Treatment of periodontal bone defects

What is a periodontal bone defect?

In periodontitis, the bone that anchors the tooth is destroyed. Sometimes the bone crest is lowered evenly and horizontally. Other times, the destruction goes deeper along one root surface than at the adjacent teeth, and a defined defect is formed, where regenerative treatment may be considered.

• Intraosseous defect: vertical bone loss along the root, where the base is deeper than the surrounding bone crest, so that bone walls remain around the defect. The number of walls is part of the assessment.
• Furcation defect: bone loss between the roots of a multi-rooted tooth. In class II, the bone is partially lost beneath the tooth, without the defect going all the way through.

Intraosseous defects are a common finding in stage III and IV periodontitis and are associated with an increased risk of disease progression, Miron et al. describe in Periodontology 2000.² Class II and III furcation defects are associated with a greater risk of tooth loss.³

How are bone defects treated step by step?

Treatment follows the steps in the clinical guidelines from the European Federation of Periodontology (EFP): step 1 is oral hygiene and supragingival debridement, step 2 is subgingival instrumentation. For many pockets, this is enough. But residual pockets of ≥ 5 mm that are associated with an intraosseous defect are a risk factor for further disease progression and may require surgery, as Iorio-Siciliano et al. describe in Journal of Clinical Periodontology.¹

Surgery can be pure flap surgery (open flap debridement, OFD) or a regenerative procedure, where a material is placed in the defect. It is well established through a large number of randomized trials that regenerative surgery with barrier membrane (GTR), enamel matrix derivative (EMD) or bone substitute material provides a significant clinical additional benefit compared to flap surgery alone, and it may be indicated for residual pockets with deep (≥ 3 mm) intraosseous defects after steps 1 and 2.² Needle holders, scissors and forceps for the procedure can be found under surgical instruments.

PRF is made from the patient's own blood and forms a fibrin matrix with platelets and leukocytes, which contributes to a more prolonged release of growth factors.² It can be placed in the defect alone during the flap surgery or mixed with a bone substitute material, and its preparation requires PRF equipment. If PRF is new to you, start with our guide to Platelet-Rich Fibrin.

What works for intraosseous defects?

PRF used as an adjunct to flap surgery provided an average of 1.27 mm more pocket reduction (95% confidence interval (CI) 1.03 to 1.51) and 1.22 mm greater attachment gain (both 22 trials) as well as 1.59 mm greater radiographic defect filling (19 trials) than flap surgery alone. This is shown by a meta-analysis of 55 randomized trials, which Miron et al. published in Periodontology 2000.²

Heterogeneity was high (I² 87-90%), and the risk of bias varied between the trials. For PRF, human histological data are missing, so it has not been shown whether new cementum, new periodontal ligament and new bone are formed. The authors' comparison with established regenerative procedures is indirect; in the direct comparisons with platelet-rich plasma (PRP), EMD and barrier membrane, there was no significant difference, but each was based on only one or two trials.²

Should PRF be combined with bone substitute material?

Both meta-analyses that have looked at the combination speak in favor of it. In the Miron analysis, the combination gave better results than each material alone, e.g. 0.63 mm more pocket reduction than bone substitute material alone (17 trials).² In a network meta-analysis of 32 randomized trials, which Zhou et al. published in BMC Oral Health in 2026 independently of the Miron group, bone substitute material combined with PRF ranked highest for pocket reduction and bone building.⁵

Heterogeneity was high, and Zhou et al. grouped PRF types and bone substitute materials into broad groups, so the results apply to the treatment strategy and not the individual product. The certainty of the evidence was assessed as moderate.^{2, 5}

Examples of particulate bone substitute materials are deproteinized bovine bone mineral such as cerabone® and human allograft such as maxgraft® cancellous; these are not the products that were tested in the trials.

What works for furcation defects?

The EFP's S3 guideline recommends bone substitute material, resorbable membranes and EMD for the regeneration of furcation defects, but could not take a position on platelet concentrates. The same research group behind the Miron analysis collected 21 randomized trials on PRF for class II, mostly in the lower jaw, in a meta-analysis in Periodontology 2000. Used as an adjunct to flap surgery, PRF reduced pocket depth 1.73 mm more than flap surgery alone (five trials), and used as an adjunct to bone substitute material, it gave 0.73 mm more pocket reduction than bone substitute material alone (six trials).³

Heterogeneity was very high (I² 94% for pocket reduction), only one trial had a low risk of bias, class III defects were not included, and there is almost no human histological data.³ In both PRF analyses, the trials followed the patients for an average of 8-9 months.^{2, 3} Because it theoretically means more to hold space in a furcation, the authors assess that combination treatment with bone substitute material appears to be the preferred choice.³

What about hyaluronic acid, CGF and other adjuncts?

Cross-linked hyaluronic acid used as an adjunct to MINST did not significantly change the primary outcome, pocket depth after six months, but pocket reduction and attachment gain were significantly greater after three months in the trial by Iorio-Siciliano et al. The trial did not use a placebo gel, and it cannot be concluded from the current evidence that hyaluronic acid improves the result after six months.¹

CGF (concentrated growth factor), another platelet concentrate, has only been studied in three trials on intraosseous defects and two on furcation defects in a meta-analysis by Chen et al. in BMC Oral Health. In two of the three, bone substitute material with CGF gave 1.41 mm more reduction of defect depth than bone substitute material alone, but from so few trials it cannot be concluded whether CGF improves the result.⁴

Metformin, bisphosphonates and statins have also been studied locally as an adjunct to PRF, but only in 1-2 trials per substance.²

What materials and what equipment are used for regenerative treatment?

The choice of material depends on several factors, including the defect type, and whether the defect itself can hold space.^{2, 3} Overall, regenerative treatment may be considered in these situations:

• Intraosseous defects: bone substitute material, barrier membrane or EMD, and PRF used as an adjunct to flap surgery. The PRF trials typically included two- and three-wall defects (see section).²
• Defects that cannot hold space themselves: bone substitute material combined with PRF (see section).^{2, 5}
• Class II furcation defects: bone substitute material and resorbable membrane, possibly combined with PRF (see section).³

Below are examples of materials and equipment for these treatments. The products are examples of the material groups in the studies, not the products that were tested, and the indications are found in the manufacturers' instructions for use. The choice of treatment, material and indication in the individual case is determined by the treating dentist.

Bone substitute material and membrane

• 

  cerabone® 5 cc

  Bovine bone mineral in particulate form, a xenograft bone substitute material.

  See cerabone® →
• 

  maxgraft® cancellous

  Human allograft granules as an alternative to xenograft material.

  See maxgraft® cancellous →
• 

  Collprotect membrane

  Resorbable collagen membrane to cover a bone substitute material.

  See Collprotect membrane →

See the entire range of biomaterials.

Equipment for PRF

The equipment below is not what was used in the trials, which used different centrifuges and protocols.²

• 

  Complete PRF setup

  Horizontal centrifuge, PRF box with instruments, tubes for PRF membranes and liquid PRF, as well as the book Understanding PRF.

  See the complete PRF setup →
• 

  Centrifuge BP 200

  Horizontal swing-out centrifuge for PRF preparation.

  See centrifuge BP 200 →
• 

  Glass tubes for PRF membranes

  Tubes for solid PRF preparation, 10 ml, 100 pcs. in the box.

  See glass tubes for PRF membranes →

See the entire range of PRF equipment→

Are you considering using PRF in the clinic? The protocol depends on the clinic's equipment and is best learned through practical training. Puredent holds courses in PRF and blood collection.

See our courses in PRF and blood collection→

Frequently asked questions

Interests

We disclose the authors' and Puredent's interests so that you can assess the sources yourself.

• Puredent sells equipment for PRF and biomaterials and holds PRF courses.
• Sources 2 and 3: The first author, Richard J. Miron, holds patents and trademarks for PRF (declared in source 2).²
• Sources 1, 2 and 3: Anton Sculean from the University of Bern is a co-author of all three, so the sources are not independent of each other.
• Source 5: The authors of the Zhou analysis declare no conflicts of interest.⁵

Sources