Contemporary Periodontal Treatment Strategies

01

Diagnostic Framework — The 2017 World Classification

Why revise the 1999 Armitage classification?

The Armitage (1999) classification distinguished "chronic" from "aggressive" periodontitis — two entities with major clinical overlap that made diagnosis imprecise. Experts at the 2017 World Workshop (AAP/EFP) concluded that the biological evidence did not support them as separate diseases. Periodontitis is now a single entity, structured along two independent dimensions: the Stage and the Grade.

This framework, inspired by oncology, enables treatment personalization based on current severity, management complexity and individual progression risk — a decisive advance toward precision periodontology.

Horizontal dimension — The Stage

Disease severity at presentation

Determined by clinical attachment loss (CAL) at the most severe site
Supplemented by radiographic bone loss and tooth losses
Four stages: I (initial) → II (moderate) → III (severe) → IV (very severe)
Stage is always assigned by the site of maximum destruction

Vertical dimension — The Grade

Progression risk and therapeutic response

Calculated from the bone loss-to-age ratio
Modified by systemic risk factors
Three grades: A (slow) → B (moderate) → C (rapid)
Automatic upgrade to Grade C if smoking > 10 cig/day or HbA1c ≥ 7.0%

02

Staging — Severity and Management Complexity

Staging parameters — Reference table

Parameter	Stage I	Stage II	Stage III	Stage IV
Interdental CAL	1–2 mm	3–4 mm	≥ 5 mm	≥ 5 mm
Bone loss	Coronal third (<15%)	Coronal third (15–33%)	Middle or apical third	Middle or apical third
Tooth loss	0	0	≤ 4 teeth	≥ 5 teeth
Probing depth (PPD)	≤ 4 mm	≤ 5 mm	≥ 6 mm	Complex rehabilitation needs
Local complexity	Initial	Moderate	Class II/III furcation	Occlusal collapse, extreme mobility

Stage III vs Stage IV — The discriminating criterion Stages III and IV often share the same tissue loss measurements. Their distinction rests on functional sequelae: Stage IV includes masticatory dysfunction, extreme tooth mobility, or fewer than 20 remaining teeth (10 opposing pairs). Stage IV mandates systematic multidisciplinary management.

03

Grading — Progression Risk and Therapeutic Response

Grade criteria — Reference table

Criterion	Grade A — Slow	Grade B — Moderate	Grade C — Rapid
Bone loss / Age ratio	< 0.25	0.25 to 1.0	> 1.0
Direct progression (5 years)	No evidence	< 2 mm	≥ 2 mm
Modifier — Smoking	Non-smoker	< 10 cig/day	≥ 10 cig/day
Modifier — Diabetes	Absent	HbA1c < 7.0%	HbA1c ≥ 7.0%

Automatic upgrade to Grade C — Major risk factors A patient with moderate bone loss (initial Grade B) who smokes more than 10 cigarettes per day is automatically reclassified as Grade C. The same applies to a diabetic patient with HbA1c ≥ 7.0%. These modifiers signal a high risk of rapid progression and a potentially poor response to treatment, justifying an enhanced adjunctive approach.

04

S3 Protocol — Step 1: Biofilm Control and Risk Factor Management

Step 1 objectives

Applies to all periodontal patients regardless of stage — mandatory prerequisite for subsequent steps
Reduce the initial microbial load and create an environment favorable to healing
Modify deleterious behaviors and systemic risk factors
Secure active patient engagement before any subgingival instrumentation

Oral hygiene instruction (OHI)

Personalized to the patient's profile

Mechanical toothbrushing (manual or powered): cornerstone of plaque control
Interdental brushes: first choice when space permits — more effective than floss for reducing gingival inflammation at periodontal sites
PMPR (Professional Mechanical Plaque Removal): supragingival scaling + removal of plaque retention factors
Elimination of restoration overhangs and poorly contoured prosthetics

Risk factor management

Environmental and systemic

Smoking cessation: brief systematic counseling — tobacco impairs periodontal vascularity and immune response
Diabetes: coordination with the medical team — target HbA1c < 7.0% to optimize periodontal stability
Stress, obesity, xerostomic medications: identify and document
Mandatory reassessment before progressing to Step 2

05

S3 Protocol — Step 2: Subgingival Instrumentation

Scaling and root planing (SRP) — Foundation of etiological treatment

Step 2 targets the elimination of subgingival biofilm and calculus to reduce probing pocket depth and promote pocket closure. Instrumentation may be performed with Gracey curettes (manual) or powered devices (ultrasonic/sonic), both showing similar clinical efficacy. The success criterion is pocket closure: PPD ≤ 4 mm with negative bleeding on probing (BOP).

Quadrant-by-quadrant instrumentation

Conventional sequential approach

One quadrant treated at a time, at 1–2 week intervals
Allows monitoring of tissue response between sessions
Suited to patients with limited compliance
Risk of bacterial recolonization of treated sites from untreated sites

Full-mouth disinfection (FMDis)

All quadrants within 24 hours

Complete instrumentation in one or two closely spaced sessions (< 24 h)
Often combined with chlorhexidine to limit recolonization
Greater reductions in bleeding score (BS) and PPD vs quadrant approach
FMDeb protocol (without antiseptic): comparable results, fewer constraints

Step 2 success criterion — Pocket closure PPD ≤ 4 mm with negative bleeding on probing (BOP) across all treated sites. This criterion conditions progression to Step 3 (surgery). Reassessment must take place 4 to 12 weeks after completion of subgingival instrumentation, with excellent oral hygiene (plaque index < 20%) as an absolute prerequisite for any surgery.

06

S3 Protocol — Steps 3 and 4: Surgery and Maintenance

Step 3 — Surgical treatment of residual sites

Step 3 is indicated for sites that did not respond adequately to Step 2: persistent pockets ≥ 6 mm, or 4–5 mm pockets with persistent positive BOP. The choice of surgical technique depends on the morphology of the bony defect and the therapeutic objective (pocket reduction vs regeneration).

Surgical modalities — Comparative overview

Surgery type	Primary objective	Indications	Key points
Open flap debridement (OFD)	Direct instrumentation	Deep pockets with difficult access	Limited pocket reduction
Resective surgery	Pocket elimination	Shallow bony defects, non-esthetic zones	Increased gingival recession
Regenerative surgery	Attachment restoration	Narrow intrabony defects, Class II furcations	Significant CAL gain

!

Periodontal regeneration — Biomaterial choice by defect type

Intrabony defects and Class II furcations

Enamel matrix derivatives (EMD) or bone grafts with or without resorbable membranes are the materials of choice. Regeneration is recommended for mandibular molars and buccal maxillary Class II furcations.

Complex furcations — Class III and maxillary interproximal

Tunneling, root separation or root resection depending on morphology. These approaches require rigorous prosthetic planning and a tooth-by-tooth prognosis before proceeding.

Step 4 — Supportive Periodontal Care (SPC)

Maintenance is the most critical step for long-term stability. It begins as soon as periodontal health is achieved and must continue for life. Frequency is personalized using the Periodontal Risk Assessment (PRA).

High risk — Recall every 3 months

High-risk criteria

Multiple sites with PPD ≥ 5 mm
High BOP despite hygiene efforts
Active smoking
Poorly controlled diabetes (HbA1c ≥ 7%)

Low risk — Recall every 6–12 months

Low-risk criteria

Good plaque control (< 20%)
Negative BOP on the majority of sites
Non-smoker and well-controlled diabetes
Radiographic stability at two successive check-ups

07

Adjunctive Therapies — Evidence and Recommendations

Systemic antibiotics — Rational, non-routine use Routine systemic antibiotic use for periodontitis is not recommended due to global antimicrobial resistance concerns. They provide meaningful additional benefit only in young adults with generalized Stage III/IV Grade C periodontitis.

Amoxicillin + Metronidazole — Reference protocol

Amoxicillin (AMX)

Broad-spectrum penicillin

500 mg × 3/day — 7 days

Mandatory combination with metronidazole. Initiate immediately after completion of full SRP — never before.

Metronidazole (MET)

Anti-anaerobic antibiotic

400–500 mg × 3/day — 7 days

400–500 mg doses associated with better CAL gains in moderate and deep pockets. Avoid alcohol throughout.

Expected results vs SRP alone: additional PPD reduction of 0.4–0.5 mm — CAL gain of 0.2–0.4 mm. Primary targets: Aggregatibacter actinomycetemcomitans and red complex bacteria.

Other adjuncts — Comparative evidence

A

Local antiseptics — Chlorhexidine

Mouthwashes used as a temporary adjunct during post-instrumentation healing. Prolonged use limited by tooth staining and taste alterations.

Local delivery systems (CHX chips, metronidazole gel, minocycline microspheres): therapeutic concentration maintained in residual pockets ≥ 5 mm. Benefit is modest but statistically significant on PPD reduction.

B

Photobiomodulation (aPDT) and Laser

aPDT (photosensitizer + low-level laser) reduces microbial load short-term, but meta-analyses show minor clinical benefits vs SRP alone — not recommended as a routine adjunct by S3 guidelines.

The LANAP protocol (Nd:YAG) selectively targets diseased tissue. Clinical studies: PPD and BOP reductions comparable or superior to SRP alone at one year, with better attachment stability.

C

Host modulation therapy (HMT)

Low-dose doxycycline (SDD) — 20 mg × 2/day: inhibits matrix metalloproteinases (MMPs) without selective bacterial pressure. Only FDA-approved systemic modulator. Not routinely recommended by EFP S3.

Natural products (curcumin, omega-3s, aloe vera): recent meta-analyses show significant improvement in PPD reduction and CAL gain as adjuncts — an interesting option requiring rigorous case selection.

D

Omega-3 fatty acids — Inflammation resolution

Omega-3 fatty acids act as precursors of lipoxins and resolvins — pro-resolution mediators of chronic periodontal inflammation.

Of particular interest in Grade C patients resistant to instrumentation alone, as a complement to systemic risk factor control.

08

Stage IV — Multidisciplinary Management

The most complex clinical challenge

Stage IV combines periodontal support destruction with major functional and structural damage to the dentition. Rehabilitation requires a multidisciplinary team including a periodontist, orthodontist, prosthodontist and sometimes an oral and maxillofacial surgeon. The 2022 S3 guideline distinguishes four case types to structure management.

The four clinical case types of Stage IV

Type	Clinical characteristics	Rehabilitation needs
Type 1	Tooth loss without major migration	Standard periodontal treatment + maintenance
Type 2	Pathological migration (diastemas, flaring)	Periodontal treatment + Orthodontics
Type 3	Partial edentulism, reduced posterior support	Fixed or removable prostheses on teeth/implants
Type 4	Complete or near-complete edentulism	Full-arch rehabilitation

Mandatory treatment sequencing in Stage IV

Steps 1–3

Inflammation control

Absolute prerequisite — no definitive restoration or orthodontic movement until inflammation is fully resolved

S3 Steps

Complete execution of Steps 1, 2 and 3 before any definitive prosthesis or orthodontic movement.

Teeth with a hopeless prognosis are extracted early to facilitate hygiene.

Provisional prosthesis

Provisional prostheses to stabilize the occlusion and assess patient cooperation.

Splinting of hypermobile teeth when necessary.

Ortho Phase

Orthodontic correction

Often necessary to correct pathological migration — strict periodontal monitoring every 3 months throughout

Objectives

Correct migrations, close diastemas and restore occlusal relationships before definitive restoration.

Monitoring

Periodontal check-up every 3 months throughout active orthodontic treatment.

Final phase

Definitive rehabilitation

Only after confirmed periodontal stability — natural tooth always preferred over implant when biologically feasible

Guiding principle

Natural tooth conservation must be prioritized over extraction for implant placement whenever biologically possible.

Prior validation

Confirmation of pocket closure, excellent oral hygiene and radiographic stability before any definitive impression.

09

Periodontitis and Systemic Health

Diabetes mellitus — Bidirectional relationship

Periodontitis affects glycemic control

Uncontrolled diabetes increases the risk and severity of periodontitis
Severe periodontitis can impair glycemic control
SRP can produce an HbA1c reduction of approximately 0.4% — comparable to adding a second antidiabetic medication
Shared goal with the treating physician: HbA1c < 7.0%

Pregnancy and maternal periodontitis

Associated obstetric risk

Documented association with preterm birth, low birth weight and preeclampsia
Periodontal treatment during pregnancy is safe and effective for improving maternal gingival health
No systematic reduction in obstetric complications proven after SRP alone
Treatment recommended in the 2nd trimester — priority on oral hygiene from the 1st trimester

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Oral-gut axis — Microbiome and systemic inflammation

Dysbiosis and oral pathobionts

Recent research suggests that oral pathobionts can migrate to the gut via the oral-gut axis, causing intestinal dysbiosis and exacerbating inflammatory conditions such as Crohn's disease, arterial hypertension and cardiovascular disease.

Impact of periodontal treatment

Periodontal treatment helps restore a healthier microbial profile both locally (gingival sulcus) and systemically (gut microbiome). An additional argument for early management of advanced stages.

Cardiovascular disease — Inflammatory link Chronic inflammation sustained by periodontitis contributes to atherosclerosis and increases the risk of cardiovascular events. Periodontal management is now integrated into cardiovascular prevention recommendations in several European countries.

10

Clinical FAQ

Both stages often share the same tissue loss measurements (CAL ≥ 5 mm, bone loss at the middle or apical third). The distinction is functional: Stage IV involves major masticatory sequelae — extreme tooth mobility (Grade III), fewer than 20 remaining teeth (fewer than 10 opposing pairs), or established occlusal collapse. Stage IV systematically mandates multidisciplinary management, complex rehabilitation and orthodontic and prosthodontic oversight in addition to standard periodontal treatment.

The AMX + MET combination is not a routine treatment. It is reserved for young adults (< 35–40 years) with generalized Stage III or IV Grade C periodontitis — i.e., with documented rapid progression (bone loss/age ratio > 1.0 or ≥ 2 mm progression over 5 years). The protocol is: amoxicillin 500 mg × 3/day + metronidazole 400–500 mg × 3/day for 7 days, initiated immediately after completion of full SRP — never before, as intact subgingival biofilm protects bacteria from antibiotics. Expected outcomes are an additional PPD reduction of 0.4–0.5 mm and a CAL gain of 0.2–0.4 mm vs SRP alone.

No, surgery is not automatic. It is indicated for residual pockets ≥ 6 mm or 4–5 mm pockets with persistent positive BOP after reassessment. Two preconditions are absolute: (1) a 4–12 week interval after SRP completion to assess tissue response, and (2) excellent oral hygiene (plaque index < 20%) — no periodontal surgery can succeed in the presence of inadequate plaque control. If the patient cannot maintain satisfactory hygiene, repeating non-surgical instrumentation is preferable to surgery doomed to fail.

Frequency is personalized using the Periodontal Risk Assessment (PRA). In practice: high-risk patients (multiple sites PPD ≥ 5 mm, BOP > 25%, smoking, HbA1c ≥ 7%) → recalls every 3 months. Stable patients with good plaque control, low BOP and no risk factors → recalls every 6 to 12 months. Maintenance is not just scaling: it includes full reassessment of periodontal status, re-instruction in hygiene if needed, and early detection of any recurrence at treated sites.

Classification must account for grade modifiers. A patient with bone loss initially corresponding to Grade B (bone loss/age ratio between 0.25 and 1.0) but with diabetes at HbA1c ≥ 7.0% is automatically reclassified as Grade C by the systemic modifier. This changes the strategy fundamentally: greater vigilance on maintenance frequency, potential indication for adjunctive antibiotherapy, and mandatory coordination with the treating physician to optimize glycemic control — which directly conditions the periodontal treatment response.

No, according to the 2022 S3 guidelines. Natural tooth preservation must be systematically prioritized over extraction for implant placement, whenever biologically feasible. Natural teeth, even with significant attachment loss, provide proprioception that implants cannot replicate. Furthermore, implants placed in the context of uncontrolled periodontitis carry a high risk of peri-implantitis. Extraction and implantation are indicated only after conservative periodontal and prosthetic options have been exhausted, and only after complete disease stabilization.

Ref

References

2017 Classification and diagnostic framework

1

Guideline Papapanou PN, Sanz M, Buduneli N, 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 Suppl 1:S173–S182.
efp.org — Consensus report workgroup 2, 2017 World Workshop
2

Review Mehta SB, Lim HC, Arora A, et al. Major highlights of the new 2017 classification of periodontal and peri-implant diseases and conditions. J Indian Soc Periodontol. 2021.
pmc.ncbi.nlm.nih.gov — Highlights of the 2017 classification
3

Review Buset SL, Walter C, Friedmann A, et al. Ease and practicability of the 2017 classification of periodontal diseases and conditions: a study of dental electronic health records. PMC. 2022.
pmc.ncbi.nlm.nih.gov — Ease and practicability of 2017 classification
4

Guideline Holtfreter B, Kocher T, Hertrampf K, et al. The 2018 EFP/AAP periodontitis case classification demonstrates high agreement with the 2012 CDC/AAP criteria. J Clin Periodontol. 2021.
ovid.com — 2018 EFP/AAP periodontitis case classification

EFP S3 guidelines — Treatment of Stages I to IV

5

S3 Guideline Sanz M, Herrera D, Kebschull M, et al. Treatment of stage I–III periodontitis — The EFP S3 level clinical practice guideline. J Clin Periodontol. 2020;47 Suppl 22:4–60.
efp.org — S3-level guideline stages I–III (2020)
6

S3 Guideline Herrera D, Sanz M, Shapira L, et al. Treatment of stage IV periodontitis: The EFP S3 level clinical practice guideline. J Clin Periodontol. 2022;49 Suppl 24:4–71.
efp.org — S3-level guideline stage IV (2022)
7

Review Saleh MHA, Dias Rodrigues I, Shaddox L. Periodontitis: all change please? Introduction to the new S3-level treatment guidelines. JIDA. 2022.
jida.scholasticahq.com — Introduction to S3-level guidelines
8

Guideline EFP. STEP 4: Supportive periodontal care (SPC) — Guideline summary. European Federation of Periodontology, 2020.
efp.org — Step 4: Supportive periodontal care
9

Review Kebschull M, Papapanou PN. Diagnosis and Evidence-Based Treatment of Stage IV Periodontitis. Journal Agent PDF. 2022.
pdf.journalagent.com — Stage IV evidence-based treatment

Instrumentation and full-mouth debridement

10

Clinical trial Eickholz P, Dannewitz B, Kimak A, et al. Management of periodontitis by three different approaches to non-surgical periodontal debridement — a randomized comparative clinical study. J Clin Periodontol. 2023.
pmc.ncbi.nlm.nih.gov — Three approaches to non-surgical debridement
11

Guideline ADA. Nonsurgical Treatment of Periodontitis Guideline. American Dental Association, 2023.
ada.org — Nonsurgical Treatment of Periodontitis Guideline
12

Guideline SDCEP. Supportive periodontal care — Prevention and Treatment of Periodontal Diseases in Primary Care. Scottish Dental Clinical Effectiveness Programme, 2022.
periodontalcare.sdcep.org.uk

Systemic adjunctive antibiotherapy

13

Meta-analysis Figuero E, Herrera D, Tobías A, et al. Efficacy of adjunctive systemic antimicrobials in periodontitis treatment: a systematic review and meta-analysis. J Clin Periodontol. 2014.
pmc.ncbi.nlm.nih.gov — Systemic antibiotic therapy in periodontics
14

Meta-analysis Mistry A, Agrawal KS, Dhadse PV, et al. Amoxicillin/Metronidazole Dose Impact as an Adjunctive Therapy for Stage II–III Grade C Periodontitis at 3- and 6-Month Follow-Ups. EJOMR / PMC. 2024.
pmc.ncbi.nlm.nih.gov — AMX/MET dose impact meta-analysis
15

Meta-analysis Nedzi-Gora M, Gorska R, Klosowska A, et al. The impact of systemic and topical antimicrobial therapy combined with non-surgical periodontal therapy: a meta-analysis. Advances in Clinical and Experimental Medicine. 2022.
advances.umw.edu.pl — Systemic and topical antimicrobial therapy
16

Review Levi I, Eini A, Kolerman R, et al. Targeted Use of Antimicrobials in Periodontal Therapy. Antibiotics / PMC. 2022.
pmc.ncbi.nlm.nih.gov — Targeted use of antimicrobials
17

Review EFP. Decision-making on systemic antibiotics in the management of periodontitis: a retrospective comparison of two concepts. European Federation of Periodontology.
efp.org — Decision-making on systemic antibiotics

Laser, aPDT and host modulation therapies

18

Meta-analysis Aljurbua A, Alqahtani S, Alafif T, et al. Efficacy of Antimicrobial Photodynamic Therapy for Treating Moderate to Deep Periodontal Pockets in Individuals with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis. MDPI / Antibiotics. 2024.
mdpi.com — aPDT and periodontal pockets in T2DM
19

Review Rajesh KS, Jacob R, Thomas B. Illuminating the path: the role of photodynamic therapy in comprehensive periodontal treatment. J Lasers Med Sci. 2024.
pubmed.ncbi.nlm.nih.gov — PDT in periodontal treatment
20

Clinical trial Nevins M, Kim SW, Camelo M, et al. Twelve-Month Follow-Up After the Treatment of Periodontal Conditions Using Scaling and Root Planning Alone vs. Laser-Assisted New Attachment Procedure. Int J Periodontics Restorative Dent. 2022.
pmc.ncbi.nlm.nih.gov — LANAP 12-month follow-up
21

Review Tuter G, Kurtis B, Serdar M. Host Modulation in Periodontology: Redefining Therapy Beyond Scaling and Root Planing. PMC. 2023.
pmc.ncbi.nlm.nih.gov — Host modulation in periodontology
22

Review Rosania AE, Low KG, McCormick CM, et al. Host modulation therapy in periodontitis, diagnosis and treatment — status update. Frontiers in Oral Health. 2023.
frontiersin.org — Host modulation therapy status update
23

Meta-analysis Naqvi SH, Ahmed Z, Tanveer A. Do Adjunctive Therapies with Natural Products Improve Periodontal Outcomes? A Systematic Review and Meta-Analysis. MDPI. 2024.
mdpi.com — Natural products as adjunctive therapies

Oral microbiome, systemic interactions and maintenance

24

Review Willis JR, Gabaldon T. Advancing periodontitis microbiome research: integrating design, analysis, and technology. Periodontol 2000. 2024.
pmc.ncbi.nlm.nih.gov — Periodontitis microbiome research
25

Longitudinal study Chen J, Chen Y, Hu L, et al. Correlation in the change of gut microbiota with clinical periodontal parameters in grade C periodontitis. PMC. 2024.
pmc.ncbi.nlm.nih.gov — Gut microbiota and grade C periodontitis
26

Longitudinal study Li Y, Zhao J, Zhang S, et al. Oral microbiome-based evaluation of periodontal treatment responses in individuals with special health care needs. J Oral Microbiol. 2023.
pmc.ncbi.nlm.nih.gov — Oral microbiome and periodontal treatment response
27

Tool Persson GR, Mancl LA, Martin J, et al. Periodontal Risk Assessment (PRA). perio-tools.com — Patient data-based periodontal risk calculator.
perio-tools.com — Periodontal Risk Assessment
28

Guideline ADA. Periodontitis — Clinical overview and management guidance. American Dental Association, 2023.
ada.org — Periodontitis overview
29

Guideline EFP. EFP Guideline: Treatment of periodontitis — Summary for clinicians. periodiabetes.org / EFP, 2020.
periodiabetes.org — EFP Guideline treatment of periodontitis