Introduction

Traumatic ulcers are a common complaint among denture wearers, caused by problems related to their dentures1,2. These ulcers typically develop within 1–2 days of inserting new removable dentures. The ulcers can manifest as red or white lesions and usually affect both the epithelium and the underlying connective tissue. They are often covered with a fibrin layer and surrounded by an erythematous halo3.

The size and shape of these ulcers can vary, appearing oval or irregular. The color of the ulcer reflects the severity of the condition, ranging from dark red in mild cases to white lesions with a red edge in more severe cases. These ulcers are most commonly found on minimal movement mucosa or lining tissues1,3.

Mucosal irritation during denture use is caused by: excessive pressure of the denture on the underlying tissues, and friction caused by the movement of the denture during function. These irritations are frequently observed in areas such as the frenum, muscle attachment regions such as retromylohyoid area, hamular notches, and buccal mucosa1,4.

Initially, these irritations may appear as mild redness and discomfort. However, if left untreated, they can progress into painful ulcers. Continued use of an ill-fitting denture can exacerbate the situation, potentially leading to deeper ulcers that affect the submucosal tissues5.Furthermore, ongoing and untreated mechanical irritation increases the risk of developing oral cancers6.

Several factors can cause mucosal irritation and subsequent ulceration. Clinically controllable factors include sharp or rough edges of dentures, improper tooth alignments such as insufficient or excessive vertical dimension, and poor denture stability caused by incorrect centric relation. Also, premature contacts in centric occlusion, buccally positioned posterior teeth beyond the residual alveolar ridge, overextended denture borders, and inaccurate impressions can contribute to these complications7,8,9,10.

Other factors, such as denture wearing time, oral hygiene habits, and dietary choices, primarily fall within the patient’s control, patients may experience discomfort due to these factors, which can make it challenging for them to wear dentures and result in pain in ulcer sites11. The development of ulcers reflects improper adaptation between the denture acrylic base and supporting tissues, this can lead to patient discomfort and avoidance of denture use, prolonging the adaptation period12.

Identifying the locations of these ulcers provides valuable insights into the most common pressure points on the mouth. allowing for a reduction in the number of adjustment visits and enhancing patient comfort. By making small changes, such as reducing pressure in specific areas and using different impression materials, this can improve the design and functionality of the denture13,14.

Traumatic ulcers are one of the most prevalent issues encountered by patients after the application of complete dentures. The presence of removable prosthodontics within the oral cavity is often surrounded by delicate and mobile tissues, which can lead to complications during the initial adjustment phase. This issue is particularly significant because these ulcers can adversely impact the success of prosthetic treatment, leading to discomfort and a reluctance among patients to wear their dentures. Unfortunately, there has been a lack of research on this matter within our community.

To address this gap, it is crucial to identify the most common locations for traumatic ulcers and understand the healing mechanisms that occur during different adjustment periods. This knowledge is valuable for practitioners, enabling them to recognize potential complications and mitigate them in the future. Our study is distinct from previous research as it focuses on the healing of ulcers across various adjustment periods, examines how adjustments affect healing, and explores different methods of measuring ulcers without the use of drug interventions. Additionally, it considers potential differences in ulcer occurrences between the upper and lower arches.

This study aims to evaluate the location and frequency of traumatic ulcers that occur after the placement of complete dentures, monitoring the size and healing of these ulcers based on their location during adjustment appointments. Additionally, the study seeks to assess potential gender differences in the prevalence of ulcers, considering both location and frequency of occurrence.

The null hypothesis of this study is that mechanical denture adjustments do not significantly affect the size or healing time of traumatic ulcers when no additional therapeutic interventions are applied.

Materials and methods

This cross-sectional study was carried out at the Faculty of Dental Medicine, Damascus University, during the 2023–2024 academic year. The study adhered to the ethical guidelines outlined in the Declaration of Helsinki15 and received approval from the Damascus University Ethics Committee (No.3707). All participants provided written informed consent prior to enrollment. The study followed the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for reporting observational studies16. the study exclusively included completely edentulous patients how came for the fabrication of the new complete dentures.

Sample size calculation

The sample size was calculated using G*Power v3.1.9.2, based on the means and standard deviations (SD) of ulcers size (8.5 ± 2.1mm2) from the Jovanović et al. study3to calculate sample size, aiming to detect a minimum difference of 1.5mm2 between follow-up visits. minimum of 60 patients was required to detect a significant difference in the proportion with 80% power and an alpha level of 0.05.

Patient population

The study included 60 patients from the Prosthodontics Department at the Faculty of Dentistry at Damascus University. The patient population was assumed to have a relatively homogenous educational and income level.

The inclusion criteria for the study consisted of fully edentulous patients who had been edentulous for at least 3 months prior to treatment and had not previously used any removable denture (new complete denture) and presence of traumatic ulcers in one or both arches and a willingness to participate and attend follow-up visits.

Exclusion criteria included patients with bony deformities, evidence of chronic mucosal changes, patients with severe ridge resorption, ulcerative manifestations of autoimmune diseases.

The stages of the fabrication of new dentures

Complete maxillary and mandibular dentures were fabricated for all patients following a standardized protocol. The clinical procedures were carried out by undergraduate students from the Department of Removable Prosthodontics at Damascus University, under the direct supervision of a postgraduate (master’s-degree) student. All prostheses were processed by the same dental technician in the university’s dental laboratory to ensure consistency in denture fabrication.

The process began with primary impressions, used to fabricate custom acrylic trays for the secondary (functional) impressions. After trimming the custom trays, border molding was performed using impression compound (Kerr green sticks), followed by final impressions made using the mucostatic technique with zinc oxide eugenol paste (SS White) as described in zarb et al.17. Final casts were mounted on semi-adjustable articulators, and a bilateral balanced occlusal scheme was established. Centric relation was recorded to confirm proper occlusion.

Denture delivery and clinical quality assessment

After denture insertion, patients were scheduled for follow-up assessments. Unlike traditional protocols where the first adjustment occurs within 24–48 h, the initial follow-up was deliberately set for one-week post-insertion to allow for the natural development of any denture-related traumatic ulcers. The clinical quality of each denture was assessed by a supervising professor using predefined criteria, including occlusion, phonetics, support, retention, stability, tissue health, and esthetics.

Follow-up schedule and ulcer evaluation

Only patients presenting with denture-related ulcers at the first follow-up were included in the study. Follow-up and adjustment visits were conducted at one-week intervals (Days 7, 14, and 21). If complete healing was observed after the second visit, no further appointments were scheduled. The timeline was as follows:

Day 7 (Week 1): Initial follow-up and ulcer assessment.

Day 14 (Week 2): Second follow-up and adjustment.

Day 21 (Week 3): Final follow-up and evaluation.

Out of the 60 initially enrolled patients, four discontinued participations due to personal reasons, resulting in a drop-out rate of 6.7%. These individuals were excluded from the final analysis.

Ulcer assessment and adjustment protocol

All data collection, denture adjustments, and ulcer evaluations were conducted by a single operator (the primary author) to maintain methodological consistency. At each follow-up, the location, number, and size of ulcers were documented using a structured, self-designed form. Pressure-indicating paste (Dentaseem) was applied to the intaglio and border surfaces of the dentures to identify pressure spots1. Traumatic ulcers were marked using a copying pencil, and adjustments were performed using tungsten carbide burs followed by smoothing with fine-grit sandpaper. Patients were advised to remove their dentures on the day of the adjustment and the following day to facilitate mucosal healing (Figs. 1 and 2).

Fig. 1
figure 1

(A) Traumatic ulcer at first visit (before adjustment). Figure 1  (B) Traumatic ulcer at second visit (after adjustment).

Full size image
Fig. 2
figure 2

(A) Traumatic ulcer at first visit (before adjustment). (B) Traumatic ulcer at second visit (after adjustment).

Full size image

Ulcer measurement methodology

Ulcer dimensions were recorded on Days 7, 14, and 21 using a Williams periodontal probe (Hu-Friedy, USA) (Fig. 3), a calibrated instrument with 1-mm increments. The ulcer area (in mm²) was calculated by multiplying the maximum length by the greatest perpendicular width. In cases where multiple ulcers were present in the same arch, only the largest lesion was recorded to ensure consistency. This measurement technique has been validated for its reliability, reproducibility, and simplicity18,19,20. Photographic documentation was also used to track healing progression over time.

Fig. 3
figure 3

Measuring ulcers with William’s probe.

Full size image

Data analysis

Data analysis was conducted using SPSS version 25. The results are presented as counts (%) or means ± standard deviation (SD), depending on the type of data. The Mann-Whitney U test was utilized to compare the differences in ulcer size between the mandibular and maxillary regions, The chi-squared test was used to evaluate the relationship between lesions and patient gender. A statistical significance level was established at P < 0.05.

Results

A total of 60 patients with traumatic ulcers related to complete dentures (120 complete dentures) participated in the study. Among these patients, 50 (83.3%) were male and 10 (16.7%) were female. All patients were examined in the adjustment appointment one week after the placement. In each visit, mechanical adjustments of the dentures and occlusal adaptations were performed without any medical intervention.

The results present measurements of ulcer areas at three adjustment visits (on days 7, 14, and 21). (Table 1).

Table 1 Mean, standard deviation, minimum, and maximum ulcers area in both arches in three adjustments visits.
Full size table

In the maxillary arch, the most frequent sites of denture-related ulceration were as follows: the vestibular sulcus between the labial and buccal frenum (43.5%), followed by the labial frenum region (21.7%) and the buccal frenum region (13%) (Table 2).

Table 2 Number of maxillary injuries related to clinical anatomic sites and gender.
Full size table

On the other hand, In the mandibular arch, the most frequent sites of denture-related ulceration were as follows: The lingual sulcus in the paralingual region (23.4%), followed by the vestibular sulcus between the labial and buccal frenum (14.1%), and retro mylohyoid ridge (12.5%) (Table 3).

Table 3 Number of mandibular injuries related to clinical anatomic sites and gender.
Full size table

The Mann-Whitney U test was employed to compare the differences in ulcer size between the mandibular and maxillary arch. The results indicate that the size of mandibular ulcers was significantly larger (P < 0.05) (Table 4).

Table 4 Mann-Whitney U test to compare the size of traumatic ulcers during different adjustment visits.
Full size table

Fisher’s Exact Test showed no significant differences between patient gender and the anatomical locations of traumatic ulcers in the maxillary and mandibular regions (P > 0.05)) P = 0.5 and 0.64 for mandibular and maxillary arch, respectively).

Discussion

Although dental implants are a viable option for replacing missing teeth, complete dentures remain widely used due to their affordability and ease of fabrication. However, edentulous patients often experience complications following denture placement, with traumatic ulcers being among the most common issues. These ulcers significantly affect patients’ quality of life and may lead to denture rejection. Therefore, understanding the.

causes and healing process of these ulcers, along with regular follow-up and timely adjustments, is crucial for successful prosthetic rehabilitation3.

This cross-sectional study included 60 edentulous patients, each receiving complete maxillary and mandibular dentures (a total of 120 dentures). The first adjustment appointment occurred one week after insertion, followed by subsequent visits at two and three weeks post-delivery.

This study, the first of its kind in Syria, was conducted in collaboration with the Faculty of Dental Medicine, Removable Prosthodontics, at Damascus University. It differs from previous studies by evaluating the progression of ulcer healing across multiple denture adjustment visits, specifically focusing on denture-related ulcers that did not receive any specific therapeutic intervention beyond adjustments.

In contrast, some previous studies have reported additional effects of therapeutic materials. For example, Jovanović et al.3. used hyaluronic acid gel in combination with denture adjustments, which resulted in faster healing, while AlZarea et al.13 applied ozone gas as an additional treatment. Conversely, Bural et al.21 found no added benefit from over-the-counter products beyond the effect of mechanical adjustment, and Geckili et al.22 reported that TGO gel (triester glycerol oxide) was not more effective than adjustment alone.

In this study, ulcer dimensions were recorded at baseline (mean area 8.4 mm2) and tracked across three visits. Measuring the area of the ulcer, rather than its linear dimensions, offers greater accuracy and consistency, as it captures changes in both width and length. This approach aligns with Jovanović’s method3who reported a similar baseline ulcer size (mean: 8.55 mm2). In contrast, Jivanescu et al.11 assessed ulcer size based on the largest diameter alone, reporting a range of 4.0–10.2 mm with a mean of 7.1 mm.

In this study, the most significant reduction in ulcer dimensions was observed after the first adjustment visit, with a healing rate of 89%, expressed as the percentage reduction in ulcer area. This highlights the critical role of the initial adjustment in alleviating tissue trauma and enhancing patient comfort.

In comparison, Jovanović’s. study3assessed two groups: one receiving only denture adjustments and the other receiving both adjustments and 0.2% hyaluronic acid gel. They reported a 67% healing rate by day 7 in the group treated with the adjustments (ulcer area reduced from 8.52 mm2 to 2.92 mm2). Another study by Jivanescu et al.11 involved a similar two-group design, where patients received either standard adjustments or treatment with a hydrogel patch. In that case, the healing rate reached 56%.

The differences between our results and those reported in previous studies may be attributed to various factors, including differences in ulcer measurement techniques, timing and frequency of follow-up visits, and patient selection criteria. For instance, in some studies, the types of prostheses used were not clearly defined, with participants receiving a mix of partial and complete dentures, or combinations of maxillary and mandibular replacements. These variations can influence ulcer occurrence and healing due to the differing load distributions and tissue pressures involved17.

Furthermore, our study ensured a standardized follow-up protocol. Patients were instructed to remove their dentures on the day of adjustment and the following day, promoting tissue rest and healing. This practice may have contributed to the higher healing rates observed.

Based on our findings, the first adjustment session appears to have the greatest impact on ulcer resolution, and two adjustment visits are typically sufficient for complete healing. However, if ulcers persist beyond two weeks, adjunctive treatment options—such as laser therapy—should be considered. Based on our findings, the null hypothesis was rejected. Mechanical adjustments significantly contributed to ulcer reduction and healing without the need for therapeutic interventions.

No previous studies have specifically examined the differences in ulcer size between the maxilla and mandible. In this study, the ulcers in the mandible were significantly larger than those in the maxilla. This difference may be attributed to variations in mechanical loading, as the average denture-bearing area of the mandible (12.25 cm2) is considerably smaller than that of the maxilla (22.69 cm2)23. (Due to differences in the mechanical forces applied, the mandibular arch bears stress differently than the maxillary arch).

Regarding patient-related factors, our analysis showed no significant association between ulcer location and gender, which is consistent with the findings of Sadr et al.7. However, Kivovics et al1. reported that males experienced more ulcers than females during the first and second adjustment visits. This discrepancy may be influenced by dietary habits, as males are generally more likely to consume harder foods early during the adaptation period, increasing tissue trauma.

Therefore, patient education is essential. Individuals should be informed about proper denture usage and advised to consume soft foods during the initial days after placement. This not only supports the healing process but also improves the overall adaptation experience. These findings reinforce the notion that denture delivery is not the final step in treatment—it must be followed by timely and targeted adjustment sessions to ensure patient comfort and prosthesis success.

The most common site of denture-induced irritation in the maxilla was found to be the vestibular sulcus, between the labial and buccal frenum. This is likely due to overextended borders1 which can impinge on the vestibular tissues. The second most common site for maxillary mucosal irritation was the labial frenum, followed by the buccal frenum.

In the mandible, the highest number of ulcerations was found in the lingual sulcus in the para lingual region. This area is characterized by thin mucosa and is highly influenced by functional tongue movements, which are used during impression-taking to record sulcus depth24.

The second most common site of irritation was the vestibular sulcus, located between the labial and buccal frenula, followed by the retro mylohyoid ridge.

According to Kivovics1many clinicians tend to overextend the denture borders to improve retention during impression-making, which increases the risk of ulceration in these specific anatomical sites. This observation is in line with our findings.

it is important to emphasize that denture delivery should never be considered the endpoint of treatment. Proper border molding, careful fabrication of custom trays, and correct extension of the denture are all essential to minimize ulcer formation. Additionally, using a pressure-indicating paste (PIP) to identify high-pressure areas can help guide accurate adjustments and minimize the number of post-insertion visits.

The limitations of the study are that it does not include patients with bone deformities or severe bone resorption, and patients with systematic diseases that can affect healing, The study population consisted exclusively of Syrian patients; thus, the findings may not be generalizable to other populations or clinical settings. Furthermore, the study did not assess potential confounding factors such as dietary habits or systemic comorbidities, which might influence ulcer healing. Additionally, the use of a single examiner to measure lesion areas and reliance on a single measurement method (William’s probe) may limit the reproducibility and objectivity of the data. These limitations should be taken into account when interpreting the results, and future studies should investigate ulcer development in more diverse populations and explore how emerging technologies like 3D-printed dentures may influence ulceration patterns and healing times.

Conclusion

Delivering and applying complete dentures is not the final step in prosthetic rehabilitation. Regular and well-timed adjustment sessions are essential to eliminate ulcer-causing factors and promote mucosal healing. The first post-insertion visit has the most substantial impact on ulcer resolution, and in most cases, two sessions are sufficient. However, if ulcers persist beyond two weeks, alternative treatment options such as laser therapy should be considered. Meticulous attention to border molding, denture extension, and soft tissue relief can significantly improve patient outcomes and reduce complications.