Apical Migration Research Articles

Microsurgical Approach for the Coverage of Gingival Recession Defects using Vestibular Incision Subperiosteal Tunnel Access (VISTATM) Technique- A Case Report

Gingival recession which is described as the loss of gingival attachment due to apical migration of the gingival margin from the cementoenamel junction leading to the exposure of the root surface, is one of the most prevalent diseases in the world. The treatment of gingival recession is therefore essential to achieve good aesthetics, relieve root hypersensitivity, prevent root caries and cervical abrasions. Till date, many root coverage techniques have been implicated for the coverage of recession defect. This case report focuses on the Vestibular Incision Subperiosteal Tunnel Access (VISTATM) technique for the root coverage procedure and simultaneous application of the microsurgical principles helps in executing the procedure in the most minimally invasive manner. Here, this technique has been accomplished in a 24-year-old female, with the chief complaint of poor aesthetics in the region of maxillary central incisors due to recession defects. Furthermore with the use of microsurgical instruments and magnifying loupes; complete coverage of the recession defects was achieved in a single stage surgery along with superior aesthetics, causing minimal trauma to the patient that was followed by an uneventful inflammatory phase.

The Use of Collagen Matrix in the Treatment of Gingival Recession-A Pilot Study.

Gingival recessions are common mucogingival deformities and conditions around teeth, which are described as the apical migration of tissues in the relation to the cementoenamel junction. One of the types of graft materials used to treat these recessions is the collagen graft material. The aim of this pilot study was to evaluate the effectiveness of the use of the collagen matrix combined with the coronally advanced flap surgery method to cover dental recessions, after a 12 month follow-up period. The following parameters were assessed in 20 patients, with 38 single or multiple Miller class I or II gingival recessions: depth of the recession-RD; width of the recession-RW; height of the keratinized tissue-HKT; and thickness of the keratinized gingivae-GT. The percentage of the root coverage after 12 months was also calculated. There was a significant difference in the RD and RW values before and after the procedure. On average, the RD decreased by 3.39 mm, and the RW by 3.87 mm. Moreover, the values of the GT and HKT, before and after the treatment, significantly increased by 0.98 mm and 1.13 mm, respectively. The partial root coverage was 43.48%, and the total root coverage was 56.52%. The use of the collagen matrix with a split thickness gingival flap to cover the gingival recessions is a predictable and effective method when the clinician carefully follows the recommendation of the producer, which was confirmed in a 1 year follow-up with good clinical results.

Immediate implant placement with or without immediate provisionalization: A systematic review and meta-analysis.

To assess the effect of immediate provisionalization (IP) on soft tissue changes, hard tissue changes, and clinical parameters following single immediate implant placement (IIP). Two independent reviewers conducted an electronic literature search in PubMed, Web of Science, Embase, and Cochrane databases as well as a manual search to identify eligible clinical studies up to September 2021. Randomized controlled trials (RCTs) comparing IIP with IP (test) and IIP without IP (control) were included for a qualitative and quantitative analysis. The primary outcome was vertical midfacial soft tissue changes. Secondary outcomes included horizontal midfacial soft tissue changes, implant survival, mesial and distal papillary changes, Pink Esthetic Score (PES) at final follow-up, marginal bone-level changes, probing depth at final follow-up, and bleeding on probing at final follow-up. Of the 8213 records, 7 RCTs reporting on 323 patients who received 323 single immediate implants (IIP + IP: 161 implants in 161 patients; IIP: 162 implants in 162 patients) were selected with a mean follow-up ranging from 12 to 60 months. Risk of bias assessment yielded some concerns for five RCTs and high risk for two RCTs. Meta-analysis on the cases with intact alveoli demonstrated 0.87 mm (95% confidence interval [CI] [0.57; 1.17], p< .001) less apical migration of the midfacial soft tissue level for IIP + IP when compared to IIP alone. Implant survival, papillary changes, marginal bone-level changes, probing depth, and bleeding on probing were not significantly affected by IP. Insufficient data were available for meta-analyses on horizontal midfacial soft tissue changes and PES. IP may contribute to midfacial soft tissue stability at immediate implants. However, high-quality RCTs are needed since the strength of this conclusion is currently rated as low according to GRADE guidelines.

Management of single tooth gingival recession using free gingival grafting followed by coronally advanced flap with cross-linked collagen matrix: A case report

Gingival recession is the exposure of root surfaces due to apical migration of the gingival margins beyond the cementoenamel junction and is considered as one of the most common esthetic concerns associated with periodontal tissues. Insufficient gingival thickness and lack of adequate width of attached gingiva are considered to be the most common reason for progressive gingival recession. This case report presented the management of gingival recession in the lower anterior tooth using two-stage recession coverage technique. In the first stage, free gingival grafting was performed which was followed by coronally advanced flap in combination with cross-linked collagen matrix (Fibro-Gide, Geistlich Biomaterials, Switzerland) for recession coverage and enhancement of gingival thickness. Three-month follow-up of the case reported significant enhancement in clinical parameters with improvement in patient’s esthetic demand.

Buccal soft tissue dehiscence defects at dental implants-associated factors and frequency of occurrence: A systematic review and meta-analysis.

To identify the factors associated with buccal peri-implant soft tissue dehiscences (BSTDs) and their frequency of occurrence. Randomized controlled trials, controlled clinical trials, cohort studies, and case series assessing the frequency of occurrence of BSTD were included. BSTD was defined as an apical migration of the peri-implant soft tissues of ≥1mm from the baseline examination (final restoration) or in comparison with the adjacent or contralateral natural tooth. Frequency distributions of BSTD related to the presence or absence of any surgical, prosthetic, or anatomic factor that may have contributed to the development of BSTD were recorded. Random-effects meta-analyses using odds ratios (OR) were performed to investigate the association of certain factors with the development of BSTD. Twenty-four articles were finally included belonging to 22clinical investigations. Patients at higher risk of developing BSTD were associated with thin biotype (OR=2.85 [1.40, 5.8], n=5, p=.003) and with buccally placed implants (OR=14.37 [4.58, 45.14], n=3, p≤.001). Patients without connective tissue grafting (CTG) had greater odds of developing BSTD (OR=9.00 [3.11, 26.02], n=5, p≤.001), while buccal bone plate thickness of <1mm and immediately placed implants were not associated with greater BSTD (OR=1.29 [0.35, 4.77], n=2, p=.704 and OR=1.56 [0.46, 5.26], n=4, p=.477, respectively). The frequency of occurrence of BSTD varied across the included studies with a range from 0% to 61%. Thin tissue biotype and buccally placed implants were associated with BSTD, whereas CTG seemed to have a protective effect. Thin buccal plates and immediately placed implants did not demonstrate a higher risk of BSTD.

Emi2 enables centriole amplification during multiciliated cell differentiation.

Massive centriole amplification during multiciliated cell (MCC) differentiation is a notable example of organelle biogenesis. This process is thought to be enabled by a derived cell cycle state, but the key cell cycle components required for centriole amplification in MCC progenitors remain poorly defined. Here, we show that emi2 (fbxo43) expression is up-regulated and acts in MCC progenitors after cell cycle exit to transiently inhibit anaphase-promoting complex/cyclosome (APC/C)cdh1 activity. We find that this inhibition is required for the phosphorylation and activation of a key cell cycle kinase, plk1, which acts, in turn, to promote different steps required for centriole amplification and basal body formation, including centriole disengagement, apical migration, and maturation into basal bodies. This emi2-APC/C-plk1 axis is also required to down-regulate gene expression essential for centriole amplification after differentiation is complete. These results identify an emi2-APC/C-plk1 axis that promotes and then terminates centriole assembly and basal body formation during MCC differentiation.

ANALYSIS OF THE GINGIVAL RECESSION PREVALENCE AMONG DENTAL PATIENTS CONSIDERING ASSOCIATED AGE-RELATED, IATROGENIC AND PATHOLOGICAL CHANGES OF DENTAL STATUS

Assessment of gingival recessions prevalence and explicitation of their distribution among studied samples of dental patients considering criteria of age, sex, severity of gingival apical migration and the facts of associated dental status changes can potentially help to identify specific risk groups. Implementation of preventive measure among such risk groups could potentially optimize the prognosis of future conservative or surgical treatment of gingival recessions.&#x0D; The objective of present study was to evaluate the prevalence of gingival recessions among dental patients, while also considering the associated age-related, iatrogenic and pathological changes of dental status. In order to assess the prevalence of gingival recessions among dental patients a study sample was formed out of the patients of the private dental clinic "Dentistry 3D Plus" (Cherkasy).&#x0D; Formation of study sample was provided by the method of block randomization according to the different age subgroups (18-19 years, 20-29 years, 3039 years, 40-49 years and 50-59 years). Each subgroup was set with 100 dental patients of the appropriate age. The diagnosis of recession was established due to the specific diagnostic criterion of marginal gingiva apical migration with exposure of the tooth root surface. The recession classification was performed according to the approach proposed by P.D. Miller’s. The depth of the recession was determined using a periodontal probe of CP 15 North Carolina design. Recessions were identified in 52 persons (52,0%) among 100 patients aged 18-19 years, in 68 persons (68,0%) among patients aged 20-29 years, in 95 persons (95,0%) among patients aged 30-39 years, in 96 persons (96,0%) among patients aged 40-49 years, and in 96 persons (96,0%) among patients aged 50-59 years. In general, the average prevalence of Miller’s class I recessions among all pathologies diagnosed within different age subgroups was 61,45±16,82%, prevalence of Miller’s class II recession reached 10,74±3,56%, prevalence of Miller’s class III recession was 21,71±10.80%, and prevalence of Miller’s class IV recession was 6,10±2.97%. Thus, Miller's class I and III recessions were the most prevalent, and the frequency of their diagnostics was statistically higher than class II (p &lt; 0,05) and class IV recessions (p &lt; 0,05). The average depth of recessions that met the diagnostic criteria for class I according to Miller was 2,31±1.35 mm, for Miller’s class II – 4,27±2,40 mm, for Miller’s class III – 6.31 ± 2.86 mm, for Miller’s class IV – 7,53±2,29 mm. Among all diagnosed recessions cases that were observed among patients of different age subgroups, 13,71±6,72% were associated with periodontitis pathology, 5,04±2,98% with overcrowding, 7,80±3,84% with signs of pathological attrition, 9,06±2,13% with non-carious cervical dental lesions, 7,85±1,60% with carious lesions of enamel and dentin, 7,97±1,83% with parafunctional activity and/or traumatic occlusion pattern, 7,85±4,26% with the fact of orthodontic intervention, 9,75±2,44% with existing problematic restorations, 8,16±1.62% with anomalies of teeth position, 7,72±0,74% with inadequate oral hygiene condition, 5,25±0,90% with bad habits that were identified during anamnesis collection, 5,28±2,60% with anomalies of mucous bundles attachment, while in 4,55±4,18% of the cases diagnosed recessions were not clinically associated with functional or structural dental status disorders.&#x0D; The results of study demonstrated a progressive increase in the number of recessions associated with periodontal disease (p &lt; 0,05), pathological attrition (p &lt; 0,05), non-carious dental lesions (p &lt;0.05) and problematic restorations (p &lt; 0,05 ) related to the parallel increase of patients’ average age, which according to the provided regression analysis was statistically significant during the comparison of such studied parameters among different age subgroups. Patients aged 30 years and older, male, and those with clinical signs of periodontitis, pathological attrition, non-carious and carious cervical lesions, poor oral hygiene, overcrowding of teeth, abnormalities of teeth position and abnormal attachment of mucous membranes could be categorized as those having potential risk for further recession development. Therefore, such patients require provision of timely comprehensive dental treatment to maintain the level of soft tissue coverage in the area of their own teeth and to correct changes in dental status associated with gingival recession development. Considering established relationship between the frequency of recession diagnostics among patients of different age subgroups and associated age-related, iatrogenic and pathological changes of dental status, it is advisable to determine how the latter may affect the prognosis of surgical treatment of gingival recessions with the use of flap displacement techniques and different soft tissue transplants for restoring soft tissue coverage of exposed root surfaces.

Immediate implant placement with or without socket grafting: A systematic review and meta-analysis.

To assess the effect of grafting the gap (SG) between the implant surface and alveolar socket on hard and soft tissue changes following single immediate implant placement (IIP). Two independent reviewers conducted an electronic literature search in Pubmed, Web of Science, Embase and Cochrane databases as well as a manual search to identify eligible clinical studies up to August 2021. Randomized controlled trials (RCTs) comparing IIP with and without SG were included for a qualitative analysis. Meta-analyses were performed when possible. Out of 3627 records, 15 RCTs were selected and reported on 577 patients who received 604 single immediate implants (IIP + SG: 298 implants in 292 patients; IIP: 306 implants in 285 patients) with a mean follow-up ranging from 4 to 36 months. Two RCTs showed low risk of bias. Meta-analysis revealed 0.59 mm (95% CI [0.41; 0.78], p< 0.001) or 54% less horizontal buccal bone resorption following IIP + SG when compared to IIP alone. In addition, 0.58 mm (95% CI [0.28; 0.88], p< 0.001) less apical migration of the midfacial soft tissue level was found when immediate implants were installed with SG. A trend towards less distal papillary recession was found (MD 0.60 mm, 95% CI [-0.08; 1.28], p= 0.080) when SG was performed, while mesial papillae appeared not significantly affected by SG. Vertical buccal bone changes were also not significantly affected by SG. Insufficient data were available for meta-analyses on horizontal midfacial soft tissue changes, pink esthetic score, marginal bone level changes, probing depth and bleeding on probing. Based on GRADE guidelines, a moderate recommendation for SG following IIP can be made. SG may contribute to horizontal bone preservation and soft tissue stability at the midfacial aspect of immediate implants. Therefore, SG should be considered as an adjunct to IIP in clinical practice.

Re-Treatment of Failing Class V Restorations with Gingival Recession

Gingival recession is common in the adult population, affecting almost all middle to older-aged individuals to some degree, is characterized by the apical migration of the gingival margin toward the cementoenamel junction (CEJ) [1].

VISTA technique combined with collagen membrane for treatment of multiple gingival recession: A case report

Gingival recession is an exposure of root surface due to the apical migration of the marginal periodontal tissues apical to cementoenamel junction. Many therapeutic options are available for the treatment of gingival recession, among these techniques, Vestibular Incision Subperiosteal Tunnel Access (VISTA) technique in combination with collagen membrane (BIO-GIDE) was used in the present study for the treatment of multiple gingival recession defects in the maxillary anterior region. In the VISTA technique, a single vestibular incision provides broader access to the entire surgical area which reduces the possibility of traumatizing the gingiva, with little or no scar formation. And the use of collagen membrane offers several advantages over other techniques as it is biocompatible, there is no need for donor site or secondary surgical procedure there by reducing post-harvesting morbidity and patient discomfort. In this case report VISTA technique in combination with collagen membrane was found to be a reliable treatment method for multiple gingival recession defects.

The Role of Lactic Acid on Wound Healing, Cell Growth, Cell Cycle Kinetics, and Gene Expression of Cultured Junctional Epithelium Cells in the Pathophysiology of Periodontal Disease.

Lactic acid (LA) is short-chain fatty acid, such as butyric acid and propionic acid, that is produced as a metabolite of lactic acid bacteria, including periodontopathic bacteria. These short-chain fatty acids have positive effects on human health but can also have negative effects, such as the promotion of periodontal disease (PD), which is caused by periodontal pathogens present in the gingival sulcus. PD is characterized by apical migration of junctional epithelium, deepening of pockets, and alveolar bone loss. Thus, the junctional epithelial cells that form the bottom of the gingival sulcus are extremely important in investigating the pathophysiology of PD. The aim of this study was to investigate the effect of LA on wound healing, cell growth, cell cycle kinetics, and gene expression of cultured junctional epithelium cells. The results showed that stimulation with 10 mM LA slowed wound healing of the junctional epithelial cell layer and arrested the cell cycle in the G0/G1 (early cell cycle) phase, thereby inhibiting cell growth. However, cell destruction was not observed. LA also enhanced mRNA expression of integrin α5, interleukin (IL)-6, IL-8, intercellular adhesion molecule-1, and receptor activator of nuclear factor kappa-B ligand. The results of this study suggest that stimulation of junctional epithelial cells with high concentrations of LA could exacerbate PD, similarly to butyric acid and propionic acid.

Surgical management of RT2 gingival recession using sub epithelial connective tissue graft and coronally advanced flap: A case report

Apical migration of the gingival fiber attachment and marginal gingiva leads to gingival recession and can be caused due to many factors such as faulty tooth brushing, masochistic habits, periodontal disease etc. This causes dentinal hypersensitivity, aesthetic problems, root caries, cervical abrasion, and difficulty in maintaining oral hygiene and often possess a challenging situation for the clinician to deliver best care to the patients. This case reports about the use of SCTG along with coronally advanced flap. To report a case of RT2 recession, older term – Millers Class II recession which showed promising result when root coverage procedure was done using sub-epithelial connective tissue and coronally advancing the flap. A 62-year-old male patient was referred to the Department of Periodontology, with a chief complaint of hypersensitivity and downward shifting of gum in upper front left teeth region which was progressive in nature with no obvious medical history.After achieving profound anaesthesia over the concerned region the recipient site was prepared. After which the donor tissue was retrieved from the palatal area using trap door method and placed over the recipient site. No root biomodification agents were used. The graft was stabilised using interrupted suture and then criss-cross suturing was done, and non-eugenol periodontal dressing was given. The follow up results showed good outcome with predictable root coverage achieved using Sub-epithelial Connective Tissue Graft (SCTG) and coronally advanced flap in the canine region which is often the most difficult one to achieve complete root coverage because of canine prominence. SCTG can be used successfully along with coronally advanced flap and clinicians must opt for such treatment modalities for patients benefit.

Periodontal outcomes of anterior fixed partial dentures on teeth treated with the biologically oriented preparation technique: A 6-year prospective clinical trial

Statement of problemOne of the most frequent complications in participants with fixed partial dentures (FPDs) is the apical migration of the gingival margin, which may be associated with factors such as fit, gingival margin location, or tooth preparation type. The prevalence of the complication in participants restored with FPDs prepared by using the biologically oriented preparation technique (BOPT) is unclear. PurposeThe purpose of this prospective clinical trial was to evaluate the clinical and biologic outcomes of FPDs on teeth prepared by using the BOPT, over a 6-year follow-up period. Material and methodsTooth-supported zirconia FPDs in the anterior region prepared by using the BOPT were evaluated. Each participant was monitored annually for 6 years by evaluating plaque index, probing depth, vestibular gingival thickness, and gingival margin stability. Biologic and/or mechanical complications were also recorded. Patient satisfaction was measured by using a visual analog scale (VAS). ResultsA total of 25 FPDs supported by 70 teeth in 24 participants were analyzed. Low plaque index values and stable probing depths were observed, whereas the gingival index was 0 for most of the teeth. Teeth treated by using the BOPT presented significant increase in gingival thickness, and the gingival margin was found to be stable in 100% of the treatments. FPD survival was 100%. ConclusionTooth supporting FPDs prepared by using the BOPT presented good periodontal health and gingival margin stability, without recession and with a 100% survival rate during a 6-year follow-up.

Asymmetric organelle positioning during epithelial polarization of C. elegans intestinal cells

While the epithelial cell cortex displays profound asymmetries in protein distribution and morphology along the apico-basal axis, the extent to which the cytoplasm is similarly polarized within epithelial cells remains relatively unexplored. We show that cytoplasmic organelles within C. elegans embryonic intestinal cells develop extensive apico-basal polarity at the time they establish cortical asymmetry. Nuclei and conventional endosomes, including early endosomes, late endosomes, and lysosomes, become polarized apically. Lysosome-related gut granules, yolk platelets, and lipid droplets become basally enriched. Removal of par-3 activity does not disrupt organelle positioning, indicating that cytoplasmic apico-basal asymmetry is independent of the PAR polarity pathway. Blocking the apical migration of nuclei leads to the apical positioning of gut granules and yolk platelets, whereas the asymmetric localization of conventional endosomes and lipid droplets is unaltered. This suggests that nuclear positioning organizes some, but not all, cytoplasmic asymmetries in this cell type. We show that gut granules become apically enriched when WHT-2 and WHT-7 function is disrupted, identifying a novel role for ABCG transporters in gut granule positioning during epithelial polarization. Analysis of WHT-2 and WHT-7 ATPase mutants is consistent with a WHT-2/WHT-7 heterodimer acting as a transporter in gut granule positioning. In wht-2(−) mutants, the polarized distribution of other organelles is not altered and gut granules do not take on characteristics of conventional endosomes that could have explained their apical mispositioning. During epithelial polarization wht-2(−) gut granules exhibit a loss of the Rab32/38 family member GLO-1 and ectopic expression of GLO-1 is sufficient to rescue the basal positioning of wht-2(−) and wht-7(−) gut granules. Furthermore, depletion of GLO-1 causes the mislocalization of the endolysosomal RAB-7 to gut granules and RAB-7 drives the apical mispositioning of gut granules when GLO-1, WHT-2, or WHT-7 function is disrupted. We suggest that ABC transporters residing on gut granules can regulate Rab dynamics to control organelle positioning during epithelial polarization.

Comparative Clinical Evaluation of Semilunar Coronally Positioned Flap Alone and Semilunar Coronally Positioned Flap in Conjunction with Free Gingival Graft for Root Coverage.

Gingival recession accounts for apical migration of the gingival margin, resulting in exposure of the cementoenamel junction and root surface, with exposure of the root surface linked to deteriorated esthetic appearance and increased dentinal hypersensitivity. Various surgical techniques have been used to correct labial gingival recession defects. The present study evaluated and compared the results of semilunar coronally positioned flap (SCPF) alone and in conjunction with free gingival graft (FGG) for the treatment of Miller Class I and II gingival recession defects in maxillary anterior teeth. A total of 20 bilateral Miller Class I and II gingival recession sites were included and randomly allocated (n = 10 sites/group) to either the semilunar coronally positioned flap technique alone (SCPF group; control) or with FGG (SCPF+FGG group; test). Longitudinal alterations in probing depth (PD), recession width (RW), recession height (RH), width of keratinized tissue (WKT), and clinical attachment level (CAL) were measured and analyzed for both groups at 1-, 3-, 6-, and 12-month follow-ups. Both groups saw a significant decrease in RH, RW, and CAL and a significant increase in WKT. No statistically significant difference was observed in the final root coverage outcome between both groups in terms of RH, RW, and CAL, but a significant increase in WKT was seen with SCPF+FGG. Both techniques demonstrated optimal results without significant differences in the final root coverage outcomes except for WKT, which had a statistically significant increase in the SCPF+FGG group.

Surgical treatment of multiple gingival recessions by the combination of autograftand allogenic lyophilized dura mater: a clinical case

Relevance. Gingival recession is the apical migration of the gingival tissues associated with the exposure of the roots and alveolar bone loss. The prevalence of single recessions in people over 18 years old is 86.7% whereas multiple recessions, i.e. where all teeth are affected, amount up to 28.6%. High prevalence of the pathology necessitates improvement of the approach and tactic of multiple recession treatment in patients with different phenotypes. Nowadays, the use of autograft is the gold standard of multiple recession treatment. However, the technique has its drawbacks. The purpose of the present work was to assess the response to surgery and evaluate the final result of multiple recession treatment in one subject where the combination of autogenic and allogenic grafts was used in the same study design.Materials and methods. The paper presents and describes a clinical case where auto- and allografts were used in one patient to treat multiple gingival recessions.Results. All parameters of the gingival recession assessment showed comparable clinical benefit in all sites of autograft and allograft (dura mater) application. The root coverage was more than 80% around 13 teeth and less than 80% around 11 teeth.Conclusion. The results of the autograft and allograft (dura mater) application were comparable, response to surgery was the same; besides, the allograft (dura mater) is attractive for combined and independent use during surgical treatment of multiple and especially full-mouth recessions.

The Effects of NF-kB Inhibition with p65-TMD-Linked PTD on Inflammatory Responses at Peri-implantitis Sites

The objective of this study was to find out if suppression of NF-kB complex function by p65-TMD-linked PTD could reduce host inflammation and bone resorption at peri-implantitis sites in rats. Twenty-one male 5-week-old SD rats were divided into three groups: untreated control group (A), silk-induced peri-implantitis group (B), and nt (nucleus transducible)-p65-TMD-treated, silk-induced peri-implantitis group (C). Implant sulcus of a rat in group C were divided into two groups, namely group Cp and Cb. Palatal implant sulcus where nt-p65-TMD solution was applied with an insulin syringe were assigned to group Cp. Buccal implant sulcus without topical nt-p65-TMD application were assigned to group Cb. H&E staining, TRAP staining, and immunohistological staining were done. The crestal bone levels of group A were significantly higher than those of group B at p<0.01. The crestal bone levels of group Cp were significantly higher than those of group Cb at p<0.05. H-E staining showed increased apical migration of junctional epithelium and inflammatory cells in group Cb. TRAP staining revealed more multinucleated osteoclasts in group Cb. As for immunohistological staining, group Cb showed many IL-6-positive cells while group Cp had none. In this study, p65-TMD-linked PTD inhibited NF-kB functions and reduced inflammation and bone resorption at peri-implantitis sites in rats.

The Symmetric 3D Organization of Connective Tissue around Implant Abutment: A Key-Issue to Prevent Bone Resorption

Symmetric and well-organized connective tissues around the longitudinal implant axis were hypothesized to decrease early bone resorption by reducing inflammatory cell infiltration. Previous studies that referred to the connective tissue around implant and abutments were based on two-dimensional investigations; however, only advanced three-dimensional characterizations could evidence the organization of connective tissue microarchitecture in the attempt of finding new strategies to reduce inflammatory cell infiltration. We retrieved three implants with a cone morse implant–abutment connection from patients; they were investigated by high-resolution X-ray phase-contrast microtomography, cross-linking the obtained information with histologic results. We observed transverse and longitudinal orientated collagen bundles intertwining with each other. In the longitudinal planes, it was observed that the closer the fiber bundles were to the implant, the more symmetric and regular their course was. The transverse bundles of collagen fibers were observed as semicircular, intersecting in the lamina propria of the mucosa and ending in the oral epithelium. No collagen fibers were found radial to the implant surface. This intertwining three-dimensional pattern seems to favor the stabilization of the soft tissues around the implants, preventing inflammatory cell apical migration and, consequently, preventing bone resorption and implant failure. This fact, according to the authors’ best knowledge, has never been reported in the literature and might be due to the physical forces acting on fibroblasts and on the collagen produced by the fibroblasts themselves, in areas close to the implant and to the symmetric geometry of the implant itself.

ДЕЯКІ АСПЕКТИ ПРОРІЗУВАННЯ ЗУБІВ. ОГЛЯД ЛІТЕРАТУРИ

In modern dental practice, one of the complaints of patients is unsatisfactory appearance due to the visually disproportionate size of teeth. Diagnostic assessment of the smile reflects the amount of gum and tooth tissue exposed. This emphasizes the growing need for the exchange of information and scientific knowledge between orthodontists and periodontists, an integrated approach to the treatment of orthodontic patients. The position of the gums is clinicalу important because it is not static. Tooth eruption involves a complex of stages that have not yet been widely studied. According to the concept of continuous eruption, it does not stop, even when the teeth are in contact with their functional antagonists, but lasts a lifetime. The normal state of passive eruption should lead to the location of the cement-enamel joint (CEJ) approximately in the area of the base of the furrow and 2 mm from the ridge of the alveolar bone. The active eruption is the movement of teeth towards the occlusal plane, whereas the passive eruption is the exposure of teeth by apical migration of the gums. The passive eruption usually occurs after teething and continues in adolescents and finally stops after facial growth. Altered passive eruption (APE) (also known as delayed passive eruption) occurs when the edge of the gums is incorrectly (occlusively) located on the anatomical crown in adulthood and does not approach the CEJ. The "normal" position of the gingival margin to the CEJ is usually considered to be on or near the CEJ in the fully incised teeth of adults. The prevalence of APE in the adult population is currently poorly studied, possibly due to the lack of clear diagnostic criteria. Thus, Volchansky and Cleaton-Jones, based on a survey of 1,025 patients aged 24.2±6.2 years, recorded 12.1% of cases of APE. The analysis of the literature did not reveal any reliable etiological factors that cause the impossibility of the tooth eruption and cause such morphology of the CEJ. The greatest clinical significance of APE is its aesthetic consequences. As a rule, this is a change in dentofacial harmony, which is manifested in the following: the square appearance of the crowns, the exposure of the gums during a smile, smoothed gingival scallops. An integrated approach to the treatment of patients with APE includes consideration of periodontal interventions, restorative manipulations, and orthodontic treatment. Thus, the altered passive eruption is an unusual physiological variation in the morphology of the dental-gum complex, which leads to aesthetic disorders and is considered a risk factor for periodontal disease. Therefore, it is necessary to pay attention to the presence of altered teeth eruption when planning the orthodontic treatment. Correction of malocclusions should be integrative.

Periodontal response to a tricalcium silicate material or resin composite placed in close contact to the supracrestal tissue attachment: a histomorphometric comparative study.

Subgingival dental restorations and periodontal health have been studied for many years; however, there is a low histological evidence on the behavior of new materials in the supracrestal tissue attachment. The aim of this study is to analyze the periodontal response when a tricalcium silicate material (TSM) or composite margin restorations is placed to 0.5 mm and 1.5 mm from the bone crest with a histomorphometric analysis in dogs. Nine mongrel dogs were used in this study: four dogs (8 canine teeth) for TSM group, 4 dogs (8 canine teeth) for composite group, and 1 dog (2 canine teeth) with cavities without restorations. Cavity preparation of 2×2×1 mm was created on the buccal aspect of the canines at 0.5 and 1.5 mm of the crestal bone. Cavities were restored with composite and TSM or were left unrestored as control. After 12 weeks of healing, the dogs were euthanized and blocks containing the tooth and soft tissues were processed. In all the specimens, the junction epithelium was stablished apical to the tooth preparations. A shorter distance to the bone (0.5 cavity) implies greater apical periodontal migration regardless of the material used. In the TSM groups, the connective tissue height and the distance between bone level and apical margin preparation were greater than those in the composite groups, while the epithelium height was less. However, there were no statistically significant differences comparing TSM and composite groups at either 0.5 mm or 1.5 mm (p > 0.05). Histologic analysis did not show periodontal reattachment to TSM or composite. In both cases, bone crest migrates apically. For that reason, it is recommended to perform composite restorations at the subgingival level whenever the distance to the bone crest is at least 2 mm. Both composite and TSM do not achieve reinsertion of the connective tissue in the biological width.