Periodontal plastic surgery

Root coverage using a connective tissue graft with epithelial striation in combination with enamel matrix derivatives - a long-term retrospective clinical interventional study

Background

The application of a connective tissue graft with epithelial striation (CTG-ES) has been shown to improve the outcome of root coverage (RC) using the coronally advanced flap (CAF) and adjunctive administration of enamel matrix derivatives (EMD). Aim of the present study was to evaluate the long-term (mean: 16.19 ± 1.80 years, range: 13 to 18 years) stability of this treatment method with special focus on the location of the gingival margin and the width of keratinized tissue (WKT).

Methods

16 patients (10 female, 6 male, aged 35.36 ± 14.70 years at surgery) with 25 Miller class I or II gingival recession (GR) defects were treated using the CAF combined with the CTG-ES and EMD. The clinical measurements recorded at baseline (t0), 6 months (t1), and 13 to 18 years (t2) after surgery included recession depth (RED), probing pocket depth (PPD), clinical attachment level (CAL), and WKT. In addition, the number of sites with complete RC (CRC) and the mean RC (MRC) were documented at t1 and t2. The statistical analysis was performed using a linear mixed model.

Results

The RED (t0: 4.52 ± 1.56 mm; t1: 0.36 ± 0.76 mm; t2: 0.30 ± 0.60 mm) and CAL (t0: 6.16 ± 1.62 mm; t1: 1.86 ± 0.87 mm; t2: 1.54 ± 0.92 mm) were significantly reduced at t1 and t2 compared to t0 (p <  0.001). The PPD was significantly reduced at t2 compared to t0 (p = 0.016). The WKT (t0: 1.18 ± 1.28 mm; t1: 3.26 ± 0.98 mm; t2: 4.26 ± 1.83 mm) significantly increased from t0 to t1, from t0 to t2 (p <  0.001) and from t1 to t2 (p = 0.007). A CRC was recorded at 19 sites (76.0%) at t1 and t2. The MRC was 93.6 ± 12.8% at t1 and 93.3 ± 13.3% at t2.

Conclusions

The use of the CAF combined with CTG-ES and EMD leads to stable long-term outcomes on teeth with Miller Class I or II GR defects. The CTG-ES represents a hybrid graft with increased position stability and advantageous properties for the healing process. We assume that the ES is responsible for the increase of the WKT.

Tunneling Technique in Conjunction With Autogenous Graft or Graft Substitutes Is a Predictable Surgical Approach to Achieve Root Coverage in Isolated or Multiple Gingival Recession Defects

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Efficacy of tunnel technique in the treatment of localized and multiple gingival recessions: A systematic review and meta-analysis. Tavelli L, Barootchi S, Nguyen TVN, Tattan M, Ravidà A, Want H-L. J Periodontol 2018;89(9):1075-90.

SOURCE OF FUNDING

Nonprofit, foundations, university support: University of Michigan Periodontal Graduate Student Research Fund.

TYPE OF STUDY/DESIGN

Systematic review with meta-analysis of data.

Multidisciplinary Approach to Cover an Apex-Exposed Tooth: A Case Report after 6-Year Follow-Up

Introduction

The prognosis for a successful treatment of gingival recessions (GRs) is one of the main criteria for deciding whether or not and how to perform root coverage surgery. The defect-related factors are the most important to predict root coverage outcomes. Thus, severe GR could make the root coverage (RC) challenging especially in cases with advanced interdental clinical attachment loss (ICAL).

Case Presentation

This case report demonstrates a challenging management of a deep localized Miller Class III GR with root apex exposure associated with ICAL. After initial therapy, the treatment had consisted of a multidisciplinary approach involving endodontic treatment, periodontal plastic surgery including a laterally positioned flap, and orthodontic treatment. The 6-year follow-up showed improvement in clinical outcomes (recession reduction (RR) and keratinized tissue (KT) augmentation) and a higher patient satisfaction.

Conclusions

This case report demonstrates the role of the multidisciplinary approach in the management of deep GRs associated with ICAL. A rational choice of the RC technique was critical to achieve good clinical outcomes.

Medical reliability of a video-sharing website: The gingival recession model

OBJECTIVES

To evaluate the quality of the scientific/clinical information in dentistry delivered by videos hosted by a popular video-sharing website.

METHODS

The gingival recession condition was used as a model and YouTube™ as the video hosting service. A systematic observation of videos containing information on gingival recession was conducted. Videos were analysed to evaluate (i) the scientific reliability and quality of the information using Global Quality Scale (GQS) and DISCREN criteria; and (ii) the understandability of this information using a tailor-made custom comprehensiveness index (CI).

RESULTS

One hundred and eighty videos were identified. Videos dealing with surgical procedures were not included in the present review. After selection, 41 videos were analysed. The mean GQS was 2.34 on a 0-5 scale, and 25 (61%) videos showed clear aims according to DISCREN criteria. Misleading content was observed in eight videos (19.5%). The scientific sources of information were unclear in 26 (63.4%) videos. All videos failed to give additional references for supplemental information. Only three videos (7%) provided basic information on aetiology, clinical presentations and management of gingival recession. Based on 0-2 CI scores, three, nine and 29 videos had a score of 2, 1 and 0, respectively.

CONCLUSION

The present model indicates that social media websites aiming to provide health information should be carefully accounted, especially when dealing with dentistry. It also suggests professional involvement to improve the quality of the delivered information.

Root Coverage for Single Deep Gingival Recessions: Outcomes Based on a Decision-Making Algorithm

AIM

The aim of this study is to report root coverage outcomes in single deep gingival recessions (GR) following a proposed decision-making algorithm.

MATERIALS AND METHODS

A retrospective, practice-based study included single deep (≥5 mm) Miller Class II and III defects. The step-by-step decision-making algorithm led to a choice among three different flap designs (coronally advanced flap (CAF), double papilla envelope flap (DPE) or modified lateral sliding flap (LSF)) used with a connective tissue graft. Recession depth (RD) at 6 months follow-up and the corresponding root coverage (RC) were the primary outcomes assessed.

RESULTS

Sixteen GR defects were included, with baseline RD of 6.7 ± 1.8 mm. Six months postoperatively, RD was significantly reduced to 1.2 ± 0.8 mm (p < 0.05). Mean RC was 81.7 ± 13.0%, without significant differences between Miller Class II (87.1 ± 9.2%; n=9) and Class III (74.6 ± 14.5%; n=7) GRs (p=0.07). Postoperatively, keratinized tissue width increase was greater for LSF (3.5 ± 1.1) and DPE (4.2 ± 1.4 mm) than for CAF (1.9 ± 0.9 mm).

CONCLUSIONS

Following the proposed decision-making algorithm, root coverage outcomes for GR defects ≥5 mm were comparable to outcomes reported for shallow defects. Prospective clinical trials are needed to validate the proposed approach and techniques.

PRACTICAL IMPLICATIONS

The proposed algorithm allows the clinician to select the appropriate surgical technique for treatment of single deep gingival recessions with good predictability.

Periodontal biotype modification using a volume-stable collagen matrix and autogenous subepithelial connective tissue graft for the treatment of gingival recession: a case series

Purpose

The purpose of this study was to propose a technique for periodontal biotype modification through thickening of the entire facial aspect using a volume-stable collagen matrix and autogenous subepithelial connective tissue graft (CTG) for the treatment of gingival recession.

Methods

Four systemically healthy patients showing Miller class I or class II gingival recession in the mandibular incisor area were included in this study. Full-mouth scaling and root planing procedures were performed at least 4 weeks prior to periodontal plastic surgery. A split-thickness flap with a horizontal intrasulcular incision and 2 vertical incisions was used in cases 1–3, and the modified tunnel technique was used in case 4 for coronal advancement of the mucogingival complex. After the exposed root surfaces were debrided thoroughly, double-layered volume-stable collagen matrix was placed on the apical part of the recession and a subepithelial CTG harvested from the palatal area was placed on the coronal part. The amount of root coverage at 3 months postoperatively was evaluated in cases 1–3, and facio-lingual volumetric changes were analyzed in cases 1 and 2.

Results

Healing was uneventful in all 4 cases and complete root coverage was shown in cases 1–3. In case 4, reduction of gingival recession was observed at 3 months after surgery. In cases 1 and 2, a comparison of stereolithographic files from the preoperative and postoperative time points demonstrated that the entire facio-lingual volume had increased.

Conclusions

The surgical technique suggested herein, using a volume-stable collagen matrix and autogenous subepithelial CTG, may be an effective method for periodontal biotype modification through thickening of the entire facial aspect for the treatment of gingival recession.

Soft tissue substitutes to increase gingival thickness: Histologic and volumetric analyses in dogs

OBJECTIVES

To evaluate the histologic and volumetric changes of gingival tissues following grafting with collagen-based matrices at labial aspect of teeth in canines.

MATERIALS AND METHODS

Gingival augmentation was performed in the mandibular incisor area using two types of xenogeneic cross-linked collagen matrices (CCMs), bovine CCM for BCCM group and porcine CCM for PCCM group, whereas the contralateral sides remained untreated (B-control group and P-control group). Descriptive histology, histometric and volumetric analyses were performed after 12 weeks. For statistical comparison between each test group and respective control group, paired t test was used for histometric analysis, and repeated-measured analysis of variance was used for volumetric analysis (p < 0.05).

RESULTS

An increased number of rete pegs and an enhanced formation of new blood vessels were observed at both grafted sites compared to the corresponding control sites. There was statistically significant gain of horizontal thickness only in BCCM group (1.36 ± 0.27 mm vs. 1.26 ± 0.34 mm; p < 0.05) compared to the B-control groups.

CONCLUSION

BCCM was effective for gingival augmentation in terms of horizontal thickness at the labial aspect of teeth at 12 weeks post-surgery.

What Is the Safety Zone for Palatal Soft Tissue Graft Harvesting Based on the Locations of the Greater Palatine Artery and Foramen? A Systematic Review

PURPOSE

Palatal soft tissue graft harvesting is a common procedure in periodontal and implant dentistry. However, most of the complications after this procedure are associated with the underestimation of anatomic structures, such as the greater palatine artery (GPA). Therefore, the aim of this study was to provide guidelines for a safety zone for palatal harvesting.

MATERIALS AND METHODS

A systematic search was conducted to identify cadaveric and computed tomography (CT) or cone beam CT studies assessing the location of the greater palatine foramen (GPF) and the path of the GPA in relation to the maxillary teeth. The effect of age, gender, and cadaveric and CT or cone beam CT studies on the location of the GPF and on the course of the GPA also was assessed.

RESULTS

This systematic review included 26 studies, investigating 5,768 hemipalates. The most common location of the GPF was in the midpalatal aspect of the third molar (57.08%). As it traverses the palate anteriorly, the distance from the GPA to the maxillary teeth gradually decreases, except in the second premolar region, where it has the tendency to increase (13.8 ± 2.1 mm). The least distance from the GPA to the teeth was found in the canine area (9.9 ± 2.9 mm), whereas the greatest distance was in the second molar region (13.9 ± 1 mm). A safety zone for palatal harvesting was proposed based on the anatomic findings.

CONCLUSIONS

This study provides guidelines for identifying the position of the GPF and defines a safety zone for harvesting a free gingival graft or connective tissue graft, minimizing the risk of GPA injury.

Clinical parameters, histological analysis, and laser Doppler flowmetry of different subepithelial connective tissue grafts

Subepithelial connective tissue graft (SCTG) presents favorable outcomes. However, the harvesting technique can influence the anatomical and histological composition of the SCTG. Within the limitations of a case report, the behavior of SCTGs removed by two techniques was evaluated bilaterally in one patient using double blade scalpel (DBS) and de-epithelialized graft (DE). Clinical parameters, laser Doppler flowmetry (LDF) and histological analysis were assessed. Complete root coverage was observed bilaterally, as well as improvement in width and thickness of keratinized tissue 2 years postoperatively. The LDF analysis demonstrated better revascularization in the DBS recipient area compared to DE. The histological evaluation showed differences in tissue composition and organization of collagen fibers. Similar clinical outcomes were observed bilaterally, nevertheless greater morbidity and aesthetic was reported in the DE harvesting area.

Gingival tissue reaction to direct adhesive restoration: A preliminary study

INTRODUCTION

It is debated whether composite resin marginal/submarginal direct restoration can be usefully performed without inflammatory consequences. This histological study is the first human analysis aimed to compare, in the same tooth, the gingival tissue close to composite resin restorations with gingival tissue close to hard tissue.

METHODS

Eight healthy patients with almost a residual strategic tooth needing endodontic therapy, and post-and-core restoration, then indirect prosthetic restoration, were selected. Direct margin relocation with composite resin was necessary to perform endodontic treatment. The crown lengthening with a secondary flap harvested was necessary to perform prosthetic rehabilitation. Three months after marginal relocation, the secondary flap was harvested, embedded in PMMA, 4-μm sectioned, and stained to analyze the inflammation degree.

RESULTS

All patients completed post-and-core reconstruction and the planned prosthetic therapy, maintaining the stringent hygienic protocol plan. The inflammation level comparison, slightly lower in gingiva close to the teeth (3.62 ± 0.38) than in gingiva close to the composite (3.75 ± 0.26), results in a p-value of 0.11 after Wilcoxon test.

CONCLUSIONS

Results highlight a minimal, statistically not significant difference in the inflammation degree after margin relocation, conceivably due to patients, teeth and cases selection, together with adopted stringent methodological and supportive measures.

Periodontitis: facts, fallacies and the future

This volume of Periodontology 2000 represents the 25th anniversary of the Journal, and uses the occasion to assess important advancements in periodontology over the past quarter-century as well as the hurdles that remain. Periodontitis is defined by pathologic loss of the periodontal ligament and alveolar bone. The disease involves complex dynamic interactions among active herpesviruses, specific bacterial pathogens and destructive immune responses. Periodontal diagnostics is currently based on clinical rather than etiologic criteria, and provides limited therapeutic guidance. Periodontal causative treatment consists of scaling, antiseptic rinses and occasionally systemic antibiotics, and surgical intervention has been de-emphasized, except perhaps for the most advanced types of periodontitis. Plastic surgical therapy includes soft-tissue grafting to cover exposed root surfaces and bone grafting to provide support for implants. Dental implants are used to replace severely diseased or missing teeth, but implant overuse is of concern. The utility of laser treatment for periodontitis remains unresolved. Host modulation and risk-factor modification therapies may benefit select patient groups. Patient self-care is a critical part of periodontal health care, and twice-weekly oral rinsing with 0.10-0.25% sodium hypochlorite constitutes a valuable adjunct to conventional anti-plaque and anti-gingivitis treatments. A link between periodontal herpesviruses and systemic diseases is a strong biological plausibility. In summary, research during the past 25 years has significantly changed our concepts of periodontitis pathobiology and has produced more-effective and less-costly therapeutic options.

Evaluation of the effect of dose-dependent platelet-rich fibrin membrane on treatment of gingival recession: a randomized, controlled clinical trial

Miller's class I gingival recessions (GR) have been treated using coronally advanced flap (CAF) with platelet-rich fibrin membrane (PRF membrane) or connective tissue graft (CTG).

Pain perception following epithelialized gingival graft harvesting: a randomized clinical trial

OBJECTIVES

The aim of this study was to compare the effects of a hemostatic collagen sponge and a collagen sponge sealed with a bio-adhesive material on the palatal donor sites with the purpose of minimizing postoperative pain after epithelialized gingival graft (EGG) harvesting.

MATERIAL AND METHODS

The present study consisted of 44 EGGs harvested in 44 patients. In the control group, a hemostatic collagen sponge was applied over the palatal wound, while the test group was treated with additional cyanoacrylate. Patients were observed for 14 days, evaluating the pain level by using the visual analogic scale. The consumption of analgesic during the postoperative period, the willingness for retreatment and the characteristic of the graft were also analyzed.

RESULTS

Statistically significant differences in pain perception were found between test and control groups in each of the studied days (p < 0.01). Analgesic consumption was lower in the test group (p < 0.01). Graft width < 14 mm was found to be associated with lower discomfort (p < 0.01).

CONCLUSIONS

Adding an additional layer of cyanoacrylate over a hemostatic collagen sponge on the palatal wound following EGG harvesting was found to be successful in minimizing the postoperative discomfort and the need for analgesics.

CLINICAL RELEVANCE

Postoperative pain after palatal tissue harvesting can be successfully minimized if the donor site open wound is protected with an external layer of cyanoacrylate over a collagen sponge.

Fifteen-Year Follow-Up of a Case of Surgical Retreatment of a Single Gingival Recession

Purpose

The aim of the present case report was to describe the retreatment of the single gingival recession in aesthetic area, in the presence of scar formation and consequent impairment of aesthetic appearance.

Methods

A young patient with one single recession of 4 mm of 2.1 was treated with coronally advanced flap and subepithelial connective tissue graft, through a microsurgical approach that aimed at the removal of the scarred fibrous tissue. The intervention was performed using a surgical microscope as a magnification device.

Results

Fifteen years after the surgical treatment, a substantial stable resolution of the gingival recession could be observed. Moreover, a further improvement of the aesthetic appearance could be observed.

Conclusions

This case report suggests that periodontal microsurgery could be an effective approach for the retreatment of gingival recessions and, in long-term evaluation, to reduce the aesthetic problem due to the presence of scar formation. Further studies with a larger sample size are needed to better evaluate its efficacy.

Preliminary evaluation of near-infrared vein visualization technology in the screening of palatal blood vessels

Background

Avoidance from palatal blood vessel rupture is a major concern during the palatal soft tissue graft surgery. There is no defined chair-side and case-specific palatal blood vessel detection approach to facilitate the harvesting process. The objective of this pilot study is to assess the feasibility of a near-infrared vein visualization system in the screening process of palatal blood vessels.

Material and Methods

An extraoral vein visualization device (AccuVein AV400) was applied to a total of 304 hemi-maxilla of 152 individuals by two blind examiners. The study groups were classified according to their maximum inter-incisal measurements. The distances between the coronal border of the vessel image and the mid-palatal gingival margins of the adjacent teeth were measured and in each group. The correlations among the measurements were evaluated within groups.

Results

The blood vessel to the adjacent teeth measurements exhibited no statistical difference between both examiners in all subjects (p<0.001). Correlations between the examiners gradually increased in all groups as the mouth opening rates of the subjects were increased (p<0.001).

Conclusions

In the current state, screening of the palatal blood vessels via near-infrared vein visualization technology seems to be not suitable for every individual due to the restrictive effect of mouth opening. However, the promising results of this preliminary study demonstrated increasing consistency between the measurements of the examiners as the inter-incisal distance increase which emphasized the need an intraoral version of the device. Considering the lack of local decision-making technology for the detection of palatal blood vessels, further studies are required for development and optimization of these systems.

Key words:Near-infrared vein visualization, palatal graft harvesting, surgical complications.

Evaluation of the Biological Behavior of Mucograft® in Human Gingival Fibroblasts: An In Vitro Study

Mucograft(r) is a resorbing porcine matrix composed of type I and type III collagen, used for soft tissue augmentation in guided tissue bony regeneration procedures. This in vitro study aimed to evaluate the biological behavior of Mucograft(r) in human gingival fibroblasts, as well as the ability of the matrix to induce production of extracellular matrix. Six resorbing Mucograft(r) matrices (MCG) were cut into 3 x 2 mm rectangles and 5 x 5 mm squares and were placed in 96- and 24-well plates, respectively. The control group (CTRL) consisted of cells plated on polystyrene without the MCG. After one, two, three and seven days, cell proliferation and viability were assessed using the Trypan exclusion method and MTT test, respectively. Type III collagen (COL 3A1) and vimentin (VIM) expression were also evaluated at 10 and 14 days, using Western blotting. Statistical analysis, using ANOVA with post hoc Bonferroni test, revealed that human gingival fibroblasts from MCG showed similar results (p>0.05) for proliferation and viability as the cells cultured on CTRL. After 14 days, a significant decrease in COL 3A1 expression (p<0.05) was observed when cultured with the MCG. VIM expression showed no significant difference at any time period (p>0.05). Although no increase in extracellular matrix secretion was observed in this in vitro study, Mucograft(r) presented cellular compatibility, being an option for a scaffold whenever it is required.

Peri-implant mucosal dehiscence coverage with a modified semilunar coronary positioned flap in posterior maxilla: a case report

Soft tissue dehiscence around dental implant has frequently been observed and it may lead to poor oral hygiene, especially around crowns that exhibit contours with prominent convexity. The present case demonstrates a peri-implant mucosal dehiscence coverage with modified semilunar coronary positioned flap (CPF) in #15 and 16. A semilunar partial-thickness incision was performed 7–10 mm apical from the facial gingival margin. Then, intrasulcular partial-thickness incision was tunneled to the semilunar incision. The tunnel preparation was extended interproximally under each papilla due to improvement of flap extension. Then, the tunneled flap was coronary positioned with a coronary-anchored suturing technique. Sub-epithelial connective tissue graft (SCTG) from the palate was inserted from the semilunar incision to the inside of the coronary positioned flap and sutured to stabilize the SCTG and supplemental site. Significant mucosal gain was achieved without any complication. The soft tissue volume was maintained at 9 months post-surgery, and the cleanability was improved. This technique has the potential in improving the graft survival and mucosa gain around implants.

Quantitative changes in palatal donor site thickness after free gingival graft harvesting: a pilot study

AIM

The aim of this study was to investigate how donor sites thickness quantitatively change over time and at different points of donor site in spontaneous palatal wound healing after free gingival graft (FGG) harvesting.

MATERIALS AND METHODS

Forty individuals were enrolled and divided into the following two groups based on the residual tissue thickness (RTT) after harvesting: Group 1, <2 mm; and Group 2, ≥2 mm. FGGs were standardized according to their dimensions and thickness and then harvested. Tissue filling was measured at three points of the defect area (mesial, central and distal) at various time points (baseline, after harvesting, and at 1, 3 and 6 months).

RESULTS

The thickness of newly formed tissue from the baseline to 1 month after harvesting was greater in Group 2 than in Group 1, whereas the thickness from 1 to 3 months and from 3 to 6 months after harvesting was greater in Group 1 than in Group 2 (p < 0.005). RTT was positively correlated with tissue filling in all the groups at all time points (p < 0.05).

CONCLUSIONS

The palatal mucosal thickness after FGG harvesting might affect the filling of the defect. Within the study period, the periphery of the palatal wounds filled earlier and to a greater extent compared with the centre of the wounds.

[Root coverage: Prognostic factors and surgical techniques]

Gingival recession is an oral exposure of the root surface due to an apical displacement of the gingival margin below the cemento-enamel junction. The root coverage is indicated for esthetic reasons, to reduce root hypersensitivity and to create or to augment keratinized tissue. Several surgical techniques have been described, the decision depending on anatomical and technical parameters. The main therapeutic goal is to achieve complete root coverage (CRC) and a satisfactory esthetic result. The purpose of this work was to make an update on the different factors that determine the success of root coverage and to evaluate the efficacy of different surgical techniques reported in literature.

Abfraction lesions: etiology, diagnosis, and treatment options

Abfraction is a type of noncarious cervical lesion (NCCL) characterized by loss of tooth tissues with different clinical appearances. Evidence supports that abfraction lesions, as any NCCLs, have a multifactorial etiology. Particularly, the cervical wear of abfraction can occur as a result of normal and abnormal tooth function and may also be accompanied by pathological wear, such as abrasion and erosion. The interaction between chemical, biological, and behavioral factors is critical and helps to explain why some individuals exhibit more than one type of cervical wear mechanism than others. In an era of personalized dentistry, patient risk factors for NCCLs must be identified and addressed before any treatment is performed. Marked variations exist in dental practice concerning the diagnosis and management of these lesions. The lack of understanding about the prognosis of these lesions with or without intervention may be a major contributor to variations in dentists’ management decisions. This review focuses on the current knowledge and available treatment strategies for abfraction lesions. By recognizing that progressive changes in the cervical area of the tooth are part of a physiologically dynamic process that occurs with aging, premature and unnecessary intervention can be avoided. In cases of asymptomatic teeth, where tooth vitality and function are not compromised, abfraction lesions should be monitored for at least 6 months before any invasive procedure is planned. In cases of abfraction associated with gingival recession, a combined restorative-surgical approach may be performed. Restorative intervention and occlusal adjustment are not indicated as treatment options to prevent further tooth loss or progression of abfraction. The clinical decision to restore abfraction lesions may be based on the need to replace form and function or to relieve hypersensitivity of severely compromised teeth or for esthetic reasons.

The gingival Stillman's clefts: histopathology and cellular characteristics

AIM OF THE STUDY

Stillman's cleft is a mucogingival triangular-shaped defect on the buccal surface of a root with unknown etiology and pathogenesis. The aim of this study is to examine the Stillman's cleft obtained from excision during root coverage surgical procedures at an histopathological level.

MATERIALS AND METHOD

Harvesting of cleft was obtained from two periodontally healthy patients with a scalpel and a bevel incision and then placed in a test tube with buffered solution to be processed for light microscopy.

RESULTS

Microscopic analysis has shown that Stillman's cleft presented a lichenoid hand-like inflammatory infiltration, while in the periodontal patient an inflammatory fibrous hyperplasia was identified.

CONCLUSION

Stillman's cleft remains to be investigated as for the possible causes of such lesion of the gingival margin, although an inflammatory response seems to be evident and active from a strictly histopathological standpoint.

Prediction of root coverage for single recessions in anterior teeth: a 6-month study

BACKGROUND

The aim of this study was to evaluate the predictive values of baseline inter-dental papilla height (IPH), loss of inter-dental papilla height (LPH), avascular exposed root surface area (AERSA) and inter-dental clinical attachment level (ICAL) measurements on complete root coverage (CRC) of single recession defects treated with coronally advanced flap and connective tissue graft technique (CAF+CTG).

MATERIAL & METHODS

A total of 122 patients with one isolated gingival recession were enrolled. All recession defects without loss of ICAL (ID-CAL) (RT1) and with an amount of ID-CAL equal or smaller to the buccal attachment loss (RT2), located at upper and lower anterior teeth were treated with CAF+CTG. IPH, LPH, AERSA and ICAL parameters were analysed for possible correlation with CRC after 6 months.

RESULTS

The CRC was 86.7% for RT1, 74.2% for RT2 groups. The ROC analyses revealed acceptable cut-off points for baseline AERSA, IPH and LPH for achieving CRC. The results of logistic regression analyses showed that having baseline AERSA≥19 mm(2) (OR:23.7), IPH lower ≤1 mm (OR:97.3) and belonging to RT2 group (OR:15.0) were found to be independent risk factors related with not achieving final CRC.

CONCLUSION

This study indicates that AERSA and IPH may be used to predict the final CRC outcomes in RT1 and RT2 defects treated with CAF+CTG.

Wound models for periodontal and bone regeneration: the role of biologic research

The ultimate goals of periodontal therapy remain the complete regeneration of those periodontal tissues lost to the destructive inflammatory-immune response, or to trauma, with tissues that possess the same structure and function, and the re-establishment of a sustainable health-promoting biofilm from one characterized by dysbiosis. This volume of Periodontology 2000 discusses the multiple facets of a transition from therapeutic empiricism during the late 1960s, toward regenerative therapies, which is founded on a clearer understanding of the biophysiology of normal structure and function. This introductory article provides an overview on the requirements of appropriate in vitro laboratory models (e.g. cell culture), of preclinical (i.e. animal) models and of human studies for periodontal wound and bone repair. Laboratory studies may provide valuable fundamental insights into basic mechanisms involved in wound repair and regeneration but also suffer from a unidimensional and simplistic approach that does not account for the complexities of the in vivo situation, in which multiple cell types and interactions all contribute to definitive outcomes. Therefore, such laboratory studies require validatory research, employing preclinical models specifically designed to demonstrate proof-of-concept efficacy, preliminary safety and adaptation to human disease scenarios. Small animal models provide the most economic and logistically feasible preliminary approaches but the outcomes do not necessarily translate to larger animal or human models. The advantages and limitations of all periodontal-regeneration models need to be carefully considered when planning investigations to ensure that the optimal design is adopted to answer the specific research question posed. Future challenges lie in the areas of stem cell research, scaffold designs, cell delivery and choice of growth factors, along with research to ensure appropriate gingival coverage in order to prevent gingival recession during the healing phase.