Comparative analysis of nerve fibers, PIEZO family and bone structural parameters difference surrounding dental implants

Abstract

Background

Nerve fibers embedded within bone tissue play a pivotal role in regulating osseous homeostasis. Emerging evidence indicates the presence of neural networks surrounding dental implants. The functional integrity of these nerve fibers is maintained through various ion channels, particularly those belonging to the PIEZO family. This study aims to: (1) characterize the spatial distribution patterns of nerve fibers and PIEZO family around dental implants, and (2) investigate their potential correlations with bone microarchitecture surrounding dental implants.

Methods

Male rat models with right maxillary first molar dental implants were established. Following a 4-week osseointegration period, spatial variations in nerve fiber density and PIEZO family expression were quantitatively assessed across 8 anatomically defined buccolingual regions. Complementary Micro-CT analyses were performed to evaluate three-dimensional bone microarchitecture surrounding dental implants.

Results

The study revealed regional heterogeneity in nerve fiber density across the 4 anatomical zones. Nerve fiber density showed no significant difference between peri-implant and adjacent tissues. While PIEZO-positive fibers generally mirrored overall nerve fiber distribution, the apical region exhibited a significantly higher proportion of PIEZO2-positive fibers in peri-implant bone versus adjacent bone.

Conclusions

Peri-implant regions exhibited higher nerve fiber density and enhanced bone microarchitecture, suggesting neurogenic modulation of osseointegration dynamics. Mechanistically, the PIEZO family may mediate this neuro-osseous crosstalk during bone remodeling around implants. These findings offer novel perspectives on the mechanistic basis of peri-implant bone adaptation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-025-07400-5.

Introduction

Bone receives dual innervation from central and peripheral nervous systems, with peripheral nerves—comprising sensory and autonomic fibers—distributed across cortical bone, trabecular bone, marrow, and periosteum [1, 2]. Nerve fibers and their secretory products, including neurotransmitters, neuropeptides, neurotrophins, and guidance factors, critically regulate bone remodeling dynamics [3, 4].

PIEZO family, comprising PIEZO1 and PIEZO2 in mammals, are prototypical mechanosensitive ion channels. PIEZO1 and PIEZO2 ion channels play crucial roles in mechanotransduction in mammals, which is mediated through changes in cell membrane tension and the influx of cations, particularly Ca²⁺ [5–7]. PIEZO1 is expressed not only in sensory neurons but also in non-sensory neurons and various other tissues [8–10]. In contrast, PIEZO2 is predominantly found in sensory neurons, such as dorsal root ganglion (DRG) neurons, trigeminal ganglion neurons, vagus ganglion neurons, Merkel cells, and other sensory neurons [11, 12]. PIEZO1 is essential in tissues subjected to substantial mechanical forces, such as those found in the cardiovascular system [13, 14], musculoskeletal system [15, 16] and skin epithelium [17]. Its expression appears to be regulated by a positive feedback loop in response to mechanical stimuli; for instance, PIEZO1 expression was upregulated under mechanical stimulation but decreased in its absence in osteoblasts and cardiac muscle cells [18, 19]. PIEZO2 plays important roles in detecting mechanical stimuli associated with touch and proprioception. Evaluation studies of electrophysiological function and behavior, in conjunction with the primary expression sites of PIEZO2, have conclusively established PIEZO2 as a key mechanotransducer that initiates tactile sensation and proprioception [20]. Bone serves as a target organ for the nervous system. Research on humans and mice has demonstrated that the loss of PIEZO2 in proprioceptive neurons not only impairs proprioception but also results in spinal dislocation, hip dysplasia, finger contracture, and foot deformity [21, 22]. These findings suggest that the PIEZO family on nerve fibers is involved in regulating bone homeostasis.

Osseointegrated dental implants retain the capacity to perceive mechanical stimuli, with subsequent signal transduction to the central nervous system via residual nerve fibers within the alveolar bone [23, 24]. Electrophysiological studies have confirmed this neural pathway by demonstrating that electrical stimulation of dental implants can elicit measurable trigeminal somatosensory evoked potentials (TSEPs) [25, 26]. Current evidence regarding the innervation patterns in peri-implant tissues remains limited, as indicated by previous studies [27–29]. Additionally, stress distribution varies across different parts of dental implants, and it remains unknown whether nerve fibers and the PIEZO family exhibit similar regional variations. Furthermore, the potential involvement of these neural elements in maintaining osseous homeostasis around dental implants is rarely reported [30].

This study evaluated nerve fiber density and PIEZO family expression within these fibers in peri-implant tissues, alongside bone structural parameters in relevant regions. These parameters were then compared between peri-implant and adjacent tissues.

Methods and materials

Animals

Healthy male Sprague-Dawley (SD) rats aged 5–6 weeks and weighing 130–160 g were used for establishment of dental implant models. The experimental animals were sourced from Shanghai Regent Technology Co. All the rats were maintained in specific pathogen-free cages with a 12-hour light/dark cycle and moderate supplementation of water and food during the experiment. Before the operation, aseptic saline was used to clean the mouth and the rats were anesthetized with an intraperitoneal injection of pentobarbital (2%, 0.25 ml/100 g). A customized titanium implant with acid etching and sandblasting treatment measuring 1.6 mm in diameter and 3 mm in length (excluding the portion above the neck) was implanted immediately after extraction of the right maxillary first molar. During postoperative anesthesia recovery, mice were maintained on a temperature-regulated electric blanket (37 ± 1 °C). Upon full consciousness, animals were transferred to their cages with close attention paying to their mental state and diet condition. Chlorhexidine (0.12%) was applied for local wiping on the implants and the surrounding oral tissues after operation. The surgical sites were monitored closely for any infection and checked if the implants loosing or have fallen off. The animals were given subcutaneous injections of penicillin(400000U/kg) for up to 3 days after operation. During the experiment and routine feeding, animals received humane care according to the criteria outlined in the Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health (NIH). The procedures performed on the rats were approved by the Institute of Animal Care and Use Committee of Tongji University (2024-DW-06).

Micro-CT analysis

4 weeks after implantation, the maxillaries of the rats (n = 3) were isolated and directly scanned with high-resolution Micro-computed tomography (Micro-CT) (SkyScan1076, Bruker Micro-CT, USA). Image acquisition of the maxillaries was performed at an energy of 70 kV and a resolution of 14 μm. CTan software (Germany) was used to observe osseointegration around the implants and analyze relative bone structural parameters: BV/TV (bone volume/tissue volume), Tb.Th (trabecular thickness), Tb.N (trabecular number) and Tb.Sp (trabecular separation). 6 sites in the peri-implant and adjacent tissue were chosen, comprising the coronal, middle, and apical regions (2 sites per region) (Fig. 1b). And a hollow cylinder formed by a series of cuboids (measuring 0.5 mm in width and 1 mm in length) surrounding the implant was defined as the region of interest (ROI) at each observation site.

Fig. 1.

Schematic illustration of implant placement and analysis sites. a Dental implant model of rats. The implant was placed in right maxillary first molar extraction site (white arrow). b Representative image of micro-CT reconstruction and relative analysis sites. peri-implant tissue analysis: white and black dashed boxes; adjacent tissue analysis: red dashed boxes. c Representative image of Masson Staining. scale bar for Micro-CT analysis: 500 μm. scale bar for Masson Staining: 250 μm. Imp implant, M mesial, D distal

Histological analysis

Maxillary specimens were fixed in 4% paraformaldehyde (PFA) (Solarbio, China) for 48 h at 4 °C and decalcified in 10% ethylenediaminetetraacetic acid (EDTA) (Solarbio, China) for 4 weeks. Subsequently, the implants were removed carefully and the bone samples were embedded in paraffin wax and sectioned into 4-µm-thick slices. Masson staining was performed according to manufacturer’s instructions (Solarbio, China). For immunofluorescence staining, the bone sections were fixed with 4% PFA for 20 min. After washing the sections with phosphate buffer saline (PBS) (Solarbio, China) 3 times, the sections were treated with 1 mg/ml hyaluronidase(Sigma, USA‌) for antigen retrieval 1 h at 37℃. And then, the sections were blocked with 10% goat serum (Maxim, China) for 0.5 h at 37 °C. A primary antibody was incubated at 4 °C for 12 h and the corresponding secondary antibody was incubated for 1 h at 37 °C. The antibodies used in the study were as follows: PIEZO1(Affinity, DF12083, 1:250), PIEZO2(Novus, NBP1-78624, 1.5 µg/ml), PGP 9.5 (Affinity, BF8240, 1:300), Donkey anti-Rabbit IgG (H + L) Highly Cross-Adsorbed Secondary Antibody Alexa Fluor™ 594 (Invitrogen, A-21207, 2 µg/mL) and Goat Anti-Mouse IgG H&L (Alexa Fluor^® 488) (Abcam, ab150113, 1:1000). Images were acquired with a Nikon DS-Ri1 microscope. 8 sites in the peri-implant and adjacent tissue (including gingiva and alveolar bone) were chosen, comprising the gingival, coronal, middle, and apical regions (2 sites per region) (Fig. 1b). An area measuring 0.5 mm in width and 1 mm in length at each observation site was defined as the region of interest (ROI). The density of trigeminal nerve fibers (N/mm², number of trigeminal nerve fibers per square millimeter) was evaluated in each ROI (n = 4). The proportion of PIEZO-positive fibers among total PGP9.5-positive fibers was calculated by counting the PIEZO protein-expressing nerve fibers in relation to the total nerve fibers in each region.

Statistical analysis

All the data were analyzed and plotted via GraphPad Prism (GraphPad Prism Software, La Jolla, USA) and IBM SPSS Statistics (Armonk, USA). The data are presented as the mean ± SD (standard deviation). First, Levene’s Test was used to conduct homogeneity test of variance. One-way analysis of variance was used for comparison between different partitions, and Student’s t test was used for comparison between different locations in the same region. Values of p < 0.05 were considered statistically significant (*).

Results

Dental implants achieve osseointegration

The intraoral image after implant implantation is shown in Fig. 1a. This study selected a 4-week post-implantation time point to assess osseointegration according to previous study [31]. Masson staining and Micro-CT scanning confirmed peri-implant bone tissue formation (Fig. 1b and c), demonstrating successful osseointegration under these experimental conditions and enabling subsequent investigations.

Comparative analysis of the density of nerve fibers in peri-implant and adjacent tissue

Residual nerve fibers in jawbone are essential for implant’s osseoperception. PGP 9.5 was used to label nerve fibers in the peri-implant and adjacent tissue. And the density of nerve fibers was further examined. Nerve fibers were detected in both the peri-implant and adjacent tissue in buccolingual direction (Fig. 2a). The nerve fibers density around the implant was higher in the gingival and apical regions than that in the coronal and middle regions (n = 4, PIT: gingival vs. coronal p < 0.001, gingival vs. middle p = 0.001, apical vs. coronal p < 0.001, apical vs. middle p = 0.003; AT: gingival vs. coronal p < 0.001, gingival vs. middle p < 0.001, apical vs. coronal p = 0.001, apical vs. middle p = 0.001). However, there was no significant difference in the density of nerve fibers between the peri-implant and adjacent tissue in the 4 regions (p > 0.05) (Fig. 2b). Supplementary Fig. 1a showed the negative control. The exact values of each group were provided in Supplementary Table 1.

Fig. 2.

Distribution of nerve fibers in peri-implant and adjacent tissue. a Representative image of nerve fiber expression in buccolingual direction (Green, PGP9.5). b Quantitative analyses of nerve fibers density in different sites of buccolingual direction (n = 4). All data are shown as mean ± SD. *p < 0.05, **p < 0.01. scale bar: 500 μm. PIT peri-implant tissue, AT adjacent tissue (including gingiva and alveolar bone)

Comparative analysis of the percentage of nerve fibers expressing PIEZO family in peri-implant and adjacent tissue

The proportion of PGP 9.5-positive nerve fibers expressing PIEZO1 was quantified. Both peri-implant and adjacent tissues exhibited higher PIEZO1 expression density within nerve fibers in the gingival and apical regions, while the middle region showed a lower percentage of PIEZO1-positive fibers amongst the total PGP 9.5-positive population. (n = 4, PIT: gingival vs. coronal p > 0.05, gingival vs. middle p = 0.010, apical vs. coronal p > 0.05, apical vs. middle p = 0.018; AT: gingival vs. coronal p = 0.035, gingival vs. middle p < 0.001, apical vs. coronal p > 0.05, apical vs. middle p = 0.034). There was no difference between peri-implant and adjacent tissue (p > 0.05) (Fig. 3a and c).

Fig. 3.

Distribution of PIEZO-positive nerve fibers in peri-implant and adjacent tissue. a Representative image of PIEZO1-positive nerve fiber expression in buccolingual direction (Green, PGP9.5; Red, PIEZO1). b Representative image of PIEZO2-positive nerve fiber expression in buccolingual direction (Green, PGP9.5; Red, PIEZO2). c Quantitative analyses of PIEZO1-positive nerve fibers ratio in different sites of buccolingual direction (n = 4). d Quantitative analyses of PIEZO2-positive nerve fibers ratio in different sites of buccolingual direction (n = 4). All data are shown as mean ± SD. *p < 0.05, **p < 0.01. scale bar: 500 μm. PIT peri-implant tissue, AT adjacent tissue (including gingiva and alveolar bone)

The expression of PIEZO2-positive nerve fibers roughly matched that of PIEZO1(n = 4, PIT: gingival vs. coronal p = 0.012, gingival vs. middle p = 0.002, apical vs. coronal p = 0.019, apical vs. middle p = 0.003; AT: gingival vs. coronal p < 0.001, gingival vs. middle p < 0.001, apical vs. coronal p = 0.023, apical vs. middle p = 0.017). However, the percentage of PIEZO2-positive nerve fibers among total PGP9.5-positive fibers in the peri-implant tissue was higher than that in the surrounding alveolar bone, especially in the apical region (p = 0.018) (Fig. 3b and d). Supplementary Fig. 1b showed the negative control. All the exact values of each group were provided in Table 1.

Table 1.

The quantitative data (mean ± standard deviation) of each observation site in histological analysis

	Observation sites	peri-implant tissue	adjacent tissue
Nerve fibers density(N/mm2)	gingival	19.500 ± 1.915	19.500 ± 2.517
	coronal	12.750 ± 1.500	12.250 ± 1.258
	middle	14.250 ± 1.708	12.250 ± 2.062
	apical	18.500 ± 1.291	18.250 ± 1.258
PIEZO1-positive nerve fibers (%)	gingival	66.240 ± 7.539	66.420 ± 3.332
	coronal	59.225 ± 8.930	53.867 ± 8.151
	middle	51.042 ± 6.900	41.132 ± 8.283
	apical	64.652 ± 3.910	53.750 ± 8.767
PIEZO2-positive nerve fibers (%)	gingival	74.317 ± 3.819	72.755 ± 4.044
	coronal	54.412 ± 17.122	38.555 ± 4.485
	middle	47.187 ± 5.413	37.532 ± 10.737
	apical	72.802 ± 5.327	53.540 ± 10.733

Comparative analysis of bone structural parameters in peri-implant bone and adjacent alveolar bone

Nerve fibers and the PIEZO family play essential roles in regulating bone homeostasis. Therefore, it is important to investigate whether differences exist in the bone microarchitecture of various regions.

Therefore, the bone structural parameters in peri-implant bone and adjacent alveolar bone were further analyzed in this study (n = 3) (Fig. 4a). For peri-implant bone, BV/TV (apical vs. coronal p = 0.009, apical vs. middle p > 0.05) and Tb.Th (apical vs. coronal p = 0.008, apical vs. middle p = 0.017) in the apical region are higher than that in the coronal and middle regions (Fig. 4b and c). BV/TV(p < 0.001), Tb.Th (p = 0.022) and Tb.N (p = 0.003) in the apical region of peri-implant bone are significantly greater than that of adjacent alveolar bone (Fig. 4b, c and d). Tb.Sp in the apical region of peri-implant bone is significantly lower than that of adjacent alveolar bone (p = 0.006) (Fig. 4e). The exact values of each group were provided in Table 2. In brief, the bone structural parameters of the peri-implant bone in the apical region were better than those in the coronal and middle regions and were also significantly higher than those of the adjacent bone. The summary chart of the experimental results could be found in Supplementary Fig. 2.

Fig. 4.

Micro-CT analysis of bone structural parameters of peri-implant bone and adjacent alveolar bone. a ROI of the peri-implant alveolar bone (top view). b c d e Quantitative analyses of bone structural parameters in different sites of buccolingual direction (n = 3). All data are shown as mean ± SD. *p < 0.05, **p < 0.01. scale bar: 500 μm. PIB peri-implant bone; AB adjacent alveolar bone

Table 2.

The quantitative data (mean ± standard deviation) of each observation site in Micro-CT analysis

	Observation sites	peri-implant bone	adjacent bone
BV/TV(%)	coronal	60.213 ± 2.052	59.680 ± 4.607
	middle	61.836 ± 12.464	72.812 ± 2.362
	apical	66.471 ± 1.038	28.595 ± 0.660
Tb.Th(mm)	coronal	0.064 ± 0.001	0.065 ± 0.007
	middle	0.066 ± 0.004	0.067 ± 0.009
	apical	0.074 ± 0.003	0.055 ± 0.008
Tb.N(1/mm)	coronal	9.349 ± 0.427	9.134 ± 0.390
	middle	9.346 ± 1.592	11.072 ± 1.372
	apical	8.992 ± 0.548	5.240 ± 0.873
Tb.Sp(mm)	coronal	0.052 ± 0.009	0.054 ± 0.005
	middle	0.0585 ± 0.016	0.049 ± 0.008
	apical	0.051 ± 0.004	0.110 ± 0.019

Discussion

Osseointegrated dental implants rely on nerve fibers within the alveolar bone to mediate sensory responses to mechanical stimulation in the absence of functional periodontal ligament mechanoreceptive input [32]. Previous studies have demonstrated that implants can enhance local innervation patterns by delivering mechanical stimuli directly to the bone [33]. However, little is known about the role of nerve fibers in regulating the homeostasis of bone tissue surrounding implants. In this study, nerve fibers were observed in both peri-implant tissues and adjacent alveolar bone, with some expressing PIEZO family proteins. Additionally, bone structural parameters around the implants were evaluated. Notably, the expression levels of nerve fibers, PIEZO-positive nerve fibers, and bone structure varied across different regions.

After dental implants are placed into the alveolar bone, a series of reconstruction processes occur between the implant surface and the alveolar bone to complete osseointegration. Within 24 h post-implantation, blood clots form around the implants, accompanied by inflammatory responses. New blood vessel formation begins within 2 to 3 days after implantation, followed by new bone formation and bone remodeling [34]. Studies have shown that the reconstructed bone tissue can extend up to 1 mm from the implant surface into the surrounding area [35]. Therefore, a comparative analysis was conducted on the 1 mm tissue surrounding the implant (0.5 mm) and the adjacent tissue (0.5 mm) for this study.

Higher nerve fiber density was observed in the gingival and apical regions. Since the gingiva is susceptible to friction, pressure, and external chemical and thermal stimuli during mastication, it is unsurprising that it exhibits abundant innervation [36]. According to statistical data, nerve fiber density in the apical region is relatively higher, which may be attributed to the heavy load experienced by the apical region of the implants [37, 38]. Research has shown that nerve fibers exhibit plasticity, with mechanical force playing a key role in axon growth [39, 40]. Song et al. [29] also found that earlier loading of the implant is more beneficial for enhancing nerve fiber regeneration, resulting in higher nerve fiber density in the apical area. This suggests that the spatial distribution pattern of nerve fibers surrounding the implant demonstrates a force-dependent organizational characteristic. Although the implants in this study did not have an attached superstructure, the threaded caps were exposed in the mouth. Food could accumulate in the space between the threads and the opposite teeth, which would still exert loading on the implants during eating. Based on the experimental results and literature analysis, it can be inferred that immediate implantation combined with early loading benefits bone remodeling around the implants and may promote osseointegration, provided the conditions are favorable. While this study observed a modest increase in peri-implant nerve fiber density within the middle and apical regions, the interregional differences were not statistically significant (p >0.05). This potential artifact may result from the limited dimensions of the ROI; therefore, further investigations are necessary for definitive verification.

Studies have shown that PIEZO1 and PIEZO2 are both expressed in bone tissue [41]. Research in humans has demonstrated that decreased bone mineral density is associated with variations in the PIEZO1 gene [42], and the expression level of PIEZO1 is reduced in patients with osteoporosis [19]. Additionally, the lack of PIEZO1 expression in bone cells was linked to a decreased bone formation rate, reduced bone mass, and an increased risk of fractures in animal studies [16–44]. Loss of PIEZO2 expression in proprioceptive neurons leads to spinal misalignment and hip joint maldevelopment [21]. Moreover, PIEZO1 and PIEZO2 play a coordinated role in regulating jawbone development and maintenance [45]. The proportions of PIEZO1-positive and PIEZO2-positive nerve fibers were also higher in the apical region, which exhibited better bone microstructure in this study. In summary, these results suggest that PIEZO-positive nerve fibers may play a significant role in bone remodeling around dental implants.

Moreover, improved bone microarchitecture was observed in areas with a high density of nerve fibers. Bone is inherently sensitive to mechanical forces. Providing adequate mechanical stimulation to bone tissue helps maintain stable remodeling. Conversely, the absence of mechanical signaling results in a significant and rapid disruption of bone remodeling processes, favoring bone resorption. This underscores the critical dependence of bone tissue on mechanical signaling [46]. Moreover, studies have shown that bone remodeling and bone microarchitecture improve around dental implants under appropriate stress conditions [47]. A substantial body of evidence has demonstrated that bone cells, such as osteocytes, osteoblasts, and osteoclasts, can sense mechanical force stimulation and subsequently secrete relevant molecules to regulate bone homeostasis, in which the PIEZO family also plays a significant regulatory role [16, 41]. Furthermore, bone metabolism is also regulated by the nervous fibers, mainly through the secretion of neurotransmitters, neuropeptides, neurotrophic factors, and neuroguiding factors. For instance, acetylcholine secreted by cholinergic neurons, its choline transporter vesicular acetylcholine transporter (VAChT) and Carnitine acetyltransferase (CarAT) are expressed in osteoblasts [48, 49].Neuropeptide CGRP, secreted by sensory neurons, can promote osteogenesis and participate in bone tissue regeneration and remodeling [50, 51]. Axon guidance factors Sema3A promote mitochondrial fusion, thereby preserving the osteogenic potential of periodontal ligament cells under mechanical force stimulation [52]. Neurotrophic factor NGF is expressed in bone marrow stromal cells and osteoblasts. Expression of NGF is upregulated during proliferation or mechanical loading [53–55]. Nonetheless, this study observed relatively better bone microstructure only in areas where PIEZO-positive nerve fibers were concentrated. It is possible that the apical region experiences greater mechanical force, which induces the accumulation of nerve fibers and promotes bone remodeling. However, whether a correlation exists between these factors requires confirmation through further experiments.

The results of this study have potential clinical implications. The distribution of nerve fibers around dental implants may be related to the forces exerted on the implants. In particular, PIEZO-positive nerve fibers may play a role in regulating the bone microstructure surrounding dental implants. This provides a new perspective for understanding the mechanisms of bone remodeling around dental implants. However, this study has several limitations. Firstly, the distribution patterns of nerve fibers and bone microarchitecture varied across different regions of the implants, potentially due to differences in stress around the implants in these areas; however, direct evidence for this was not provided in the study. Secondly, the nerve fibers examined were not subclassified. Thirdly, although the presence of PIEZO-positive nerve fibers in the peri-implant bone was confirmed and their expression appeared to correlate with bone microarchitecture, it remains unclear whether and how these fibers contribute to the regulation of bone homeostasis. Experiments to eliminate the expression of the PIEZO family may be necessary for further verification. Fourthly, the magnitude of bite force, implant size, and force distribution patterns differ between rats and humans. Developing a more suitable animal model to study the forces exerted on implants may be beneficial in the future.

Conclusions

In conclusion, higher nerve fiber density, a greater percentage of PIEZO2-positive nerve fibers, and improved bone microstructure were observed in the apical region surrounding dental implants. Considering the forces acting on the implants, these findings suggest that PIEZO2-positive nerve fibers may play a role in bone remodeling around dental implants. The results of this study may offer a clearer understanding of the mechanisms underlying bone remodeling in the vicinity of dental implants.

Abbreviations

DRG

Dorsal root ganglion

SD

Sprague-Dawley

BV/TV

Bone volume/tissue volume

Tb.Th

Trabecular thickness

Tb.N

Trabecular number

Tb.Sp

Trabecular separation

Micro-CT

Micro-Computed Tomography

PFA

Paraformaldehyde

EDTA

Ethylenediaminetetraacetic acid

PBS

Phosphate buffer saline

ROI

Region of interest

PIT

Peri-implant tissue

AT

Adjacent tissue

Authors’ contributions

J.X.T: Conceptualization, Funding acquisition, Writing - review & editing, Resources, Project administration. Y.W: Data curation, Writing - original draft, Validation. Q.Y.L: Formal analysis, Investigation, Methodology. J.Y: Software, Supervision; Visualization.

Funding

This research was supported by the national Natural Science Foundation of China (Grant No. 81970962) and the Shanghai Municipal Commission of Health and Family Planning (No. 202340063) to Jianxiang Tao.

Data availability

The data and materials that support the findings of this study are available from the corresponding authors upon reasonable request. Corresponding author: Jianxiang Tao. Email: taojxtohoku@tongji.edu.cn.

Declarations

Ethics approval and consent to participate

During the experiment and routine feeding, animals received humane care according to the criteria outlined in the Guide for the Care and Use of Laboratory Animals published by the National Institutes of Health (NIH). The procedures performed on the rats were approved by the Institute of Animal Care and Use Committee of Tongji University (2024-DW-06).

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.