The composite resin restorations are popular in modern restorative dentistry due to their superior esthetic qualities, minimal tooth preparation, good mechanical characteristics, and ability to bond to dental tissues. But, the clinical performance of a composite restoration is not only dependent on the material used but also the finishing and polishing performed after placement. Poorly completed composite surfaces can be plagued with irregularities and roughness that may impact the esthetic outcome, stain resistance, marginal integrity, patient comfort, and maintenance of oral hygiene (1-4).

Surface roughness, especially, is important because it can allow the food scraps, microorganisms and salivary proteins to adhere to the composite surface. These surface irregularities offer good early opportunities for bacterial contact with a tooth and the subsequent maturation of dental biofilm. Established biofilm can cause an increase in plaque accumulation and lead to local inflammatory changes. The level of smoothness on the surface produced is dependent on the polishing system, type of polishing material used, number of polishing passes, particle size, pressure, and time of polishing.

Several finishing/polishing systems have been introduced to enhance the properties of resin based restorations. One-step systems attempt to finish and polish with a single instrument or fewer steps, while multi-step systems are usually a series of abrasives that progressively reduce in size. In clinical practice, conventional (disc) based systems are also commonly used. While there are systems that can save chairside time, these can often not achieve the same level of smoothness on the surface as more complex, multi-step solutions. To this end, the selection of the protocol which provides the best surface properties is clinically relevant (5-7).

Oral biofilm accumulation may become especially important in patients undergoing surgical dental procedures. After the extraction of the third molars, there is a complex microbial environment that is exposed to the wound site, and during tissue repair. In the early post-op period, pain, swelling, and decreased mouth opening may make it more difficult for the patient to maintain proper oral hygiene, which can lead to a buildup of plaque and buildup of bacteria around adjacent teeth and restorations. A rough composite restoration near the surgical area may then be a potential secondary location to trap biofilm (8-10).

Postoperative healing after third molar surgery is influenced by several factors, including surgical trauma, duration and difficulty of extraction, oral hygiene, smoking, systemic health, tissue handling, and postoperative infection. Commonly evaluated postoperative outcomes include pain, swelling, delayed soft-tissue closure, wound dehiscence, alveolar osteitis and infection. Early wound healing complications are multifaceted, but the role of the local oral microbial environment could be crucial in shaping the quality and rate of healing (11, 12).

The potential link between the surface quality of the restorative and recovery of surgical outcomes after surgery has been studied less extensively. Previous studies of composite polishing have primarily examined surface morphology, gloss, discoloration, plaque adhesion, or material properties, whereas past studies on third molar healing have primarily investigated surgical technique, medications, impaction characteristics, and patient-related risk factors. This interaction of composite surface roughness, biofilm buildup and wound healing following oral surgery is thus an area worthy of further clinical study (13, 14).

Accordingly, the present study was designed to evaluate the association between composite resin surface roughness and oral biofilm accumulation after different finishing and polishing protocols and their relationship with postoperative healing following third molar surgery. The study aimed to compare surface roughness and biofilm accumulation among different polishing protocols and to determine whether increased roughness and greater biofilm accumulation were associated with postoperative pain and impaired wound healing.

This prospective comparative study was conducted at Faryal Dental College, Lahore, from April 2025 to October 2025. A total of 97 patients who underwent third molar surgery and fulfilled the predefined eligibility criteria were included in the study. Participants were enrolled through non-probability consecutive sampling after obtaining written informed consent. Patients of either sex, aged 18 years and above, who required surgical removal of a third molar and had a composite resin restoration in the relevant posterior oral region were considered eligible. Patients with uncontrolled systemic illness, active oral infection unrelated to the third molar, severe periodontal disease, poor compliance with postoperative follow-up, current immunosuppressive therapy, or conditions likely to interfere with wound healing were excluded. Demographic and baseline clinical data were collected on a structured proforma prior to surgery. The data recorded were age, sex, oral hygiene status, plaque index, smoking habits, site and type of third molar impaction, and any surgical features. Assessment of the composite resin restorations was done before and after finishing and polishing. The participants were classified on the basis of the finishing and polishing method. Group A was treated with a conventional disc finishing and polishing, Group B was treated with a multi-step rubber polishing and polishing protocol and Group C was treated with a one-step polishing protocol. The polishing was carried out as recommended by the manufacturers, and standard operating conditions were used wherever possible. The composite resin surface was examined before and after polishing by surface profilometry method. The mean surface roughness value was presented as Ra, in micrometers, or in short as Ra. Several readings were taken from each restoration surface and the mean reading was noted to minimise measurement error. The surface roughness after polishing was compared to that before polishing and the difference was considered to be the reduction in surface roughness due to polishing. The measurements were made with the standard technique and in identical clinical conditions. The procedure used for surface roughness measurement was the same for all study subjects. Third molar surgery was performed under local anesthesia and a standard surgical protocol was used. The following variables were recorded: surgical duration, bone removal, sectioning of the tooth, elevation of the flap, and the number of sutures. Standardisation of postoperative instructions and medicine was standard, to the extent that clinically appropriate. Patients were called back on the postoperative days 3, 7, and 14. Oral biofilm was evaluated every visit using a plaque/biofilm scoring system and the percentage of biofilm on the composite surface was noted. The postoperative pain was assessed by the visual analogue scale ranging from 0 (no pain) to 10 (worst pain possible). Clinical healing was also evaluated by a standardized wound-healing score and postsurgical infection, wound dehiscence, erythema, edema, discharge, bleeding and alveolar osteitis were recorded if present. The main study variables included finishing and polishing protocol, surface roughness of composites after polishing, accumulation of oral biofilm and the postoperative wound-healing status. Secondary outcomes included pain score, and post op complications. The correlation between composite surface roughness and accumulation of biofilms and between composite surface roughness and postoperative healing were evaluated. Other factors that could have influenced the results, such as age, sex, baseline plaque score, type of third molar impaction, surgical duration, bone removal and sectioning of the tooth, were also documented to facilitate interpretation of the results. IBM SPSS Statistics version 25.0 was used to enter and analyze data. Data were summarized as mean ± standard deviation for continuous variables and frequencies and percentages for categorical variables. Before conducting inferential analysis, the normality of quantitative variables was checked. For each of the three polishing groups, the differences between the mean surface roughness, mean biofilm accumulation, mean pain score, and mean healing score were compared using a one-way analysis of variance (ANOVA) in cases where normality of data was assumed, and by an appropriate non-parametric alternative when it was not assumed. The chi-square test or Fisher's exact test was used to compare categorical outcomes, if applicable. Pearson or Spearman correlation analysis was appropriate to be used to investigate the relationship between the surface roughness and biofilm formation with postoperative pain and healing scores. Throughout the analysis, a p value of less than 0.05 was considered as statistically significant.

The total number of participants in this study was 97 patients which underwent third molar surgery. The participants were allocated to three groups: the conventional disc polishing (Group A, n = 32), the multi-step rubber polishing (Group B, n = 33) and the one-step polishing (Group C, n = 32) groups based on the finishing and polishing technique used for the composite restoration. Assessment was performed at the planned postoperative stages and all participants were analyzed. The median age of the participants in the study was 26.84 years (range, 19-38 years). Of the 97 participants, 51 (52.6%) were females and 46 (47.4%) were males. Most third molar surgeries were performed on the molars in the bottom jaw (78.4%). The age, sex distribution, baseline plaque index, time of surgery, type of impaction and number of bone removed were comparable among the three polishing groups. The other baseline differences between the groups were not statistically significant (p > 0.05), so there was no reason to believe that these were significant enough to introduce significant differences in the groups before postoperative evaluation.

Table 1. Baseline demographic, oral, and surgical characteristics of the study participants

The three finishing/ polishing protocols showed significant difference in surface roughness. The mean surface roughness was the highest for the one-step polishing group and the lowest for the multi-step rubber polishing group. Mean surface roughness was 0.41 ± 0.10 µm in Group A, 0.27 ± 0.08 µm in Group B, and 0.52 ± 0.13 µm in Group C. The difference was statistically significant between all of the groups (p < 0.001). The improvement in surface smoothness between pre and post polishing was also largest in Group B, and hence they were the most effective at smoothing the surface compared to the other protocols.

Table 2. Surface roughness of composite resin according to finishing and polishing protocol

There was a significant variation in the accumulation of biofilm depending on the finishing and polishing technique. The plaque and biofilm level in Group B was the lowest while Group C had the highest. On postoperative day 7, the mean biofilm accumulation was 32.8 ± 9.7% in Group A, 23.6 ± 7.9% in Group B, and 42.1 ± 11.4% in Group C. This was a statistically significant difference (p < 0.001). The same trend was seen on day 14, though there was less biofilm as seen on day 7. Multi-step polishing group exhibited a significantly smaller amount of biofilm than the other groups did, even after the polishing was completed.

Table 3. Oral biofilm accumulation according to finishing and polishing protocol

Postoperative pain levels were decreased over time in all three groups. The multi-step rubber polishing group had significantly lower pain scores on days 3 and 7 than the conventional and one-step polishing groups, however. Mean pain scores on day 3 were 4.31 ± 1.21, 3.58 ± 1.06, and 4.78 ± 1.30 for Groups A, B, and C, respectively (p < 0.001). The difference between healing scores was also significant between the groups. The mean healing score was best in group B on day 7 and 14, signifying better wound recovery in this group. However, Group C had relatively poor healing scores and higher postoperative inflammation.

Table 4. Postoperative clinical outcomes according to finishing and polishing protocol

The incidences of postoperative infections, wound dehiscence, and alveolar osteitis were statistically similar but were numerically higher in Group C. A highly positive correlation was found between the composite surface roughness and oral biofilm accumulation using correlation analysis. There was a positive correlation (r = 0.64, p < 0.001) between higher surface roughness and higher day 7 biofilm accumulation. Surface roughness was also negatively correlated with postoperative healing with greater roughness resulting in lower healing scores at day 7 (r = −0.46, p < 0.001). Likewise there was a significant negative correlation between healing score and day 7 biofilm accumulation (r = −0.53, p < 0.001). There was a strong positive correlation between the development of biofilm and the postoperative pain (r = 0.43, p < 0.001).

Table 5. Correlation of composite surface roughness and biofilm accumulation with postoperative clinical outcomes

Overall, the multi-step rubber polishing protocol resulted in significantly smoother composite resin surfaces and lower oral biofilm accumulation than the conventional disc and one-step polishing protocols. Participants in this group also demonstrated lower postoperative pain and more favorable wound-healing scores following third molar surgery. In contrast, greater composite surface roughness was significantly associated with increased biofilm accumulation, greater postoperative pain, and poorer healing scores. These findings indicate that the quality of composite finishing and polishing may have an important relationship with the local oral environment and postoperative healing following third molar surgery.

Figure 1. Mean post-polishing surface roughness (Ra, µm) according to finishing and polishing protocol among the study groups. Error bars represent standard deviation. A statistically significant difference was observed among the groups (p < 0.001).

The present study evaluated the association between composite resin surface roughness, oral biofilm accumulation, and postoperative healing following third molar surgery after the use of different finishing and polishing protocols. The findings demonstrated clear differences among the three polishing approaches. The multi-step rubber polishing protocol produced the lowest mean post-polishing surface roughness, while the one-step protocol resulted in the greatest residual roughness. This finding is clinically important because the final surface quality of a composite restoration may influence plaque retention, bacterial adhesion, and the overall condition of the surrounding oral environment. A smoother restoration surface is generally easier to maintain and may reduce niches that favor early biofilm retention (14, 15). There was a strong positive correlation between the composite surface roughness and oral biofilm accumulation. The participants having rougher composite surface had more biofilm on postoperative follow-up especially on day 7. This correlation is biologically realistic as disturbances on a restorative surface can create protected locations for bacterial adherence and maturation of dental plaque. Rough surfaces could also be harder to clean properly in the initial post-op period when patients might not brush around the surgery area due to discomfort. In the current study, the multi-step rubber polishing group always had less biofilm accumulation than the conventional disc polishing and one-step polishing groups, indicating the significance of precise finishing and polishing to keep the local oral environmental clean (16, 17). The multi-step polishing group also had greater postoperative healing. The patients in the one-step polishing group had significantly poorer results in healing scores and higher postoperative pain during follow-up when compared to the other patients. While the influence of oral hygiene, tissue manipulation, surgical trauma and duration of surgery, as well as individual biological response are all important factors in the healing of the operated wound, the present findings indicate that the status of the surrounding restorative surfaces can have an indirect effect through influencing the local plaque and biofilm burden. A healthier oral cavity might decrease the inflammatory stimulus around the surgical site and promote healing of the soft tissue (18, 19). This was confirmed by the correlation analysis. A higher surface roughness was significantly associated with increased biofilm accumulation and decreased postoperative healing score; increased biofilm accumulation was associated with increased pain and decreased wound healing. The relationships indicate that sub-optimal surface finishing may lead to more plaque retention, which can then lead to localised inflammation and a slow rate of healing. This association should be interpreted with caution, however, because it is not necessarily indicative of adverse postoperative outcomes when caused solely by composite surface roughness. Healing of the third molar is multi-factors and other surgical and patient-related factors can play a significant role in the outcome of the surgery (20). The study also revealed that there were more postoperative infections, wound dehiscence and alveolar osteitis in the one-step polishing group but these differences were not statistically significant. The absence of statistical significance may be attributable to the size of the number of postoperative complications and the overall sample size. Even so, the trend of these results is in agreement with the one found in the experiments and in the patients with rougher restorative surfaces, who experienced a greater biofilm buildup and were less likely to heal well. These differences may be seen in larger studies to determine if these are clinically relevant differences in postoperative complications. Interpretation of these findings should take several factors into consideration: Limited generalizability of the results due to the study taking place in one dental institution and the relatively small number of participants (97). Oral hygiene and diet, smoking, surgical difficulty, medication and individual immune response can all influence biofilm accumulation and healing following surgery. Residual confounding cannot be ruled out as important clinical and surgical variables were recorded. Furthermore, the relatively short follow-up period primarily reflects the early healing of the wounds, and not the long-term periodontal and restorative outcomes. Further multicenter studies, larger samples, longer follow-ups, and uniform microbiological evaluation, with multivariable analysis, are recommended to better define the results of composite surface roughness and biofilm accumulation on postoperative recovery. Even with these restrictions, the study still points to a clinically relevant relationship between restorative surface quality and the postoperative oral environment. Restorative care should therefore be regarded as an integral part of finishing and polishing, especially in planning and treatment of composite adjacent to oral surgical procedures. A smoother composite surface can help prevent biofilm accumulation, and ease postoperative oral hygiene, and promote better healing conditions. The results also indicate that the multi-step rubber polishing process can yield more clinical surface quality than the one-step and conventional disc polishing process used in this research.

The study demonstrated that different finishing and polishing protocols significantly influenced composite resin surface roughness and subsequent oral biofilm accumulation. The multi-step rubber polishing protocol produced the smoothest composite surfaces, the lowest biofilm accumulation, lower postoperative pain, and the most favorable healing scores following third molar surgery. In contrast, increased surface roughness was significantly associated with greater biofilm accumulation and poorer postoperative healing. These findings suggest that effective finishing and polishing of composite restorations may contribute to improved local oral cleanliness and may support better postoperative recovery following third molar surgery.

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