Abstract
Aim
To evaluate the adjunctive clinical efficacy of manual root planing following ultrasonic subgingival debridement (SD) in the treatment of generalized severe periodontitis.
Material and methods
Twenty-nine patients diagnosed with Stage III or IV periodontitis were enrolled in this single-blind, split-mouth, randomized controlled trial (RCT). Quadrants were randomly assigned to receive either ultrasonic subgingival debridement alone (SD group) or ultrasonic subgingival debridement followed by manual root planing (SRP group). Clinical parameters, including Probing Pocket Depth (PPD), Clinical Attachment Level (CAL), and Bleeding Index (BI), were recorded at baseline, 3, and 6 months.
Results
Twenty-nine patients completed the study. Both treatment modalities yielded statistically significant improvements in all clinical parameters compared with baseline (p < 0.05). The SRP group resulted in superior outcomes compared with ultrasonic subgingival debridement alone. Analysis revealed a significantly greater PPD reduction in the SRP group at 3 months (adjusted MD: 0.20 mm; 95% CI [0.13, 0.27]; p < 0.01), and this advantage was sustained at 6 months (adjusted MD: 0.11 mm; 95% CI [0.05, 0.18]; p < 0.01). SRP achieved superior CAL gain at 3 months (adjusted MD: 0.10 mm; 95% CI [0.01, 0.19]; p < 0.05). Crucially, regarding clinical endpoints, the SRP group exhibited a significantly lower prevalence of residual deep pockets (PPD ≥ 5 mm) at 3 months and 6 months compared with the SD group (p < 0.05), indicating a higher rate of pocket closure. Both treatment modalities achieved significant reductions in Bleeding Index (BI) scores compared to baseline (p < 0.05), with no statistically significant inter-group differences observed at any time point.
Conclusions
While ultrasonic debridement alone is effective, the adjunctive use of manual root planing yields statistically significant, though modest, additional benefit in PPD reduction and CAL gain in generalized severe periodontitis. While it effectively reduces the burden of residual pockets in the short term, its long-term advantage is attenuated, highlighting the necessity of strict supportive periodontal therapy.
Keywords: Ultrasonic subgingival debridement combined with manual root planing, Ultrasonic subgingival debridement, Severe periodontitis, Split-mouth design
Clinical relevance
Scientific rationale for the study
Evidence suggests that debridement with either hand curettes or ultrasonic devices leads to similar clinical improvement of periodontal conditions. However, whether subgingival debridement with ultrasonic instruments alone can achieve the same clinical effect as ultrasonic subgingival debridement combined with manual root planing is still not clear.
Principal findings
Both treatments resulted in significant improvement of periodontal parameters, while more PPD reduction and CAL gain were found in teeth treated with ultrasonic subgingival debridement combined with manual root planing.
Practical implications
Root planing with hand instruments is suggested to be carried out following ultrasonic subgingival debridement.
Introduction
Dental plaque biofilm initiates periodontal disease, while calculus serves as a critical predisposing factor facilitating bacterial retention. Thorough removal of subgingival calculus and plaque is an effective way to eliminate periodontal inflammation. A variety of manual instruments (e.g., scalers, curettes) are used for scaling, which could fundamentally destroy the structure of biofilm, reduce the number of subgingival microorganisms and change the composition of subgingival plaque. Historically, "root planing" dominated periodontal therapy from the 1970s, predicated on the concept that endotoxins penetrate the cementum, necessitating aggressive removal of the "diseased" root surface to ensure biocompatibility [1–4]. However, subsequent research in the 1980s demonstrated that endotoxins are primarily surface-adsorbed and loosely adherent, challenging the biological rationale for extensive cementum removal [5–9]. Therefore, the concept of "subgingival debridement" emerged, prioritizing biofilm disruption and calculus removal while preserving tooth structure [10].
Ultrasonic instrumentation is currently favored for its efficiency, ergonomics, and cavitation effects. Numerous studies have reported similarly favorable clinical outcomes following ultrasonic and hand instruments [12–18]. However, mainstream international guidelines still frequently recommend combining ultrasonic debridement with manual root planing to ensure thoroughness [19]. This creates a clinical dilemma: Is the additional time and effort of manual root planing strictly necessary, or can ultrasonic instrumentation alone achieve comparable results? Despite numerous studies comparing these modalities, uncertainty remains regarding the added value of manual instrumentation, particularly in patients with severe periodontitis where deep pockets and complex root anatomy pose significant challenges.
This randomized controlled trial aimed to compare the clinical efficacy of ultrasonic subgingival debridement (SD) alone versus ultrasonic subgingival debridement combined with manual root planing (SRP). The priori primary endpoints were the reduction in Probing Pocket Depth (PPD) and gain in Clinical Attachment Level (CAL) at 3 months and 6 months. We hypothesized that the adjunctive use of manual root planing would provide superior clinical outcomes compared to ultrasonic subgingival debridement alone in the treatment of severe periodontitis.
Methods
Study design
This single-blind, split-mouth randomized controlled trial (RCT) was conducted at the Department of Periodontology, Peking University Hospital of Stomatology. The protocol was approved by the Biomedical Ethics Committee (PKUSSIRB-201734032) and registered on the China Clinical Trial Registration Platform (ChiCTR1800017122). All procedures adhered to the Declaration of Helsinki. All participants provided written informed consent after receiving detailed oral and written explanations of the study procedures. The study was conducted and reported in accordance with the Consolidated Standards of Reporting Trials (CONSORT) guidelines.
Subjects
Twenty-nine patients diagnosed with generalized severe periodontitis (Stage III/IV, Grade C), according to the 2018 World Workshop Classification [20], were recruited between January 2017 and April 2019. Inclusion criteria were: (1) age ≥ 18 years; (2) presence of at least two sites with PPD ≥ 5 mm and CAL ≥ 5 mm per quadrant; (3) generalized disease extent ≥ 50% of teeth involved with PPD ≥ 5 mm and radiographic bone loss > 30% and (4) minimum of 20 functional teeth and at least one molar in each quadrant. Exclusion criteria included: (1) periodontal therapy within the previous 6 months; (2) use of systemic antibiotics or anti-inflammatory drugs within 3 months; (3) significant medical history, systemic disease or disorder that might affect the outcome; (4) pregnancy or lactation; (5) patients allergic to penicillin; (6) current smoking and (7) refusal to sign informed consent.
Randomization and blinding
A split-mouth design was employed to control for inter-individual variability. Quadrants within each patient were randomized to either the Test group (SRP) or Control group (SD) using a computer-generated random sequence prepared by an independent researcher who was not involved in the clinical procedures. To ensure allocation concealment, the treatment assignments were enclosed in sequentially numbered, opaque, sealed envelopes (SNOSE). These envelopes were opened by the operator only after the completion of baseline examinations and immediately prior to the treatment intervention.
All treatments were performed by a single experienced periodontist. Clinical parameters were recorded by a calibrated examiner (Cohen’s kappa: PPD = 0.95; CAL = 0.92) who was blinded to the treatment allocation. Due to the distinct nature of the instruments, the operator could not be blinded.
Treatment procedures
One week following full-mouth supragingival scaling and oral hygiene instructions (OHI), baseline measurements were recorded. All treatments were performed by a single experienced periodontist under local anesthesia in two visits at a 1-week interval.
Control group (SD)
Subgingival instrumentation was performed exclusively using a magnetostrictive ultrasonic device (Gen-130B, 25 kHz; Dentsply Sirona, USA).
Test group (SRP)
Following the identical ultrasonic protocol, adjunctive manual root planing was performed using site-specific Gracey curettes (Hu-Friedy, USA) until a smooth, hard root surface was achieved based on tactile evaluation.
To ensure comparability of treatment intensity, the total instrumentation time was standardized between groups for each patient. In the control quadrants (SD), ultrasonic debridement was extended to match the total duration of the test quadrants (SRP), ensuring that both groups received an equivalent duration of mechanical instrumentation. In both groups, instrumentation was continued until the operator determined the site was clinically free of deposits. No systemic or local antibiotics were prescribed or administered at any stage of the study to avoid confounding effects on periodontal healing. Instruments were inspected and sharpened/replaced prior to every session.
Clinical assessment
At baseline, oral hygiene was assessed by the full-mouth plaque index (PLI) [21]. Other clinical parameters were assessed at baseline, 3 months, and 6 months post-therapy. Parameters included:
Probing Pocket Depth (PPD): Distance from the gingival margin to the pocket base; Measurements were recorded at six sites (mesiobuccal, buccal, distobuccal, mesiolingual, lingual and distolingual) using a Williams probe.
Clinical Attachment Level (CAL): Distance from the cemento-enamel junction (CEJ) to the pocket base recorded at six sites.
Bleeding Index (BI): Assessed according to Mazza et al. [22]. Were recorded at two sites (buccal and lingual).
Furcation Involvement (FI): Assessed using a Nabers probe.
Post-operative hypersensitivity was assessed at 2 weeks using a Visual Analogue Scale (VAS) ranging from 0 (none) to 10 (very intense). At follow-up visits, sites with residual PPD ≥ 4 mm received reinforcement of OHI and re-debridement using the originally assigned modality. At the end of the study, patients were referred for periodontal surgery or supportive periodontal therapy according to their individual needs.
According to the formula of split-mouth trial [23], sample size calculation indicated that 19 subjects were required to detect a 0.3 mm difference in PPD reduction (α = 0.05, power = 90%), based on research data in Chinese population [16, 24, 25].
The primary outcome parameters were PPD and CAL and the secondary outcome parameters were BI and VAS (except for the hopeless teeth designed to be extracted, the third molars and the distal sites of all second molars). Data were analyzed using R (Version 4.5.2; R Foundation for Statistical Computing, Vienna, Austria). Linear Mixed-Effects Models (LMM) were employed for site-level continuous outcomes (PPD, CAL) restricted to disease sites (baseline PPD ≥ 4 mm), incorporating random subject intercepts and adjusting for baseline values, age, sex, jaw position, and tooth type. At the patient level, full-mouth proportions of pocket closure (PPD ≤ 4 mm) and residual disease (PPD ≥ 5 mm) were evaluated using Generalized Estimating Equations (GEE). Significance was set at p < 0.05.
Results
Thirty patients participated in the study initially, with one dropout due to relocation. The flow of participants through each stage of the trial is illustrated in the CONSORT flow diagram (Fig. 1). 29 subjects (16 females, 13 males) with a mean age of 38.21 ± 8.40 years completed the 6-month follow-up. A total of 2594 sites with initial PPD ≥ 4 mm belonging to 735 teeth were included in the final analysis. The distribution of sites treated with SRP or SD in 29 patients is presented in Table 1.
Fig. 1.
CONSORT flow diagram showing the enrollment, allocation, follow-up, and analysis of study participants
Table 1.
Distribution of sites treated with SRP or SD in 29 patients
| Number | SRP | SD | Total |
|---|---|---|---|
| upper jaw | 692 | 699 | 1391 |
| lower jaw | 620 | 583 | 1203 |
| PPD 4-6 mm | 955 | 970 | 1925 |
| PPD ≥ 7 mm | 357 | 312 | 669 |
| anterior teeth | 509 | 471 | 980 |
| premolars | 363 | 367 | 730 |
| molars | 440 | 444 | 884 |
| without FI | 122 | 128 | 250 |
| with FI | 121 | 111 | 232 |
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement, PPD Probing pocket depth, FI Furcation involvement
PLI and BI
Oral hygiene compliance was maintained at a high standard throughout the study, with Plaque Index (PLI) scores stabilizing at 0–1 across all visits. Regarding gingival inflammation, both treatment modalities achieved a statistically significant reduction in Bleeding Index (BI) scores at 3 months and 6 months compared to baseline (p < 0.05). However, inter-group comparisons revealed no statistically significant differences between the SRP and SD groups at either 3 months or 6 months, indicating comparable efficacy in resolving gingival inflammation.
Probing assessments
Baseline PPD and CAL parameters showed no statistically significant inter-group differences (p > 0.05). The number and proportion of sites with PPD ≥ 5 mm at different time points in two groups are shown in Table 2. Both treatment modalities resulted in marked and statistically significant improvements in probing parameters at all follow-up intervals compared to baseline (p < 0.05). Regarding therapeutic efficacy, SRP demonstrated a significant advantage over SD in disease sites. The SRP group exhibited a statistically greater reduction in PPD compared to the SD group at 3 months (adjusted MD: 0.20 mm, 95% CI [0.13, 0.27]; p < 0.01). This therapeutic advantage was sustained at 6 months, with the SRP group maintaining a statistically greater PPD reduction (adjusted MD: 0.11 mm; 95% CI [0.05, 0.18]; p < 0.01). The results are presented in Table 3.
Table 2.
Distribution of sites with PPD ≥ 5 mm in SRP and SD group at different time points
| SRP | SD | |||
|---|---|---|---|---|
| number | proportion | number | proportion | |
| baseline | 1009 | 76.91% | 974 | 75.98% |
| 3 months | 133 | 10.14% | 176 | 13.73% |
| 6 months | 142 | 10.82% | 170 | 13.26% |
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement, PPD Probing pocket depth, M Month
Table 3.
PPD and CAL scores of sites with PPD ≥ 4 mm before and after treatment
| Baseline (mm) | 3 months (mm) | 6 months (mm) | ||
|---|---|---|---|---|
| Mean PPD | SRP | 5.61 ± 1.42 | 3.14 ± 1.16#** | 3.11 ± 1.21#** |
| SD | 5.51 ± 1.40 | 3.32 ± 1.23#** | 3.20 ± 1.17#** | |
| Mean CAL | SRP | 4.94 ± 2.13 | 3.13 ± 2.20#* | 3.27 ± 2.23# |
| SD | 4.80 ± 2.07 | 3.18 ± 2.08#* | 3.25 ± 2.09# | |
| Mean BI | SRP | 3.40 ± 0.72 | 1.99 ± 0.80# | 1.97 ± 0.88# |
| SD | 3.45 ± 0.65 | 2.13 ± 0.89# | 2.06 ± 0.96# | |
| △PPD | SRP | —— | 2.48 ± 1.31** | 2.54 ± 1.38** |
| SD | —— | 2.21 ± 1.35** | 2.35 ± 1.34** | |
| △CAL | SRP | —— | 1.82 ± 1.88* | 1.72 ± 1.95 |
| SD | —— | 1.67 ± 1.83* | 1.61 ± 1.85 |
Data are presented as mean ± standard deviation (SD)
Inter-group comparisons were performed using linear mixed-effects models (LMM) with the patient as a random effect, adjusted for baseline values, age, sex, jaw position, and tooth type
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement alone, PPD Probing pocket depth, CAL Clinical attachment level, BI Bleeding index
*Statistically significant difference between groups (p < 0.05)
**Statistically significant difference between groups (p < 0.01)
#Statistically significant difference from baseline (p < 0.05)
Regarding clinical attachment, the SRP group demonstrated a statistically significant advantage in CAL gain at 3 months (adjusted MD: 0.10 mm; 95% CI [0.01, 0.19]; p < 0.05). However, by the 6-month follow-up, the difference in CAL gain narrowed and was no longer statistically significant, suggesting that while SRP may accelerate initial attachment gain, the long-term attachment outcomes are largely similar between the two protocols.
To assess clinical stability beyond mean value reductions, the percentage of sites in full-mouth dentition at the patient level achieving periodontal stability (PPD ≤ 4 mm) and the prevalence of residual deep pockets (PPD ≥ 5 mm) were analyzed, presented in Table 4. The SRP group achieved a significantly higher rate of pocket closure (PPD ≤ 4 mm) at 3 months (adjusted MD: 2.20%; 95% CI [0.24, 4.17]; p < 0.05) and 6 months (adjusted MD: 1.74%; 95% CI [0.18, 3.30]; p < 0.05). Consequently, the burden of residual disease was significantly lower in the SRP group (p < 0.05).
Table 4.
Per-patient percentage of sites achieving pocket closure (PPD ≤ 4 mm) and residual pockets (PPD ≥ 5 mm)
| Baseline (%) | 3 months (%) | 6 months (%) | ||
|---|---|---|---|---|
| PPD ≤ 4 mm | SRP | 51.42 ± 20.63 | 91.72 ± 10.33#* | 91.31 ± 9.18#* |
| SD | 53.57 ± 20.18 | 90.04 ± 12.90#* | 90.16 ± 9.15#* | |
| PPD ≥ 5 mm | SRP | 48.58 ± 20.63 | 8.28 ± 10.33#* | 8.69 ± 9.18#* |
| SD | 46.43 ± 20.18 | 9.96 ± 12.90#* | 9.84 ± 9.15#* |
Data are presented as mean ± standard deviation (SD)
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement alone
SRP Ultrasonic subgingival Inter-group comparisons were performed using Generalized Estimating Equations (GEE) to account for clustering, adjusted for baseline proportions and age
*Statistically significant difference between groups (p < 0.05)
**Statistically significant difference between groups (p < 0.01)
#Statistically significant difference from baseline (p < 0.05)
Stratified probing assessments of upper/lower jaws and tooth position
Anatomical stratification revealed distinct healing patterns. Stratification by jaw position (Maxilla vs. Mandible) in Table 5 showed no statistically significant inter-group differences in PPD reduction or CAL gain at either 3 months or 6 months, suggesting that the efficacy of the combined therapy is not dependent on the dental arch.
Table 5.
PPD and CAL scores of upper/lower jaws before and after treatment
| Baseline (mm) | 3 months (mm) | 6 months (mm) | |||
|---|---|---|---|---|---|
| upper jaw | mean PPD | SRP | 5.63 ± 1.42 | 3.10 ± 1.02# | 3.05 ± 1.08# |
| SD | 5.59 ± 1.43 | 3.30 ± 1.20# | 3.12 ± 1.05# | ||
| mean CAL | SRP | 5.00 ± 2.08 | 3.03 ± 2.11# | 3.15 ± 2.12# | |
| SD | 4.90 ± 2.03 | 3.08 ± 2.04# | 3.10 ± 1.99# | ||
| △PPD | SRP | —— | 2.53 ± 1.31** | 2.63 ± 1.35 | |
| SD | —— | 2.30 ± 1.44** | 2.51 ± 1.37 | ||
| △CAL | SRP | —— | 1.98 ± 1.90 | 1.88 ± 1.94 | |
| SD | —— | 1.83 ± 1.97 | 1.84 ± 1.97 | ||
| lower jaw | mean PPD | SRP | 5.59 ± 1.41 | 3.17 ± 1.29# | 3.17 ± 1.33# |
| SD | 5.43 ± 1.36 | 3.34 ± 1.26# | 3.30 ± 1.30# | ||
| mean CAL | SRP | 4.87 ± 2.18 | 3.25 ± 2.29# | 3.40 ± 2.34# | |
| SD | 4.68 ± 2.11 | 3.31 ± 2.12# | 3.42 ± 2.18# | ||
| △PPD | SRP | —— | 2.42 ± 1.31 | 2.45 ± 1.41 | |
| SD | —— | 2.10 ± 1.24 | 2.15 ± 1.27 | ||
| △CAL | SRP | —— | 1.65 ± 1.84 | 1.54 ± 1.95 | |
| SD | —— | 1.47 ± 1.64 | 1.34 ± 1.65 |
Data are presented as mean ± standard deviation (SD)
Inter-group comparisons were performed using linear mixed-effects models (LMM) with the patient as a random effect, adjusted for baseline values, age, sex, jaw position, and tooth type
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement alone, PPD Probing pocket depth, CAL Clinical attachment level
*Statistically significant difference between groups (p < 0.05)
**Statistically significant difference between groups (p < 0.01)
#Statistically significant difference from baseline (p < 0.05)
However, analysis by tooth type revealed widespread benefits for the combined therapy, as shown in Table 6. In the anterior region, the SRP group achieved significantly lower mean PPD values (p < 0.01) and greater PPD reduction at 3 months compared to SD alone. Significant inter-group differences favoring SRP were also observed in PPD reduction at both 3 months (p < 0.01) and 6 months (p < 0.01) at premolars sites. Notably, CAL gain was also significantly greater in the SRP group at 3 months (p < 0.05). Despite anatomical complexity, molars treated with SRP exhibited significantly greater PPD reduction at both 3 months and 6 months compared to those treated with SD (p < 0.05). These findings indicate that the adjunctive benefit of manual root planing is not limited to single-rooted teeth but extends to posterior segments.
Table 6.
PPD and CAL scores of different tooth types before and after treatment
| Baseline (mm) | 3 months (mm) | 6 months (mm) | |||
|---|---|---|---|---|---|
| anterior teeth | mean PPD | SRP | 5.43 ± 1.36 | 2.69 ± 0.82#** | 2.64 ± 0.95# |
| SD | 5.38 ± 1.36 | 2.94 ± 1.13#** | 2.69 ± 0.85# | ||
| mean CAL | SRP | 4.89 ± 2.36 | 3.00 ± 2.37# | 3.11 ± 2.42# | |
| SD | 4.59 ± 2.15 | 2.89 ± 2.13# | 2.81 ± 2.09#* | ||
| △PPD | SRP | — | 2.74 ± 1.23** | 2.83 ± 1.37 | |
| SD | — | 2.46 ± 1.44** | 2.73 ± 1.34 | ||
| △CAL | SRP | — | 1.95 ± 1.66 | 1.89 ± 1.81* | |
| SD | — | 1.81 ± 1.69 | 1.89 ± 1.71* | ||
| premolars | mean PPD | SRP | 5.52 ± 1.35 | 2.98 ± 0.86#** | 2.91 ± 0.93#** |
| SD | 5.26 ± 1.14 | 3.10 ± 0.98#** | 3.04 ± 0.95#** | ||
| mean CAL | SRP | 4.72 ± 1.94 | 2.78 ± 1.89#* | 2.87 ± 1.99#** | |
| SD | 4.40 ± 1.64 | 2.82 ± 1.80#* | 3.00 ± 1.78#** | ||
| △PPD | SRP | — | 2.53 ± 1.29** | 2.64 ± 1.31** | |
| SD | — | 2.16 ± 1.17** | 2.26 ± 1.15** | ||
| △CAL | SRP | — | 1.92 ± 1.96* | 1.87 ± 2.01** | |
| SD | — | 1.58 ± 1.76* | 1.43 ± 1.76** | ||
| molars | mean PPD | SRP | 5.83 ± 1.49 | 3.67 ± 1.37#* | 3.70 ± 1.35#* |
| SD | 5.80 ± 1.54 | 3.81 ± 1.31#* | 3.76 ± 1.31#* | ||
| mean CAL | SRP | 5.14 ± 1.98 | 3.51 ± 2.17# | 3.71 ± 2.12# | |
| SD | 5.26 ± 2.17 | 3.70 ± 2.11# | 3.82 ± 2.16# | ||
| △PPD | SRP | — | 2.18 ± 1.34* | 2.20 ± 1.37* | |
| SD | — | 2.02 ± 1.36* | 2.07 ± 1.38* | ||
| △CAL | SRP | — | 1.64 ± 2.01 | 1.45 ± 2.02 | |
| SD | — | 1.59 ± 1.99 | 1.48 ± 2.00 |
Data are presented as mean ± standard deviation (SD)
Inter-group comparisons were performed using linear mixed-effects models (LMM) with the patient as a random effect, adjusted for baseline values, age, sex, jaw position, and tooth type
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement alone, PPD Probing pocket depth, CAL Clinical attachment level
*Statistically significant difference between groups (p < 0.05)
**Statistically significant difference between groups (p < 0.01)
#Statistically significant difference from baseline (p < 0.05)
Stratified probing assessments of moderate/deep pockets
A focused analysis was conducted on sites with baseline PPD ≥ 5 mm to assess efficacy in Table 7. In the moderate pockets (PPD 4–6 mm), the SRP group resulted in significantly greater PPD reduction compared to SD group. The SRP protocol resulted in significantly greater PPD reduction compared to SD alone at both 3 months (adjusted MD: 0.19 mm; 95% CI [0.12, 0.26]; p < 0.01) and 6 months (adjusted MD: 0.10 mm; 95% CI [0.04, 0.16]; p < 0.05). Considering the deep pocket group (PPD ≥ 7 mm), the SRP group achieved a significantly greater reduction in PPD at 3 months compared to SD, with an adjusted MD of 0.18 mm (95% CI [0.01, 0.36]; p < 0.05). By 6 months, while the trend favored SRP, the difference did not reach statistical significance.
Table 7.
PPD and CAL scores of moderate/deep pockets before and after treatment
| Baseline (mm) | 3 months (mm) | 6 months (mm) | |||
|---|---|---|---|---|---|
|
PPD 4–6 mm |
mean PPD | SRP | 4.82 ± 0.63 | 2.82 ± 0.80#** | 2.80 ± 0.88#** |
| SD | 4.79 ± 0.62 | 3.00 ± 0.92#** | 2.90 ± 0.88#** | ||
| mean CAL | SRP | 4.18 ± 1.78 | 2.68 ± 1.92#* | 2.82 ± 1.96# | |
| SD | 4.12 ± 1.71 | 2.76 ± 1.84#* | 2.80 ± 1.83# | ||
| △PPD | SRP | —— | 2.00 ± 0.91** | 2.03 ± 0.95** | |
| SD | —— | 1.80 ± 0.99** | 1.91 ± 0.95** | ||
| △CAL | SRP | —— | 1.52 ± 1.59* | 1.38 ± 1.65 | |
| SD | —— | 1.41 ± 1.60* | 1.37 ± 1.58 | ||
|
PPD ≥ 7 mm |
mean PPD | SRP | 7.55 ± 0.81 | 3.92 ± 1.48#* | 3.82 ± 1.53# |
| SD | 7.54 ± 0.90 | 4.20 ± 1.52#* | 4.01 ± 1.45# | ||
| mean CAL | SRP | 6.80 ± 1.71 | 4.24 ± 2.44# | 4.30 ± 2.48# | |
| SD | 6.69 ± 1.79 | 4.34 ± 2.26# | 4.44 ± 2.26# | ||
| △PPD | SRP | —— | 3.64 ± 1.40* | 3.74 ± 1.48 | |
| SD | —— | 3.35 ± 1.56* | 3.54 ± 1.51 | ||
| △CAL | SRP | —— | 2.56 ± 2.29 | 2.50 ± 2.32 | |
| SD | —— | 2.37 ± 2.22 | 2.26 ± 2.31 |
Data are presented as mean ± standard deviation (SD)
Inter-group comparisons were performed using linear mixed-effects models (LMM) with the patient as a random effect, adjusted for baseline values, age, sex, jaw position, and tooth type
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement alone, PPD Probing pocket depth, CAL Clinical attachment level
*Statistically significant difference between groups (p < 0.05)
**Statistically significant difference between groups (p < 0.01)
#Statistically significant difference from baseline (p < 0.05)
Stratified probing assessments in root bifurcation
The efficacy of the protocols was further evaluated in molar sites with and without FI. This subpopulation consisted of 250 sites without FI and 232 sites with FI in Table 8. In sites without FI, SRP group showed significantly greater PPD reduction (p < 0.01) and lower mean PPD (p < 0.01) compared to SD at 3 months and 6 months. In contrast, sites with furcation involvement showed no statistically significant inter-group differences in PPD reduction or CAL gain at any time point.
Table 8.
PPD and CAL scores of sites in root bifurcation area before and after treatment
| Baseline (mm) | 3 months (mm) | 6 months (mm) | |||
|---|---|---|---|---|---|
| without FI | mean PPD | SRP | 5.57 ± 1.40 | 3.09 ± 1.11#** | 3.04 ± 1.15#** |
| SD | 5.48 ± 1.38 | 3.28 ± 1.22#** | 3.15 ± 1.16#** | ||
| mean CAL | SRP | 4.89 ± 2.11 | 3.10 ± 2.16#* | 3.22 ± 2.20# | |
| SD | 4.75 ± 2.03 | 3.16 ± 2.05#* | 3.21 ± 2.06# | ||
| △PPD | SRP | —— | 2.49 ± 1.30** | 2.57 ± 1.37** | |
| SD | —— | 2.22 ± 1.34** | 2.37 ± 1.32** | ||
| △CAL | SRP | —— | 1.81 ± 1.87* | 1.72 ± 1.93 | |
| SD | —— | 1.64 ± 1.79* | 1.60 ± 1.82 | ||
| with FI | mean PPD | SRP | 6.17 ± 1.59 | 3.87 ± 1.48# | 4.04 ± 1.59# |
| SD | 6.01 ± 1.61 | 3.99 ± 1.20# | 3.99 ± 1.04# | ||
| mean CAL | SRP | 5.64 ± 2.27 | 3.57 ± 2.66# | 3.92 ± 2.57# | |
| SD | 5.59 ± 2.44 | 3.54 ± 2.44# | 3.81 ± 2.36# | ||
| △PPD | SRP | —— | 2.30 ± 1.46 | 2.12 ± 1.49 | |
| SD | —— | 2.02 ± 1.56 | 2.02 ± 1.59 | ||
| △CAL | SRP | —— | 2.08 ± 2.07 | 1.72 ± 2.19 | |
| SD | —— | 2.05 ± 2.32 | 1.78 ± 2.29 |
Data are presented as mean ± standard deviation (SD)
Inter-group comparisons were performed using linear mixed-effects models (LMM) with the patient as a random effect, adjusted for baseline values, age, sex, jaw position, and tooth type
SRP Ultrasonic subgingival debridement combined with manual root planing, SD Ultrasonic subgingival debridement alone, PPD Probing pocket depth, CAL Clinical attachment level
*Statistically significant difference between groups (p < 0.05)
**Statistically significant difference between groups (p < 0.01)
#Statistically significant difference from baseline (p < 0.05)
Treatment discomfort
A majority of patients reported no obvious postoperative discomfort. If any, the discomfort was short-lived and lasted no more than 3 days. Two weeks after treatment, VAS scores were ranging from 0 to 3 in 20 patients, 4 to 5 in 6 patients, 5 to 6 in 2 patients, and 7 to 8 in one patient. Further analysis revealed that teeth treated with SRP were more sensitive than those treated with SD in the upper jaw (SRP vs. SD: 2.74 ± 2.26 vs. 1.63 ± 1.96, p < 0.01), while no significant inter-group difference was found in the lower jaw (SRP vs. SD: 1.47 ± 1.61 vs. 1.39 ± 1.85). No adverse events or unintended effects were reported by any participant or observed by the clinicians throughout the entire study period.
Discussion
Data from the Fourth Chinese Oral Health Survey reveals a high prevalence of calculus (90.3% to 96.7%) and deep periodontal pockets (6.9% to 15.1%) among adults aged 35 to 74 years. Compared with prior data, there has been a significant decrease in periodontal health and an increase in gingival bleeding and deep pockets from 2005 to 2015 [26, 27]. This high disease burden presents a substantial challenge for public health and necessitates efficient, effective therapeutic protocols. The primary objective of non-surgical periodontal therapy (NSPT) is the disruption of the subgingival biofilm and the removal of calculus to establish a biologically compatible root surface [28]. Historically, "scaling and root planing" implied the intentional removal of cementum to eliminate endotoxins. However, contemporary evidence suggests that endotoxins are surface-adsorbed, thus, "subgingival debridement" is now the preferred concept, emphasizing the preservation of tooth structure while effectively removing deposits [11, 29].
The present split-mouth randomized controlled trial demonstrates that in patients with generalized severe periodontitis, ultrasonic subgingival debridement combined with manual root planing yielded statistically greater improvements in periodontal parameters compared to ultrasonic subgingival debridement alone. Our analysis revealed that SRP conferred a specific advantage in both PPD reduction and CAL gain. The adjusted MD in PPD reduction was 0.20 mm (95% CI: [0.13, 0.27]) favoring SRP at 3 months, which persisted as a 0.11 mm advantage at 6 months (95% CI: [0.05, 0.18]). Crucially, regarding CAL, which serves as a vital indicator of true periodontal support, SRP group demonstrated a concurrent adjusted gain of 0.10 mm (95% CI: [0.01, 0.19]) over SD at 3 months. Although the CAL difference narrowed and lost statistical significance by 6 months, the initial gain suggests that manual instrumentation facilitates a more rapid stabilization of the clinical benefit. With respect to patient-level clinical endpoints, our analysis of full-mouth dentition indicated that SRP significantly increased the rate of pocket closure (PPD ≤ 4 mm). The adjusted risk difference was 2.20% (95% CI: [0.24%, 4.17%]) at 3 months and 1.74% (95% CI: [0.18%, 3.30%]) at 6 months. From a mechanistic interpretation, these findings imply that while ultrasonic instrumentation is efficient for bulk debridement, the adjunctive use of manual curettes provides superior tactile feedback and facilitate the removal of adherent subgingival calculus and biofilm from root irregularities. Although this absolute magnitude appears modest, it remains clinically significant. By pushing more borderline sites across the threshold into the "closed" category (PPD ≤ 4 mm), the combined therapy effectively reduces the overall burden of residual disease. Nevertheless, long-term periodontal stability is contingent upon strict compliance with supportive periodontal therapy (SPT). Indeed, systematic evaluation indicates that retreatment constitutes an integral component of the maintenance phase to prevent disease progression and tooth loss [30].
The necessity of SD with SRP remains a subject of ongoing clinical debate. Some studies show the similar results to the present study [25, 32], However, recent systematic reviews concluded that manual and power-driven instrumentation are generally equivalent in terms of clinical outcomes, The weighted mean PPD reduction for deep pockets reported in meta-analyses typically ranges from 1.7 mm to 2.6 mm, with no consistent superiority attributed to a single modality [31]. While ultrasonic instrumentation is efficient, the supplemental tactile precision of manual curettes remains indispensable for the definitive resolution of advanced periodontal defects [34]. The analysis shows the advantage of SRP was evident in both moderate (4–6 mm) and deep (≥ 7 mm) pockets, aligning with recent meta-analyses suggesting that manual instrumentation may provide superior PPD reduction in deep pockets compared to ultrasonic instrumentation alone [35].
Subgroup analyses further elucidated the influence of local anatomy on treatment outcomes. When analyzing jaw position, outcomes were generally comparable between the upper and lower jaws, suggesting that the complexity of the maxilla versus the mandible plays a less critical role than the specific tooth type in determining the added benefit of manual instrumentation. In contrast to the assumption that manual instrumentation is primarily effective in accessible areas [36], our subgroup analysis revealed that the advantage of SRP was consistent across all tooth types. Anterior teeth and premolars treated with SRP exhibited highly significant PPD reduction and CAL gain compared to those treated with SD (p < 0.01). This finding likely reflects the accessibility of single-rooted teeth, where the precise adaptation of curettes allows for thorough debridement of root surfaces that might be less effectively instrumented by ultrasonic tips alone due to curvature or angulation. Notably, statistically significant improvements favoring SRP were also observed in molars (p < 0.05), although the significance level was slightly lower compared to single-rooted teeth. While specific studies have previously reported superior outcomes with manual root planing in bifurcations [28], the slightly attenuated advantage in our molar subgroup suggests that anatomical complexities, particularly furcation involvement, may partially mitigate the benefits of mechanical debridement. This observation underscores the inherent limitation of non-surgical therapy in complex posterior sites, where anatomical concavities often shelter biofilm from both ultrasonic and manual instruments [37]. Therefore, despite the statistical benefit of SRP in molars, for advanced furcation defects, non-surgical therapy serves primarily as a preparatory phase, and surgical access or regenerative procedures may be inevitable for definitive management [31].
Regarding patient-reported outcomes, the incidence of hypersensitivity was low in both groups, likely attributable to the strict plaque control regimen implemented during the maintenance phase [38]. This aligns with systematic reviews indicating that patient acceptance and pain perception are generally comparable between hand and ultrasonic instrumentation [33]. Dentine hypersensitivity is a reported adverse effect of root instrumentation [39]. In present study, treatment procedure employed reduced this risk by restricting manual curettes to the final smoothing phase, optimized clinical endpoints without compromising patient comfort.
This study is limited by its 6-month follow-up period, which precludes the assessment of long-term tooth survival and disease stability. Furthermore, the effectiveness of manual root planing is inherently operator-sensitive, potentially limiting the generalizability of findings to clinicians with varying levels of proficiency. Future research should focus on long-term cost-effectiveness analyses to determine if the modest clinical gains provided by combined therapy translate into reduced surgical needs and improved tooth retention over extended periods.
Conclusion
Within the limits of this split-mouth randomized controlled trial, both ultrasonic debridement alone and the combined protocol resulted in significant clinical improvements. However, the adjunctive use of manual root planing yielded a statistically significant, though modest, additional benefit in reducing probing pocket depths and increasing clinical attachment levels, particularly in the early healing phase. Crucially, the combined therapy reduced the frequency of residual deep pockets, which may lower the immediate need for surgical intervention in severe periodontitis cases. Clinicians should view this combined approach as part of a comprehensive, stepwise treatment strategy that invariably requires ongoing maintenance and potential retreatment. Future research should focus on long-term tooth survival and cost-effectiveness to further delineate the role of manual instrumentation in modern periodontal therapy.
Authors’ contributions
Cheng Lin and You-Min Mei designed the study. Cheng Lin and You-Min Mei conducted the study. Yue Yan and Xian-E Wang collected the data. Chang Shu and Yue Yan drafted the manuscript. Yi Feng revised the manuscript content. Cheng Lin and You-Min Mei were devoted to project administration. Jian-Xia Hou and You-Min Mei contributed to funding acquisition. All authors agreed to the published version of the manuscript.
Funding
This work was supported by the Guiding Project of Jiangsu Provincial Scientific Research on Preventive Medicine (YL2023021) and the Preventive Medicine Research Project of Jiangsu Province (QN2023051).
Data availability
No datasets were generated or analysed during the current study.
Declarations
Ethics approval and consent to participate
This clinical trial was registered with the Chinese Clinical Trial Registry (Registration No. ChiCTR1800017122) on July 12, 2018. The study protocol was reviewed and approved by the Ethics Committee of Peking University School and Hospital of Stomatology. All research procedures involving human participants were conducted in strict accordance with the ethical standards outlined in the Declaration of Helsinki (as revised in 2013) and in compliance with institutional and national regulations. Prior to enrollment, written informed consent was obtained from all participants after providing a full explanation of the study objectives, procedures, and potential risks.
Consent for publication
All authors agree to publication.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Cheng Lin and You-Min Mei contributed equally to this work.
References
- 1.Aleo JJ, De Renzis FA, Farber PA. In vitro attachment of human gingival fibroblasts to root surfaces. J Periodontol. 1975;46(11):639–45. 10.1902/jop.1975.46.11.639. [DOI] [PubMed] [Google Scholar]
- 2.Aleo JJ, De Renzis FA, Farber PA, Varboncoeur AP. The presence and biologic activity of cementum-bound endotoxin. J Periodontol. 1974;45(9):672–5. 10.1902/jop.1974.45.9.672. [DOI] [PubMed] [Google Scholar]
- 3.Assad DA, Dunlap RM, Weinberg SR, Ahl DR. Biologic preparation of diseased root surfaces. J Periodontol. 1987;58(1):30–3. 10.1902/jop.1987.58.1.30. [DOI] [PubMed] [Google Scholar]
- 4.Jones WA, O’Leary TJ. The effectiveness of in vivo root planing in removing bacterial endotoxin from the roots of periodontally involved teeth. J Periodontol. 1978;49(7):337–42. 10.1902/jop.1978.49.7.337. [DOI] [PubMed] [Google Scholar]
- 5.Daly CG, Seymour GJ, Kieser JB. Bacterial endotoxin: a role in chronic inflammatory periodontal disease? J Oral Pathol Med. 1980;9(1):1–15. 10.1111/j.1600-0714.1980.tb01383.x. [DOI] [PubMed] [Google Scholar]
- 6.Hughes FJ, Auger DW, Smales FC. Investigation of the distribution of cementum-associated lipopolysaccharides in periodontal disease by scanning electron microscope immunohistochemistry. J Periodontal Res. 1988;23(2):100–6. 10.1111/j.1600-0765.1988.tb01341.x. [DOI] [PubMed] [Google Scholar]
- 7.Hughes FJ, Smales FC. Immunohistochemical investigation of the presence and distribution of cementum-associated lipopolysaccharides in periodontal disease. J Periodontal Res. 1986;21(6):660–7. 10.1111/j.1600-0765.1986.tb01503.x. [DOI] [PubMed] [Google Scholar]
- 8.Hughes FJ, Smales FC. The distribution and quantitation of cementum-bound lipopolysaccharide on periodontally diseased root surfaces of human teeth. Arch Oral Biol. 1990;35(4):295–9. 10.1016/0003-9969(90)90046-D. [DOI] [PubMed] [Google Scholar]
- 9.Nakib NM, Bissada NF, Simmelink JW, Goldstine SN. Endotoxin penetration into root cementum of periodontally healthy and diseased human teeth. J Periodontol. 1982;53(6):368–78. 10.1902/jop.1982.53.6.368. [DOI] [PubMed] [Google Scholar]
- 10.Smart GJ, Wilson M, Davies EH, Kieser JB. The assessment of ultrasonic root surface debridement by determination of residual endotoxin levels. J Clin Periodontol. 1990;17(3):174–8. 10.1111/j.1600-051X.1990.tb01082.x. [DOI] [PubMed] [Google Scholar]
- 11.Laleman I, Cortellini S, De Winter S, Rodriguez Herrero E, Dekeyser C, Quirynen M, et al. Subgingival debridement: end point, methods and how often? Periodontol 2000. 2017;75(1):189–204. 10.1111/prd.12204. [DOI] [PubMed] [Google Scholar]
- 12.Badersten A, Nilveus R, Egelberg J. Effect of nonsurgical periodontal therapy. J Clin Periodontol. 1981;8(1):57–72. 10.1111/j.1600-051X.1981.tb02024.x. [DOI] [PubMed] [Google Scholar]
- 13.Badersten A, Nilveus R, Egelberg J. Effect of nonsurgical periodontal therapy. J Clin Periodontol. 1984;11(1):63–76. 10.1111/j.1600-051X.1984.tb01309.x. [DOI] [PubMed] [Google Scholar]
- 14.Badersten A, Nilveus R, Egelberg J. Effect of nonsurgical periodontal therapy III. Single versus repeated instrumentation. J Clin Periodontol. 1984;11(2):114–24. 10.1111/j.1600-051X.1984.tb00839.x. [DOI] [PubMed] [Google Scholar]
- 15.Christgau M, Männer T, Beuer S, Hiller KA, Schmalz G. Periodontal healing after non-surgical therapy with a new ultrasonic device: a randomized controlled clinical trial. J Clin Periodontol. 2007;34(2):137–47. 10.1111/j.1600-051X.2006.01031.x. [DOI] [PubMed] [Google Scholar]
- 16.Geng S, Xu L, Cao C, Ying P. Clinical effects and image analysis of subgingival scaling with hand or ultrasonic instruments. Shanghai J Stomatol. 1992;1(2):73–6. [PubMed] [Google Scholar]
- 17.Torfason T, Kiger R, Selvig KA, Egelberg J. Clinical improvement of gingival conditions following ultrasonic versus hand instrumentation of periodontal pockets. J Clin Periodontol. 1979;6(3):165–76. 10.1111/j.1600-051X.1979.tb02196.x. [DOI] [PubMed] [Google Scholar]
- 18.Ioannou I, Dimitriadis N, Papadimitriou K, Sakellari D, Vouros I, Konstantinidis A. Hand instrumentation versus ultrasonic debridement in the treatment of chronic periodontitis: a randomized clinical and microbiological trial. J Clin Periodontol. 2009;36(2):132–41. 10.1111/j.1600-051X.2008.01347.x. [DOI] [PubMed] [Google Scholar]
- 19.Krishna R, De Stefano JA. Ultrasonic vs. hand instrumentation in periodontal therapy: clinical outcomes. Periodontol 2000. 2016;71(1):113–27. 10.1111/prd.12119. [DOI] [PubMed] [Google Scholar]
- 20.Papapanou PN, Sanz M, Buduneli N, Dietrich T, Feres M, Fine DH, et al. Periodontitis: consensus report of workgroup 2 of the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases and Conditions. J Periodontol. 2018;89(S1):S173–82. 10.1002/JPER.17-0721. [DOI] [PubMed] [Google Scholar]
- 21.Silness J, Löe H. Periodontal disease in pregnancy II. Correlation between oral hygiene and periodontal condition. J Periodontal Res. 1964;22(1):121–35. 10.3109/00016356408993968. [DOI] [PubMed] [Google Scholar]
- 22.Mazza JE, Newman MG, Sims TN. Clinical and antimicrobial effect of stannous fluoride on periodontitis. J Clin Periodontol. 1981;8(3):203–12. 10.1111/j.1600-051X.1981.tb02031.x. [DOI] [PubMed] [Google Scholar]
- 23.Pozos-Guillén A, Chavarría-Bolaños D, Garrocho-Rangel A. Split-mouth design in paediatric dentistry clinical trials. Eur J Paediatr Dent. 2017;18(1):61–5. 10.23804/ejpd.2017.18.01.13. [DOI] [PubMed] [Google Scholar]
- 24.Feng X, Lu R, He L. A short-term clinical evaluation of periodontal treatment with an Er: YAG laser for patients with chronic periodontitis: a split-mouth controlled study. Journal of Peking University (Health Sciences). 2011;43(6):886–90. [PubMed] [Google Scholar]
- 25.Gao X, Liang Y. Clinical evaluation of using subgingival ultrasonic scaling and combined with hand scaling. Chin J Dent Mater Devices. 2012;21(3):137–9. [Google Scholar]
- 26.Feng, X. Oral health status of Chinese residents -- the fourth epidemiological survey of oral health in China. Paper presented at the 18th annual meeting of oral preventive medicine for Chinese stomatological association, Xi'an. 2018.
- 27.Meng Y, Liu X, Zheng S. Status and analysis of oral disease burden comparison of the domestic and overseas data. Chin J Stomatol. 2017;52(6):386–9. [DOI] [PubMed] [Google Scholar]
- 28.Sanz M, Herrera D, Kebschull M, Chapple I, Jepsen S, Berglundh T, et al. Treatment of stage I-III periodontitis-the EFP S3 level clinical practice guideline. J Clin Periodontol. 2020;47(S22):4–60. 10.1111/jcpe.13290. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Suvan J, Leira Y, Moreno Sancho FM, Graziani F, Derks J, Tomasi C. Subgingival instrumentation for treatment of periodontitis. A systematic review. J Clin Periodontol. 2020;47(S22):155–75. 10.1111/jcpe.13236. [DOI] [PubMed] [Google Scholar]
- 30.Leow N, Needleman I, Salvi GE, Guerrero A, Nibali L. Recurrence and progression of periodontitis and methods of management in long-term care: a systematic review and meta-analysis. J Clin Periodontol. 2022;49(S24):144–77. [DOI] [PubMed] [Google Scholar]
- 31.Dommisch H, Walter C, Dannewitz B, Eickholz P. Resective surgery for the treatment of furcation involvement: a systematic review. J Clin Periodontol. 2020;47(S22):375–91. [DOI] [PubMed] [Google Scholar]
- 32.Zhang Y, Liu X, Zheng R, Yang X, Ren Y. Clinical observation on the effect of Gracey curettage combined with P5 therapy device for subgingival debridement of periodontitis. China Mod Doctor. 2010;48(18):21–3. [Google Scholar]
- 33.Muniz FWMG, Langa GPJ, Pimentel RP, Martins JR, Pereira DH, Rösing CK. Comparison between hand and sonic/ultrasonic instruments for periodontal treatment: systematic review with meta-analysis. J Int Acad Periodontol. 2020;22(4):187–204. [PubMed] [Google Scholar]
- 34.Graziani F, Karapetsa D, Mardas N, Leow N, Donos N. Surgical treatment of the residual periodontal pocket. Periodontol 2000. 2018;76(1):150–63. 10.1111/prd.12156. [DOI] [PubMed] [Google Scholar]
- 35.Zhang X, Hu Z, Zhu X, Li W, Chen J. Treating periodontitis-a systematic review and meta-analysis comparing ultrasonic and manual subgingival scaling at different probing pocket depths. BMC Oral Health. 2020;20(1):176. 10.1186/s12903-020-01117-3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 36.Bower RC. Furcation entrance anatomy in relation to periodontal curette blades. J Periodontol. 1979;50(1):23–7. 10.1902/jop.1979.50.1.23-27. [DOI] [PubMed] [Google Scholar]
- 37.Nibali L, Zavattini A, Nagata K, Di Iorio A, Lin GH, Needleman I, et al. Tooth loss in molars with and without furcation involvement: a systematic review and meta-analysis. J Clin Periodontol. 2016;43(2):156–66. 10.1111/jcpe.12497. [DOI] [PubMed] [Google Scholar]
- 38.Gong Y, Ding X, Ren Y. Clinical evaluation of dentine sensitivity after scaling and root planing. Int J Stomatol. 2009;36(3):256–9. [Google Scholar]
- 39.Puglisi R, Santos A, Pujol A, Ferrari M, Nart J, Pascual A. Clinical comparison of instrumentation systems for periodontal debridement: a randomized clinical trial. Int J Dent Hyg. 2022;20(2):328–38. 10.1111/idh.12520. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
No datasets were generated or analysed during the current study.