Effectiveness of Ultrasonic and Manual Instrumentation in Nonsurgical Periodontal Therapy: Are Additional Therapies More Effective? A Systematic Review

Abstract

Nonsurgical periodontal therapy aims to remove supragingival and subgingival biofilm to restore periodontal health. This systematic review aims to assess the clinical effectiveness of manual and/or ultrasonic instruments and to determine whether other therapies can improve periodontal clinical outcomes. Case-control, cross-sectional and cohort studies and clinical trials of patients undergoing nonsurgical periodontal therapy with ultrasonic and/or manual instruments (and any adjunctive therapies, such as glycine, erythritol, ozone, laser and glycine) from 2013 to 2023 were analyzed using Pub-med/MEDLINE, Scopus and Google Scholar. To assess the risk of bias in this review, blinding, randomization, allocation concealment, outcome data and outcome recording were assessed. No differences between treatments were found; all methods, including manual and ultrasound, were helpful in improving clinical parameters (primary outcome). Although the results were mixed, adjunctive therapies seemed to be helpful in the treatment of periodontal disease. The results of this systematic review are consistent with the previous scientific literature and have shown that both manual and ultrasonic instruments are effective in nonsurgical periodontal therapy. This review could not show how complementary therapies could further improve nonsurgical periodontal therapy. For future research, it would be good to standardize the sample with regard to the degree and stage of periodontal disease and to evaluate the risks and benefits of the instruments (manual and ultrasonic scalers).

1. Introduction

Periodontal disease is a chronic condition that affects the supporting tissues of the teeth and is becoming increasingly prevalent worldwide. In fact, according to the Global Burden of Disease Study, periodontal disease is the 11th most common disease in the world, with over 40% of the population in developed countries showing clinical signs [1,2].

Nonsurgical periodontal therapy plays a fundamental role in the treatment of periodontal disease and consists of removing the main aetiological factors, i.e., supra- and subgingival biofilm and bacterial toxins, with the aim of reducing gingival inflammation, bleeding on probing and the probing depth. The cause is usually bacterial, although, depending on the situation, there may be several causes that alone are not able to induce the disease state but can be recognized as independent inflammatory states (oedematous and bleeding tissue, gingival hypertrophy, bleeding) [3,4,5,6].

Periodontal debridement can be performed using either ultrasonic or manual instruments, as has been well documented in the scientific literature [3,4,5,6].

In recent years, more and more innovative instruments have been studied: manual instrumentation with handles of appropriate diameters, which ensure the ergonomic control of the instrument and, through the choice of the working part, the effectiveness of the therapy, even in the presence of complex anatomical situations, and ultrasonic instrumentation with scalers, which allow for different treatment modes and are used increasingly with perio-anatomical inserts [7,8].

It seems that the combination of instruments is the most effective treatment to avoid an overtreatment: several studies have shown that an excessive use of manual instruments is not very effective in the treatment of moderate and/or severe pockets and that the width of the blade does not allow an excellent access in the forks of multi-radicular teeth [9].

Over the years, other therapies have been proposed for nonsurgical periodontal treatment, such as laser and ozone therapies and the use of powders with air and perio-flow systems, such as glycine and/or erythritol. These therapies support the traditional scaling and root planning, using ultrasonic and manual instruments.

Lasers have been the subject of clinical trials to highlight their benefits, such as a reduction in the probing pocket depth and bleeding on probing, along with a reduction in pro-inflammatory parameters [10,11].

Due to the increased local oxygen supply, ozone is used as a potent disinfectant that can regulate and cleanse the soft tissue, thereby facilitating healing. It is also a thousand times more effective than other antibacterial agents, killing bacteria much faster at high doses [12]; some studies have shown improvements in the probing pocket depth, plaque index and bacterial counts (including Aggregatibacter actinomycetemcomitans) [13]. However, a recent review of the literature found no additional benefit from ozone [14].

Finally, powders (glycine/erythritol) have been widely used in clinical practice in recent years to remove subgingival biofilm and reduce the bacterial count of Porphyromonas gingivalis [15].

The aim of this review is to analyze the effectiveness of manual and/or ultrasonic instruments in nonsurgical periodontal treatment (primary outcome) in terms of reducing clinical indices, such as the probing pocket depth, loss of clinical attachment and bleeding on probing. However, gingival recessions are a factor to be considered as they are inevitable after periodontal treatment due to post-treatment swelling and tissue contraction: this may be due in part to limited vision and inadequate access, which would compromise the stability of the gingival tissue and affect the healing process [16]. This result does not show a significant difference between manual and ultrasonic treatment [9]; therefore, the second aim of this review is to show whether additional therapies, such as laser, ozone and glycine and/or erythritol therapies, can provide better clinical results in terms of periodontal indices (secondary outcome).

2. Materials and Methods

2.1. Focused Question

The present literature review aims to evaluate the efficacy of ultrasonic debridement and/or manual debridement in nonsurgical periodontal therapy (NSPT) (primary outcome) and to assess whether additional therapies, such as laser, ozone and glycine and/or erythritol therapies, can provide better clinical results in periodontal indices (secondary outcome).

2.2. Eligibility Criteria

Studies in accordance with the following inclusion criteria were included:

Type of studies. Case-control, cross-sectional, and cohort studies and clinical trials.

Type of participants. Patients with periodontitis undergoing nonsurgical periodontal therapy (NSPT)

Type of interventions. Case-control, cross-sectional, and cohort studies and clinical trials that evaluated ultrasonic and/or manual debridement as a test or as a control in NSPT or laser/ozone/powders.

Outcome type. Improvement of clinical indices (mainly PPD, CAL and BoP) to understand the effectiveness of ultrasonic and/or manual debridement and, if possible, to understand if these were better than other therapies (primary outcome). Improvement of clinical indices (mainly PPD, CAL and BoP) to understand the effectiveness of adjunctive therapies (laser, ozone, glycine/erythritol).

Research that satisfied all inclusion criteria were included in the second phase, which involved analyzing the chosen research in accordance with the exclusion criteria, which were studies (I) without at least one clinical outcome reported by the authors; studies (II) conducted in vitro or on animals; studies (III) conducted without Ethics Committee approval; reviews and metanalysis; studies (IV) not published in English; and studies (VI) focused on supportive periodontal therapy.

2.3. Search Strategy

The review is founded on studies that were found by searching electronic databases for bibliographic information and by looking through the article bibliographies on Pubmed/MEDLINE, Scopus and Google Scholar. At first, every study abstract was taken into account.

2.4. Research

We used the following keywords in our search: “Non-surgical periodontal therapy” AND “ultrasonic devices”; “Non-surgical periodontal therapy” AND “ultrasonic scalers”; “Non-surgical periodontal therapy” AND “ultrasonic debridement”; “Non-surgical periodontal therapy” AND “ultrasonic instrumentation”; “Periodontitis” AND “ultrasonic devices”; “Periodontitis” AND “ultrasonic scalers”; “Periodontitis” AND “ultrasonic debridement”; “Periodontitis” AND “ultrasonic instrumentation”; “Periodontal treatment” AND “ultrasonic devices”; “Periodontal treatment” AND “ultrasonic scalers”; “Periodontal treatment” AND “ultrasonic debridement”; “Periodontal treatment” AND “ultrasonic instrumentation”; “Non-surgical periodontal therapy” AND “hand instruments”; “Non-surgical periodontal therapy” AND “manual instrumentation”; “Non-surgical periodontal therapy” AND “curettes”; “Periodontitis” AND “hand instruments”; “Periodontitis” AND “manual instrumentation”; “Periodontitis” AND “curettes”; “Periodontal treatment” AND “hand instruments”; “Periodontal treatment” AND “manual instrumentation”; “Periodontal treatment” AND “curettes”; “Non-surgical periodontal therapy” AND “laser”; “Periodontitis” AND “laser”; “Periodontal treatment” AND “laser”; “Non-surgical periodontal therapy” AND “ozone”; “Periodontitis” AND “ozone”; “Non-surgical periodontal therapy” AND “ozone”; “Non-surgical periodontal therapy” AND “glycine”; “Periodontitis” AND “glycine”; “Periodontal treatment” AND “glycine”; “Non-surgical periodontal therapy” AND “erythritol”; “Periodontitis” AND “erythritol”; “Periodontal treatment” AND “erythritol”. The search used a temporal range from 2013 to 2023, to analyze the most recent findings.

2.5. Screening and Selection of Articles

Search by keywords yielded 690 results (S.S; C.M; J.B; S.C; G.DT; E.F; R.I; I.M; A.B).

Immediately, all duplicates that emerged from the different searches were removed (C.M).

In the first phase, the results (abstracts) were filtered based on the use of ultrasonic and manual instrumentation in nonsurgical periodontal therapy; all those that did not meet the eligibility criteria were discarded [(IV) reviews and metanalysis; (V) studies not published in English].

The same authors (S.S.; C.M.; J.B.; S.C.; G.D.T.; E.F.; R.I.; I.M.; A.B.) then continued reading the articles included (full-text).

After reading the selected articles, all those that had not considered at least one clinical outcome (mainly PPD and CAL) and the studies that had considered the use of the instruments in periodontal support therapy were removed (S.S.; A.B.) [17], Figure 1.

Of these, after removing those not relevant to the eligibility criteria, 45 articles were selected for review. The review has been registered in an online register (PROSPERO; ID 511202).

2.6. Risk of Bias and Results

An author was involved in the analysis of the articles included to evaluate the results based on the problem, intervention/comparison (type of instrumentation) and outcome. Another author was then responsible for evaluating the quality of the RCTs (Randomized Clinical Trials) included, on the basis of information that emerged from the reading of the articles [17,18].

3. Results

3.1. RCTs (Ultrasonic and Manual Instruments)

Population: a total of 827 patients were included in the trials analyzed; an average of males and females cannot be taken into account because the sex of the patients is missing in two trials.

Comparison: the test or control group had to have undergone nonsurgical periodontal treatment with an ultrasonic scaler or hand instruments: For ultrasonic treatment, piezoelectric or magnetostrictive scalers, mostly with perioslim inserts, were used (66.7% and 33.3%, respectively; one study did not specify the type of ultrasonic scaler used); for hand instruments, gracey, gracey mini-five or universal curettes were used (66.7%, 11.1% and 11.1%, respectively; two studies did not specify the type of curettes used).

Indices: the indices evaluated were the probing pocket depth (PPD; 100%), loss of clinical attachment (CAL; 88.9%), bleeding on probing (BoP; 55.5%), gingival bleeding index (GBI, 11.1%), full-mouth bleeding score (FMBS, 11.1%), plaque index (PI; 77.8%), full-mouth plaque score (FMPS, 11.1%), gingival recessions (GR/REC; 44.4%) and gingival index (GI, 33.3%).

Outcomes: all treatments, ultrasonic instrumentation and manual instrumentation are effective in improving clinical parameters (primary outcome); no significant differences were found between the different treatments,

Table 1. RCTs included (ultrasonic and manual instruments) [19,20,21,22,23,24,25,26,27].

Articles	Type of Study	Problem	Intervention/Comparison	Clinical Indeces/Follow-Up	Outcome
Arpağ et al., 2017 [19]	RCT	Determine the effect of vector ultrasonic system (VUS) on the levels of TNF-α in gingival crevicular fluid (GCF) and the clinical parameters in patients with chronic periodontitis	30 patients were included for a split-mouth treatment: (A) scaling and root planing with hand instrument; (B) vector ultrasonic systems	PPD, CAL, PI, GI 6 months	Significant clinical improvements were seen with all treatments, yet there was no discernible variation across the groups.
Puglisi et al., 2022 [20]	RCT	Examine the clinical effectiveness, chairside duration and hypersensitivity following treatment of four instruments utilized in subgingival periodontal debridement	This split-mouth design was used to enroll 17 patients with stage II and III periodontitis in a randomized clinical trial. Four treatment groups were randomly selected from the quadrants: Group D, piezosurgery ultrasonic with PP1 insert; Group C, diamond burs, 40 µm; Group D, piezoelectric ultrasonic with No.1S insert; Group A, gracey curettes.	PPD, CAL, PI, REC 2 months	All treatments resulted in a significant clinical improvement, but there were no significant differences among groups.
Petelin et al., 2015 [21]	RCT	Compare the effect of subgingival ultrasonic scaling followed by repeated (three times) antimicrobial photodynamic therapy (PDT), ultrasonic scaling alone (US), and scaling and root planing with hand instruments (SRP) for initial periodontal treatment	27 non-smoking, systemically healthy chronic periodontitis patients were included. Residual pockets ≥ 4 mm deep and bleeding on probing were debrided either with SRP, US alone or US followed by a single episode of PDT during supportive periodontal treatment.	PPD, CAL BoP 12 months	All treatments resulted in a significant clinical improvement, but there were no significant differences among groups.
Malali et al., 2012 [22]	RCT	Compare the clinical parameters and crevicular cell population, particularly leukocyte counts, and changes after initial periodontal therapy with different instruments in severe periodontitis patients	30 systemically healthy subjects with severe chronic periodontitis were randomly assigned to three groups (n = 10) and were treated either with hand curettes, ultrasonic scalers or an Er:YAG laser alone.	PPD, CAL, BoP, PI, GI 3 months	All treatments resulted in a significant clinical improvement, but there were no significant differences among groups.
Kargas et al., 2015 [23]	RCT	Evaluate the efficacy of glycine powder air-polishing in treatment periodontal pockets equal or up to 4 mm	Each quadrant of 25 subjects was randomly assigned to the following treatments: subgingival scaling with hand instruments (SRP), GPAP, subgingival ultrasonic debridement (UD) and no subgingival treatment (NT).	PPD, CAL, PI, GI, REC	All treatments resulted in a significant clinical improvement, but there were no significant differences among groups.
Tomasi et al., 2022 [24]	RCT	Evaluate the effectiveness of two nonsurgical treatment protocols for periodontitis patients in general dental practice	615 patients were divided into two groups: (A) single session of ultrasonic instrumentation (guided periodontal infection control [GPIC]) or (B) conventional nonsurgical therapy (CNST), including patient education and scaling and root planing integrated in multiple sessions.	PPD, BoP 6 months	All treatments resulted in a significant clinical improvement, but there were no significant differences among groups.
Johnston et al., 2020 [25]	RCT	Investigate whether the immediate systemic inflammatory response following full-mouth debridement differs following use of hand compared with ultrasonic instruments	37 periodontitis patients were randomized to treatment with full-mouth debridement using either hand or ultrasonic instrumentation completed within 24 h.	PPD, CAL, FMBS, FMPS 3 months	All treatments resulted in a significant clinical improvement, but there were no significant differences among groups.
Dilsiz et al., 2015 [26]	RCT	Examine and contrast the immediate impact of tool trauma on the clinical attachment level following nonsurgical periodontal therapy using Nd:YAG lasers and ultrasonic scalers	24 patients with untreated chronic periodontitis were entered into the study. Each quadrant was randomly allocated in a split-mouth design either to treatment with Nd:YAG laser using an energy of 1 W, 100 mj and 1064 nm (test group) or to periodontal treatment using ultrasonic scalers (control group).	PPD, CAL, BoP, PI No clear follow-up	All treatments resulted in a significant clinical improvement, but there were no significant differences among groups.
Meulman et al., 2013 [27]	RCT	Evaluate the effectiveness of a full-mouth ultrasonic debridement technique in treating smokers’ severe chronic periodontitis in contrast to a quadrant-wise therapy involving scaling and root planing	30 patients with periodontitis were split into three groups: Group SRP (scaling and root planing performed in a quadrant-wise manner for smokers; n = ten); Group FMUD (full-mouth ultrasonic debridement); and Group Control (scaling and root planing for nonsmokers; n = ten), treated using the same protocol as the SRP group.	PPD, CAL, BoP, PI, REC 6 months	Significant clinical improvements were seen with all treatments, yet there was no discernible variation across the groups.

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The results indicate that ultrasonic and manual instrumentation are comparable in terms of reductions in the probing pocket depth, loss of clinical attachment, bleeding on probing, plaque index/plaque score, gingival index and gingival recessions. Any type of instrumentation, whether ultrasonic or manual, is still effective (primary outcome).

3.2. RCTs (Laser)

Population: a total of 570 patients were included in the trials analyzed; an average of males and females cannot be taken into account because in a few trials the sex of the patients was missing.

Comparison: the test group had to have undergone nonsurgical periodontal therapy with an ultrasonic scaler or hand instruments and laser, while the control group must have undergone SRP only; PDT was used in 45% of the studies, a diode laser was used in 35% of the studies and Er,Cr:YSGG laser (20%), LLT (20%), KTP laser and Er:YAG were used in the remaining studies.

Indices: the indices evaluated were the probing pocket depth (PPD; 100%), loss of clinical attachment (CAL; 90%), bleeding on probing (BoP; 70%), gingival bleeding index (GBI, 10%), sulculus bleeding index (10%), plaque index (PI; 65%), full-mouth plaque score (FMPS, 5%), gingival recessions (GR/REC; 20%) and gingival index (GI, 30%).

Outcomes: all treatments are effective in improving clinical parameters; in 65% of the studies, significant differences in clinical parameters were found for SRP treatment followed by laser therapy,

Table 2. RCTs included (laser) [28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47].

Articles	Type of Study	Problem	Intervention/Comparison	Clinical Indices/Follow-Up	Outcome
Dukic et al., 2013 [28]	RCT	35 patients with chronic periodontitis	Test: SRP + diode laser Control: SRP	CAL, PPD, BOP, API; 18 weeks	The current study shows that only significant periodontal pockets demonstrated PD improvements with several adjunctive administrations of a 980 nm diode laser combined with SRP, as opposed to SRP alone.
De Melo Soares et al., 2019 [29]	RCT	30 patients with chronic periodontitis	Test: SRP + PDT (diode laser) Control: SRP	CAL, PPD, BOP, PI, MB; 3 months	When compared to SRP alone, aPDT as an adjuvant to SRP did not show statistically significant advantages on clinical parameters.
Gurpegui et al., 2022 [30]	RCT	30 patients with generalized moderate-to-severe chronic periodontitis of generalized stages II or III and Grade B periodontitis	Test: SRP + Er:YAG laser Control: SRP	CAL, PPD, BOP, PI, GR; 3 months	Both treatments resulted in overall improvement, but no significant differences were found between modalities for clinical attachment gain or probing depth reduction.
Pai et al., 2021 [31]	RCT	15 patients with chronic periodontitis	Test: SRP + diode laser Control: SRP	CAL, PPD, BI, GI; 3 months	After three months, this study revealed a statistically significant decrease in clinical indices in both the test and control groups. After three months, the sclerostin levels in GCF were statistically significant in both groups, with the test group exhibiting a highly significant drop.
Dilsiz et al., 2013 [32]	RCT	24 patients with chronic periodontitis	Test 1: SRP + KTP laser Test 2: SRP + PDT Control: SRP	CAL, PPD, BOP, PI, GI; 6 months	KTP laser group showed a greater reduction in PD compared to the other groups (p < 0.05). In addition, KTP laser group showed a greater CAL gain compared to the other groups (p < 0.05).
Dereci et al., 2016 [33]	RCT	60 patients with chronic periodontitis	Test: SRP + Er,Cr:YSGG laser Control: SRP + placebo	CAL, PPD, BOP, PI; 6 months	Er,Cr:YSGG laser assisted conventional periodontal therapy is more effective in improving periodontal healing compared to conventional periodontal therapy alone.
Hatipoglu et al., 2017 [34]	RCT	40 patients with chronic periodontitis	Test: SRP + indium–gallium–aluminium–phosphate diode laser Control: SRP	CAL, PPD, BOP, PI, GI; 6 months	The present study indicates that compared to SRP solely, adjunctive applications of a 940 nm diode laser with SRP showed lower bleeding on probing.
Matarese et al., 2017 [35]	RCT	31 patients with a diagnosis of GAgP	Test: SRP + diode laser Control: SRP + placebo	CAL, PPD, BOP, FMPS; 1 month	At 1 year, SRP + diode laser yielded a significant reduction in some clinical parameters.
Ustun et al., 2018 [36]	RCT	40 patients with chronic periodontitis	Test: SRP + Er,Cr:YSGG laser Control: SRP	CAL, PPD, BOP, PI, GI; 6 months	After periodontal treatment, CAL, PD, BOP, GI and PI, which are clinical parameters analyzed, decreased significantly (p < 0.05) in both test and control groups.
Alwaeli et al., 2013 [37]	RCT	16 patients with chronic periodontitis	Test: SRP + PDT (diode laser) Control: SRP	CAL, PPD, BOP; 12 months	For all three time points in both groups, there was a significant decrease in PPD and BOP and a significant increase in CAL from the baseline. Furthermore, at all three time points, there were noticeably more reductions and gains for SRP + aPDT than for SRP.
Pourabbas et al., 2014 [38]	RCT	22 patients with moderate-to-severe chronic periodontitis	Test: SRP + PDT (diode laser) Control: SRP	CAL, PPD, BOP, GR; 3 months	In patients with CP, a single application of PDT did not provide any additional benefit to SRP in terms of clinical parameters or inflammatory markers 3 months following the intervention.
Birang et al., 2015 [39]	RCT	20 patients with chronic periodontitis	Test 1: diode laser Test 2: SRP + PDT Control: SRP	CAL, PPD, PI, PBI; 3 months	The 6-week evaluation revealed a statistically significant increase in CAL in the laser groups compared to the control group (p < 0.05). Additionally, Test 2 with the laser group showed a higher PPD reduction than the other treatment methods (p < 0.05).
Queiroz et al., 2015 [40]	RCT	20 patients with chronic periodontitis	Test: SRP + PDT (diode laser) Control: SRP	CAL, PPD, BOP, PI, GR; 3 months	The adjunctive effect of aPDT did not warrant improvements on clinical parameters.
Balata et al., 2013 [41]	RCT	22 patients with severe chronic periodontitis	Test: SRP + PDT (diode laser) Control: SRP	CAL, PPD, GR, BOP, GBI, VPI; 6 months	While there were notable clinical benefits with both methods for treating severe chronic periodontits, the PDT did not yield any further advantages over full-mouth ultrasonic debridement alone.
Malgikar et al., 2015 [42]	RCT	24 patients with chronic periodontitis	Test: SRP + PDT (diode laser) Control: SRP	CAL, PPD, SBI, GBI, PI; 6 months	In terms of clinical factors, a single PDT session may be applied in conjunction with scaling and root planing for the nonsurgical treatment of chronic periodontitis.
Gundogar et al., 2016 [43]	RCT	25 with generalized chronic periodontitis	Test: SRP + LLT Control: SRP	CAL, PPD, PI, GI; 1 month	LLLT as an adjunct to nonsurgical periodontal treatment has a positive impact on clinical parameters.
Manjunath et al., 2020 [44]	RCT	40 patients with chronic periodontitis	Test: SRP + diode laser Control: SRP	CAL, PPD, BOP; 3 months	There was a significant improvement in clinical parameters in the test group (SRP + laser) as compared to the control group (SRP alone).
Euzebio et al., 2013 [45]	RCT	36 patients with severe chronic periodontitis	Test: SRP + diode laser Control: SRP + placebo	CAL, PPD, BOP, PI; 6 months	After 6 months of evaluation, the high-intensity diode laser has not shown any additional benefits compared to the conventional periodontal treatment.
Bundidpun et al., 2020 [46]	RCT	20 patients with generalized moderate-to-severe chronic periodontitis	Test: SRP + PDT (diode laser) Control: SRP	CAL, PPD, PI, GBI, GI; 6 months	One visit full-mouth ultrasonic SRP seems to have a good enough effort for the periodontal status till 6 months. The adjunct treatment of PDT provided a positive effect in terms of GBI and GI.
Mishra et al., 2018 [47]	RCT	20 patients with chronic generalized periodontitis	Test: SRP + LLT (diode laser) Control: SRP	CAL, PPD, MGI, SBI; 3 months	Only in the test group did MGI, SBI and PD exhibit a significant difference; however, from baseline to three months, every parameter showed a statistically significant difference. MGI, SBI and CRP levels varied statistically significantly throughout the groups in intergroup comparison.

.

The results suggest that lasers as an adjuvant therapy to scaling and root planing can provide better clinical outcomes, although in 35% of cases it appears to provide no additional improvement (secondary outcome).

3.3. RCTs (Ozone)

Population: a total of 317 patients were included in the trials analyzed; an average of males and females cannot be taken into account because in a few trials the sex of the patients was missing.

Comparison: the test group had to have undergone nonsurgical periodontal therapy with an ultrasonic scaler or hand instruments and ozone, while the control group must have undergone SRP only; ozone gas was used in 40% of the studies, while ozonated water was used in 60% of the studies.

Indices: the indices evaluated were the probing pocket depth (PPD; 90%), loss of clinical attachment (CAL; 70%), bleeding on probing (BoP; 50%), plaque index (PI; 50%) and gingival index (GI, 60%). Microbiological samples were collected in three studies.

Outcomes: all treatments are effective in improving clinical parameters; in 50% of the trials, significant differences in clinical parameters were found for SRP treatment followed by ozone therapy,

Table 3. RCTs included (ozone) [48,49,50,51,52,53,54,55,56,57].

Articles	Type of Study	Problem	Intervention/Comparison	Clinical Indices/Follow-Up	Outcome
Seydanur Dengizek et al., 2019 [48]	RCT	40 patients with moderate generalized chronic periodontitis	Test: SRP + ozone gas Control: SRP	CAL, PPD, PI, GI; 1 month	SRP plus gaseous ozone versus SRP alone does not correlate to a significant improvement in periodontal recovery.
Tasdemir et al., 2019 [49]	RCT	36 patients with moderate and/or severe generalized periodontitis	Test: SRP + ozone gas Control: SRP	CAL, PPD, BOP, PI, GI; 3 months	Ozone therapy did not have any additional effect on periodontal parameters.
Rapone et al., 2022 [50]	RCT	90 patients with moderate or severe generalized chronic periodontitis	Test: SRP + ozone gas Control: SRP	CAL, PPD, BOP; 6 months	When SRP and ozone therapy were used together to treat periodontitis, the results were better than when SRP was used alone. From the baseline, there was a statistically significant difference between the groups’ scores for CAL, PPD and BOP.
Piva et al., 2020 [51]	RCT	10 patients with chronic periodontitis	Test: SRP + ozonated water Control: SRP	Microbiological samples; 7 days	T. forsythia and T. denticola were eradicated in the ozone group.
Uraz et al., 2019 [52]	RCT	18 patients with generalized chronic periodontitis	Test: SRP + ozone gas Control: SRP	PPD, BOP, PI, GI; 3 months	Ozone therapy did not provide additional benefits to clinical, microbiological and biochemical parameters over SRP in chronic periodontitis patients.
Al Habashneh et al., 2015 [53]	RCT	41 patients with chronic periodontitis	Test: SRP + ozonated water Control: SRP	CAL, PPD, BOP, PI, GI; 3 months	As an adjuvant therapy to SRP, ozonated water irrigation yields no statistically significant benefit.
Issac et al., 2015 [54]	RCT	30 patients with chronic periodontitis	Test: SRP + ozonated water Control: SRP	CAL, PPD, GI; microbiological samples; 4 weeks	When combined with cleaning and root planing, ozonized water subgingival irrigation can help patients with chronic periodontitis by improving their clinical and microbiological parameters.
Pandya et al., 2016 [55]	RCT	10 patients with chronic periodontitis	Test: SRP + chlorhexidine Test: SRP + ozonated water Test: SRP + saline solution Control: SRP	PPD, GI; microbiological samples; 1 month	When compared to the other two subgingival irrigants, ozonated water and 0.2% chlorhexidine gluconate were found to be the most efficacious, while saline proved to be useless.
Kaur et al., 2019 [56]	RCT	20 patients with chronic periodontitis	Test: SRP + chlorhexidine Test: SRP + ozonated water	CAL, PPD, PI; 3 months	Utilizing ozonized water for subgingival irrigation is more advantageous than current traditional treatment approaches. By limiting the production of tooth plaque and lowering the quantity of subgingival bacteria, ozonated water helps treat periodontal diseases.
Hayakumo et al., 2013 [57]	RCT	22 patients that exhibited mild to moderate chronic periodontitis	Test: SRP + ozonated water Control: SRP	CAL, PPD, BOP; 8 weeks	Subgingival irrigation with ozonated water may be a valuable adjunct to periodontal treatment.

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The results suggest that ozone as an adjuvant to scaling and root planing offers contrasting clinical results and that further clinical trials are needed to better define its efficacy in improving periodontal tissues and healing processes (secondary outcome); a recent literature review has shown that the use of ozone as an adjunct to nonsurgical periodontal therapy does not bring any additional benefit [14].

3.4. RCTs (Glycine(Erythritol))

Population: a total of 343 patients were included in the trials analyzed; an average of males and females cannot be taken into account because a few trials did not report the sex of the patients.

Comparison: the test group had to have received nonsurgical periodontal therapy with an ultrasonic scaler or hand instruments and glycine/erythritol, while the control group had to have received SRP only (or similar therapies); erythritol was used in 67% of the studies and glycine in 33% of the studies.

Indices: the indices evaluated were the probing pocket depth (PPD; 100%), loss of clinical attachment (CAL; 100%), bleeding on probing (BoP; 100%), plaque index (PI; 33%), approximal plaque index (GI; 33%) and gingival recessions (GR/REC; 33%).

Outcomes: all treatments are effective in improving clinical parameters; in 83% of the studies, significant differences in clinical parameters were found for SRP treatment followed by glycine/erythritol,

Table 4. RCTs included (glycine/erythritol) [58,59,60,61,62,63].

Articles	Type of Study	Problem	Intervention/Comparison	Clinical Indices/Follow-Up	Outcome
Divnic-Resnik et al., 2022 [58]	RCT	21 patients with generalized stage 2 and 3 grade B periodontitis	Test: SRP + erythritol Control: SRP	CAL, PPD, BOP, API, SBI; 6 months	After 6 months, there was a greater attachment gain and a substantial reduction in the number of initially deep pockets (PPD > 5.5 mm) to shallow pockets (PPD ≤ 3.4 mm) in the test group.
Park et al., 2018 [59]	RCT	21 patients with moderate chronic periodontitis	Test: SRP + erythritol Control: SRP	CAL, PPD, BOP, PI, REC; 3 months	Clinically and microbiologically, SRP and SRP + EPAP proved to be efficacious nonsurgical periodontal treatments. With P. gingivalis in particular, the SRP + EPAP group demonstrated an antibacterial effect.
Jentsch et al., 2020 [60]	RCT	42 patients with chronic periodontitis	Test: SRP + erythritol Control: SRP	CAL, PPD, BOP, API; 6 months	BOP is not decreased by subgingival instrumentation with adjunctive erythritol air-polishing powder. However, as compared to subgingival instrumentation alone, it might have additional positive effects, such as lowering the probing depth as indicated by the frequency of residual periodontal pockets with PD ≥ 5 mm.
Caygur et al., 2017 [61]	RCT	60 patients with moderate chronic periodontitis	Test: SRP + glycine Control: SRP	CAL, PPD, BOP, PI, GI; 1 month	There are no advantages to using GPAP in addition to mechanical instruments for halitosis or periodontal parameters.
Tsang et al., 2018 [62]	RCT	27 systematically health non-smoking patients with chronic periodontitis	Test: SRP + glycine Control: SRP	CAL, PPD, BOP, GR; 6 months	When determined by gingival crevicular fluid volume, GPAP may be helpful as an additional nonsurgical periodontal therapy strategy for the temporary alleviation of subclinical inflammation.
Stein et al., 2021 [63]	RCT	172 patients with stage 3 and 4 periodontitis	Test 1: full mouth Test 2: full-mouth disinfection Test 3: full-mouth disinfection + erythritol Control: SRP	CAL, PPD, BOP; 6 months	Every treatment modality was successful, and there were no appreciable variations between full-mouth techniques. After six months, FMDAP (erythritol) outperformed Q-SRP in terms of clinical outcomes for both moderate and deep pockets.

.

The results indicate that glycine/erythritol as an adjuvant to scaling and root planing provides better clinical results in terms of improvement in periodontal indices (secondary outcome).

3.5. Risk of Bias of RCTs Included

The evaluation of blinding, randomization, allocation concealment, outcome data and outcome recording was conducted to assess the bias risk of this review. According to the variable taken into consideration, a green symbol was assigned where the information was complete and accurate; a yellow symbol was allocated where information was missing; and a red symbol was assigned where the information did not meet the requirements.

Table 5. Risk of bias of articles (ultrasonic and manual instruments) [19,20,21,22,23,24,25,26,27]. The table shows the risk of bias of each study included in the review (a green symbol was assigned where the information was complete and accurate; a yellow symbol was allocated where information was missing).

	Adequate Sequence Generated	Allocation Concealment	Blinding	Incomplete Outcome Data	Registration Outcome Data
Arpağ et al., 2017 [19]
Puglisi et al., 2022 [20]
Petelin et al., 2015 [21]
Malali et al., 2012 [22]
Kargas et al., 2015 [23]
Tomasi et al., 2022 [24]
Johnston et al., 2020 [25]
Dilsiz et al., 2015 [26]
Meulman et al., 2013 [27]

,

Table 6. Risk of bias of articles (laser) [28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47]. The table shows the risk of bias of each study included in the review (a green symbol was assigned where the information was complete and accurate; a yellow symbol was allocated where information was missing; a red symbol was assigned where the information did not meet the requirements).

	Adequate Sequence Generated	Allocation Concealment	Blinding	Incomplete Outcome Data	Registration Outcome Data
Dukic et al., 2013 [28]
De Melo Soares et al., 2019 [29]
Gurpegui et al., 2022 [30]
Pai et al., 2021 [31]
Dilsiz et al., 2013 [32]
Dereci et al., 2016 [33]
Hatipoglu et al., 2017 [34]
Matarese et al., 2017 [35]
Ustun et al., 2018 [36]
Alwaeli et al., 2013 [37]
Pourabbas et al., 2014 [38]
Birang et al., 2015 [39]
Queiroz et al., 2015 [40]
Balata et al., 2013 [41]
Malgikar et al., 2015 [42]
Gundogar et al., 2016 [43]
Manjunath et al., 2020 [44]
Euzebio et al., 2013 [45]
Bundidpun et al., 2020 [46]
Mishra et al., 2018 [47]

,

Table 7. Risk of bias of articles (ozone) [48,49,50,51,52,53,54,55,56,57]. The table shows the risk of bias of each study included in the review (a green symbol was assigned where the information was complete and accurate; a yellow symbol was allocated where information was missing).

	Adequate Sequence Generated	Allocation Concealment	Blinding	Incomplete Outcome Data	Registration Outcome Data
Seydanur Dengizek et al., 2019 [48]
Tasdemir et al., 2019 [49]
Rapone et al., 2022 [50]
Piva et al., 2020 [51]
Uraz et al., 2019 [52]
Al Habashneh et al., 2015 [53]
Issac et al., 2015 [54]
Pandya et al., 2016 [55]
Kaur et al., 2019 [56]
Hayakumo et al., 2013 [57]

and

Table 8. Risk of bias of articles (glycine/erythritol) [58,59,60,61,62,63]. The table shows the risk of bias of each study included in the review (a green symbol was assigned where the information was complete and accurate; a yellow symbol was allocated where information was missing).

	Adequate Sequence Generated	Allocation Concealment	Blinding	Incomplete Outcome Data	Registration Outcome Data
Divnic-Resnik et al., 2022 [58]
Park et al., 2018 [59]
Jentsch et al., 2020 [60]
Caygur et al., 2017 [61]
Tsang et al., 2018 [62]
Stein et al., 2021 [63]

show the risk of bias in the main articles examined (RCTs).

4. Discussion

The aim of this review was to assess the efficacy of ultrasonic and/or hand instrumentation in nonsurgical periodontal therapy in terms of improving clinical conditions; in addition, another focus of this review was to understand whether adjunctive therapies such as laser, ozone and glycine/erythritol could provide better clinical outcomes.

According to the studies included in the review [19,20,21,22,23,24,25,26,27], there was no statistically significant differences between the treatments proposed, demonstrating the achievement of clinical outcomes with the use of ultrasonic scalers and hand instruments. These results are consistent with previous research [64,65,66,67]. A number of RCTs included in the review have shown that both treatment modalities are effective in terms of probing pocket depth, loss of clinical attack and bleeding on probing; these results are in agreement with the scientific literature, because other authors did not find any significant differences between the two modalities [65,67].

It is well known that the goal of typical nonsurgical periodontal treatment is to remove biofilm to create the ideal environment for efficient bacterial plaque management [5,68,69]. Historically, scaling and root planing with manual instrumentation has been the most commonly used method of root surface debridement, with both clinical and microbiological benefits [70,71,72], as demonstrated by the studies included in this review [19,20,21,22,23,24,25,26,27]. Manual instrumentation also appears to be more effective in reducing the probing depth in moderate and severe periodontal pockets, according to Zhang et al., although no particular statistically significant differences were found with ultrasonic instrumentation [64]. However, even the most skilled operators do not always achieve the desired result of a biologically acceptable, clean and smooth root surface, largely due to the rather complicated anatomy and the skill of the operators [73,74]. In addition, manual instrumentation can result in a loss of root substance due to excessive instrumentation [73,75].

Following the cavitation effect, ultrasonic devices have been shown to be effective in reducing the probing pocket depth (PPD) and improving the overall effect of therapy [73,76,77]. This finding is consistent with an analysis of the literature by Oza et al., who found that while the use of ultrasonic scalers improved the probing pocket depth, the use of manual instruments did not result in a statistically significant difference [67]. With the use of recently developed micro-ultrasonic tips, these can more effectively reach challenging areas, such as deep defects, root grooves and furcations, and progressively penetrate further into the pocket [78]. As can be seen from the results, numerous RCTs have shown that the results achieved with ultrasonic instruments are comparable to those achieved with manual instruments. In addition, the use of ultrasound devices appears to reduce pain and increase patient comfort: a study by Liss et al. in 2021 suggests using a visual analogue scale (VAS) to assess the patient’s experience after ultrasound therapy, with the experience of pain and discomfort related to the therapy rated in the lower range of the scale [79]. Patients are even more likely to accept this therapy if the water temperature of the instruments used can be adjusted [80].

They also cause less damage to the root surface because there is less tissue loss, although the statistics do not show a significant difference [81,82]. There are conflicting opinions on the roughness of the surface: there are those who argue that you get a rougher surface with the hand tools (they would leave damage compatible with their blades) [83,84] and who have shown the same effect with ultrasound (depending on the type of power chosen by the operator) [85,86]. Despite these controversies, it can be concluded that the surface roughness produced is the same and biologically compatible [6,87].

This review is consistent with the literature regarding the effectiveness of the use of ultrasonic and/or manual instruments in nonsurgical periodontal therapy, even without additional therapies. The main limitation of this review is the heterogeneity of the included studies with respect to the treatment modality used: not all studies evaluated the effectiveness of the same type of curette or the same type of ultrasonic scaler; moreover, it must be taken into account that each clinician often uses a combination of the two tools in daily practice. Given the different views on tissue damage or surface roughness [81,82,83,84,85,86,87,88,89], it may be hoped that an ultrasonic scaler with perio-slim inserts that fit the periodontal pocket will be used to remove most deposits, thereby attempting to reduce the use of manual instruments. In addition to the specification of the type of heterogeneous instrumentation, another limitation is that the included studies have not evaluated the same degree of periodontal disease, but, still, the use of ultrasonic instrumentation, reducing the use of curettes to the necessary amount, would seem to be the best clinical alternative.

This review is unprecedented in that it compares all the instruments and techniques currently available for periodontal treatment, enhancing the skills of the operator and evaluating additional therapies for proper patient management.

For future research and RCTs, it would therefore be good to choose the same type of instrumentation for nonsurgical periodontal treatment at the same stage of the disease and also to assess whether there is a difference in terms of the cost and adverse effects (such as root sensitivity and patient pain/comfort) between the proposed treatments, in order to provide the operator with the choice of treatment.

In certain cases, the use of additional therapies in addition to scaling and root planing may be the best way to improve tissue recovery. In fact, some of the studies considered suggested that the use of lasers could be beneficial in terms of the probing pocket depth, clinical attack loss and bleeding on probing [28,30,32,33,34,35,37,39,43,44,45,48]. This is supported by the literature [89], which shows short-term results, but the long-term benefits are still unknown [90]. As the studies included in the reviews and meta-analyses that are now available are heterogeneous, it would be helpful to know what type of laser and wavelength to use [91].

Ozone is a powerful disinfectant that has been used in dentistry for a number of years, but it does not appear to provide significant improvements over standard nonsurgical periodontal therapy alone [14,49,50,53,54]. Further studies are needed to determine whether it can be a useful treatment for periodontal disease.

Finally, the use of powders may be useful in the removal of subgingival biofilm, favoring a reduction in the probing pocket depth, as has been demonstrated in the literature [92]. Currently, no treatment is better than another in addition to nonsurgical periodontal treatment; it is necessary to evaluate the possible therapy according to the condition and needs of the patient.

5. Conclusions

The results of this review are consistent with the previous literature, i.e., ultrasonic and manual instruments are equally effective in the treatment of nonsurgical periodontal disease; therefore, when choosing the type of therapy and instrumentation, it would be necessary to evaluate the pros and cons presented by the patient. The combination of ultrasonic and hand instruments is indicated in nonsurgical periodontal therapy, as indicated by the results of this review. For future research, it would be good to standardize the sample with regard to the degree and stage of periodontal disease and to evaluate the risks and benefits of the instruments (manual and ultrasonic scalers) both in vitro and on the patients themselves.

With regard to adjunctive therapies, this review was unable to demonstrate any further improvement in nonsurgical periodontal therapy. Further studies are needed to better understand their potential efficacy.