillary lateral incisors. This subject divides the opinion of orthodontists and oral rehabilitation clinicians, due to the advantages and disadvantages of each treatment option, which may involve opening spaces for future implants and/or prosthetic restorations, or closing the spaces by positioning the maxillary canines in the place of lateral incisors. The correct diagnosis and careful evaluation of each patient allow to determine the best therapeutic approach. This paper discusses the main topics to be considered when planning these cases. Objectives: To evaluate the main aspects related to orthodontic treatment planning in cases of congenital absence of maxillary lateral incisors, to aid the decision-making, with clinical and scientific basis.

This comprehensive review aimed (1) to characterize the sub- and supragingival microbiome in patients with biofilm-induced gingivitis (including experimental gingivitis), (2) to assess its stability and evolution over time, and (3) to assess the impact of biofilm control measures on this stability. An electronic search of the MEDLINE^®/PubMed^® database until December 2023 was conducted. NCBI Taxonomy, eHOMD 16S rRNA Reference Sequence, and Tree Version 15.23 databases were used to standardize taxonomic nomenclature. Out of 89 papers initially retrieved, 14 studies were finally included: 11 using experimental gingivitis as a model and three randomized clinical trials evaluating the impact of biofilm control measures. Among them, five characterized the subgingival microbiome, nine the supragingival microbiome, and one both the sub- and supragingival microbiome. In addition, five studies evaluated the effect of toothpaste, and four studies evaluated the effect of mouth rinses. The diversity and structure of the microbiome differed significantly between patients with periodontal health and those with biofilm-induced gingivitis (including experimental gingivitis). Those differences were not reversed through conventional oral hygiene measures. Specific antiseptic agents, especially if delivered as mouth rinses, may have an impact on the supra- and subgingival microbiome in gingivitis.

The primary objective was to assess the safety of a new toothpaste formulation containing cetylpyridinium chloride (CPC) and cymenol as active agents. In addition, clinical efficacy and patient perception were evaluated. A 6-week randomized clinical trial was designed and patients were randomly allocated to use a test or control dentifrice. Adverse effects were assessed at 3- and 6-week follow-up visits, together with the following clinical parameters: Turesky plaque index (PlI), bleeding on marginal probing (BOMP), bleeding on probing (BOP) and Gründemann modification of the stain index (GMSI). Patient-reported outcome measures (PROMs) were also evaluated. A total of 60 patients were randomized and 55 were finally included in the analysis (test, 29; control, 26). Both toothpastes were safe and well tolerated by the patients. Statistically significant differences between test and control groups were observed for BOP changes between baseline week 6 (p = 0.031) and lower levels of plaque were registered in the test group at the 3- and 6-week visits (p < 0.05). No differences were observed for staining or PROMs. The use of a toothpaste containing CPC and cymenol was safe and not associated with any adverse effects. Significantly better clinical results were observed for the test group in terms of PlI levels and BOP reductions.

Background: The subgingival microbiome plays a key role in the gingivitis development, but the impact of toothbrushing with toothpaste on the subgingival microbial composition is not well understood. Therefore, this study aimed to evaluate the microbiological safety and subgingival impact of a toothpaste containing CPC and cymenol, compared to a fluoride-based toothpaste, and assessed overall subgingival microbiome changes after 6 weeks of routine toothbrushing in patients with gingival inflammation. Methods: A 6-week randomized clinical trial was conducted in patients with gingival inflammation allocated to the use of either a toothpaste with cetylpyridinium chloride and cymenol or a toothpaste with sodium monofluorophosphate. Subgingival samples were collected at baseline and after 6 weeks and processed using high-throughput sequencing technology (Miseq®). Diversity metrics were calculated and the microbiome composition was analyzed using PERMANOVA, ANOSIM and PERMDISP. Results: A total of 116 samples from 60 patients were analyzed. No significant changes in diversity were observed in either group after 6 weeks. Among taxa with > 1% abundance, the toothpaste with cetylpyridinium chloride and cymenol exhibited a higher reduction in Aggregatibacter (p = 0.023) and a significant decrease in Fusobacterium nucleatum (p = 0.030), while the toothpaste with sodium monofluorophosphate showed a significant increase in the phylum Firmicutes (p = 0.033). The relative abundance of Porphyromonas gingivalis, Prevotella intermedia and Tannerella forsythia were not affected by either toothpaste (p > 0.05). Conclusions: The daily use of a CPC/cymenol toothpaste was microbiologically safe, with no negative effects on the composition of the subgingival microbiome in patients with gingival inflammation, when compared to a fluoride-based toothpaste. The overall composition of the subgingival microbiome was not significantly affected by the daily use of either toothpaste after 6 weeks. In both groups, the observed changes affected mainly the low-abundance taxa. Trial registration: Registration Number: ISRCTN17497809; Registration Date: 12/07/2023 (ISRCTN.org).