Cleaning Teeth Reduces the Inflammatory Response of Macrophages to Acid Dentine Lysate

Abstract

Particulate autogenous tooth roots are used for alveolar bone augmentation surgery; however, dental plaque may provoke an inflammatory response that may counteract the desired graft consolidation process. Traditional mechanical cleaning of extracted teeth may be of support to lower a possible inflammatory response of the autograft. To test this assumption, extracted porcine teeth were left either uncleaned or underwent mechanical cleaning with a toothbrush and toothpaste before being fragmented and subjected to acid lysis, termed as unclean acid dentine lysate (ucADL) and clean acid dentine lysate (cADL), respectively. The inflammatory responses of murine macrophage RAW 264.7 cells being exposed to the respective acid dentine lysates were evaluated at the level of inflammatory gene expression and IL6 immunoassays. We report here that acid lysates obtained from uncleaned teeth provoked a robust increase in IL1β, IL6, and COX2 in RAW 264.7 cells. The mechanical removal of dental plaque significantly reduced the inflammatory response. Consistently, Limulus tests revealed that tooth cleaning lowers the presence of endotoxins in dentine lysates. To further prove the involvement of endotoxins, a toll-like receptor 4 (TLR4) inhibitor TAK242 was introduced. TAK242 abolished the inflammatory response provoked by acid lysates obtained from uncleaned teeth in RAW 264.7 cells. Moreover, nuclear translocation and phosphorylation of the TLR4 downstream NFκB-p65 were attenuated at the presence of cleaned versus uncleaned dentine lysates. Taken together, our data support the importance of dental plaque removal of teeth being extracted for alveolar bone augmentation surgery.

Proteomic and genomic analysis of acid dentin lysate with focus on TGF-β signaling

“…These genes are all upregulated and considered as “pro-inflammatory”. Even though the extracted teeth were mechanically cleaned with a tooth brush and dentifrice, there might be some dental plaque remnants with bacterial endotoxins that are capable of eliciting an inflammatory response 48 , 49 . In support of these observations, cleaning of extracted teeth reduced but not fully abolished the inflammatory response of macrophages to ADL 49 .…”

Acid Dentin Lysate Failed to Modulate Bone Formation in Rat Calvaria Defects

“…Likewise, we have recently identified TGF-β as a major growth factor in ADL by a combined proteomics and RNA sequencing approach (Nasirzade et al under revision). More recently, our group, showed that ADL induces an inflammatory response when being prepared from uncleaned teeth [ 21 ]. This inflammatory response, nevertheless, was not triggered when teeth had been cleaned with toothpaste and a toothbrush [ 21 ].…”

“…More recently, our group, showed that ADL induces an inflammatory response when being prepared from uncleaned teeth [ 21 ]. This inflammatory response, nevertheless, was not triggered when teeth had been cleaned with toothpaste and a toothbrush [ 21 ]. Therefore, it appears that ADL is capable of causing a strong cellular response in vitro, however, the translation of these findings into a preclinical scenario remains largely unknown.…”

Tooth shell technique: A proof of concept with the use of autogenous dentin block grafts

“…Studies have shown that the mechanical removal of dental plaque significantly reduced the inflammatory reaction. 28 If a complete tooth root is used as augmentation material, as described by Schwarz et al, 9 the dimension of the root will limit the augmentation width. With the tooth shell technique described here, a larger horizontal deficit can be augmented, in analogy to the bone block grafting technique by Khoury.…”

“…Furthermore, the preparation of the tooth also seems to have an influence on the success rate. Studies have shown that the mechanical removal of dental plaque significantly reduced the inflammatory reaction 28 …”