Culture of human gingival fibroblasts on a biodegradable scaffold and evaluation of its effect on attached gingiva: a randomized, controlled pilot study

BACKGROUND: An adequate width of attached gingiva is necessary to maintain healthy periodontium, especially in orthodontics or restorative treatments in periodontics. The purpose of this study was to evaluate the width of attached gingiva after clinical application of a cultured gingival graft compared to a periosteal fenestration technique. METHODS: This study was conducted on nine patients (18 sites) with insufficient attached gingiva adjacent to at least two teeth in contralateral quadrants of the same jaw. A small portion (approximately 3 x 2 x 1 mm) of attached gingiva (epithelial + connective tissue) was removed with a surgical blade. After culture of gingival fibroblasts, 2 x 10(5) cells in 250 microl nutritional medium were added to 250 microl collagen gel. One tooth in each patient was randomized to receive a periosteal fenestration technique for gingival augmentation (control) or a tissue-engineered mucosal graft (test). Clinical parameters measured at baseline and 3 months included width of keratinized tissue, probing depth, and width of attached gingiva. RESULTS: An increased amount of keratinized tissue was seen at all treated sites after 3 months. The mean increased amount of attached gingiva was 2.8 mm at test sites and 2 mm at control sites; this difference was significant (P < 0.05). CONCLUSION: Based on the results of this investigation, the tissue-engineered mucosal graft is safe and capable of generating keratinized tissue.     

Role of attached gingiva for maintenance of periodontal health

The present study was undertaken to analyze the role of attached gingiva for the maintenance of periodontal health in sites with normal and reduced height of the supporting apparatus. Furthermore, the effect of excision and grafting of gingiva on some parameters describing dimensions and location of the periodontal tissues was evaluated. 7 beagle dogs were used. A baseline examination comprised assessments of dental plaque, gingival conditions, attachment level, position of the gingival margin and width of the keratinized and the attached gingiva. In the right side of the jaws (experimental side) a 6-month period of periodontal tissue breakdown was followed by surgical excision of the entire zone of the gingiva. After another 4-month period of healing with daily plaque control, a gingival graft was inserted in one quadrant of the experimental side to regain a zone of attached gingiva while the other quadrant of the experimental side was left ungrafted. In the left side of the jaws (control side), the teeth were subjected to daily meticulous plaque control during the entire study. In one of the control quadrants the entire zone of the keratinized and attached gingiva was excised at a time point corresponding to the grafting procedure in the experimental side, while the gingiva in the remaining control jaw quadrant was left unoperated. Clinical examinations of all control and experimental tooth units were repeated at certain time intervals during the course of the study. The final examination was carried out 4 months after grafting. The results of the experiment showed that in sites exposed to careful plaque control measures gingival health could be established and maintained without sign of recession of the gingival margin or loss of attachment, independent of (1) presence or absence of attached gingiva, (2) width of keratinized gingiva or (3) height of the supporting attachment apparatus. Following surgical excision of the entire gingiva, all buccal sites regained a zone of keratinized gingiva, but most sites were lacking attached gingiva. Furthermore, grafting of gingival tissue significantly increased the width of the keratinized and the attached gingiva but had no obvious effect on the position of the gingival margin or the level of the attachment.     

Evaluation of the safety and efficacy of periodontal applications of a living tissue-engineered human fibroblast-derived dermal substitute. I. Comparison to the gingival autograft: a randomized controlled pilot study

BACKGROUND: Periodontists have found the gingival autograft to be an effective and predictable technique to increase the amount of attached gingiva around teeth, but this technique requires the surgeon to harvest donor tissue from a remote surgical site. The present study seeks to evaluate the safety and effectiveness of a tissue-engineered skin equivalent, a living human fibroblast-derived dermal substitute (HF-DDS), compared to a gingival autograft (GA) consisting of donor tissue harvested from the patient's palate in a procedure designed to increase the amount of keratinized tissue around teeth that do not require root coverage. METHODS: Twenty-five patients with insufficient attached gingiva associated with at least two teeth in contralateral quadrants of the same jaw were treated. One tooth in each patient was randomized to receive either a GA (control) or a HF-DDS graft (test). Clinical parameters measured at baseline and 3, 5, 7, 9, and 12 months included recession, clinical attachment level, keratinized tissue height, and plaque index. Probing depth was measured at 7, 9, and 12 months. Inflammation of each site was scored and texture and color of the grafted tissue were compared to the surrounding tissue. Resistance to muscle pull was evaluated and a questionnaire was used to determine patient preference. Surgical position of the graft and alveolar bone level were recorded at the surgical visit and patients were evaluated weekly for the first 4 weeks at which time recession and level of oral hygiene were measured. Biopsies and persistence studies were performed on a subset of the patients. RESULTS: Results for both test and control groups were similar for all measured clinical parameters with the exception of amount of keratinized tissue and percent shrinkage of keratinized tissue. The control group exhibited an average of 1.0 to 1.2 mm more keratinized tissue over time than the test group (P <0.001) and the control group had about half as much shrinkage as the test group over time (P <0.001). Test sites demonstrated significantly better color match over time compared to control sites. Similarly, tissue texture for test sites was significantly better than control sites over time. CONCLUSIONS: Based on the results of this investigation, the tissue engineered HF-DDS graft was safe and capable of generating keratinized tissue without the morbidity and potential clinical difficulties associated with donor site surgery. The GA generated more keratinized tissue and shrank less than the HF-DDS graft, but the test graft generated tissue that appeared more natural.     

牙龈退缩根面覆盖治疗1例

目的 牙龈退缩常常导致根面敏感、菌斑控制不良和牙龈美学等问题,影响患者的口腔健康和颜面美观。本病例采用根面覆盖术治疗牙龈退缩,以改善患者牙齿敏感问题。诊治经过：手术采用冠向复位瓣联合结缔组织移植瓣双层技术治疗退缩类型（recession type,RT）为1类的牙龈退缩。结果 术后2周,受区龈缘略水肿;术后12个月复诊,龈缘位置趋于稳定,根面覆盖率达100%,角化龈宽度及临床附着水平增加。患者无牙齿敏感、系带牵拉和瘢痕形成等不适症状,牙龈美学效果良好。结论 冠向复位瓣联合结缔组织移植瓣双层技术治疗RT 1类牙龈退缩效果良好,不仅能够获得完全根面覆盖、牙龈美学效果良好,而且增加了术区角化牙龈的宽度和临床附着水平。     

Re-epithelialization of a palatal connective tissue graft transplanted in a non-keratinized alveolar mucosa: A histological and biochemical study in humans

This study was undertaken to evaluate the type of tissue obtained after transplantation of a connective tissue graft, from the same palatal donor site, into a non-keratinized oral mucosa in humans. In 6 human volunteers, a thick palatal epithelio-connective tissue graft was excised, split into two thinner grafts (a thin epithelio-connective tissue graft and a connective tissue graft) and transplanted into controlateral areas lacking keratinized gingiva. The biopsies, excised 3 months post-operatively, were examined using routine histology, immunofluore-scence techniques with different anticy to keratin antibodies and biochemical techniques with non-equilibrium two-dimensional gel electrophoresis. The results show that the epithelio-connective tissue grafts display the histological and biochemical characteristics of keratinized gingiva, whereas the connective tissue grafts expressed features belonging both to keratinized and non-keratinized gingival tissues. It is concluded that the deep palatal connective tissue does not have the full potential to induce non-keratinized epithelial cells to keratinize and that a gingival or palatal connective tissue graft without its overlying epithelium is not likely to yield genuine attached gingiva.     

Role of attached gingiva in the extension of gingival inflammation. An experimental study in monkeys

The purpose of this study was to evaluate the inflammatory response in dento-gingival units with or without attached gingiva in monkeys. Two different types of dento-gingival units with or without attached gingiva were established in premolar and first molar areas of three monkeys. In the experimental group, a part of the keratinized gingiva was removed with periodontal scissors following mucoperiosteal flap procedure, while in the control group, sham surgery was performed. After the surgery, plaque control was performed by mechanical tooth cleaning procedures three times a week for 3 months. As baseline examinations, width of the keratinized gingiva, probing pocket depth, position of the gingival margin, and the clinical attachment level were recorded and oral photographs were taken. Following these examinations silk ligatures were placed around the neck of the teeth to induce gingival inflammation in both the experimental and control groups. A soft diet which allowed plaque accumulation on the teeth was given during the experimental periods. The clinical examinations were carried out at 0, 1, 2, 3, 5 and 12 weeks and all monkeys were sacrificed for histological examination. The results obtained were as follows: 1. The use of silk ligature and a soft diet produced moderate to severe gingival inflammation in the monkeys. 2. The degree of gingival inflammation was greater in the experimental group which was characterized by the absence of the attached gingiva. 3. Marked marginal tissue recession with an apical shift of the attachment level was found in the gingival units of the experimental group at 12 weeks. 4. Histologically, a distance between the level of notch on the root surface and the most apical position of epithelial cell was greater in the experimental groups at 5 and 12 weeks, compared with the pre-experimental level. 5. The degree of alveolar bone resorption was higher in the experimental group at 5 and 12 weeks. These results suggest that an attached gingival tissue plays a certain role as a barrier against the extension of gingival inflammation.     

An autologous cell hyaluronic acid graft technique for gingival augmentation: a case series

BACKGROUND: An autologous cell hyaluronic acid graft was used for gingival augmentation in mucogingival surgery. METHODS: Seven sites from 6 patients were used in this study. Five patients (5 sites) needed gingival augmentation prior to prosthetic rehabilitation, and one patient (2 sites) needed augmentation because of pain during daily toothbrushing. Full-mouth plaque score (FMPS), full-mouth bleeding score (FMBS), probing depth (PD), and clinical attachment level (CAL) were recorded for the sites at baseline and 3 months after surgery. The amount of keratinized tissue (KT) was measured in the mesial, middle, and distal sites of each involved tooth. A small 2 x 1 x 1 mm portion of gingiva (epithelium and connective tissue) was removed from each patient, placed in a nutritional medium, and sent to the laboratory. The gingival tissue was processed: keratinocytes and fibroblasts were separated and only fibroblasts were cultivated. They were cultured on a scaffold of fully esterified benzyl ester hyaluronic acid (HA) and returned to the periodontal office under sterile conditions. During the gingival augmentation procedure, the periosteum of the selected teeth was exposed, and the membrane containing cultivated fibroblasts was adapted to and positioned on the site. RESULTS: Three months after surgery, an increased amount of gingiva was obtained, and the histological examination revealed a fully keratinized tissue on all the treated sites. CONCLUSION: Tissue engineering technology using an autologous cell hyaluronic acid graft was applied in gingival augmentation procedures and provides an increase of gingiva in a very short time without any discomfort for the patient.     

The use of mucograft collagen matrix to augment the zone of keratinized tissue around teeth: a pilot study

This prospective split-mouth pilot case series compared the use of a bilayer collagen matrix (CM) to an autogenous gingival graft (AGG) in the ability to increase the zone of keratinized attached gingiva. Five patients with inadequate amounts of keratinized attached gingiva bilaterally in the posterior mandible were enrolled using a split-mouth design. There were statistically significant increases in attached gingiva at all test (CM) and control (AGG) sites. The CM sites at 12 months blended well with surrounding tissues, while the AGG sites were morphologically dissimilar to the adjacent areas. Biopsy results showed intrapatient histologic similarity between CM and AGG treatments, with all sites exhibiting mature connective tissue covered by keratinized epithelium. Thus, the obtained data support further investigations in evaluating the role of CM as a viable alternative to AGG in augmenting areas deficient in keratinized gingiva.     

Development of the dento-gingival junction of the free gingival graft

Although numerous histological studies have been reported on the healing of the free gingival graft, little attention has been paid to the development of its relationship to the tooth. This is surprising as the placement of a graft of keratinized tissue against the tooth might be supposed to form a more effective barrier to the antigens of dental plaque. The purpose of this study was to investigate the histology of the dento-gingival junction formed from free gingival grafts. Autografts of palatal mucosa were secured coronal to the crest of the alveolar process at six recipient sites on each of four adult cynomolgus male monkeys. All procedures were carried out sequentially so as to yield postoperative specimens of 1, 2, 3, 4, 5 & 6 weeks.
At sacrifice all animals were perfused with 10% formalin and the specimens were prepared by routine histological methods for examination by light microscopy. By two weeks the epithelium had migrated to the tooth surface. It exhibited wide intercellular spaces and was supported by a disturbed connective tissue. By four weeks the inflammation in the connective tissue at the facial aspects of the graft had resolved and the epithelium keratinized; while at the tooth surface, the connective tissue remained inflamed and the dento-gingival junction developed over this disturbed tissue. The sulcular epithelium was not keratinized and the junctional epilhelium demonstrated wide intercellular spaces. Since the dento-gingival junction developed from a free gingival graft does not seem to provide a more effective barrier to the antigens of dental plaque than that normally found, it is suggested that the use of the free gingival graft in some periodontal procedures be seriously questioned.     

脱细胞真皮基质在牙龈退缩治疗中的应用评价

目的评价脱细胞真皮基质（acellular dermal matrix,ADM）代替上皮下结缔组织瓣在Ⅰ类牙龈退缩治疗中的应用效果。方法在犬尖牙上制造Ⅰ类牙龈退缩模型,实验组用ADM加冠向复位瓣治疗,对照组用单纯冠向复位瓣治疗。观察和测量比较基线和术后8周时牙龈退缩高度、临床附着水平、角化龈的宽度和厚度等。结果术后8周,实验组治疗牙龈退缩的根面覆盖率为52.53%,明显高于对照组的15.89%,差异有高度显著性（P〈0.01）;实验组的角化龈宽度和高度比基线时分别增加1.06mm和0.18mm,而对照组则比基线时分别减少1.19mm和0.27mm,两者比较,差异也有高度显著性（P〈0.01）。结论 ADM代替上皮下结缔组织瓣治疗Ⅰ类牙龈退缩,能比单纯冠向复位瓣获得更高的根面覆盖率,并显著增加角化龈的宽度和厚度。     

A preliminary comparative study of the guided tissue regeneration and free gingival graft procedures for adjacent facial root coverage.

OBJECTIVE: The purpose of this study was to compare the clinical efficacy of guided tissue regeneration with expanded polytetrafluoroethylene membranes to that of free gingival graft for treatment of adjacent facial gingival recession. METHOD AND MATERIALS: Eight adjacent gingival recession sites with Miller class I or II defects containing at least a maxillary or mandibular canine were selected in 6 patients. Four recession sites in 3 patients were treated with guided tissue regeneration, and the other 4 sites in the remaining 3 patients were treated with free gingival graft. Probing depth, gingival recession, attachment level, width of keratinized gingiva, and root coverage were recorded before surgery (baseline) and 6 months and 1 year postoperatively. RESULTS: Statistically significant improvements were found for gingival recession, attachment level, and root coverage from baseline to 6 months and 1 year postoperatively in both groups. Both procedures produced the same average reduction in gingival recession, gain in attachment level, and amount of root coverage after 1 year. Probing depths did not differ between groups throughout the study. The width of keratinized gingiva was significantly greater in the grafted group than in the guided tissue regeneration group. CONCLUSION: Both procedures produced the same average amount of root coverage, reduction in gingival recession, and gain in clinical attachment. The guided tissue regeneration procedure provided a better esthetic appearance without any difference in gingival color or architecture in cases of adjacent facial gingival recession.     

The role of gingival connective tissue in determining epithelial differentiation

Free grafts of connective tissue, without epithelium, were transplanted from either the keratinized gingiva or the non-keratinized alveolar mucosa (controls) into areas of the alveolar mucosa in seven monkeys. The grafts were placed in pouches created in the connective tissue as close as possible to the overlying epithelium. After 3–4 weeks, the transplants were exposed by removal of the overlying tissue in order to allow epithelialization from the surrounding non-keratinized alveolar mucosa. The transplants were examined clinically and histologically at time periods between 1 and 12 months.
The gingival connective tissue grafts became covered with keratinized epithelium displaying the same characteristics as those of normal gingival epithelium. The alveolar mucosa transplants were covered with non-keratinized epithelium. This indicates that gingival connective tissue is capable of inducing the formation of a keratinized gingival epithelium.     

Changes in gingival dimensions following connective tissue grafts for root coverage: comparison of two procedures

BACKGROUND: The purpose of this study was to investigate the changes in gingival dimensions and root coverage using the same surgical procedure but varying the amount of the connective tissue graft left uncovered. METHODS: Twenty-five Class I or II recession defects in 20 healthy subjects were randomly assigned to test (exposed connective tissue group; E group) or control (fully covered connective tissue group; FC group) groups and treated with a connective tissue graft procedure. In the E group, 1 to 2 mm of the graft was left uncovered at the completion of the surgery, whereas the FC group had the graft completely covered by the flap. Clinical parameters assessed included probing depth, recession depth, clinical attachment level, width of keratinized tissue, mobility, and plaque score. RESULTS: At 12 weeks, the mean root coverage percentages for FC and E groups were 93% and 88%, respectively. The difference between the groups was not statistically significant (P=0.48). Complete root coverage was observed in 79% and 64% of the subjects in FC and E groups, respectively. There was greater increase in the width of keratinized tissue in the E group (1.5+/-1.1 mm) than the FC group (0.9+/-0.9 mm), although this difference did not reach statistical significance (P=0.16). There were no statistically significant differences between the groups for the changes in other parameters. CONCLUSIONS: Both procedures resulted in successful root coverage with an increase in the width of keratinized tissue. Leaving a portion of the graft exposed resulted in a greater increase of keratinized tissue, and complete coverage of the graft resulted in greater root coverage. However, these differences did not reach statistical significance.     

Acellular dermal matrix allografts to achieve increased attached gingiva. Part 1. A clinical study

BACKGROUND: Freeze-dried acellular dermal matrix (ADM) allograft, originally used for full-thickness burn wounds, was recently introduced as an alternative to the autogenous free gingival graft (FGG) in achieving increased attached keratinized tissue. The aim of part 1 of this study was to investigate the clinical efficacy of the ADM allograft for this particular purpose. METHODS: Twelve patients, 7 males and 5 females, with attached gingiva < or =1 mm on the facial aspect of mandibular anterior teeth demonstrating a tendency of progressive marginal tissue recession, were randomly assigned to either test or control treatment. Six patients received ADM graft (test) and 6 patients received an autogenous FGG harvested from the hard palate (control). Clinical variables including plaque index (PI), gingival index (GI), probing depth (PD), attached tissue width (AT), and gingival recession (GR) were recorded immediately before surgery and at the 6-month postoperative visit. Patients were seen at 2, 4, 6, 8, and 12 weeks to monitor wound healing and oral hygiene performance (PI and GI). Graft width was also measured, in corono-apical direction, on individually involved teeth during the surgery. RESULTS: When values between baseline and 6 months were compared in both groups, there was no statistically significant difference in changes of PI, GI, PD, and GR (P>0.05) with the exception of PD in the FGG group (1.01 +/- 0.03 versus 1.27 +/- 0.20 mm, P= 0.042). There was a statistically significant (P <0.05) increase in AT in both groups. Although the ADM group received wider grafts than the FGG group (8.81 +/- 0.46 versus 6.70 +/- 0.89 mm), the AT gain was significantly smaller (2.59 +/- 0.92 versus 5.57 +/- 0.44 mm) and the graft shrinkage significantly greater (71 +/- 10% versus 16 +/- 12%) in the ADM group than in the FGG group (P<0.01). CONCLUSIONS: The results of this study suggest that in procedures aiming at increasing the width of attached gingiva: 1) the ADM allograft was less effective and less predictable than the autogenous FGG in terms of increasing attached keratinized tissue due to considerable shrinkage and inconsistent quality of the attached tissue gained and 2) the esthetic results using the ADM allograft might be better than those using the autogenous FGG.     

Role of keratinized gingiva for gingival health

Abstract The present study was carried out in the Beagle dog in order to determine if variations of the width of the zone of keratinized gingiva occur in the canine dentition, if the width alters during the development of destructive periodontitis and if, subsequent to surgical excision of the periodontal lesion, the regenerated gingival margin differs from that of a normal, noninflamed gingiva. Five dogs were used. A baseline examination comprised assessments of dental plaque, gingival conditions and width of the zone of keratinized gingiva. Cotton floss ligatures were placed around the teeth on the right side of the jaws and plaque was allowed to accumulate in order to induce periodontal tissue breakdown. After 150 days the inflamed periodontal tissues around the experimental teeth were removed surgically using a “gingivectomy” or a flap procedure. In the “gingivectomy” procedure the entire zone of the keratinized gingiva was excised whereas the main part of the keratinized tissue was maintained with the flap procedure. During a healing period of 120 days plaque control was carried out daily. On the left side of the jaws (control side) a careful toothcleaning program was performed during the entire observation period of 270 days. Clinical examinations of all control and experimental tooth units were repeated on days 150 and 270. Biopsies were sampled from both sides of the jaws on day 270. In histological sections the free gingival tissue was subjected to histometric assessments and a stereologic analysis based on a standardized morphometric point-counting procedure. In addition, the number of leukocytes residing within the junctional epithelium was determined. The results showed that in Beagle dogs the width of the keratinized gingiva (WKG), on the facial aspect of premolars and molars, varies between 2 and 6 mm. During a period of 270 days of careful plaque control, the WKG was maintained unaltered. In comparison, a phase of experimental periodontitis resulted in a substantial decrease of the WKG. Subsequent to the excision of the inflamed periodontal tissues, which in some cases included the entire zone of the keratinized gingiva, a new free gingival unit developed. In most respects the structural composition of this regenerated gingival unit was similar to that of a normal control unit. Furthermore, in the absence of plaque, the regenerated soft tissue was free from signs of inflammation independent of presence or absence or width of the keratinized zone.     

Evaluation of human recession defects treated with coronally advanced flaps and either enamel matrix derivative or connective tissue. Part 1: Comparison of clinical parameters

BACKGROUND: Recession defects around teeth have been treated with a variety of surgical techniques. Most of the literature suggests that the subepithelial connective tissue graft has the highest percentage of mean root coverage with the least variability. Previous studies have demonstrated that enamel matrix derivative (EMD) has the ability to improve clinical parameters. The purpose of this study was to compare the clinical efficacy of enamel matrix derivative placed under a coronally advanced flap to subepithelial connective tissue placed under a coronally advanced flap in patients with recession type defects. METHODS: Twenty patients with incisors or premolars presenting with a facial recession of > or = 4 mm in contralateral quadrants of the same jaw were treated; 17 patients completed the study. One tooth in each patient was randomized to receive either a coronally advanced flap with a subepithelial connective tissue graft (control) or a coronally advanced flap with EMD (test). Clinical parameters measured at baseline and at 6, 9, and 12 months included amount of recession; width at the coronal extent of the gingival defect; width of keratinized tissue; probing depth; clinical attachment level; inflammation score; plaque score; plaque index; alveolar bone level; tissue texture and color; and patient perception of pain, bleeding, swelling, and sensitivity. RESULTS: Results for both the test and control groups were similar for all measured clinical parameters with the exception of early healing, self-reported discomfort, and the amount of keratinized tissue obtained. The coronally advanced flap with EMD was superior to the subepithelial connective tissue graft with regard to early healing and patient-reported discomfort, whereas the subepithelial connective tissue graft demonstrated greater amount of keratinized tissue during the 12-month evaluation period. However, both the test and control showed a significant increase in the amount of keratinized tissue at 9 and 12 months compared to baseline. No significant difference in the amount of root coverage was found between the test and control groups (n = 19; P = 0.82). On average, a gain of 4.5 mm (range 4 to 8 mm) tissue covering the previously exposed root surfaces was achieved with both treatment groups. The average percentages of root coverage for control and test groups were 93.8% and 95.1%, respectively. One hundred percent root coverage was obtained 89.5% of the time with the coronally advanced flap with EMD and 79% of the time with the subepithelial connective tissue graft. CONCLUSION: Based on the results of this investigation, the addition of EMD to the coronally advanced flap resulted in root coverage similar to the subepithelial connective tissue graft but without the morbidity and potential clinical difficulties associated with the donor site surgery.     

A clinical and histologic evaluation of gingival fibroblasts seeding on a chitosan-based scaffold and its effect on the width of keratinized gingiva in dogs

Background: Finding biocompatible matrix materials capable of enhancing the procedures of gingival augmentation is a major concern in periodontal research. This has prompted the investigation of a safe grafting technique by means of synthetic or natural polymers. The objective of this study is to examine the effect of a gingival fibroblast cultured on a naturally derived (i.e., chitosan‐based) scaffold on the width of keratinized gingiva in dogs. Methods: Gingival fibroblasts were cultured from a small portion of hard palates of five dogs. A bilayered chitosan scaffold was seeded with the gingival fibroblasts and transferred to dogs. Surgery was performed bilaterally, and the regions were randomly divided into two groups: chitosan only (control site) and chitosan + fibroblast (test site). Periodontal parameters, including probing depth and width of keratinized and attached gingiva, were measured at baseline and 3 months after surgery. A histologic evaluation was also performed on the healed grafted sites. Results: Comparison of width of keratinized and attached gingiva in control and test sites showed that the mean width of keratinized and attached gingiva increased in each group after surgery. However, the difference between control and test groups was not statistically significant. Concerning the existence of the keratinized epithelium, exocytosis, and epithelium thickness, no significant difference was observed in test and control sites. The difference was significant in relation to rete ridge formation. Conclusion: The tissue‐engineered graft consisting of chitosan + fibroblast was applied to gingival augmentation procedures and generated keratinized tissue without any complications usually associated with donor‐site surgery.     

Histologic changes following the grafting of connective tissue into human gingiva.

Grafting connective tissue from the palate to partial-thickness sites prepared in patients with an inadequate width of attached gingiva resulted in an increased width of keratinized mucosa. Biopsies of these grafts at the newly created mucogingival junction at 24 weeks showed the epithelium to be keratinized with a normal architecture, except over scar tissue at the edges of the grafts, where rete-peg formation was absent. The results support the concept that morphodifferentiation of gingival epithelium is influenced by the underlying connective tissue.     

Comparative clinical study of a subepithelial connective tissue graft and acellular dermal matrix graft for the treatment of gingival recessions: six- to 12-month changes

Different techniques have been proposed for the treatment of gingival recession. This study compared the clinical results of gingival recession treatment using a subepithelial connective tissue graft and an acellular dermal matrix allograft. Seven patients with bilateral Miller class I or II gingival recession were selected. Twenty-six recessions were treated and randomly assigned to the test group. In each case the contralateral recession was assigned to the control group. In the control group, a connective tissue graft in combination with a coronally positioned flap was used; in the test group, an acellular dermal matrix allograft was used as a substitute for palatal donor tissue. Probing depth, clinical attachment level, gingival recession, and width of keratinized tissue were measured two weeks prior to surgery and at six and 12 months post-surgery. There were no statistically significant differences between the groups in terms of recession reduction, clinical attachment gain, probing pocket depth, and increase in the width of the keratinized tissue after six or 12 months. There was no statistically significant increase in the width of keratinized tissue between six and 12 months for either group. Within the limitations of this study, it can be suggested that the acellular dermal matrix allograft may be a substitute for palatal donor tissue in root coverage procedures and that the time required for additional gain in the amount of keratinized tissue may be greater for the acellular dermal matrix than for the connective tissue procedures.     

Clinical evaluation of 3 techniques to augment keratinized tissue without root coverage

BACKGROUND: The importance of keratinized tissue is a controversial subject. However, in some situations most clinicians would agree that surgical procedures to increase the amount of keratinized tissue without root coverage are indicated. In this study, 3 surgical procedures were compared in their ability to increase the width of keratinized tissue. They are: the epithelized autogenous masticatory mucosa graft (free gingival graft), autogenous predominately connective tissue graft (connective tissue graft), and acellular dermal matrix. METHODS: Forty-five patients referred for treatment of areas with inadequate keratinized tissue were randomly assigned into 1 of 3 groups of 15 each. Each group was treated with 1 of the 3 surgical procedures to increase the width of keratinized tissue. The width of keratinized tissue pre- and postsurgery was evaluated. RESULTS: All 3 groups started with a similar width of keratinized tissue. All of the surgical procedures resulted in a statistically significant increase in the width of keratinized tissue: free gingival graft, 4.1 mm; connective tissue graft, 3.6 mm; and acellular dermal matrix, 4.1 mm. CONCLUSION: A statistically significant increase in the amount of keratinized tissue was obtained with all 3 surgical procedures evaluated.