Salivary contamination during implant placement: effects on titanium surface properties and early osseointegration- a systematic review

Abstract

Background

Dental implants demonstrate high long-term success rates; however, contamination of the implant surface by saliva during implant placement surgery is a common intraoperative event. Experimental studies suggest that saliva contamination may alter the physicochemical properties of titanium surfaces, impair early cellular responses, and adversely affect the initial phase of osseointegration. This systematic review aimed to evaluate the effects of saliva contamination occurring during dental implant surgery on titanium surface characteristics, early biological responses, and the osseointegration process.

Methods

Electronic searches were performed in PubMed, Web of Science, Scopus, and Google Scholar databases covering the period from January 2000 to January 2026. A total of 54 studies (in vitro, in vivo, and clinical) meeting the predefined PICO (Population, Intervention, Comparison, Outcome) criteria were included. The methodological quality of the included studies was assessed using the Quality Assessment Tool for In Vitro Studies in Dentistry (QUIN) tool for in vitro studies and the Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) risk-of-bias tool for animal studies.

Results

Saliva contamination induces rapid protein adsorption on implant surfaces, leading to a marked reduction in surface wettability and surface energy. These changes are associated with decreased osteoblast adhesion and reduced alkaline phosphatase (ALP) activity, thereby negatively affecting early bone healing and osseointegration. The formation of a salivary pellicle may, under certain conditions, promote bacterial adhesion, and endotoxin-related surface alterations may persist even after surface cleaning procedures. None of the investigated decontamination methods, including saline irrigation, antimicrobial photodynamic therapy, or air-polishing, were able to fully restore the original bioactive surface characteristics.

Conclusions

Current evidence consistently indicates that saliva contamination may adversely affect early biological responses and the osseointegration process by altering titanium surface properties, particularly surface wettability and surface energy. However, as these data are largely derived from in vitro and animal models, caution is warranted when extrapolating the findings to clinical practice. The current literature does not provide sufficient clinical evidence to justify the routine replacement of implants following short-term intraoperative saliva contamination. Considering that no decontamination method has been shown to fully restore the original bioactive surface characteristics, prevention of contamination appears to be a more reliable strategy than post-contamination decontamination protocols. Future studies should focus on investigating the long-term effects of saliva contamination on implant survival using standardized, well-designed prospective clinical protocols.

Introduction/general information

Dental implantology has become one of the most common practices in modern dentistry and oral and maxillofacial surgery [1]. Questions regarding the long-term durability of implants are gaining increasing importance in the literature. Systematic reviews and high-quality meta-analyses have shown that dental implants have a survival rate of over 90% even after 10 years [2]. These reported results have generally been obtained in well-controlled clinical settings where trained surgeons work according to strict protocols; however, these conditions may not always reflect the treatment environment in general dental practice [3]. Some studies have reported an 18% lower success rate in the practices of general practitioners compared to experienced academics and specialists [4].

Implant treatment failures can be divided into two categories: early implant loss and late implant loss. In early implant loss, factors such as implant design, history of periodontal and systemic disease, quality and quantity of alveolar bone, and disruption of the bone healing process prevent osseointegration between the implant and the bone; microbial factors, parafunctions, and prosthetic errors also cause late implant loss [4–6]. Similarly, surgical technique, surgeon experience, and grafts used for bone augmentation can negatively affect implant success [5].

Studies conducted with an electron microscope show that osteoblasts can establish direct and strong connections to the implant surface on the first day following implant placement [7]. However, it is important to note that most evidence regarding the effect of saliva on implant surfaces comes from preclinical studies, with limited clinical data available. One of the few studies investigating this effect reported that contamination with saliva significantly reduced osteoblast number, differentiation, and alkaline phosphatase (ALP) production, an important indicator of osteoblast activity [8, 9].

The interaction of cells surrounding the implant is critically important for implant stability and sustainability. Among the cells surrounding the implant, human gingival fibroblasts are the fundamental cellular components of oral soft tissue [10]. Human gingival fibroblasts are essential for maintaining implant health through multiple functions, such as repairing tissue damage and protecting implants from the oral microflora environment [11]. It has been observed that the microstructure of the implant surface can affect the growth of epithelial cells and the adhesion of fibroblasts [12, 13]. The inability to completely eliminate saliva contamination can lead to decreased adhesion, proliferation, and spread of fibroblasts and epithelial cells on the implant surface. Consequently, saliva contamination may disrupt the formation of a strong biological barrier. This could increase the risk of pre-implant tissue infection and implant failure [14].

This systematic review specifically focuses on the effects of salivary contamination during or immediately after dental implant placement on implant surface properties and early osseointegration outcomes. Direct experimental studies on saliva contamination are summarized separately from contextual mechanistic literature in the results section.

This review aims to evaluate the current evidence regarding the effects of saliva contamination during or after dental implant placement on osseointegration and long-term implant success; it also aims to reveal the effectiveness of surgical strategies to reduce contamination and the gaps in the literature. Based on the results obtained, this review has the potential to guide clinical decision-making and may also highlight the need for further research on unanswered questions regarding the effects of saliva contamination on implant success.

Materials and methods

This systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 guidelines [15]. A PRISMA flow diagram illustrating the study selection process is presented in Fig. 1.

Fig. 1.

PRISMA Flow Diagram of the Literature Review

Research question

The research question of this systematic review was formulated using a PICO (Population, Intervention, Comparison, Outcome) framework adapted to predominantly in vitro and preclinical evidence.

The PICO framework applied in this review was defined as follows:

• Population (P): Dental implant and abutment surfaces evaluated in in vitro, animal, or clinical studies.

• Intervention/Exposure (I/E): Salivary contamination occurring during or immediately after implant placement, or experimental exposure of implant surfaces to saliva under controlled conditions.

• Comparison (C): Non-contaminated implant surfaces or alternative handling protocols.

• Outcomes (O): Early osseointegration, bone–implant contact (BIC), implant surface characteristics, surface wettability/hydrophilicity, protein adsorption, cell adhesion and proliferation, cellular responses, and ALP activity.

Among studies experimentally and clinically examining dental implant or abutment surfaces, how does salivary contamination occurring during or immediately after implant placement affect early osseointegration, implant surface properties, and cellular responses when compared with non-contaminated conditions?

Search strategy and data sources

A comprehensive search was conducted in three electronic databases (PubMed, Web of Science, and Scopus) to identify studies published between January 2000 and January 2026. In addition, Google Scholar was used as a supplementary search source to identify potentially relevant studies that may not have been captured in the primary database search. Google Scholar was searched using the same keywords, and records were screened manually to identify additional eligible studies. Furthermore, the reference lists of relevant articles and reviews identified through Google Scholar were also examined to ensure comprehensive coverage of the available literature.

The search strategy was developed using a combination of MeSH (Medical Subject Headings) terms and free-text keywords. The search string used was: (“dental implant” OR “implant-abutment connection”) AND (“saliva” OR “salivary contamination”).

A total of 1528 articles were identified in the searches. After the search, duplication control was performed using Endnote X8; a total of 427 duplicate records were removed, leaving 1101 studies for evaluation. These 1101 studies were reviewed based on their titles and abstracts, and 939 publications that did not meet the inclusion criteria were excluded. After the title-abstract review, 162 studies were identified as suitable for full-text review. Titles, abstracts, and full texts were screened by two reviewers, and disagreements were resolved through consultation with a third reviewer.

Study selection and eligibility

Titles and abstracts were screened first, followed by full-text assessment of 152 potentially relevant studies. The full-text assessment stage 108 studies were excluded because they did not meet the eligibility criteria.

The reasons for exclusion at the full-text stage were as follows:

• Inadequate data methodology: 24 studies

• Lack of saliva parameter: 56 studies

• Not an implant study: 28 studies

Following the full-text review, 54 studies met the inclusion criteria (Fig. 1). The distribution of study designs is shown in Fig. 2.

Fig. 2.

Distribution of included studies according to study design

Studies meeting the following criteria were considered eligible:

1. Experimental or clinical studies involving dental implants;

2. Evaluation of salivary exposure occurring during or immediately after implant placement, or experimental exposure of implant or abutment surfaces to saliva under controlled conditions;

3. Inclusion of a comparison group, such as non-contaminated implant surfaces or alternative handling conditions;

4. Reporting outcomes related to osseointegration, BIC, implant surface characteristics, surface wettability/hydrophilicity, cell adhesion and proliferation, cellular responses, ALP activity, or protein adsorption.

An additional restriction was the inclusion of English-language publications with full-text availability. Studies not related to dental implants, studies without data on salivary exposure, methodologically inadequate reports, case reports, conference proceedings, and letters were excluded.

Risk of bias / methodological quality assessment

The risk of bias of the included in vitro studies was assessed using QUIN, which was specifically developed for in vitro dental research. Of the twenty-two in vitro studies, four were classified as having a low risk of bias, while eighteen were judged to have a moderate risk of bias. Overall, the methodological quality of the in vitro evidence generally ranged from predominantly moderate risk of bias. The results of the quality assessment were considered when interpreting the findings, with particular attention to consistency across studies with comparable methodological quality [16].

The risk of bias of the included animal study was assessed using SYRCLE’s Risk of Bias tool. Although most domains were rated as having a low risk of bias, several items related to allocation concealment, random housing, and blinding of caregivers and outcome assessment were judged as unclear due to insufficient reporting [17].

Data extraction

From the 54 included studies, the study design, sample characteristics, implant types, saliva parameters, measurement methods, and outcome data were extracted according to standard data forms.

Data synthesis

A quantitative meta-analysis was not considered appropriate due to substantial heterogeneity among the included studies with respect to study design (in vitro, animal, and limited clinical studies), implant systems and surface characteristics, saliva collection and contamination protocols, exposure duration, outcome measures, and follow-up periods. Therefore, a qualitative narrative synthesis was performed.

Initially, the included studies were classified according to study model (in vitro, animal, and clinical). In the synthesis of findings, experimental approaches involving salivary contact with implant or abutment surfaces during placement or immediately thereafter were taken as the basis. The outcomes of these studies were evaluated in relation to implant surface properties, cellular responses, and parameters associated with early osseointegration.

Results were structured according to predefined outcome domains: implant surface characteristics (surface wettability, hydrophilicity, chemical composition, and protein adsorption), cellular responses (osteoblast and fibroblast adhesion, proliferation, and alkaline phosphatase activity), and early osseointegration-related outcomes (bone–implant contact and early healing responses in animal models).

Within each outcome domain, findings were summarized descriptively by considering both common patterns across experimental models and model-specific differences. Given that the evidence was predominantly preclinical in nature and characterized by methodological heterogeneity, results were not quantitatively pooled, and no statistical weighting was applied.

Protocol registration

This systematic review was not registered in the PROSPERO database because it primarily focuses on in vitro and preclinical experimental studies, and PROSPERO registration is not mandatory for this type of research and falls outside the core scope of the database. The lack of prior registration is acknowledged as a methodological limitation of the present review.

Results

In this section, studies directly evaluating saliva contamination are summarized separately from mechanistic or contextual studies addressing general implant surface biology. The findings of the 22 in vitro, 1 animal, and 13 clinical studies evaluated in this review indicate that saliva contamination may negatively affect implant surface biology, but there is insufficient evidence regarding its effect on clinical success. Eighteen studies did not directly examine saliva contamination, focusing instead on general implantology, surface modification, or biomaterial properties.

Overall, the risk-of-bias assessment indicated that the majority of included studies presented moderate methodological limitations. Common concerns included small sample sizes, lack of standardized contamination protocols, and limited reporting of blinding procedures. While experimental studies demonstrated relatively controlled conditions, the absence of robust clinical trials highlights the need for cautious interpretation of the findings.

Characteristics of included studies

Within the scope of this systematic review, existing experimental studies investigating the effects of salivary contamination on dental implant surfaces were thoroughly evaluated and systematically summarized in Table 1. This table provides a comparative analysis of the studies in terms of study design, implant surface characteristics, type of saliva, contamination protocols, employed cell/tissue models, assessment parameters, main findings, interpretation of salivary effects, and overall conclusions.

Table 1.

Comparative summary of existing experimental studies evaluating surface alterations, cellular responses, and biological outcomes following saliva contamination of dental implant surfaces

Author / Year	Study Type	Implant Surface	Saliva Type	Contamination Protocol	Cell / Tissue Model	Evaluation Parameters	Main Findings	Interpretation of Saliva Effect	Result
Jinno Y et al., 2023 [4]	Animal	SLA / Anodized	Human saliva	Contact during surgery	Sheep calvaria / BIC	BIC measurement; histology	BIC ratio decreased	Decreased	Different surface types tested; limited clinical generalizability
Shams N et al., 2015 [8]	In vitro	Ti	Human saliva	30 min exposure	MG63 osteoblast	ALP activity; adhesion; morphology	Cell adhesion and ALP decreased	Decreased	Short exposure duration; limited clinical relevance
Proksch S et al., 2012 [9]	In vitro	Ti	Human saliva	24-hour incubation	Osteoblast	Proliferation; ALP	Proliferation and ALP production decreased	Decreased	Human saliva used; in vitro enviroment limitations
Hirota M et al., 2019 [44]	In vitro	Ti	Human saliva	1-hour exposure	Osteoblast	Adhesion; gene expression; ALP	Adhesion and spreading decreased; ALP change not significant	Decreased	UV-mediated restoration effect demonstrated
Dorkhan M et al., 2012 [37]	In vitro	Ti	Human saliva	Surface coating	Streptococcus oralis	Bacterial adhesion	S. oralis adhesion increased	Increased	Bacteria-focused; cellular parameters not assessed
Martínez-Hernández M et al., 2023 [46]	In vitro	Ti	Human saliva	Pellicle formation	Biofilm	Bacterial count; biofilm thickness	Biofilm formation decreased in some conditions	No effect / Decreased	Dependent on surface and bacterial species

As shown in Table 1, most studies elaborate on the influence of saliva on cellular adhesion, proliferation, and the osseointegration process of implant surfaces, using diverse biochemical, microbial, and immunological parameters. This comprehensive comparison offers important insights into both the physicochemical alterations induced by salivary contamination on implant surfaces and the associated cellular response mechanisms and biological outcomes. Furthermore, the table reveals that methodological heterogeneity across different study models and protocols limits the generalizability of the findings.

Four of the 22 in vitro studies were classified as having a low risk of bias, whereas eighteen were assessed as having a moderate risk of bias. The included animal study showed predominantly low risk of bias, with several domains rated as unclear.

The mechanism of osseointegration is directly related to multifaceted parameters such as bone quality and type, biocompatibility and surface properties of the implant material, surgical technique used, individual factors affecting the healing process (e.g., age, oral hygiene, systemic diseases), aseptic surgical conditions, and functional loading [18]. The literature emphasizes the importance of sterile conditions during surgery for successful osseointegration. It is stressed that implant surgery must be performed on a clean, intact surface that is not contaminated with saliva and bacteria [19, 20].

Saliva composition and interaction with implant surfaces

Saliva is the first fluid to interact with any material or compound introduced into the oral cavity from the external environment [21, 22]. Saliva consists largely of water (99%), proteins, various minerals, dead cells, and large amounts of bacteria [21, 23]. Compared to water, saliva has higher viscosity, a heterogeneous structure, and higher density [24]. Saliva inevitably interacts with biomaterials used in oral rehabilitation and tissue regeneration; this interaction can cause chemical, physical, and biological changes on biomaterials [25, 26].

Saliva plays a role in the formation of a protein layer called the saliva pellicle, which is formed by the adsorption of saliva components onto surfaces such as natural teeth and dental biomaterials [21]. When a clean implant abutment surface is exposed to the oral cavity, it is immediately covered with salivary pellicle [27], which significantly affects the adhesion of microorganisms to the Titanium substrate [28, 29]. It has been reported that Titanium surfaces can be colonized by bacteria within 30 min after dental implant placement [30] and can form a complex biofilm within a few weeks [31]. In this context, there is substantial evidence that biofilm accumulation at the implant-abutment interface can lead to inflammatory cell infiltration and ultimately cause bone loss [32].

In vitro evidence suggests early biological impairment due to saliva contamination, but clinical relevance remains unclear. Standardized prospective clinical studies are needed to clarify the true impact on implant success.

Effects of saliva contamination on implant surface biology

The primary cause of early clinical failure in dental procedures is biomaterial contamination [33, 34]. Additionally, conditions such as periodontitis, gingivitis, candida infection, and infections in adjacent teeth can increase the number of bacterial species in contact with saliva and promote bacterial proliferation [35, 36]. Studies evaluating the adhesion of Streptococcus oralis to titanium surfaces have reported a marked increase in bacterial adhesion in samples contaminated with saliva and with increased surface roughness; in parallel, significant changes in the chemical adhesion characteristics of the surface were observed [37].

Promising properties of dental implant surfaces have been reported to control bacterial proliferation through the application of nano-texture techniques or antibiotic-loaded surfaces [38, 39]. Such surface modifications may provide a protective effect by acting as a potential barrier in contaminated environments. However, preclinical and clinical studies evaluating the effect of innovative surface treatments on saliva-contaminated implants are quite limited.

Saliva contamination may impair early cellular adhesion and increase bacterial colonization, but clinical evidence linking this to implant failure is insufficient.

Effect of saliva contamination on surface hydrophilicity and protein adsorption

Changes in the hydrophilicity of titanium surfaces may adversely affect the osseointegration process, as hydrophilicity is considered important for early cell adhesion and protein synthesis [40, 41]. The degree of adsorption of saliva proteins or other impurities onto micro- or nanotextured surfaces may be influenced by the surface morphology, roughness, and other physicochemical properties. These interactions may directly determine the success of osseointegration in the subsequent process [42, 43].

Saliva contamination alters surface properties critical for osseointegration, yet clinical implications remain to be fully determined.

Discussion

This systematic review highlights consistent preclinical evidence suggesting that salivary contamination occurring during implant placement may influence early interactions between the implant surface and the biological environment. In particular, in vitro and animal studies have reported adverse changes in cell adhesion and early indicators of osseointegration on titanium surfaces exposed to saliva. Because direct and ethical assessment of these early biological and electrochemical processes under clinical conditions is challenging, preclinical models continue to serve as a fundamental reference for elucidating the underlying mechanisms. Accordingly, the available data should be interpreted not as definitive clinical evidence, but as mechanistic findings indicating that salivary contamination may represent a biologically relevant risk factor.

Most in vitro studies report that saliva contamination negatively affects osteoblast adhesion and proliferation. However, small sample sizes, short-term protocols, and contamination models that do not fully reflect clinical reality limit the generalizability of the findings. For example, although Jinno et al. [4] reported a significant decrease in BIC following exposure to human saliva, variations in saliva type, exposure duration, and the absence of standardized surface treatments reduce the interpretive strength of these results. Other studies using MG63 and MC3T3-E1 cell lines [8] demonstrated impaired cell morphology and reduced ALP activity; however, these immortalized cell models represent the osteogenic microenvironment only to a limited extent. Similarly, Hirota et al. [44] reported a significant reduction in osteoblast adhesion without a corresponding decrease in ALP activity, suggesting that saliva contamination may primarily interfere with early cell–surface interactions rather than later stages of osteogenic differentiation.

High-affinity proteins in saliva, such as albumin and mucin, rapidly adsorb to the titanium surface, triggering a binding mechanism known as the Vroman effect, which can inhibit integrin-mediated adhesion of osteoblasts ( Fig. 3). It should also be noted that saliva can affect not only osteoblast function but also the immune response. It has been demonstrated that saliva carries endotoxins that can increase macrophage activation [12] and can transmit signals that suppress osteoclastogenesis [10]. Taken together, these findings suggest that saliva contamination may induce multidimensional biological alterations at the implant–bone interface. Nevertheless, experimental evidence remains fragmented, and the extent to which these mechanisms vary across different titanium surface chemistries and contamination timings is still insufficiently characterized.

Fig. 3.

Schematic illustration of the proposed biological cascade triggered by intraoperative saliva contamination during implant placement. Salivary proteins rapidly adsorb onto the titanium surface, leading to reduced surface energy and impaired early osteoblast adhesion, which may ultimately compromise early osseointegration

Supporting this concept, studies focusing on peri-implantitis-associated pathogens have demonstrated that lipopolysaccharides, particularly from gram-negative bacteria such as Porphyromonas gingivalis, significantly alter titanium surface wettability by increasing contact angle values and promoting surface hydrophobicity. Even when mechanical or chemical decontamination methods—such as curettage, saline irrigation, chlorhexidine application, or ultrasonic cleaning—were able to reduce bacterial residues, osteoblast adhesion remained significantly lower compared to uncontaminated titanium surfaces [45]. These findings suggest that endotoxin-mediated alterations of surface energy may persist despite apparent surface cleaning, reinforcing the notion that early biological impairment following contamination may not be fully reversible.

The data in the literature regarding the effects of saliva contamination on bacterial colonization are more complex. Dorkhan et al. [37] found that saliva coating increased S. oralis adhesion, while Martínez-Hernández et al. [46] showed that the number of bacteria decreased on titanium surfaces coated with saliva pellicle. This suggests that the role of saliva pellicle may vary depending on surface properties, bacterial type, and microenvironmental conditions. Although it has been reported that nano-textured or antibiotic-loaded surfaces may reduce bacterial colonization [40, 41], the limited number of preclinical and clinical studies directly evaluating saliva-contaminated implant systems prevents meaningful clinical extrapolation.

Beyond surface-level bacterial adhesion, saliva may also contribute to microbial colonization through alternative pathways within implant systems. Although Do Nascimento et al. [47] did not directly investigate salivary contamination during implant placement, their in vitro findings provide mechanistic evidence that saliva-derived microorganisms can penetrate the implant–abutment interface even under unloaded conditions, with increased microbial ingress observed under simulated functional loading. These observations suggest that salivary contamination should not be regarded solely as a transient surface event, but rather as a potential contributor to early microbial colonization of both external and internal implant components. While direct conclusions regarding osseointegration or implant survival cannot be drawn, these findings reinforce the clinical relevance of strict contamination control throughout implant placement and subsequent restorative procedures.

In recent years, preclinical studies on titanium dioxide nanotubes have shed light on their antibacterial and drug delivery potential. Recent reviews on titanium dioxide nanotube-based drug delivery systems emphasize that nanoparticle- or antibiotic-loaded surfaces show promising antibacterial performance; however, the current evidence remains largely limited to in vitro and preclinical models, with a lack of standardized contamination protocols and clinical validation [38].

Furthermore, recent in vivo evidence suggests that non-bacterial surface contaminants introduced during implant placement may adversely affect early osseointegration. In line with this, Heon-Young Kim et al. [48] provided in vivo evidence that internal surgical contamination is not limited to saliva. Mineral oil residues from rotary instruments contaminated implant surfaces in a rabbit tibia model, reducing early BIC to 56.3% at 4 weeks compared with controls. These findings suggest that lubricant contamination may induce subacute cytotoxicity and localized bone necrosis, highlighting that apparently sterile operative conditions do not guarantee biologically clean implant surfaces.

Additionally, surface treatments such as sandblasting and anodic oxidation are known to increase implant surface roughness and hydrophobicity, properties essential for osseointegration. However, irregular surfaces are more prone to trap contaminants and may release metallic particles into the bone during insertion [49]. This suggests that salivary contamination on rough surfaces may be more difficult to decontaminate compared to machined surfaces. To minimize iatrogenic contamination during surgery, the use of gauze soaked in chlorhexidine is recommended when handling implants, as it prevents fiber release and reduces particle transfer to the titanium surface [49].

In addition to salivary contamination, iatrogenic surface alterations and non-biological contaminants introduced during implant handling may further compromise surface integrity. Supporting this, Zogheib et al. [49] showed that titanium implants may already carry surface contaminants from manufacturing, such as carbon, Polyvinyl chloride, and aluminum particles. Intraoperative handling further influences contamination: nitrile gloves caused the highest particle transfer, whereas gauze soaked in chlorhexidine minimized contamination. Implant insertion and removal into bovine bone also increased particle deposition, emphasizing that standard handling may alter surface chemistry and topography and that contamination risk extends beyond saliva exposure.

The literature on the decontamination of contaminated surfaces indicates that, despite differences in efficacy between methods, a common standard has not yet been established. In a pilot animal study [50], it was reported that after cleaning the contaminated implant surface with saline, there was no gingival inflammation and the rate of re-establishment of BIC was not negatively affected. This data points to the potential benefit of irrigating the surface with saline after contamination. However, parameters such as surface energy or cell adhesion were not reported in detail in this study, and studies specifically on saliva are limited. In the current literature, there is no specific and quantitative study on the application of irrigation with sterile saline alone to implant surfaces contaminated with saliva and the resulting significant recovery of both surface energy and cell adhesion. This gap is an important void for future research.

An in vitro study [51] reported that antimicrobial photodynamic therapy was more effective than other protocols in biofilm-contaminated implants; however, the biofilm-focused nature of the model prevents generalization to the saliva contamination commonly encountered in clinical practice. Naghsh et al. [14] compared four different decontamination methods in 2024 and showed that “air-polishing” and “3% sodium hypochlorite” applications reduced residual contamination more, but surface biology was not measured and a saliva model was not used. Prospective clinical data are also limited. De Barros Lucena et al. [52] demonstrated early bacterial colonization on implant inner surfaces but did not evaluate surgical saliva contamination and biological parameters. Collectively, these findings indicate that optimal decontamination strategies for saliva-contaminated implant surfaces remain undetermined.

Notably, even decontamination approaches that appeared effective in removing bacterial biofilm, such as ultrasonic cleaning, did not fully restore osteoblast adhesion or surface hydrophilicity to baseline levels. This observation highlights an important distinction between macroscopic surface cleanliness and true biological restoration, and further underscores the limitations of extrapolating decontamination success from biofilm-focused models to acute saliva contamination occurring during implant placement [45].

In this regard, an in vitro study by Cai et al. in 2025 reported that the presence of the salivary pellicle significantly impedes biofilm removal and reduces the effectiveness of disinfectants, particularly on hydrophobic titanium surfaces. The study showed that the pellicle layer cannot be completely removed with chemical agents and that this facilitates biofilm reattachment [53]. This mechanism may partly explain why current decontamination protocols fail to fully restore surface energy and cellular adhesion following saliva contamination, suggesting that the salivary pellicle represents a critical yet often underestimated factor in post-contamination biofilm development.

Studies conducted by Park [54] and Al-Hashedi [55] show that neither mechanical nor chemical decontamination methods can fully restore the chemical composition, surface energy, and hydrophilic properties of the implant surface to their initial state. Therefore, the current evidence supports the idea that preventing contamination is a more effective and predictable approach than decontamination.

The clinical literature is much weaker and methodologically inadequate compared to in vitro studies. There are no prospective clinical studies that directly evaluate the effect of saliva contamination on implant success. In the majority of retrospective analyses, implant losses are associated with systemic factors, surgical technique, bone quality, or peri-implant infections; saliva contamination is generally not recorded or analyzed as a separate variable [56, 57]. Given that factors such as the amount of saliva, duration of contact, and degree of removal by irrigation cannot be reliably controlled or quantified intraoperatively, the absence of clinical evidence likely reflects both methodological constraints and inherent variability rather than definitive proof of clinical irrelevance.

In a review published in 2026 [58], the contamination of titanium dental implant surfaces with human saliva prior to implant placement was experimentally investigated. The study reported a statistically significant increase in average surface roughness (Ra) following salivary exposure, and this finding was confirmed by scanning electron microscopy analyses. Electrochemical evaluations showed a reduction in corrosion resistance, an increase in corrosion current density in potentiodynamic polarization tests, and a decrease in the stability of the passive oxide layer as demonstrated by electrochemical impedance spectroscopy analyses. These findings indicate that saliva contamination leads to early, measurable physicochemical changes on titanium implant surfaces.

The fact that most existing studies vary greatly in terms of saliva type, contamination duration, implant surface morphology, and biological evaluation parameters seriously limits the possibility of meta-analysis and generalization of findings. Therefore, although the results obtained regarding the effect of saliva contamination on osseointegration are consistent with the general trend in the literature, the quality of evidence is low and the interpretive power is limited.

Limitations of the study

Among the limitations of this review is that the vast majority of studies are based on in vitro or animal models; therefore, the direct generalization of findings to clinical conditions is limited. In vitro studies are often performed under sterile conditions and do not fully mimic actual clinical saliva content, enzyme activity, or patient variability. Furthermore, there is significant methodological heterogeneity among the included studies in terms of saliva types, implant surface characteristics, and experimental protocols. The limited number of keywords used in the search strategy and the fact that only English studies were evaluated also create potential language bias. These factors require caution in interpreting the results.

Conclusion

Based on the available evidence, routine removal or replacement of implants following short-term salivary contamination during surgery is not supported. Nevertheless, experimental and preclinical studies consistently indicate that salivary contamination may represent a biologically relevant risk factor by inducing early cellular and biochemical alterations at the implant surface.

In particular, clinical scenarios characterized by poor bone quality, immediate implant placement, limited primary stability, or compromised host healing capacity should be regarded as more susceptible to the potential biological effects of even brief salivary contact. In this context, the current body of evidence suggests that prevention of contamination is a more predictable and reliable strategy than existing decontamination protocols. Accordingly, preventive measures aimed at minimizing salivary contamination during implant surgery should be prioritized.

However, these considerations should not be interpreted as a definitive clinical treatment algorithm, as the existing literature is predominantly based on in vitro and preclinical data. Until robust and standardized clinical evidence becomes available, salivary contamination during implant placement should be regarded not as a proven determinant of implant failure, but as a biologically meaningful risk factor. Clinical decision-making should therefore be guided by a cautious approach and individualized risk assessment.

Authors’ contributions

Assistant Professor Sezai Çiftçi and Sudenur Kocamemik contributed to the design of the study and the preparation of the manuscript.Kaan Anıl Aktaş, Bahar Maide Kösen, and Fatih Çağlayan contributed to conducting the literature review and creating the figures and tables.All authors reviewed and approved the final version of the article and accept responsibility for all aspects of the work.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Data availability

All data analysed during this study are included in this published article and its tables.

Declarations

Ethics approval and consent to participate

Not applicable.

Since the study is based solely on published literature, it does not require ethical approval.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.