Periodontal Regeneration - Furcation Defects: Practical Applications From the AAP Regeneration Workshop

Cervical enamel projections from a periodontal perspective: A scoping review

Cervical enamel projections (CEPs) represent a unique developmental and anatomical anomaly wherein the enamel structure extends apically beyond the cemento-enamel junction of the tooth. In this scoping review, the existing literature on CEPs was evaluated to delineate their characteristics, prevalence, predilection for specific teeth and surfaces, clinical significance, and management approaches. Searches were conducted on MEDLINE (PubMed), Cochrane Library, and Embase databases using the keywords "enamel projection(s)" or "ectopic enamel." In total, 24 studies meeting inclusion criteria were included in the review. The prevalence of CEPs varied widely (8.3%-85.1%), predominantly manifesting as grade I or grade III. Mandibular first and second molars exhibited a higher incidence of CEPs, with a notable predilection for buccal surfaces. The consensus in most studies was that CEPs are associated with localized periodontal diseases. Recommendations inclined toward the removal of ectopic enamel during periodontal surgery to enhance periodontal attachment formation. However, decision-making should involve careful consideration of the benefits and drawbacks based on individual circumstances.

Furcation Involvement in Periodontal Disease: A Narrative Review

Furcation-involved teeth, commonly seen in dental practice, have a higher likelihood of needing extraction as the severity of periodontal furcation involvement increases. Studies consistently show that periodontitis in teeth with multiple roots significantly increases the risk of tooth loss, especially in the area where the furcation is involved. These furcation defects pose a major problem for dentists because of their location, accessibility issues, and the unpredictable healing process. The biggest hurdle in treating furcation defects is their irregular shape, which makes it hard to achieve complete debridement. While various treatments have been explored, non-surgical methods have not shown much success. This article comprehensively provides a review and discussion on the classification, assessment, and treatment options, including surgical and non-surgical management of furcation-involved molar teeth. Properly understanding the severity of the disease and its confounding factors and managing and treating the lesions appropriately have been shown to impart satisfactory survival rates for these teeth. Enhancing the understanding of managing these teeth can also lead to better outcomes for patients.

Clinical outcomes of periodontal regenerative therapy with carbonate apatite granules for treatments of intrabony defects, Class II and Class III furcation involvements: A 9-month prospective pilot clinical study

Introduction

Carbonated apatite (CO3Ap) has unique properties as an alloplastic bone substitute and has been reported the safety and efficacy for bone regeneration. However, no previous studies reported the clinical application of CO3Ap for periodontal regeneration therapy. The aim of this study was to evaluate the safety and efficacy of periodontal regeneration with CO3Ap in treating intrabony defects, Class II and Class III furcation involvement (FI).

Methods

A single-arm and single-center prospective pilot clinical study was performed to verify the safety and efficacy of CO3Ap in patients with periodontitis. A total of four patients with seven teeth, including three deep intrabony defects, two Class II FI, and two Class III FI, were treated with CO3Ap. The clinical parameters, including probing pocket depth (PPD), clinical attachment level (CAL), bleeding on probing (BOP), tooth mobility (Mo), Plaque index (PI), and Gingival index (GI) were evaluated at baseline, 6 months, and 9 months after the surgery. Radiographic analysis was conducted on images of dental X-ray and cone beam computed tomography (CBCT) at baseline and 9 months post-surgery.

Results

The postoperative healing in all cases was uneventful, with no abnormal bleeding, pain, or swelling. The mean PPD reduction and CAL gain were 5.0 ± 1.0 mm, 4.5 ± 0.7 mm, 1.5 ± 0.7 mm, and 4.7 ± 1.2 mm, 4.5 ± 0.7 mm, 0.0 mm for intrabony defect, Class II and Class III FI, respectively. According to radiographic analysis, linear bone height in intrabony defects and vertical subclassification of FI in Class II FI were improved.

Conclusions

The clinical application of CO3Ap for the treatment of intrabony defects and Class II FI could be effective for periodontal regeneration, although its efficacy in treating Class III FI might be limited. Despite the limitations of this study, the findings in this study suggested that CO3Ap has the potential to be a promising bone graft substitute for periodontal regeneration.

Complications and treatment errors related to regenerative periodontal surgery

Regenerative periodontal surgical procedures are an important component in the treatment of advanced periodontitis. They aim to improve the long-term prognosis of teeth that are periodontally compromised by the presence of intrabony and/or furcation defects, resulting biologically in formation of root cementum, periodontal ligament, and alveolar bone and evidenced clinically by reduction of deep pockets to maintainable probing depths and/or improvements of vertical and horizontal furcation depth. Over the last 25 years, substantial clinical evidence has been accumulated to support the value of regenerative procedures in periodontally compromised dentitions. However, treatment success requires close attention to certain factors on the level of the patient, the tooth/defect, and the operator. Ignoring these factors in case selection, treatment planning, and treatment execution will increase the risk of complications that may jeopardize clinical success and may even be considered as treatment errors. Based on the currently available evidence from clinical practice guidelines, treatment algorithms, and on expert opinion, the present article provides an overview on the main factors, which influence the outcomes of regenerative periodontal surgery and gives recommendations on how to prevent complications and treatment errors.

The influence of interradicular anatomy on the predictability of periodontal regenerative therapy of furcation defects: a retrospective, multicenter clinical study

BACKGROUND

The relationship between the anatomy of the interradicular space and success in regenerative therapy of furcation defects is discussed in this paper. The goal of this retrospective, multicenter clinical study is to clinically evaluate the relationship between the interradicular conformation and regenerative therapy success with the use of a novel measurement method.

METHODS

One hundred thirty-eight radiographs of mandibular molars with furcation defects that had been treated with regenerative therapy were collected from six clinical centers. Data on the type of therapy and clinical parameters before and after treatment (follow-up of at least 12 months) were collected. The radiographs (before surgery and at least 12 months postoperatively) were measured with a visual evaluation method by a blind operator using graphics software.

RESULTS

Success, defined as a reduction in horizontal and vertical furcation involvement, decrease in probing depths, and increase in clinical attachment level, was statistically assessed on 138 regenerated molars sites and were related to clinical variables such as age, sex, center, and treatment. No correlation was found between success in regenerative therapy and the conformation of the interradicular space, measured with a visual ratio method and a standard linear measurement. At the univariate analysis, the parameters that had a correlation with success were center, extent of furcation involvement, treatment, and sex. The use of enamel matrix derivative (EMD) seemed to be the most favorable therapy, with increase in CAL gain and reduction of vertical or horizontal furcation involvement.

CONCLUSIONS

The regenerative outcome was not significantly influenced by the anatomy of furcation. The center, the degree of furcation involvement, sex, and treatment (EMD) were significantly associated with higher success of periodontal regeneration.

Radiographic ratios for classifying furcation anatomy: proposal of a new evaluation method and an intra-rater and inter-rater operator reliability study

OBJECTIVES

Even if it seems to be an important anatomical parameter for tissue regeneration, few studies in literature evaluate the "mean measure" of root divergence. Most of them are linear measurements, which hardly describe the dental furcation conformation in its entirety. It is left to the subjectivity of the operator deciding whether a furcation is convergent or divergent. The goal of this study is to create a visual evaluation method using specific measurements applied on endo-oral X-rays to overcome these problems, giving a conformation of the entire interradicular space and its divergence.

MATERIAL AND METHODS

A user-friendly software (Paint®, Windows10®) was used to take three different measurements on endo-oral radiographs of upper and lower molars. Three blind operators measured 20 radiographs, to analyze the intra- and inter-operator reproducibility of the measurements. Then, the technique was repeated on 250 radiographic images to identify an average value and define a main conformation of the interradicular space. The ratio of these three measurements allowed to develop a new visual evaluation method of the interradicular space.

RESULTS

Intra and inter-operator reproducibility was statistically confirmed on a sample of 20 anonymous endo-oral radiographs measured by 3 blind operators, indicating that the measurement technique was not operator dependent. Measurement made on 250 X-rays obtained with this technique permitted to subdivide in five groups the conformation of the interradicular space and define a mean value of the interradicular space.

CONCLUSIONS

A new anatomical evaluation of the interradicular space in its entirety, which could help the clinicians in diagnostic and decisional phase in the therapy of furcated molars, can be obtained.

CLINICAL RELEVANCE

A pre-operative evaluation of interradicular space conformation could affect therapy treatment choice.

Induction of periodontal ligament-like cells by co-culture of dental pulp cells, dedifferentiated cells generated from Epithelial cell Rests of Malassez, and umbilical vein endothelial cells

INTRODUCTION

Apart from the Epithelial Cell rests of Malassez (ERM), the dental pulp (DP) contains the same types of mesenchymal cells as the periodontal ligament (PDL). The ERM may affect the characteristics of mesenchymal cells in the PDL. The aim of this study was to examine whether DP cells cultured with ERM and human umbilical vein endothelial cells (HUVECs) could transform into PDL-like cells.

METHODS

Progenitor-dedifferentiated into stem-like cells (Pro-DSLCs) were produced by the induction of ERM with 5-Azacytidine and valproic acid. DP cells were cultured in mesenchymal stem cell (MSC) medium for 1 week under the following conditions: DP cells alone (controls); PDL cells alone; co-culture of DP cells and ERM (DP+ERM) or Pro-DSLCs (DP+Pro-DSLC); co-culture of DP cells, HUVECs, and ERM cells (DP+ERM+HUVEC) or Pro-DSLCs (DP+Pro-DSLC+HUVEC). qRT-PCR, qMSP, and flow cytometry were performed.

RESULTS

The expression levels of PDL-related markers, Msx1, Msx2, Ncam1, Postn, S100a4, and MSC-positive markers, Cd29, Cd90, Cd105, were significantly higher in the PDL cells and DP+Pro-DSLC+HUVEC cultures than in the controls (p < 0.05). The DNA methylation levels of Msx1 and Cd29 in the PDL cells and DP+Pro-DSLC+HUVEC culture were significantly lower than in the controls (p < 0.01). We found a significant increase in the number of cells stained with MSX1 (p < 0.05) and CD29 (p < 0.01) in the DP+Pro-DSLC+HUVEC culture than in the controls.

CONCLUSIONS

Co-culture of DP cells with Pro-DSLCs and HUVECs induced their transformation into PDL-like cells. This method may prove useful for periodontal regeneration via tissue engineering.

Two-stage approach for class II mandibular furcation defect with insufficient keratinized mucosa: a case report with 3 years' follow-up

Periodontal regenerative treatment is useful for intrabony defects and furcation involvement, but is difficult when there is insufficient keratinized mucosa to cover and maintain the regenerative material, particularly in the mandibular molar region. We report the case of a 27-year-old woman who underwent a two-stage surgical approach for a class II furcation defect with gingival recession and insufficient keratinized mucosal width (KMW) and vestibular depth at the mandibular left first molar. We first improved the KMW and keratinized mucosal thickness using an epithelial embossed connective tissue graft with enamel matrix derivative, and then focused on periodontal regeneration at the furcation defect using an enamel matrix derivative and a bovine-derived xenograft. Probing depth reduction, clinical attachment gain, horizontal probing depth reduction, KMW gain, and gingival recession reduction were observed 3 years postoperatively. This case report suggests that this novel staged approach may be effective for treating furcation defects with insufficient keratinized mucosa, thus providing useful insights into periodontal regeneration therapy.

Regenerative Medicine Technologies to Treat Dental, Oral, and Craniofacial Defects

Additive manufacturing (AM) is the automated production of three-dimensional (3D) structures through successive layer-by-layer deposition of materials directed by computer-aided-design (CAD) software. While current clinical procedures that aim to reconstruct hard and soft tissue defects resulting from periodontal disease, congenital or acquired pathology, and maxillofacial trauma often utilize mass-produced biomaterials created for a variety of surgical indications, AM represents a paradigm shift in manufacturing at the individual patient level. Computer-aided systems employ algorithms to design customized, image-based scaffolds with high external shape complexity and spatial patterning of internal architecture guided by topology optimization. 3D bioprinting and surface modification techniques further enhance scaffold functionalization and osteogenic potential through the incorporation of viable cells, bioactive molecules, biomimetic materials and vectors for transgene expression within the layered architecture. These computational design features enable fabrication of tissue engineering constructs with highly tailored mechanical, structural, and biochemical properties for bone. This review examines key properties of scaffold design, bioresorbable bone scaffolds produced by AM processes, and clinical applications of these regenerative technologies. AM is transforming the field of personalized dental medicine and has great potential to improve regenerative outcomes in patient care.