Surgical manipulations performed in the oral cavity often require wound closure. Suturing remains the most commonly used conventional method in the oral and maxillofacial region [1]. The medical field offers various types of suture materials, each suited for different applications [1,2]. Research shows that suturing technique influences healing after oral surgical interventions [3-5]. In addition, used suture material also impacts surgical outcomes in third molar surgery [6-8]. The type of suture material used can significantly affect microbial colonization, which may affect the wound healing process and increase the risk of infection after surgery [9,10].

Bacterial growth continues to present a significant challenge in surgical practice [11]. Moreover, bacterial colonization and tissue reactions, influenced by the suture’s surface properties, can further complicate healing, particularly in dentoalveolar surgery, where material choice is always critical to minimizing complications and promoting recovery [12-14].

Sutures used after third molar surgery provides a surface for bacterial attachment, which can trigger an inflammatory response. Due to their ability to adhere to sutures, bacteria can act as a source of odontogenic infections [15,16]. In the wound healing process, infections, along with other factors, play a crucial role [17]. The incidence of postoperative infections after third molar removal is estimated to range from 1.94% to 42.6% [18-22].

Innovations in suturing materials have significantly reduced post-surgical complications and infections [23-25]. Antibacterial sutures represent a significant milestone in the advancement of sutures with enhanced properties [26]. In 2002, the U.S. Food and Drug Administration (FDA) approved Coated Vicryl^® Plus (Ethicon, Inc. - Johnson & Johnson MedTech Co.; Somerville, New Jersey, USA), the first antibacterial (polyglactin 910) synthetic absorbable suture, to reduce infection risk [27]. Nowadays, new suture technologies like antimicrobial, drug-releasing, stem cell-infused, and electronic sutures are being actively researched [28]. Novel sutures are being developed with enhanced properties, including antimicrobial agents [29], bioactive molecules like DNA [30], drugs [28], growth factors [31], antibodies [32], silver [33], and proteins [34]. Braided sutures can trap bacteria, to prevent this, they can be coated with antibiotics like tetracycline or levofloxacin hydrochloride, which effectively combats Escherichia coli [35,36]. Levofloxacin-loaded sutures, made from hydrophilic biocompatible polymers, help inhibit Staphylococcus epidermidis growth [37]. Sutures coated with totarol show antibacterial activity against Staphylococcus aureus [38]. Triclosan-coated polyglactin 910 sutures were evaluated for their effectiveness in stopping the growth of wild-type and methicillin-resistant S. aureus and S. epidermidis [39]. Sutures treated with K21, a quaternary ammonium compound demonstrated antimicrobial activity against Porphyromonas gingivalis and Enterococcus faecalis, with effectiveness varying by suture type [40]. Silk and polyglycolic acid (PGA) sutures coated with hyaluronic acid showed increased resistance to S. aureus and E. coli [41]. The polydioxanone sutures were the least prone to E. coli and S. aureus attachment [42]. AgNP-coated silk sutures exhibited strong antimicrobial activity against Streptococcus mutans and S. aureus [43].

Understanding suture materials and its properties can help enhance clinical protocols, minimize infection risks, and improve patient recovery outcomes. The aim of this systematic review is to assess how different types of surgical sutures impact the microbiological composition of bacterial plaque in patients undergoing impacted third molar removal surgery.

This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines [44].

The study protocol was registered at the International Prospective Registry of Systematic Reviews (PROSPERO) database (registration number: CRD420251010120).

The protocol can be accessed at: www.crd.york.ac.uk/PROSPERO/view/CRD420251010120

Focus question

The focus question was developed using the Population, Intervention, Comparison, and Outcome (PICO) framework: patients undergoing impacted third molar removal surgery (P), use of different types of surgical sutures (I), comparison between various types of sutures (C), and microbiological analysis of bacterial plaque (O).

The formulated focus question was: “How do different types of surgical sutures influence the microbiological composition of bacterial plaque following impacted third molar removal?”

Table 1 outlines the development of the focus question based on the PICO framework.

Information sources

The systematic electronic literature search was conducted across PubMed, Google Scholar, ResearchGate, and Web of Science databases, employing both electronic databases and hand searches.

Search

As per PRISMA guidelines, resource databases were searched using advanced methods. Keywords such as “suture,” “third molar,” “wisdom teeth,” “impacted teeth,” “surgical extraction” were used in various combinations with boolean operators (AND, OR) to conduct online search. A 10-year filter, English language, and full-text access filter were applied to all searches. The research spanned the period from January 1, 2016, to January 1, 2025, and incorporated studies on humans published in English.

Selection of studies

The article titles were independently screened by two reviewers (A.B. and V.K.) according to the inclusion and exclusion criteria. Full-text analysis was performed for articles that met the eligibility criteria. Any disagreements were resolved through discussion with the third investigator (J.S.M.).

Types of publication

The systematic literature review included all human randomized clinical trials, prospective cohort studies, cross-sectional studies, and quantitative pilot studies that examined how different types of surgical sutures influence the microbiological composition of bacterial plaque after impacted third molar removal.

Types of studies

In this review were included studies published from January 1, 2016 and January 1, 2025. The systematic literature review included studies on humans published in the English language. Letters, editorials, meta-analyses, systematic literature reviews, scoping reviews, conference abstracts, guidelines, PhD theses, case reports, and in vitro studies were excluded.

Types of participants

This systematic literature review assessed patients who underwent impacted third molar removal surgery and where sutures were used.

Inclusion and exclusion criteria

All studies met the following inclusion criteria:

The following articles were excluded based on the following criteria:

Sequential search strategy

The selection process involved four stages: (1) selection based on the relevance of the title, (2) duplicate removal, (3) assessment of abstract relevance, and (4) full-text analysis. Titles and abstracts were reviewed by two authors (A.B. and V.K.), followed by a thorough full-text evaluation based on eligibility criteria. Reviewers were calibrated by calculating Cohen’s kappa coefficient (κ) values to ensure inter-rater reliability of abstracts and titles on a sample of 10% of publications.

Rayyan^® (Qatar Computing Research Institute; HBKU, Doha, Qatar [www.rayyan.ai]) was used for title and abstract screenings.

Data extraction

The data were independently collected from the studies based on the review’s aims and themes.

Data items

Data was gathered from the included studies and classified into the following categories:

Risk of bias assessment within studies

The Joanna Briggs Institute (JBI) Critical Appraisal Checklist for randomized controlled studies (Table 2), JBI Critical Appraisal Checklist for cohort studies (Table 3), and JBI Critical Appraisal Checklist for quasi-experimental studies (Table 4) were used to evaluate the methodological quality of the included studies (https://joannabriggs.org/). “Yes“, “no“, “unclear“, or “not applicable“ was assigned to each criterion. Methodological quality was assessed as follows: high risk of bias for studies with 49% or fewer positive responses, moderate risk of bias for 50 to 69%, and low risk of bias for more than 70%.

Statistical analysis

Article management was conducted using Mendeley^® Reference Manager version 2.85.0 (Elsevier; London, UK [www.mendeley.com]). The level of agreement between the two raters in selecting abstracts and studies to be read in full-text were measured using Cohen’s kappa coefficient (κ). Due to the considerable diversity of the data, it was decided that a quantitative analysis via meta-analysis could not be conducted.

Study selection

The initial database search resulted in a total of 1370 records. After removing duplicates (n = 289) and non-relevant titles and abstracts (n = 1055), 26 full-text articles remained for eligibility assessment. Of these, 15 articles were excluded based on exclusion criteria. A total of 11 studies were included in the systematic review. The level of agreement between the two authors (A.B. and V.K.) in selecting abstracts were measured at κ = 0.88. Figure 1 provides an overview of the article selection process, illustrated through the PRISMA flow diagram.

Study exclusion

The rationale for excluding 15 studies [45-59] is listed in Table 5. Articles were excluded for the following reasons 4 in vitro studies [49,55,57,58]; 1 scoping review [45]; 1 study in which the extracted teeth were not third molars [46]; 7 studies describing oral surgical procedures unrelated to tooth extractions [47,48,50,51,53,54,56]; 1 study in which additional materials were placed on or around the sutures or within the surgical site [52] and 1 study that investigated only a single suture group and did not include a comparative analysis [59].

Quality assessment of the included studies

The quality of the included studies is summarized in the Tables 6, 7, and 8. All studies were characterized as high quality according to the JBI score. Seven randomized controlled trials [9,10,60-64] had a score of ≥ 10, three cohort studies [65-67] had a mean score of ≥ 8, and one quasi-experimental study [68] was characterized 9.

Study characteristics

Eleven publications were included in the systematic literature review (Table 9). Seven publications [9,10,60-64] were randomized controlled trials, three publications [65-67] were cohort studies, and one publication [68] was a quasi-experimental study. A total of 649 suture samples from 360 patients (aged 16 to 75) were included in the results.

The review of third molars extraction and wound suturing in these studies showed that, initially, all procedures were performed correctly. All the selected articles reported microbiological contamination on suture samples that were removed seven days post-surgery. There were used 25 different kinds of sutures. The most commonly used suture was silk.

All patients were locally anesthetized before the procedure. The mucoperiosteal flap was raised, osteotomy was done, and the tooth was elevated, luxated, and removed. After achieving haemostasis, each patient’s flap was closed using different suture materials. The suture removal was done by the surgeon following the standard protocol under sterile conditions. Suture removal was done using separate sterile instruments and sutures were collected for microbiological examination.

In four studies [9,10,64,68] a postoperative antibiotic regimen was prescribed; in one study [67] antibiotic prophylaxis was administered. In three studies [60,65,68] patients were instructed not to use any antiseptic solutions, while in two studies [64,67] they were advised to rinse with physiological saline three times a day for seven days, and in three studies [9,10,63] they were instructed to use chlorhexidine mouthwash three times daily for seven days.

In all studies, microbiological analysis was conducted in a laboratory setting using various methods. Four studies [60,62,63,65] utilized Gram staining, while six studies [10,60,61,63-65] employed microscopy techniques, including scanning electron microscopy, light microscopy, and optical microscopy. Additionally, six studies [60,64-68] included colony forming units (CFUs) measurements.

Silk suture and its bacterial retention

Silk contamination between other independent analysed sutures

Six out of seven studies that examined silk separately from other suture materials [61,63-68]. Repeated result highlights that silk is more prone to microbial build up compared to other suture materials: in five studies it exhibited highest CFU scores [64-67,68], in one study researchers found significantly higher gene copy number of bacteria on silk [61], in another silk had the highest level of retention of cocci and bacilli (P = 0.01) [63].

Silk as a multifilament and non-absorbable suture

Silk, as a multifilament and non-absorbable suture, was evaluated in three studies, all of which concluded that it had a higher bacterial load than monofilament and absorbable sutures: Dragovic et al. [10] (P = 0.000), Yaman et al. [9] (P < 0.001), Dragović et al. (P = 0.005) [61]. This suggests that the structural composition of silk, which consists of multiple intertwined filaments, provides a more favourable environment for bacterial adhesion and colonization.

Vicryl^® Plus comparison with various suture materials

Comparison between Vicryl^® and Vicryl^® Plus

Sh et al. [60] compared the bacterial load of Vicryl^® and Vicryl^® Plus (Ethicon, Inc. - Johnson & Johnson MedTech Co.) in a clinical study. The study results indicated that Vicryl^® Plus significantly reduced bacterial colonization. The total bacterial count decreased in 21 of 27 patients (77.78%), while Lactobacillus levels declined in 20 of 27 patients (74.07%), with statistical significance (P = 0.005 and P = 0.019, respectively).

Findings indicate that Vicryl^® Plus is superior to conventional Vicryl^® sutures in reducing bacterial contamination, highlighting its enhanced antibacterial activity.

Comparison with Ethicon^® Prolene^®

However, Krishna et al. [65] conducted a comprehensive evaluation of the microbiological properties of Ethicon^® Prolene^®, Monocryl^®, Perma-Hand^® silk, and Vicryl^® Plus sutures (Ethicon, Inc. - Johnson & Johnson MedTech Co.). The findings indicated that among the tested suture materials, Prolene^® exhibited the lowest CFU count (P = 0.001), suggesting its superior resistance to bacterial adherence and colonization compared to the other sutures examined.

The findings suggest that Prolene^® outperforms Vicryl^® Plus in minimizing bacterial adherence, despite the antimicrobial characteristics of Vicryl^® Plus.

Ethicon^® Monocryl^® Plus and its antibacterial effect

Two studies by Sala-Pérez et al. [64] and Anand et al. [67] compared Ethicon^® Perma-Hand^® silk to Monocryl^® Plus (Ethicon, Inc. - Johnson & Johnson MedTech Co.), a suture developed with antibacterial properties.

Sala-Pérez et al. [64] observed that after three days, bacterial counts were significantly lower on Monocryl^® Plus compared to Perma-Hand^® silk (P < 0.001), with reductions in Streptococcus viridans (P = 0.004), Neisseria spp. (P = 0.001), Veillonella spp. (P = 0.043), and Lactobacillus spp. (P = 0.043). By day seven, the bacterial differences between Perma-Hand^® silk and Monocryl^® Plus had decreased, however, Monocryl^® Plus continued to exhibit significantly lower bacterial retention (P = 0.033).

Anand et al. [67] provided further evidence that Monocryl^® Plus exhibited a significantly lower bacterial load across nearly all examined species. Statistical analysis confirmed a highly significant reduction in bacterial presence within the Monocryl^® Plus group (P = 0.000).

These findings establish that Monocryl^® Plus is more resistant to bacterial colonization than silk, supporting its preference in oral surgeries where infection control is essential.

Multifilament and monofilament sutures

Bacterial load comparison

Yaman et al. [9] analysed 10 different suture materials. Those were monofilament sutures: polydioxanone, poly-glycolic acid-cocaprolactone, polypropylene, polyvinylidene difluoride, polyamide, polytetrafluoroethylene polymer, and multifilament sutures: poly-glycolide-colactide, fast absorbable poly-glycolide-colactide, silk, polyester.

Findings highlighted that bacterial accumulation was notably greater in multifilament sutures compared to monofilament sutures (P < 0.001).

Dragović et al. [61] reaffirmed that multifilament sutures exhibit greater dental plaque accumulation than monofilament sutures (2.33E + 10 ± 2.60E + 10SD).

Silk as a multifilament suture

Further analysis across 10 sources provided strong confirmation that silk, as a multifilament suture, exhibited consistently high bacterial retention [9,10,61-68]. Nine out of 10 studies demonstrated greater bacterial load on silk compared to other suture materials, reinforcing concerns regarding its susceptibility to microbial colonization. This consistent trend suggests that the structural properties of silk sutures may contribute to an environment conducive to pathogen adherence.

Absorbable and non-absorbable sutures

Yalçın et al. [62] examined the bacterial load on absorbable (PGA, polyglycolide-co-lactide) and non-absorbable (silk, polyester) sutures. The results indicated that Corynebacterium spp. was the most frequently found aerobic strain, detected in 60% of silk samples. Peptostreptococcus spp., the most frequent anaerobic strain, was observed in 12 of 60 samples (20%), with the highest concentration in silk and polyglycolide-co-lactide sutures (Boz Tibbi Malzeme A.S; Ankara, Turkey) (26.7%).

This suggests that silk, as a non-absorbable multifilament suture, is highly susceptible to bacterial contamination.

Summary of evidence

This systematic literature review is based on the analysis of 11 publications. Despite differences in microbiological analysis methods, all studies indicate a link between biofilm formation and various suture materials.

Following third molar surgery, sutures can provide a surface for bacterial adhesion, which may contribute to the development of an inflammatory response [16]. This response can be linked to several factors, including trauma caused by needle insertion, the physical presence of sutures within the extraction site that may irritate surrounding tissues, and the accumulation of bacterial plaque on the suture material [69]. It has been estimated that as few as 100 CFU of bacteria on conventional sutures, such as natural black silk, can be enough to induce a surgical site infection [70].

Sutures can be classified based on their origin, biological behaviour, and structure [71]. They are either natural or synthetic. Natural sutures include those of animal (e.g., catgut, silk), plant (e.g., linen, cotton), and mineral (e.g., metals) origins, while synthetic sutures are made from materials like glycolic acid, lactic acid, nylon, polyesters, and polypropylene. Sutures are further divided into absorbable and non-absorbable types based on their ability to degrade. Absorbable sutures (e.g., catgut, collagen, glycolic acid) degrade within 60 days, while non-absorbable sutures (e.g., silk, cotton, nylon, polytetrafluoroethylene) remain in the body. Structurally, sutures can be monofilament, multifilament, or pseudo-monofilament. Absorption of natural sutures occurs via lymphocytes and macrophages, while synthetic sutures degrade through hydrolytic scission of their polymer chains [15,17]

Silk from Bombyx mori has been used as a biomedical suture material for centuries [72]. Silk is a braided, siliconized protein suture from silk worms, known for its excellent handling, elasticity, low cost, and knot security. On the other hand, it can collect bacteria and fluids (the wick effect), leading to a higher risk of infection and inflammation [61,71]. In the current review it was the most regularly used suture material. In this review, silk consistently demonstrated the highest bacterial load compared to others, supporting previous research that identifies multifilament and non-absorbable sutures as more susceptible to microbial adhesion than monofilament and absorbable alternatives [9,10,61-68].

A study by Yalçın et al. [62] found that on the nonresorbable sutures were the biggest amount of aerobic bacteria, while anaerobic bacteria was found on both absorbable and nonresorbable samples. The authors also recommends to remove any kind of suture as soon as possible, regardless of whether they are absorbable since all materials can become reservoirs for oral pathogens. In a study by Sala-Pérez [64] absorbable Monocryl^® Plus resulted in a reduced count for nearly all isolated bacterial species. Anand et al. [67] also reported that nonresorbable silk exhibited a higher level of microbial colonization compared to absorbable Monocryl^®. Additional literature only confirms that nonresorbable sutures tend to harbor more bacteria than absorbable types, with facultative anaerobic bacterial counts reported to be nearly twice as high [13,74].

A key observation across multiple studies included in this review is that monofilament sutures harbor fewer bacteria than multifilament sutures. This supports previous literature claiming that the smooth surface of monofilament sutures inhibits bacterial adherence, while the braided structure of multifilament sutures should be avoided in contaminated wounds, as they can trap bacteria and lead to infection [71]. Notably, the studies by Yaman et al. [9] and Dragovic et al. [10] reported a statistically significant difference in bacterial load, with multifilament sutures accumulating more plaque than monofilament sutures (P = 0.000 and P < 0.001, respectively). These findings confirm the role of surface topography in microbial adhesion.

Among monofilament sutures, polyamide, polypropylene, and polyvinylidene difluoride showed the lowest bacterial accumulation. This result is consistent with earlier studies suggesting that synthetic, non-braided materials resist bacterial colonization better than their multifilament counterparts [9,10]. Literature supports these findings, as monofilaments (single-strand fibers) have a smooth surface that resists microorganism harbouring, resulting in a low inflammatory response [25]. On the other hand, poly-glycolide-colactide sutures exhibited the highest microbial load among the examined monofilaments, possibly due to their biodegradable properties, which may contribute to bacterial retention and proliferation [9].

This review also highlights the antimicrobial benefits of antibacterial-coated sutures, particularly Monocryl^® Plus and Vicryl^® Plus. Triclosan is a bacteriostatic antiseptic that, at low concentrations, inhibits many nonsporulating gram-positive and gram-negative oral bacteria, with minimum inhibitory concentration (MIC) around 0.001 to 7.8 μg/ml [74]. Previously mentioned sutures significantly reduced bacterial CFU compared to non-coated alternatives, with Vicryl^® Plus decreasing bacterial load by 77.78% in one study (P = 0.005) [60]. This supports the hypothesis that antibacterial-coated sutures can play a crucial role in minimizing post-surgical infections, as previously documented in the literature [61,62,64].

Limitations

This study has certain limitations that need to be addressed. In some of the analysed studies, antibiotic therapy was administered during the perioperative period, while others recommended antiseptic mouthwashes as part of the postoperative protocol. Although all included studies involved impacted third molars, variations in position, depth, angulation, and classification led to differences in surgical approaches and individualized suturing techniques. Additionally, the establishment and assessment of microbiological parameters varied among several studies.

The evidence suggests that monofilament, synthetic, and antibacterial-coated sutures are preferable for reducing bacterial colonization, whereas multifilament silk sutures should be avoided when possible due to their high bacterial retention.