Gingival Retraction Research Articles

EFFECTIVENESS OF APPLYING HYALURONIC ACID GEL IN GINGIVAL RETRACTION

The interdental papilla is a small part of the free gingiva that fills the space between the teeth, apical to its contact area. The objective of this study was to analyze the effectiveness of the application of hyaluronic acid gel in gingival retraction. The methodology used was a literature review with an exploratory qualitative approach, using academic platforms and bibliographies: SCIELO, PUB MED and GOOGLE ACADEMICO. The inclusion criteria were articles from the last few years in Portuguese and English. The effectiveness of the use of HA gel in reducing the area of ​​the black triangle was 85.06%. In addition, the length of the papilla increased by 70.256%, while the distance from the contact to the papilla decreased by 83.026%. At the different times, the values ​​of the variables studied at the three levels were significantly different (p < 0.05). We concluded that injection of HA with a concentration of 1.6% at two points of the interdental papilla was effective in reconstructing the interdental papilla in the esthetic zone, especially in long-term follow-ups (especially 6 months).

Longitudinal study of root resorption on incisors caused by impacted maxillary canines-a clinical and cone beam CT assessment.

To evaluate the long-term status of incisors with canine-induced root resorption (CIRR). Subjects with impacted maxillary canines (IMC) and persisting incisors with CIRR examined with cone beam computed tomography (CBCT), diagnosed ≥ 5 years earlier, were recalled. The resorption grade in the horizontal and vertical plane was assessed on CBCT images at baseline (T0) and follow-up (T1). Clinical examination was done at T1 which included probing depth, gingival retraction, mobility, ankylosis, discoloration and vitality test. In addition, patients completed a questionnaire regarding symptoms from the incisors. Forty subjects (mean age 13.7 ± 2.1 years) with 43 IMC and 47 incisors with CIRR were recruited. The IMC either spontaneously erupted, were surgically exposed or surgically removed. Thirty-four of the patients were treated with a fixed appliance and six had no orthodontic treatment. The follow-up range was 5.5-14.6 years. None of the incisors were lost or endodontically treated at T1. The horizontal resorption grade was unchanged in 38, improved in 7, and worsened in 2 teeth. The corresponding results for the vertical resorption grade were unchanged in 20 and worsened in 27 teeth. Three incisors with severe horizontal resorption at T0 were significantly more obliterated at T1 (P = .01). No significant differences were found in clinical parameters or patient-reported outcomes between incisors with CIRR and non-resorbed contralateral incisors at T1. The extent of root resorption during active orthodontic treatment was not possible to assess as only CBCT images from T0 and T1 were available. Incisors with CIRR caused by IMC have a high survival rate in a long-term perspective and do not cause more symptoms or exhibit more signs of pathology than non-resorbed contralateral incisors. Extraction of asymptomatic incisors based solely on root resorption should not be performed routinely.

Periodontal Evaluation for a New Alkasite Restorative Material in Noncarious Cervical Lesions: A Randomized-Controlled Clinical Trial.

This study aims to evaluate the periodontal condition adjacent to Cention N (CN) restorations applied for noncarious cervical lesions (NCCL) compared with resin-modified glass ionomer cement (RM-GIC) restorations in terms of plaque accumulation, attachment loss, and gingival inflammation. This is a double-blind split-mouth three-armed randomized-controlled clinical trial. The study arms are RM-GIC (FUJI II LC), CN + adhesive system, and CN + retentive groove. The study included 25 restorations per arm. Follow-ups were performed at 1 week, 3, 6, and 9 months after the application of the restorations. The periodontal condition was evaluated using the plaque index (PI), the bleeding on probing index (BOP), and the probing depth (PD). Appropriate tests were used to perform statistical analyses (α = 0.05). There was no significant difference between Cention N and RM-GIC regarding the studied variables. However, after the application of the restorations, it was noted that the PI and the PD mean values increased. The average increase after 9 months was 0.06 and 0.34 for PI and PD, respectively, with that of PD being significant. It was also noted that the percentage of positive BOP sites increased at the 1-week follow-up for all study groups and afterward dropped to near preintervention values at the 3-month and later follow-ups. The two ion-releasing materials Cention N and RM-GIC have a comparable and clinically acceptable effect on the gingival tissue when restoring NCCLs. The combined effect of the gingival retraction cord and the rubber dam clamp on the periodontal tissues might be more important to consider, especially in relation to the probing depth. Future long-term studies are needed to evaluate the effect of Cention N on the subgingival biofilm in comparison with nonion-releasing restorative materials, and subsequently, its effect on gingival inflammation. This clinical trial was registered in clinicaltrial.gov clinical registry under protocol #NCT05593159.

New intraoral digital impression with pneumatic gingival retraction used in the restoration of crown for posterior teeth: a case report

In fixed prosthodontics, clear exposure of the preparation margin is the prerequisite for obtaining accurate digital impressions and improving the marginal fit of restorations. To resolve the issues associated with the cord retraction technique, such as pain, acute injury, and prolonged procedural time, this study proposes a new technology for intraoral digital impression taking with pneumatic gingival retraction. The new scanning head blows a high-speed airflow that instantaneously separates the free gingiva, locally exposing the subgingival preparation margin. Combined with the farthest point preservation stitching algorithm based on the distance from the normal vector and high-speed laser scanning photography, it achieves global preparation edge data and gingival reconstruction, realizing painless, non-invasive, and efficient precise acquisition of the preparation margin. Using this new technique, a patient with a full porcelain crown restoration on a posterior tooth was treated. The digital impression revealed a clear margin of the preparation, and the crown made from this data has a good marginal fit.

Clinical assessment of monolithic zirconia crowns fabricated using an intraoral scanner.

This in vivo study assessed the accuracy of single-tooth monolithic zirconia crowns made using an intraoral scanner (IOS) and computer-aided design/computer-aided manufacturing (CAD/CAM) technology. Thirty patients requiring single posterior crowns were selected. The teeth were prepared with a deep chamfer finish line with a 1-mm extension subgingivally and a 1-mm reduction in all surfaces by one prosthodontist. The gingival margins were retracted using a gingival retraction paste before making impressions using a Trios scanner. All the digital impression files were sent to one laboratory using the dental designer software (3Shape, Copenhagen, Denmark). After completing the milling and sintering processes, the crowns were dyed and glazed. After removing the temporary crown, the qualitative assessment of proximal contacts of definitive monolithic zirconia crowns was performed according to the CDA criteria. Data were analyzed with Friedman's two-way analysis and independent t-test at α=0.05. The difference in axial and total gaps between premolar and molar teeth was not significant; however, the mean marginal gap of molars was higher than that of the premolars (P=0.043). Furthermore, the comparison of the axial, total, and marginal gaps between the upper and lower jaws showed no significant difference (P>0.05). The distribution of occlusal and proximal contacts indicated 60% and 66.7% proper contacts and no contacts in 6.7% and 10% of cases, respectively. Using IOSs could result in accurate monolithic zirconia crowns in terms of adaptation. Also, most occlusal and proximal contacts did not need any adjustments.

Changes in Periodontal Tissues With Periodontally Accelerated Orthodontics: A Systematic Review and Meta-Analysis.

Periodontally accelerated orthodontic (PAO) therapy has been found to increase hard tissue, helping to decrease orthodontic relapse rates and improve retention capacity. The aim of this study was to synthesize available evidence on clinical and tomographic changes in periodontal tissues when using PAOtechniques. A systematic review with meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and registered in the International Prospective Register of Systematic Reviews (PROSPERO). The search was carried out in PubMed, Embase, Cochrane, Web of Science, Scopus, and Google Scholar. Randomized and non-randomized clinical trials comparing PAO versus conventional orthodontics were included. Quality assessment was performed using the Downs & Black scale, and the risk of bias was assessed using the revised Cochrane risk-of-bias tool. Mean differences and 95% confidence intervals (CIs) were calculated, and the mean difference was divided by a t-test. During the initial search, 465 studies were identified. Five articles studying 130 patients were included, which assessed both clinical and tomographic changes, along with treatment duration. PAO was administered to patients with skeletal class III in three studies, to class II patients in one study, and to individuals with dental crowding in another study. Two studies showed a moderate risk of bias, and the rest showed a low risk. The meta-analysis revealed a vestibular bone thickness increase of 0.32 mm (0.56-008; P = 0.008), a reduction of 3.12 mm (2.15-4.08; P= 0.001) in gingival retraction, and a treatment duration that was 7.07 months (8.79-5.36;P = 0.001) shorter in patients subjected to PAO compared to those undergoing conventional orthodontic treatment. Considering the limitations of the study and acknowledging that definitive conclusions cannot be drawn, the findings suggest that treatment time decreased in patients undergoing PAO, with an increase in vestibular bone thickness and less gingival retraction observed in those undergoing this intervention.

A Comparative Evaluation of Different Gingival Retraction Methods: A Double-blinded In Vivo Randomized Controlled Trial

A Comparative Evaluation of Different Gingival Retraction Methods: A Double-blinded In Vivo Randomized Controlled Trial

Absorptive Capacity of Gingival Retraction Cords in Hemostatic Solutions: An In Vitro Study.

Background and Objectives: Gingival retraction is a critical pre-impression procedure in fixed prosthodontics, crucial for exposing tooth margins and ensuring accurate impressions for restorations like crowns and bridges. This study aimed to evaluate the absorptive capacity of different gingival retraction cords. Materials and Methods: Ninety samples each of Ultrapak (Ultradent, South Jordan, UT, USA) #00, braided cord, coreless thread, and monofilament thread (totaling 270 samples) were immersed in 0.9% NaCl, 10% aluminum chloride, and 12.7% ferrous sulfate solutions for 120, 300, and 1200 s. The liquid absorption capacity was measured using a gravimetric method, and the data were analyzed using an F-test, setting the significance threshold at p < 0.05. Results: The results revealed statistically significant differences in absorption, particularly for aluminum chloride and ferric sulfate (p < 0.001). Ultrapak demonstrated the highest absorption, followed by the coreless cotton thread, while the monofilament thread absorbed the least, especially at 1200 s. Conclusions: These findings indicate that Ultrapak's superior absorption could enhance moisture control during procedures, highlighting the importance of selecting an appropriate retraction cord for optimal clinical outcomes. Further research is needed to confirm these findings in a clinical setting.

A multifunctional gingival retraction cord with antibacterial and hemostasis properties based on Chitosan/Propolis/Tranexamic acid for dental treatment

A novel gingival retraction cord named P/TA@CSy was prepared using chitosan yarns (CSy) loaded with tranexamic acid (TA) and Propolis (P). P/TA@CSy has good toughness with a breaking strength of 41.3 Pa, benefiting from the twisting structure and Propolis coating. A short coagulation time of 456 s was achieved for P/TA@CSy because of the potent blood absorption ability from the effective attachment of tranexamic acid. Moreover, excellent antibacterial ability was obtained with the antibacterial rates against E. coli of 94.73 %, S. aureus of 99.99 % and S. mutans of 99.99 %, contributing to Propolis's antibacterial ability. In addition, suppression of the expression of pro-inflammatory cytokines (IL-6 and TNF-α) was found, which could prevent wound infection. P/TA@CSy displayed excellent cytocompatibility with the cell activity of 100 % after 24 h. Therefore, P/TA@CSy could rapidly respond to gingival hemostasis and infection prevention, showing excellent potential in dental treatment.

Efficacy of Conventional versus Cordless Displacement System on Gingival Retraction for Use with Intra-Oral Scanner: A Clinical Study.

The present clinical study aimed to assess the efficacy of conventional versus cordless displacement systems on gingival retraction for use with an intra-oral scanner and changes in periodontal indices. A total of 20 participants were selected for a split-mouth study (20 sites - Group Sc, 20 sites - Group Es). The outcomes were measured at day 0, day 1, and day 7 of follow-up in terms of Immediate horizontal displacement, Plaque Index, and Bleeding Index. Unpaired and Paired t-test was used as the parametric tests and statistical analysis was performed. A statistically significant change was observed in terms of BI on day 0, but no statistically significant change was observed for either group in terms of IHD and PI. The cordless material caused the least trauma to gingival tissue and was more compatible with intra-oral scanning devices.

Periodontal changes induced by fixed orthodontic therapy.

Orthodontic therapy is a complex process involving a series of specialists in the dental field: the oral-maxillo-facial surgeon, the periodontologist, sometimes even the prosthetist, implantologist, or general practitioners. The injuries of the oral mucosa induced by orthodontic therapy include gingival overgrowths, traumatic lesions of the oral mucosa, different degrees of periodontal damage manifested by gingival retraction, alveolar bone resorption. From a total of 327 subjects who came to the Dental Clinic in Craiova 74 subjects were selected, who presented with gingival overgrowth associated with fixed orthodontic therapy. Subjects' age ranged from 14 to 56 years and experienced bleeding and gingival discomfort as well as alterations in physiognomic function. None of the patients included in the study have systemic diseases and are not under medical treatment. The clinical and statistical study took place between May 2022 and December 2023. Each patient was given a personal record containing personal data as well as oral and systemic health status. The examination of the periodontal status aimed at the evaluation of the following indices: assessment of oral hygiene using the OHI-S index and the O'Leary plaque index, assessment of superficial periodontal status using the Löe/Silness gingival inflammation index, periodontometry was performed in order to determine the depth of periodontal pockets, the level of gingival insertion, and the McGaw gingival overgrowth index. OHI-S index comprises two elements: the Debris Index and the Calculus Index. The purpose of our study is to present the incidence of cases of gingival overgrowth induced by fixed orthodontic therapy and to highlight how certain irritating factors can exacerbate the symptoms of gingival overgrowth of orthodontic etiology. The majority of patients were female, aged between 30 and 55 years. Most clinically examined patients have presented with Grade II gingival hyperplasia. Factors that have exacerbated the symptoms of orthodontically induced gingival overgrowth include: incorrectly adapted prosthetic restorations, unpolished massive coronal fillings, root remnants, bacterial plaque, and tartar. Clinical examination of the oral cavity revealed the presence of gingival inflammation (localized or generalized), simple or complicated, treated and untreated odontal lesions, and coronal fillings made of light-curing composite material of significant size, being unfinished and unpolished, sometimes with sharp edges directly injuring the adjacent gingival mucosa, marginally incorrectly adapted prosthetic works. In the case of child and adolescent patients, significant amounts of bacterial plaque and tartar buildup were observed. In most of the cases examined, it was observed that the gingival overgrowth had a firm consistency, pinkish-reddish colour and gingival bleeding was evident during probing. Gingival overgrowth caused by orthodontics induces a number of important periodontal changes. It is worth noting that gingival overgrowth induced by fixed orthodontic therapy, in most of the cases examined, co-exists with favouring factors that amplify its severity. In our study, the favouring factors were bacterial plaque and calculus accumulation, sharp-edged odontal lesions, marginally ill-fitting prosthetic restorations or massive unfinished crown fillings. Therefore, removing the contributing factors can help improve the symptoms but also to reverse the inflammatory phenomena.

Comparative evaluation of the effect of impregnated retraction cord versus laser on gingival attachment level and pain perception following retraction for subgingival margins - A prospective, split-mouth, controlled, clinical study.

To evaluate and compare the effect of impregnated retraction cord vs Laser on gingival attachment level and pain perception following retraction for subgingival margins. Many methods for achieving and measuring the amount of gingival retraction in fixed prosthodontic work have been advocated. Though the gingival attachment level is crucial in Periodontology, the literature available regarding the effect of these retraction methods on the same is scarce. Hence, this clinical study was designed to compare the pain perception and amount of gingival recession when impregnated cord and laser were used for retraction. In 40 subjects (age range of 20 to 40 years) with single missing maxillary incisor, the abutments were prepared with subgingival margins, to receive a full coverage metal-ceramic fixed dental prosthesis. The gingiva was retracted on one of the abutments with impregnated retraction cord and on the other with diode laser. Gingival attachment levels were compared at six sites per abutment using superimposition of digital scans, preoperative and four weeks after cementation of final prosthesis. Statistical analysis of the data for gingival recession was done using t-test. Pain perception was analysed with Chi-square test. Pain perception by patients following retraction was compared with VAS scale. The average values of gingival recession on buccal side were 0.61 mm and 0.38 mm and on the palatal side were 0.58 mm and 0.35 mm for impregnated retraction cord and laser respectively. The P values of <0.01 indicated a highly significant difference between the two groups. Intragroup comparison did not show significant differences between various sites. Pain and discomfort produced by cord method was moderate in comparison with mild/no pain with diode laser and the difference was highly significant.Conclusion: Retraction cord produced more gingival recession than the diode laser, which was statistically highly significant on both buccal and palatal aspects of the teeth. Patients experience with diode laser technique was less painful in comparison with retraction cord method.

Socket-shield Technique and immediate implant placement for ridge preservation in the aesthetic region: a 1-year clinical and tomographic follow-up

Objective: To describe the clinical, radiographic and tomographic aspects, as well as complications, success, aesthetic and functional results of an implant placed using the “socket shield” technique. Case Details: Represents a 46-year-old patient, with increased mobility of the crown in the bucco-palatal direction, with indication for extraction replaced by immediate implant. Atraumatic extraction, socket preservation technique and immediate implant placement were performed. The socket-shield technique was designed for placing implants to protect the oral bone and achieve adequate aesthetics. The buccal fragment of the tooth was kept fixed and the implant was placed in contact with the tooth fragment. Cone Bean computed tomography showed bone formation in the buccal aspect 1 year later, and demonstrated stability of the peri-implant bone tissue and replacement of the root remnant by bone. The clinical appearance demonstrated maintenance of peri-implant soft tissues and good aesthetics without gingival retraction. Final considerations: One-year follow-up shows adequate healing and healthy peri-implant tissue, suggesting that the socket-shield technique with immediate implant placement can be an excellent alternative for preserving the vestibular cortex and implant placement, especially in the aesthetic area.

Clinical and immunological aspects of gingival retraction systems in fixed dental prostheses: A systematic review

Objective To describe the existing knowledge on the efficacy of the different gingival retraction systems (GRSs) in gingival displacement, to know their effects on biological functions of human gingival fibroblasts (HGFs), and on the expression of inflammatory mediators (TNF-α and MCP-1) in gingival crevicular fluid (GCF), and saliva. Methods The protocol used for this systematic review was registered in INPLASY: 202410005. A digital search was performed in the databases PubMed/MEDLINE, Scopus, Science Direct, Web of Science, and Google Scholar of the literature published in the English language in the last 17 years (from December 10th, 2006, to May 15th, 2023), and included retrospective randomized clinical studies, prospective, and in vitro experimental studies. In addition, PRISMA criteria were followed. The methodological validity of the selected articles was assessed using Joanna Briggs Institute (JBI) critical appraisal tool, and the modified Consolidated Standards of Reporting Trials checklist (CONSORT). Results 27 articles published between 2006 and 2023 were evaluated. Six hundred 32 subjects, aged between 18 and 65, participated in the clinical studies. 93.7% of the studies assessed periodontally healthy patients, and only 6.3% evaluated patients with mild gingivitis. Also, 882 teeth were samples, of which the majority were posterior teeth (54%). The most commonly used GRSs was aluminum chloride gingival retraction paste (74%). The GCF samples were taken in 67% of the studies, and ELISA was used in all studies (100%) to determine inflammatory mediators. The most frequently analyzed marker was TNF-α (67%). Conclusion The system Merocel Strips (Mystic, conn, USA) achieved the highest level of gingival displacement (1.66 ± 3.7 mm). In addition, the braided cords produced the lowest TNF-α levels (0.43 ± 0.08pg/mL). Astringent systems such as ferric sulfate had higher toxicity in HGFs.

Comparative Evaluation of Gingival Displacement and Patient Outcomes with Different Gingival Retraction Techniques: A Cross-over Clinical Trial

Comparative Evaluation of Gingival Displacement and Patient Outcomes with Different Gingival Retraction Techniques: A Cross-over Clinical Trial

Therapeutic challenges in temporomandibular disorders.

This study aimed at evaluating the etiology and treatment challenges of temporomandibular disorders (TMDs). 160 subjects with TMDs, 38 males (23.8%) and 122 females (76.3%) were studied. A personalized coefficient was designated, which included the resolution of the main symptom, correction of secondary symptoms, patient collaboration (emotional parameter), treatment duration, and cost. The most frequent cause for consultation was muscle impairment (42.5%), or limitation of mouth opening, followed by joint impairment (23.1%). Muscle pain was noticed, particularly in the masseter (57.5%) and lateral pterygoid muscles (51.9%). Tooth pain or gingival retraction was frequently associated with tooth wear (48.1%) and dental abfraction (31.3%). Remote symptomatology was dominated by otologic symptomatology. Iatrogenic etiology was highest (69.4%), followed by untreated missing teeth (66.9%). Treatment options included muscle relaxation, occlusal balancing (equilibration), kinesitherapy, medication, and swallowing re-education. Most patients benefited from four to seven different types of therapy, which resulted in a higher cost and a longer and more uncomfortable treatment. The primary symptom was relieved in 82.3% of cases, with recurrence occurring in 15.7%. The treatment of temporomandibular joint dysfunction is time-consuming, demanding, and intricate. Most patients required four to seven different types of therapy, which increased the expense, treatment duration, and suffering.

A review and clinical tips on gingival retraction methods

Gingival retraction is commonly employed in dentistry. There are several methods that may be used, which fall into mechanical, chemo-mechanical and surgical techniques. The application of these methods depends on the clinical activity the clinician is performing, and there are advantages and disadvantages to each method. This review reflects on the current literature available on gingival retraction methods to provide clinicians with guidance on which methods to consider when undertaking the three most common clinical scenarios: master impression taking; cementation of indirect restorations whether tooth or implant retained; and for direct adhesive dentistry. CPD/Clinical Relevance: Selecting an appropriate gingival retraction method, for example for master impression taking, cementation of restorations and in adhesive dentistry is of value.

Comparative study on the efficacy of gingival retraction using Retraction cord and Expasyl paste in implant patients In-vivo study

Introduction: The precise reproduction of the abutment (implant) provides clinician with crucial clinical information of the relative position and orientation of the implant to other implants, teeth and soft tissue that allow them to fabricate exact- fitting, bio-integrated restoration. For that it is necessary to expose, access &amp; isolate the implant region, especially when cement retained implant prosthesis are in consideration, where conventional crown and bridge impression and optical impression technique is used. Material and Method: Patient who accepted to participate were chosen for the study. Coincidentally all 15 patients were female. They were explained the purpose and methodology, agreed for periodic follow up at the interval of one month after placement of healing abutment and 7 days after using the retraction cord. Conclusion: The conclusions that were drawn from this study are: Both materials showed clinically and statistically significant amount of vertical soft tissue displacement. Among the both soft tissue displacement agents, non-impregnated retraction cord showed the more vertical soft tissue displacement than Expasyl Paste. But, the amount of retraction offered by this paste is limited with extremely subgingival margins. But the advantages with Expasyl paste over the retraction cord were its ease of application, painless, quick, and without agony to the patient.

Comparison of the efficacy and long-term stability of tunnel technique and coronally advanced flap in the treatment of gingival recession: a Meta-analysis.

This study aimed to evaluate the efficacy and long-term stability of tunnel technique (TUN) and coronally advanced flap (CAF) combined with connective tissue graft (CTG) in treating gingival recession. Databases including PubMed, Web of Science, Embase, and CNKI were electronically searched to collect randomized controlled trial (RCT) of CAF+CTG compared to TUN+CTG in the treatment of Miller class Ⅰ or Ⅱ gingival recession on September 1, 2022. There were 8 RCTs with 305 patients (454 recession sites) participating. The results of the Meta-analysis revealed that, in terms of mean root coverage (MRC) of main indicators, no significant difference was found between the CAF group and the TUN group in both short- and long-term results, which were [MD: 1.45%, 95%CI (-2.93%, 5.82%), P=0.52] and [MD: -0.70%, 95%CI (-6.41%, 5.00%), P=0.81]. However, the CAF group outperformed the TUN group in the long term [MD: 5.69%, 95%CI (0.87%, 10.50%), P=0.02], and the results of complete root coverage (CRC) analysis were similar to those of MRC. In the short term, the TUN group grew keratinized gingiva significantly faster than the CAF group [MD: -0.38 mm, 95%CI (-0.67 mm, -0.10 mm), P=0.008]. Long-term findings revealed no significant difference between the two groups [MD: -0.26 mm, 95%CI (-0.94 mm, 0.43 mm), P=0.46]. The TUN group's secondary index root coverage esthetic score (RES) was statistically significantly higher than the CAF group's [MD: 0.62, 95%CI (0.28, 0.96), P=0.000 3]. Given that there were few results included in the literature and the heterogeneity was too great, no significant difference was observed in the postoperative VAS pain index score [MD: 0.53, 95%CI (-1.96, 3.03), P=0.68]. This study discovered that both CAF+CTG and TUN+CTG can achieve good root coverage in treating gingival recession, with CAF outperforming TUN and both groups achie-ving good long-term stability. After the operation, the TUN group had a higher RES than the CAF group. Given the limitations of this study, more high-quality studies are needed in the future to demonstrate the efficacy of TUN in gingival retraction surgery.

Induction of Periodontitis Using Bacterial Strains Isolated from the Human Oral Microbiome in an Experimental Rat Model.

Periodontal disease is that condition resulting in the destruction of periodontal tissues, bone resorption, and tooth loss, the etiology of which is linked to immunological and microbiological factors. The aim of this study was to evaluate the potential trigger of periodontal disease in a rat model using bacterial species incriminated in the pathology of human periodontitis and to establish their optimal concentrations capable of reproducing the disease, with the idea of subsequently developing innovative treatments for the condition. In this study, we included 15 male Wistar rats, aged 20 weeks, which we divided into three groups. In each group, we applied ligatures with gingival retraction wire on the maxillary incisors. The ligature and the gingival sac were contaminated by oral gavage with a mixture of fresh cultures of Aggregatibacter actinomycetemcomitans (A.a), Fusobacterium nucleatum (F.n) and Streptococcus oralis (S.o) in concentrations of 108, 109, and 1010 CFU/mL each for 5 days a week for 4 weeks. During the clinical monitoring period of 28 days, overlapped with the period of oral contamination, we followed the expression of clinical signs specific to periodontitis. We also monitored the evolution of body weight and took weekly samples from the oral cavity for the microbiological identification of the tested bacteria and blood samples for hematological examination. At the end of the study, the animals were euthanized, and the ligated incisors were taken for histopathological analysis. The characteristic symptomatology of periodontal disease was expressed from the first week of the study and was maintained until the end, and we were able to identify the bacteria during each examination. Hematologically, the number of neutrophils decreased dramatically (p < 0.0001) in the case of the 109 group, unlike the other groups, as did the number of lymphocytes. Histopathologically, we identified neutrophilic infiltrate in all groups, as well as the presence of coccobacilli, periodontal tissue hyperplasia, and periodontal lysis. In the 109 group, we also observed pulpal tissue with necrotic bone fragments and pyogranulomatous inflammatory reaction. By corroborating the data, we can conclude that for the development of periodontal disease using A.a, F.n, and S.o, a concentration of 109 or 1010 CFU/mL is required, which must necessarily contaminate a ligature thread applied to the level of the rat's dental pack.