Adjunctive azithromycin in the treatment of aggressive periodontitis: Microbiological findings of a 12-month randomized clinical trial

Sestrin2 inhibits RANKL-induced osteoclastogenesis through AMPK activation and ROS inhibition

Sestrins are stress-responsive proteins with antioxidant properties. They participate in cellular redox balance and protect against oxidative damage. This study investigated the effects of Sestrin2 (Sesn2) on osteoclast differentiation and function. Overexpressing Sesn2 in osteoclast precursor cells significantly inhibited receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastogenesis. This was assessed as reduced expression of various osteoclast markers, including c-Fos, nuclear factor of activated T cells 1 (NFATc1), osteoclast-associated receptor, tartrate-resistant acid phosphatase, and cathepsin K. Conversely, downregulation of Sesn2 produced the opposite effect. Mechanistically, Sesn2 overexpression enhanced AMPK activation and the nuclear translocation of nuclear factor erythroid-derived factor 2-related factor 2 (Nrf2), promoting antioxidant enzymes. Moreover, azithromycin (Azm) induced Sesn2 expression, which suppressed RANKL-induced osteoclast differentiation. Specifically, Azm treatment reduced RANKL-induced production of reactive oxygen species in osteoclasts. Furthermore, intraperitoneal administration of Azm ameliorated RANKL-induced bone loss by reducing osteoclast activity in mice. Taken together, our results suggested that Azm-induced Sesn2 act as a negative regulator of RANKL-induced osteoclast differentiation through the AMPK/NFATc1 signaling pathway. Concisely, targeting Sesn2 can be a potential pharmacological intervention in osteoporosis.

Current Infections of the Orofacial Region: Treatment, Diagnosis, and Epidemiology

Undoubtedly, diagnosing and managing infections is one of the most challenging issues for orofacial clinicians. As a result of the diversity of symptoms, complicated behavior, and sometimes confusing nature of these conditions, it has become increasingly difficult to diagnose and treat them. It also highlights the need to gain a deeper insight into the orofacial microbiome as we try to improve our understanding of it. In addition to changes in patients' lifestyles, such as changes in diet, smoking habits, sexual practices, immunosuppressive conditions, and occupational exposures, there have been changes in patients' lifestyles that complicate the issue. Recent years have seen the development of new infection treatments due to the increased knowledge about the biology and physiology of infections. This review aimed to provide a comprehensive overview of the types of infections in the mouth, including the types that viruses, fungi, or bacteria may cause. It is important to note that we searched the published literature in the Scopus, Medline, Google Scholar, and Cochran databases from 2010 to 2021 using the following keywords: "Orofacial/Oral Infections," "Viral/Fungal/Bacterial Infections", "Oral Microbiota" And "Oral Microflora" without limiting our search to languages and study designs. According to the evidence, the most common infections in the clinic include herpes simplex virus, human papillomavirus, Candida albicans, Aspergillus, Actinomycosis, and Streptococcus mutans. The purpose of this study is to review the new findings on characteristics, epidemiology, risk factors, clinical manifestations, diagnosis, and new treatment for these types of infectious diseases.

SARS-CoV-2 and Prevotella spp.: friend or foe? A systematic literature review

During this global pandemic of the COVID-19 disease, a lot of information has arisen in the media and online without scientific validation, and among these is the possibility that this disease could be aggravated by a secondary bacterial infection such as Prevotella, as well as the interest or not in using azithromycin, a potentially active antimicrobial agent. The aim of this study was to carry out a systematic literature review, to prove or disprove these allegations by scientific arguments. The search included Medline, PubMed, and Pubtator Central databases for English-language articles published 1999-2021. After removing duplicates, a total of final eligible studies (n=149) were selected. There were more articles showing an increase of Prevotella abundance in the presence of viral infection like that related to Human Immunodeficiency Virus (HIV), Papillomavirus (HPV), Herpesviridae and respiratory virus, highlighting differences according to methodologies and patient groups. The arguments for or against the use of azithromycin are stated in light of the results of the literature, showing the role of intercurrent factors, such as age, drug consumption, the presence of cancer or periodontal diseases. However, clinical trials are lacking to prove the direct link between the presence of Prevotella spp. and a worsening of COVID-19, mainly those using azithromycin alone in this indication.

Azithromycin as an adjunct to subgingival professional mechanical plaque removal in the treatment of grade C periodontitis: a systematic review and meta-analysis

The aim of this systematic review was to evaluate clinical and microbiological outcomes with the use of azithromycin as an adjunct to non-surgical subgingival professional mechanical plaque removal (PMPR) in the treatment of grade C periodontitis. Online database searches using high-level MeSH terms in a PICO structure were conducted along with hand-searching of relevant periodontal journals. Titles and abstracts of identified studies were independently reviewed by both authors and the full texts of studies meeting the inclusion criteria were independently reviewed. In total, 122 studies were identified through searches, of which 6 were included in the qualitative analysis and 4 in the meta-analysis. Three studies included in the meta-analysis were deemed at low risk of bias and 1 at serious risk. There were conflicting results on whether azithromycin reduced the number of subgingival pathogens or detectable subgingival Aggregatibacter actinomycetemcomitans between the included studies. The meta-analysis revealed a statistically significant probing depth reduction difference in favour of azithromycin compared to the control at 3 months (weighted mean difference [WMD]=−0.39 mm; 95% confidence interval [CI], −0.66 to −0.13 mm; I²=0%) and 12 months (WMD=−1.32 mm; 95% CI, −1.71 to −0.93 mm; I²=0%). The clinical attachment level change was also statistically significant in favour of azithromycin compared to the control at 3 months (WMD=−0.61 mm; 95% CI, −1.13 to −0.10 mm; I²=71%) and 12 months (WMD=−0.88 mm; 95% CI, −1.32 to −0.44 mm; I²=0%). Based upon these results, azithromycin offers additional improvements in some clinical parameters when used in conjunction with subgingival PMPR in patients with aggressive periodontitis over control groups. These improvements appear to be maintained for up to 12 months after treatment completion. However, due to a lack of well-designed studies, the conclusions that can be drawn from the available evidence are limited.

Adjunctive Application of Systemic Antibiotics in Non-surgical Aggressive Periodontitis Treatment: Clinical and Microbiological Findings

BACKGROUND: Aggressive periodontitis (AgP) is associated with an extensive and rapid destruction of periodontal tissues. Unpredictable treatment outcomes of the disease are consequences of various cross-linked factors. Antimicrobial adjunctive treatment is routinely used as a part of non-surgical periodontal treatment (NSPT) of AgP. AIM: Therefore, the aim of this study was to compare the effects of active periodontal treatment (APT) combined with systemic antibiotics with mechanical debridement alone, in patients with generalized AgP (GAgP). METHODS: Two groups, consisting of 10 participants each, were randomly formed. Both groups were clinically and microbiologically tested and monitored for 3 months. Test group received APT with antimicrobial supplementation (amoxicillin and metronidazole [AMX-MET]). Patients from the control group were treated by APT only. Clinical and microbiological parameters were recorded at baseline and 3 months following the NSPT. Clinical measurements involved probing depth, clinical attachment level, bleeding on probing, and plaque index. Samples of subgingival crevicular fluid were analyzed by qualitative polymerase chain reaction. RESULTS: Significant improvement of all clinical parameters was observed 3 months following the NSPT (p < 0.05), but significant difference between groups was not found (p > 0.05). Periodontal pathogens’ detection between baseline and 3 months follow-up was also not statistically significant in both examined groups (p > 0.05). CONCLUSION: Similarity of results obtained in both treatment groups underlined the key role of APT in the treatment of AgP. The AMX-MET supplementation did not improve clinical and microbiological outcomes, when compared to APT alone. Longer follow-up period, with larger sample, could provide a more comprehensive insight into this issue.

Adjunctive systemic antimicrobials for the non-surgical treatment of periodontitis

BACKGROUND

Systemic antimicrobials can be used as an adjunct to mechanical debridement (scaling and root planing (SRP)) as a non-surgical treatment approach to manage periodontitis. A range of antibiotics with different dosage and combinations are documented in the literature. The review follows the previous classification of periodontitis as all included studies used this classification.

OBJECTIVES

To assess the effects of systemic antimicrobials as an adjunct to SRP for the non-surgical treatment of patients with periodontitis.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases to 9 March 2020: Cochrane Oral Health's Trials Register, CENTRAL, MEDLINE, and Embase. The US National Institutes of Health Ongoing Trials Register ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) which involved individuals with clinically diagnosed untreated periodontitis. Trials compared SRP with systemic antibiotics versus SRP alone/placebo, or with other systemic antibiotics.

DATA COLLECTION AND ANALYSIS

We selected trials, extracted data, and assessed risk of bias in duplicate. We estimated mean differences (MDs) for continuous data, with 95% confidence intervals (CIs). We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

We included 45 trials conducted worldwide involving 2664 adult participants. 14 studies were at low, 8 at high, and the remaining 23 at unclear overall risk of bias. Seven trials did not contribute data to the analysis. We assessed the certainty of the evidence for the 10 comparisons which reported long-term follow-up (≥ 1 year). None of the studies reported data on antimicrobial resistance and patient-reported quality of life changes. Amoxicillin + metronidazole + SRP versus SRP in chronic/aggressive periodontitis: the evidence for percentage of closed pockets (MD -16.20%, 95% CI -25.87 to -6.53; 1 study, 44 participants); clinical attachment level (CAL) (MD -0.47 mm, 95% CI -0.90 to -0.05; 2 studies, 389 participants); probing pocket depth (PD) (MD -0.30 mm, 95% CI -0.42 to -0.18; 2 studies, 389 participants); and percentage of bleeding on probing (BOP) (MD -8.06%, 95% CI -14.26 to -1.85; 2 studies, 389 participants) was of very low certainty. Only the results for closed pockets and BOP showed a minimally important clinical difference (MICD) favouring amoxicillin + metronidazole + SRP. Metronidazole + SRP versus SRP in chronic/aggressive periodontitis: the evidence for percentage of closed pockets (MD -12.20%, 95% CI -29.23 to 4.83; 1 study, 22 participants); CAL (MD -1.12 mm, 95% CI -2.24 to 0; 3 studies, 71 participants); PD (MD -1.11 mm, 95% CI -2.84 to 0.61; 2 studies, 47 participants); and percentage of BOP (MD -6.90%, 95% CI -22.10 to 8.30; 1 study, 22 participants) was of very low certainty. Only the results for CAL and PD showed an MICD favouring the MTZ + SRP group. Azithromycin + SRP versus SRP for chronic/aggressive periodontitis: we found no evidence of a difference in percentage of closed pockets (MD 2.50%, 95% CI -10.19 to 15.19; 1 study, 40 participants); CAL (MD -0.59 mm, 95% CI -1.27 to 0.08; 2 studies, 110 participants); PD (MD -0.77 mm, 95% CI -2.33 to 0.79; 2 studies, 110 participants); and percentage of BOP (MD -1.28%, 95% CI -4.32 to 1.76; 2 studies, 110 participants) (very low-certainty evidence for all outcomes). Amoxicillin + clavulanate + SRP versus SRP for chronic periodontitis: the evidence from 1 study, 21 participants for CAL (MD 0.10 mm, 95% CI -0.51 to 0.71); PD (MD 0.10 mm, 95% CI -0.17 to 0.37); and BOP (MD 0%, 95% CI -0.09 to 0.09) was of very low certainty and did not show a difference between the groups. Doxycycline + SRP versus SRP in aggressive periodontitis: the evidence from 1 study, 22 participants for CAL (MD -0.80 mm, 95% CI -1.49 to -0.11); and PD (MD -1.00 mm, 95% CI -1.78 to -0.22) was of very low certainty, with the doxycycline + SRP group showing an MICD in PD only. Tetracycline + SRP versus SRP for aggressive periodontitis: we found very low-certainty evidence of a difference in long-term improvement in CAL for the tetracycline group (MD -2.30 mm, 95% CI -2.50 to -2.10; 1 study, 26 participants). Clindamycin + SRP versus SRP in aggressive periodontitis: we found very low-certainty evidence from 1 study, 21 participants of a difference in long-term improvement in CAL (MD -1.70 mm, 95% CI -2.40 to -1.00); and PD (MD -1.80 mm, 95% CI -2.47 to -1.13) favouring clindamycin + SRP. Doxycycline + SRP versus metronidazole + SRP for aggressive periodontitis: there was very low-certainty evidence from 1 study, 27 participants of a difference in long-term CAL (MD 1.10 mm, 95% CI 0.36 to 1.84); and PD (MD 1.00 mm, 95% CI 0.30 to 1.70) favouring metronidazole + SRP. Clindamycin + SRP versus metronidazole + SRP for aggressive periodontitis: the evidence from 1 study, 26 participants for CAL (MD 0.20 mm, 95% CI -0.55 to 0.95); and PD (MD 0.20 mm, 95% CI -0.38 to 0.78) was of very low certainty and did not show a difference between the groups. Clindamycin + SRP versus doxycycline + SRP for aggressive periodontitis: the evidence from 1 study, 23 participants for CAL (MD -0.90 mm, 95% CI -1.62 to -0.18); and PD (MD -0.80 mm, 95% CI -1.58 to -0.02) was of very low certainty and did not show a difference between the groups. Most trials testing amoxicillin, metronidazole, and azithromycin reported adverse events such as nausea, vomiting, diarrhoea, mild gastrointestinal disturbances, and metallic taste. No serious adverse events were reported.

AUTHORS' CONCLUSIONS

There is very low-certainty evidence (for long-term follow-up) to inform clinicians and patients if adjunctive systemic antimicrobials are of any help for the non-surgical treatment of periodontitis. There is insufficient evidence to decide whether some antibiotics are better than others when used alongside SRP. None of the trials reported serious adverse events but patients should be made aware of the common adverse events related to these drugs. Well-planned RCTs need to be conducted clearly defining the minimally important clinical difference for the outcomes closed pockets, CAL, PD, and BOP.

Randomized clinical trial of the effects of azithromycin use in the treatment of peri-implantitis

BACKGROUND

The aim of this clinical trial was to establish a proof of concept that the adjunctive use of systemic azithromycin (AZM) in conjunction with mechanical debridement has an increased benefit in reducing soft tissue inflammation in the treatment of peri-implantitis.

METHODS

In a randomized, double-blind, clinical trial, the treatment group (nine patients) received AZM as well as mechanical debridement in a single course of treatment, whereas the control group (eight patients) received a placebo and mechanical debridement. The primary outcome variables studied were bleeding on probing, suppuration, pocket probing depth and gingival recession. The secondary variables studied were gingival index, plaque index, microbiological and interleukin-1β status. The observation period was 6 months.

RESULTS

Over the 6 months' observation period, the treatment patients showed a consistently greater reduction of gingival inflammation and an improvement in soft tissue healing than the control patients.

CONCLUSIONS

The adjunctive use of a single course of systemic azithromycin can assist in the control of peri-implant mucositis in the treatment of peri-implantitis.

Clarithromycin as an Adjunct to One-Stage Full-Mouth Ultrasonic Periodontal Debridement in Generalized Aggressive Periodontitis: A Randomized Controlled Clinical Trial

BACKGROUND

The aim of the present study is to evaluate the periodontal clinical and microbiologic responses and possible adverse effects of clarithromycin (CLM) combined with periodontal mechanical therapy in the treatment of patients with generalized aggressive periodontitis.

METHODS

Forty patients were selected and randomly assigned into one of two groups: 1) CLM (n = 20): one-stage full-mouth ultrasonic debridement (FMUD) associated with CLM (500 mg, every 12 hours for 3 days); and 2) placebo (n = 20): FMUD associated with placebo pills. Clinical and microbiologic parameters were evaluated at baseline and 3 and 6 months postoperatively.

RESULTS

Both treatments presented statistically significant clinical and microbiologic improvements. However, the CLM group presented lower means of probing depth for pockets ≥7 mm at 6 months (4.0 ± 1.7 mm) compared with the placebo group (4.7 ± 1.3 mm) (P = 0.04). In addition, the CLM group also presented greater reduction of Porphyromonas gingivalis (Pg) DNA counts at 6 months (P = 0.0001).

CONCLUSION

Results from this study suggest both treatments are effective; however, adjunct use of CLM to FMUD leads to better reduction of deep pockets and Pg at 6 months compared with FMUD alone.

Systemic antibiotics in the treatment of periodontitis

Despite the fact that several clinical studies have shown additional benefits when certain systemic antibiotics are used as adjuncts to periodontal treatment, clear guidelines for the use of these agents in the clinical practice are not yet available. Basic questions concerning the use of systemic antibiotics to treat periodontitis remain unanswered, such as: which drug(s) should be used; which patients would most benefit from treatment; which are the most effective protocols (i.e. doses and durations); and in which phase of the mechanical therapy should the drug(s) be administered? Although not all of those questions have been directly addressed by controlled randomized clinical trials, recent concepts related to the ecology of periodontal diseases, as well as the major advances in laboratory and clinical research methods that have occurred in the past decade, have significantly broadened our knowledge in this field. This article endeavored to provide a 'state of the art' overview on the use of systemic antibiotics in the treatment of periodontitis, based on the most recent literature on the topic as well as on a compilation of data from studies conducted at the Center of Clinical Trials at Guarulhos University (São Paulo, Brazil) from 2002 to 2012.

Antibiotic effects against periodontal bacteria in organ cultured tissue

Mechanical reduction of infectious bacteria by using physical instruments is considered the principal therapeutic strategy for periodontal disease; addition of antibiotics is adjunctive. However, local antibiotic treatment, combined with conventional mechanical debridement, has recently been shown to be more effective in periodontitis subjects with type 2 diabetes. This suggests that some bacteria may invade the inflamed inner gingival epithelium, and mechanical debridement alone will be unable to reduce these bacteria completely. Therefore, we tried to establish infected organ culture models that mimic the inner gingival epithelium and aimed to see the effects of antibiotics in these established models. Mouse dorsal skin epithelia were isolated, and periodontal bacteria were injected into the epithelia. Infected epithelia were incubated with test antibiotics, and colony-forming ability was evaluated. Results indicated that effective antibiotics differed according to injected bacteria and the bacterial combinations tested. Overall, in organ culture model, the combination of amoxicillin or cefdinir and metronidazole compensate for the effects of less effective bacterial combinations on each other. This in vitro study would suggest effective periodontal treatment regimens, especially for severe periodontitis.

Azithromycin enhances phagocytic killing of Aggregatibacter actinomycetemcomitans Y4 by human neutrophils

BACKGROUND

Aggregatibacter actinomycetemcomitans resists killing by neutrophils and is inhibited by azithromycin (AZM) and amoxicillin (AMX). AZM actively concentrates inside host cells, whereas AMX enters by diffusion. The present study is conducted to determine whether AZM is more effective than AMX at enhancing phagocytic killing of A. actinomycetemcomitans by neutrophils.

METHODS

Killing assays were conducted in the presence of either 2 μg/mL AZM or 16 μg/mL AMX (equipotent against A. actinomycetemcomitans). Neutrophils were loaded by incubation with the appropriate antibiotic. Opsonized A. actinomycetemcomitans strain Y4 was incubated with the indicated antibiotic alone, with loaded neutrophils and antibiotic, or with control neutrophils (without antibiotic) at multiplicities of infection (MOIs) of 30 and 90 bacteria per neutrophil.

RESULTS

Neutrophil incubation with 2 μg/mL AZM yielded an intracellular concentration of 10 μg/mL. At an MOI of 30, neutrophils loaded with AZM failed to kill significantly more bacteria than control neutrophils during the 60- and 90-minute assay periods. At an MOI of 90, neutrophils loaded with AZM killed significantly more bacteria than either AZM alone or control neutrophils during 60- and 90-minute incubations (P < 0.05), and killed significantly more bacteria after 90 minutes than the sum of the killing produced by AZM alone or neutrophils alone. Neutrophils incubated with AMX under identical conditions also killed significantly more bacteria than either AMX alone or control neutrophils, but there was no evidence of synergism between AMX and neutrophils.

CONCLUSIONS

Neutrophils possess a concentrative transport system for AZM that may enhance killing of A. actinomycetemcomitans. Its effects are most pronounced when neutrophils are greatly outnumbered by bacteria.

[Clinical efficiency of short and long-term adjuvant therapy of chronic periodontal disease with azithromycin]

The purpose of the study was to compare the clinical response to two regimes of azithromycin use in the complex of non-surgical periodontal therapy. After initial periodontal therapy of chronic generalized periodontitis (CGP), 60 patients were randomly assigned to 3 groups. In group 2 and 3 azithromycin was administered: 500 mg 1 time per day, 3 days, and by 500 mg 1 time per day, 7 days, followed by 500 mg 1 time per week for 12 weeks. Clinical indexes were record before treatment and after 1, 3, 6 and 12 months. After 3 months 13 patients in group 1st had the exacerbation of CGP, and only 1 and 2 patients (p<0.05) in the 2nd and 3rd groups, respectively. After 12 months, significantly fewer patients on the 3rd group (as compared with the 1st (p=0.0015) and the 2nd (p=0.0040) had clinical exacerbation. Unscheduled visits were significantly less in the 3rd group as compared with the 1st (χ(2)=8.03; p=0.0046). The long-term adjunctive azithromycin results in a significantly clinical benefit of 80% patients for 1 year with satisfactory tolerance.

Non-surgical periodontal therapy with systemic antibiotics in patients with untreated chronic periodontitis: a systematic review and meta-analysis

OBJECTIVE

The purpose of this meta-analysis is to evaluate the effectiveness of different systemic antibiotics in combination with scaling and root planing (SRP) when compared to SRP alone in patients with untreated chronic periodontitis.

BACKGROUND

Although chronic periodontitis is mostly treated without adjunctive systemic antibiotics, some recent meta-analyses have shown clinical benefit for some systemic antibiotics when used as an adjunct to SRP. However, there is a wide variety of systemic antibiotic regimens used today. It remains unclear if the selected type of systemic antibiotic influences the magnitude of clinical benefit.

MATERIAL AND METHODS

The MEDLINE-PubMed database was searched from their earliest records through May 16, 2013. Several journals were hand searched and some authors were contacted for additional information. Outcome measures analysed were mean bleeding on probing change, mean clinical attachment level gain and mean probing pocket depth reduction. Extracted data were pooled using a random effect model. Weighted mean differences were calculated and heterogeneity was assessed.

RESULTS

The search yielded 281 abstracts. Ultimately, 95 studies were selected, describing 43 studies meeting the eligibility criteria. Systemic antibiotics showed a significant (p < 0.05) additional pocket depth reduction for moderate (at 3 mo 0.27 mm ± 0.09, at 6 mo 0.23 mm ± 0.10 and at 12 mo 0.25 mm ± 0.27) and deep pockets (at 3 mo 0.62 mm ± 0.17, at 6 mo 0.58 mm ± 0.16 and at 12 mo 0.74 mm ± 0.30). Statistically, no specific type of antibiotic was superior over another. However, when analysing the clinical data for initially moderate pockets or deep pockets, some trends became apparent.

CONCLUSION

Systemic antibiotics combined with SRP offer additional clinical improvements compared to SRP alone. Although there were no statistically significant differences, there was a trend that for initially moderate and deep pockets, metronidazole or metronidazole combined with amoxicillin, resulted in clinical improvements that were more pronounced over doxycycline or azithromycin. Additionally, there was a trend that the magnitude of the clinical benefit became smaller over time (1 year).

Surgical and nonsurgical periodontal therapy. Learned and unlearned concepts

This review aims to highlight concepts relating to nonsurgical and surgical periodontal therapy, which have been learned and unlearned over the past few decades. A number of treatment procedures, such as gingival curettage and aggressive removal of contaminated root cementum, have been unlearned. Advances in technology have resulted in the introduction of a range of new methods for use in nonsurgical periodontal therapy, including machine-driven instruments, lasers, antimicrobial photodynamic therapy and local antimicrobial-delivery devices. However, these methods have not been shown to offer significant benefits over and above nonsurgical debridement using hand instruments. The method of debridement is therefore largely dependent on the preferences of the operator and the patient. Recent evidence indicates that specific systemic antimicrobials may be indicated for use as adjuncts to nonsurgical debridement in patients with advanced disease. Full-mouth disinfection protocols have been proven to be a relevant treatment option. We have learned that while nonsurgical and surgical methods result in similar long-term treatment outcomes, surgical therapy results in greater probing-depth reduction and clinical attachment gain in initially deep pockets. The surgical technique chosen seems to have limited influence upon changes in clinical attachment gain. What has not changed is the importance of thorough mechanical debridement and optimal plaque control for successful nonsurgical and surgical periodontal therapy.