Supracrestal Connective Tissue Research Articles

Supracrestal tissue attachment: an update

Supracrestal tissue attachment (STA) is a relatively new term that was introduced in 2017 following the World Workshop on the Classification of Periodontal and Peri-implant Diseases and Conditions, co-sponsored by the American Academy of Periodontology (AAP) and the European Federation of Periodontology (EFP), which included expert participants from all over the world. It has replaced the term biological width, and refers to the junctional epithelium and supracrestal connective tissue. This article provides an updated review of the anatomy of STA, highlights the negative effects of violation and discusses its clinical relevance in restorative dentistry, including the use of crown lengthening. The impact of implants on STA is highlighted, and a summary of the relevance of STA in implant dentistry is also discussed. CPD/Clinical Relevance: To allow dental practitioners to have more confidence providing adequate function, comfort, and aesthetics in the dentition, while maintaining periodontal health.

Soft tissue management at delayed implant loading in the aesthetic zone: A case report

Emergence profile of implant-supported crowns is defined by the characteristics of supracrestal connective tissue (SCT), located between the implant platform and cervical soft tissue margin. This paper reflects the soft tissue contour management of implant-supported screw-retained crowns and the transfer of emergence profile using an indirectly customized impression coping. A 27-year-old male was referred for endosseus implant placement (Straumann BLT 0 4.1 mm ? 12 mm) in a region of a maxillary right central and lateral incisor. Teeth were extracted due to a cystic formation in the mentioned region. Following the delayed implant loading protocol, implants were exposed, and provisional crowns were fabricated to support marginal mucosa and papillae and to mimic the contralateral site. During the three months of temporization, three-dimensional peri-implant soft tissue changes were validated, and temporary crowns were re-contoured every two weeks to obtain dynamic compression. When adequate soft tissue architecture was achieved, the impression for definitive crowns was taken using customized transfer technique to be able to register the emergence profile of provisional crowns. This case report described a soft tissue management technique, where remodeling the provisional restoration allowed soft tissue to be reshaped. Individual transfer impression technique provides an accurately captured emergence profile of the soft tissue contours around implants in the aesthetic zone. This technique enables contouring of the transmucosal part of the definitive restoration according to the results obtained by individual dynamic compression, which leads to healthy soft tissue contours as well as satisfactory aesthetic results.

A fogágybetegség és a peri-implant betegségek új klasszifikációja

Az új klasszifikációs rendszer több ponton módosította, illetve felülírta a plakk okozta fogágybetegség 1999-es nevezéktanát és klasszifikációját. A korábban krónikus és agresszív parodontitist egységesen parodontitisnek nevezte el és ezen belül két dimenziós diagnosztikai kategóriát különít el, nevezetesen (staging) stádium és (grading) osztály fokozatot. A stádium (staging) az első vizsgálat során felmért parodontális állapot súlyosságát és a kezelés szempontjábóla komplexitását foglalja magába. Az osztály (grading) pedig további információval szolgál a betegség biológiai hátteréről, az anamnézisről, a betegség progressziójáról, a rizikófaktorokról, a további progresszió rizikójáról, a lehetséges kezelési eredményeket negatívan befolyásoló tényezőkről, valamint mindazokról a rizikófaktorokról, amelyeket maga a betegség vagy a parodontális kezelés jelent a páciens általános egészségi állapotára.A necrotizáló fogágybetegség, amelyhez klinikailag jellemző egyedülálló jelek (papilla necrozis, spontán vérzés és fájdalom) társulnak megváltozott szervezeti immun válasszal, továbbra is a korábbi, 1999-es klasszifikáció diagnózisát használja. Az endo-parodontális léziók körébe az új besorolás azokat a patológiás folyamatokat sorolja, amelyben egy adott fognál a pulpa és a parodontium között valamilyen kommunikációs csatorna nyílik meg. Ez lehet akut és krónikus lefolyású. Ezen belül olyan alcsoportokat állít fel, amelyek hatással vannak a folyamat lefolyására és a kezelési lehetőségekre. A parodontális abscessus olyan akut folyamat, amelyben a sulcus/tasak falszövetében genny gyűlik össze, amely nagyon rapid szöveti destrukciót eredményez és nagy a veszélye a folyamat tovaterjedésének.

Early histological, microbiological, radiological, and clinical response to cemented and screw-retained all-ceramic single crowns.

To assess the early histological, microbiological, radiological, and clinical response to cemented and screw-retained all-ceramic single-tooth implant-supported reconstructions. Patients with single-tooth implants were randomly allocated to receive a cemented lithium disilicate crown on a customized zirconia abutment (CEM) or a screw-retained crown with a directly veneered zirconia abutment (SCREW). At the screening visit, at crown insertion and at the 6-month follow-up, clinical parameters were measured at the implant and the contralateral tooth. Marginal bone levels, technical parameters, and esthetic outcomes were measured at the implants. At the 6-month follow-up, a microbiological test was performed and a soft tissue biopsy was harvested at the implants for histological analysis. Inflammatory cells and fibroblasts/-cytes were analyzed at the level of the sulcular epithelium, junctional epithelium, and connective tissue. The histological parameters were analyzed by means of a linear mixed model. Thirty-three patients completed the study, and implant and crown survival rates were 100% at 6months. Histologically, the number of inflammatory cells tended to be higher in group CEM (p>0.05). Moreover, significantly less inflammatory cells and fibroblasts/-cytes were found in the sulcular epithelium compared to the junctional epithelium and supracrestal connective tissue (p<0.001). Four patients were tested positive for periodontal marker pathogens at the 6-month follow-up, and three of them belonged to group CEM. From crown insertion to the 6-month follow-up, median marginal bone levels changed only minimally and measured 0.31 and 0.32mm in group CEM and 0.47 and 0.36mm in group SCREW, respectively. Clinical and esthetic parameters remained stable over time and were comparable between natural teeth and implants as well as between the groups. Cemented reconstructions were associated with more inflammatory cells, and more patients were diagnosed with periodonto-pathogens. Both types of reconstructions resulted in similar radiological (marginal bone levels) and clinical outcomes (bleeding on probing and probing depth).

Dental prostheses and tooth-related factors.

This narrative review summarizes the current evidence about the role that the fabrication and presence of dental prostheses and tooth-related factors have on the initiation and progression of gingivitis and periodontitis. Placement of restoration margins within the junctional epithelium and supracrestal connective tissue attachment can be associated with gingival inflammation and, potentially, recession. The presence of fixed prostheses finish lines within the gingival sulcus or the wearing of partial, removable dental prostheses does not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. However, hypersensitivity reactions to the prosthesis dental material can be present. Procedures adopted for the fabrication of dental restorations and fixed prostheses have the potential to cause traumatic loss of periodontal supporting tissues. Tooth anatomic factors, root abnormalities, and fractures can act as plaque-retentive factors and increase the likelihood of gingivitis and periodontitis. Tooth anatomic factors, such as root abnormalities and fractures, and tooth relationships in the dental arch and with the opposing dentition can enhance plaque retention. Restoration margins located within the gingival sulcus do not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. Tooth-supported and/or tooth-retained restorations and their design, fabrication, delivery, and materials have often been associated with plaque retention and loss of attachment. Hypersensitivity reactions can occur to dental materials. Restoration margins placed within the junctional epithelium and supracrestal connective tissue attachment can be associated with inflammation and, potentially, recession. However, the evidence in several of the reviewed areas, especially related to the biologic mechanisms by which these factors affect the periodontium, is not conclusive. This highlights the need for additional well-controlled animal studies to elucidate biologic mechanisms, as well as longitudinal prospective human trials. Adequate periodontal assessment and treatment, appropriate instructions, and motivation in self-performed plaque control and compliance to maintenance protocols appear to be the most important factors to limit or avoid potential negative effects on the periodontium caused by fixed and removable prostheses.

Dental prostheses and tooth-related factors.

This narrative review summarizes the current evidence about the role that the fabrication and presence of dental prostheses and tooth-related factors have on the initiation and progression of gingivitis and periodontitis. Placement of restoration margins within the junctional epithelium and supracrestal connective tissue attachment can be associated with gingival inflammation and, potentially, recession. The presence of fixed prostheses finish lines within the gingival sulcus or the wearing of partial, removable dental prostheses does not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. However, hypersensitivity reactions to the prosthesis dental material can be present. Procedures adopted for the fabrication of dental restorations and fixed prostheses have the potential to cause traumatic loss of periodontal supporting tissues. Tooth anatomic factors, root abnormalities, and fractures can act as plaque-retentive factors and increase the likelihood of gingivitis and periodontitis. Tooth anatomic factors, such as root abnormalities and fractures, and tooth relationships in the dental arch and with the opposing dentition can enhance plaque retention. Restoration margins located within the gingival sulcus do not cause gingivitis if patients are compliant with self-performed plaque control and periodic maintenance. Tooth-supported and/or tooth-retained restorations and their design, fabrication, delivery, and materials have often been associated with plaque retention and loss of attachment. Hypersensitivity reactions can occur to dental materials. Restoration margins placed within the junctional epithelium and supracrestal connective tissue attachment can be associated with inflammation and, potentially, recession. However, the evidence in several of the reviewed areas, especially related to the biologic mechanisms by which these factors affect the periodontium, is not conclusive. This highlights the need for additional well-controlled animal studies to elucidate biologic mechanisms, as well as longitudinal prospective human trials. Adequate periodontal assessment and treatment, appropriate instructions, and motivation in self-performed plaque control and compliance to maintenance protocols appear to be the most important factors to limit or avoid potential negative effects on the periodontium caused by fixed and removable prostheses.

A modified approach to horizontal augmention of soft tissue around the implant: omega roll envelope flap. Description of surgical technique.

The flap's design, as applied to implant surgery procedures for implant-prosthetic therapy, takes inspiration from the roll technique of Abrams (1980) and subsequent modifications. This article describes a modified flap design for the correction of horizontal alveolar mucosa defects in implant-supported rehabilitation with one-stage and two-stage approache. The omega roll envelope flap (OREF) is a roll flap combined with a modified pouch technique. The goal of this type of flap design is to correct localized horizontal alveolar ridge defects and augment peri-implant soft tissue thickness. OREF is a flap technique that avoids harvesting autologous connective tissue from another donor site by using the supracrestal connective tissue of the implant surgical site. The proposed technique allows for increased horizontal buccal soft tissue thickness during implant-prosthetic rehabilitation. The OREF technique is practical for one- and two-stage implant approaches, and when it is applied with an immediate non-functional loading procedure, this technique can optimize surgical and prosthesis chair times. This technique has shown advantages as maximizes the amount of connective tissue that can be rolled within the buccal flap. The OREF technique can be applied with a one-technique can be applied with a one-stage or two-stage implant-prosthetic approach.

Perio-Prostho Relationship-A Review

An adequate understanding of the relationship between periodontal tissues and restorative dentistry is paramount to ensure adequate form, function, esthetics and comfort of the dentition. While most clinicians are aware of this important relationship, uncertainty remains regarding specific concepts such as biologic width, its maintenance and applications of crown lengthening in cases of biologic width violation. It has been shown that 3 mm between the preparation margin and alveolar bone maintains periodontal health.This 3 mm constitutes for 1 mm supracrestal connective tissue attachment, 1 mm junctional epithelium and 1 mm for gingival sulcus on average. Biologic width violations can be corrected by either surgically removing bone away from proximity to the restoration margin, or orthodontically extruding the tooth.

Blood vessels of the peri-implant mucosa: a comparison between flap and flapless procedures

The vascularity of a peri-implant tissue is a very important parameter in the establishment and maintenance of healthy tissue after dental implant insertion. The purpose of this study was to compare the vascularity of the peri-implant mucosa between flap and flapless implant surgeries by using a canine mandible model. In six mongrel dogs, bilateral, edentulated, and flat alveolar ridges were created in the mandible. After 3 months of healing, 2 implants were placed in each side by either flap or flapless procedure. After another healing period of 3 months, biopsies were obtained, prepared for light microscopy, and exposed to morphometric measurements. The supracrestal connective tissue lateral to the implant was found to be more richly vascularized in the flapless group than in the flap group. These results suggest that the flapless procedure may increase the vascularity of the peri-implant mucosa.

Periodontal healing following orthodontic movement of rat molars with intact versus damaged periodontia towards a bony defect

The aim of this research was to determine whether orthodontic tooth movement influences periodontal healing. In 16 male Wistar rats, 12 week of age, a bony defect was created mesial to both maxillary first molars, not including the attachment apparatus (group 1), and in 15 animals, the defect included the periodontal ligament (group 2). In both groups, the right first molar was moved mesially (orthodontic side) for 2 weeks followed by a 1-week retention period; the contralateral molar was not moved (control side). Histomorphometric analysis was performed. The results within and between the different treatment groups and sides were statistically compared by t-test and analysis of variance with repeated measures on logarithmic transformation. Junctional epithelium was significantly larger at the control than at the orthodontic side of both groups (P = 0.024), and significantly larger in group 2 than in group 1 (P < 0.001). A significantly (P = 0.034) larger pocket depth was found at the control side in group 1. Supracrestal connective tissue was larger at the control than at the orthodontic side for both groups and significantly larger in group 2 than in group 1 (P = 0.004). Root resorption was found infrequently only at the orthodontic side in both groups (five out of 31 cases). The principal findings suggest favourable effects of orthodontic tooth movement on restraining epithelial apical down-growth and decreasing pocket depth. Orthodontic treatment could not completely avoid formation of a long epithelial attachment. Therefore, periodontal regenerative surgery might be indicated prior to orthodontic tooth movement. Orthodontic movement, shortly after periodontal surgery, had no detrimental effect on periodontal soft tissue healing or on diminished but non-inflamed periodontal tissues.

Effect of Enamel Matrix Protein Derivative on Healing of Surgical Supra‐Infrabony Periodontal Defects in the Rat Molar: A Histomorphometric Study

Enamel matrix protein derivative (EMD) has proven to enhance periodontal regeneration in human and animal studies. The present histomorphometric study evaluated healing of combined supra-infrabony periodontal defects with EMD. The study comprised two groups of 10 Wistar rats each, 7 to 8 months old. Bony defects were created on the mesial aspect of the mesial root of the first maxillary molar. The root surface was planed and 24% EDTA gel applied for 2 minutes and then rinsed with water. In the study group, EMD was applied, and in the control group, only propylene glycol alginate was applied. Animals were sacrificed 12 weeks after surgery, and block sections were removed, demineralized, and embedded in paraffin. For histomorphometric analysis, three sections from the central area of the defect were selected. Root, surgical defect, epithelial attachment, sulcus, supracrestal connective tissue, ankylosis, and the length and area of new cementum and new bone were measured. No statistically significant differences between the two groups were found for root and defect measures. The remaining parameters were calculated as a percentage of the defect. In the study group, smaller gingival recession (P = 0.05), deeper gingival sulcus (P = 0.05), and shorter junctional epithelium (P = 0.01) were found. New cementum was observed in the study group only (P = 0.02). Ankylosis was six times larger in the control group but not statistically significant. New bone formation was similar in both groups. Enamel matrix protein derivative enhanced periodontal healing in this model by reducing gingival recession and junctional epithelium along the root surface and enhancing the formation of new cementum.

Periimplant Soft Tissue Barrier at Experimental One‐Piece Mini‐implants with Different Surface Topography in Humans: A Light‐Microscopic Overview and Histometric Analysis

Following connection to the oral cavity, osseointegrated dental implants and surrounding tissues are exposed to microbiologic and biomechanical challenges. The establishment of a firm functional periimplant soft tissue barrier (PSTB) is considered to be important to protect the implant's interface from invasion of bacteria. The current knowledge on the histologic architecture of the PSTB is mainly based on animal experiments. The aim of this study was to histologically characterize the PSTB formed in humans around experimental one-piece mini-implants with different surface topography. Five patients received a total of 12 experimental titanium, one-piece mini-implants with an oxidized (n = 4), an acid-etched (n = 4), or a machined (n = 4) surface distal to therapeutic implants. Following transmucosal healing of 8 weeks and at abutment connection of the regular implants, the mini-implants were harvested with a layer of surrounding hard and soft tissue. The specimens were fixed and processed for histologic sectioning according to standard procedures. The most central bucco-oral section cut in the long axis was used for morphologic analyses of the PSTB. The vertical soft tissue morphology was quantified using histometric measurements. The overall height of the soft tissue, that is, the biologic width, was around 4 to 4.5 mm and consisted of an epithelial and a supracrestal connective tissue barrier. The junctional epithelium established the attachment to the implant surface, whereas the collagen fibers and fibroblasts of the connective tissue seal were oriented parallel to the implant. The epithelial attachment was shorter at the oxidized and acid-etched surfaces compared with the machined surfaces. Accordingly, the oxidized and acid-etched mini-implants exhibited a longer zone of connective tissue seal. The periimplant soft tissue formed at the experimental one-piece mini-implants in humans was of a character similar to that described in animal studies. The oxidized and acid-etched implants revealed less epithelial downgrowth and longer connective tissue seal than machined implants.

Immunohistochemical analysis of soft tissues in implants with healthy and peri‐implantitis condition, and aggressive periodontitis

Today, implant-supported prostheses are widely accepted as a reliable treatment modality, but failures in longitudinal studies have been shown. In some cases, peri-implantitis with a progressive periodontal bone loss takes place, and mechanical or load factors and biological or plaque-induced lesions have been claimed as main etiologic factors. We compared five cases of peri-implantitis, with five cases of healthy peri-implant tissues and five cases of aggressive periodontitis in order to give new findings on the osseointegration loss process. Biopsy specimens from the peri-implant tissues including oral (O), sulcular, and junctional epithelium and the underlying and supracrestal connective tissue, were taken in all cases for histological and immunohistochemical analysis. T lymphocytes were the most prominent cell in the peri-implantitis (PG) and aggressive periodontitis (AG) groups, but not in the peri-implant healthy group (HG). CD1a-positive cells (Langerhans and immature dendritic cells) were observed more frequently in the O than in the sulcular-junctional (S-J) epithelium: they were located in the basal and parabasal layers, without any differences between the three groups. Vascular proliferation analysed by immunoreactivity for CD34, Factor VIII, and vascular endothelial growth factor was more prominent in the PG comparing with HG and AG in the S-J area. Apoptosis, analysed by bcl2 and p53 immunoreactivity, was similar in the three groups. In conclusion, we suggest that the osseointegration loss process is due to an inflammatory process similar to that observed in aggressive periodontitis according to the number of T lymphocytes, but not to the vascular proliferation.

Healing after standardized clinical probing of the perlimplant soft tissue seal: a histomorphometric study in dogs.

Clinical probing of the soft tissues around oral implants has become a frequently used parameter for clinical monitoring. However, the healing of the disruption of the soft tissue seal as a result of probing has not yet been studied. The purpose of this study was to evaluate the healing events in the periimplant mucosal tissues following standardized clinical probing. In three foxhounds the mandibular premolars were extracted and, after 3 months of healing, TPS screw-shaped implants (ITO Dental Implant System) were installed. A plaque control regimen was performed throughout the duration of the experiment. After 3 months of healing of the transmucosal implants, clinical implant stability and healthy periimplant mucosal tissues with mostly absence of bleeding on probing were obtained. Clinical probing of the mesial and distal implant sites was performed immediately before 1, 2, 3, 5 and 7 days prior to the sacrifice of the animals. A specially manufactured titanium cylinder with a mesial and distal groove was fixed to the implants to standardize the insertion geometry of a pressure-sensitive probe (0.2-0.25 N, tip diameter 0.45 mm). The distances from the alveolar crest to the coronal border of the connective tissue adaptation to the implant and the length of the epithelial attachment were measured histomorphometrically in nondecalcified ground sections. The buccal and lingual aspects of the implants were used to determine the components of the biological width in unprobed control sites. The probe caused a separation between the surface of the implant and the junctional epithelium, but not within the connective tissue adaptation. In general, the probe tip was located at the most coronal level of the supracrestal connective tissue as determined histologically. By 1 day after separation of the periimplant mucosal tissue by probing, an epithelial attachment of approximately 0.5 mm in the apico-coronal direction was observed. The length of the epithelial adaptation showed a tendency to increase over time (day 2: 1.15 mm, day 3: 1.52 mm), and was complete at day 5 (1.92 mm). At the unprobed sites the epithelial attachment showed a mean length of 1.69 mm. Inflammatory infiltrates were practically nonexistent, indicating the absence of tissue trauma or infection as a result of probing. Clinical probing around osseointegrated implants does not appear to have detrimental effects on the soft tissue seal and, hence, does not seem to jeopardize the longevity of oral implants. The 'healing of the epithelial attachment' seems to be complete 5 days after clinical probing.

Organization of the connective tissue barrier around long-term loaded implant abutments in man.

The study aimed to investigate the connective tissue seal and the spatial organization of collagen fibers around long-term loaded implants in man. Block specimens containing smooth titanium implant abutments and the surrounding supracrestal connective tissue were obtained from patients rehabilitated for at least 1 year with implant-retained overdentures or implant-supported fixed prostheses and were histologically investigated. The histological features of the connective tissue around long-term loaded titanium abutments were specific: the tissue was rich in collagen fibers, organized in bundles, presenting a constant spatial arrangement, similar to that reported in animal studies. Circular fibers, the most numerous, were located externally, and longitudinal fibers internally. Radial fibers inserted on the abutment surface, similar to those of the periodontal system, were not observed in any case. No histological differences were found between tissue sampled around implants supporting a fixed restoration and those anchoring an overdenture.

Relationship between Oral Alveolar Bone Loss and Aging among African-American and Caucasian Individuals

Background: The periodontal attachment apparatus consists of the periodontal ligament, alveolar bone, cementum and supra-crestal connective tissue. They are interdependent and provide protection and support to the dentition. It is theorized that the integrity of the periodontal apparatus can be maintained throughout life by exercising comprehensive oral hygiene practices and routine dental care. Additionally, it appears to be unaffected by aging. As a consequence, the investigators performed a study to determine the effects of chronological aging on alveolar bone loss. Objective: The present study was conducted to determine the relationship between oral alveolar bone loss, oral hygiene, and aging among African-American and Caucasian populations. Methods: The population consisted of 229 individuals. There were 131 men and 98 women. With respect to race there were 89 African-Americans and 140 Caucasians. Oral examinations, oral hygiene and missing teeth determinations and bitewing radiographs were performed on all the individuals. Radiographs were digitized and measurements were made from the cementum/enamel junction to the alveolar bone crest. Measurements were made for both the maxillary and mandibular jaws. Results: The results of the study showed a significant multiple linear regression model relationship between oral bone loss and aging. Oral hygiene was a factor, but contributed only slightly to the overall model. Race, gender and the number of missing teeth were not significant variables in the overall model. Conclusion: The results of this study suggest age-related alveolar bone loss.

Dental Implant Tissue Interface - An Appraisal

Endoseous Implant insertion for the replacement of missing teeth is the state of the art at present times. An understanding of the biology of the perimplant tissues is imperative for the overall success in the dental rehabilitation of a patient with fixture supported prosthesis. The dental implant tissue interface comprises bone, both cortical and cancellous bone; supracrestal connective tissue and the epithelial attachment. A comprehensive review of the response of bone during the postoperative or healing phase, the loading or remodelling phase and during the steady phase is described.

Implant-tissue interfaces following treatment of peri-implantitis using guided tissue regeneration: a light and electron microscopic study.

This study details the structural and ultrastructural features of the interfaces between titanium implants and their surrounding tissues. The material stemmed from an experiment in dogs in which guided tissue regeneration with Gore-Tex membranes was used to treat peri-implant, ligature-induced tissue breakdown around submerged and nonsubmerged commercially pure titanium implants. Specimens from the nonsubmerged group were evaluated under light microscopy and scanning and transmission electron microscopy. A healthy gingiva and a gingival sulcus were formed around the implant necks. A regenerated junctional epithelium provided the epithelial union between implant and gingiva. The supracrestal connective tissue was characterized by a 3-dimensional network of collagen fibers, fibroblasts and blood vessels. Near the implant surface the collagen fibers ran parallel to the titanium surface or were orientated perpendicular to the implant. The connective tissue-implant interface was characterized by a fine fibrillar material interposed between the implant surface and the connective tissue. An unidentified material was also observed between the endings of functionally orientated collagen fibrils and the metallic surface. The apical portions of the implants were anchored in compact bone. At the bone-implant interface, either mineralized bone matrix was intimately adapted to the titanium surface without any intervening space or a 0.5-micron wide unmineralized layer was interposed. These findings indicate that a perimucosal seal was formed around the implants consisting of a junctional epithelium-implant union coronally and supported by the connective tissue-implant junction apically. The implants were integrated in connective tissue, but only tightly adapted to bone.

The topography of the vascular systems in the periodontal and peri-implant tissues in the dog.

The present investigation reports an animal experiment the objective of which was to study the vascular topography of the periodontium and the peri-implant soft and hard tissues in the beagle dog. 2 beagle dogs were used. The right mandibular premolars were extracted and healing allowed for 3 months. 2 titanium fixtures a.m. Brånemark were installed in the right premolar region. Abutment connection was performed 3 months later. The contra-lateral mandibular sites were used as tooth harboring control units. A 4-month period of meticulous plaque control was initiated. A clinical and radiographical examination was performed towards the end of this period and revealed that the gingiva and peri-implant mucosa were clinically healthy and that the bone tissue at teeth and implants had a normal height. The carotid arteries were perfused with a mixture of carbon and calf serum. 2 bucco-lingual sections, about 100-150 microns thick, and one mesio-distal section comprising the junctional epithelium and underlying connective tissue were sampled. The sections were treated, cleared and examined in a microscope. The results of the present investigation demonstrated that the vasculature of the gingiva and the supracrestal connective tissue at teeth is derived from two sources, namely the supraperiosteal vessels lateral of the alveolar process and the vessels of the periodontal ligament. The blood vessels of the peri-implant mucosa were found to be terminal branches of larger vessels originating from the periosteum of the bone of the implant site.(ABSTRACT TRUNCATED AT 250 WORDS)

Supracrestal circular collagen fiber network around osseointegrated nonsubmerged titanium implants.

Eight non-submerged titanium implant screws were placed in the first upper molar edentulous sites of monkeys and subsequently kept loaded with single crown prosthesis 1 month following implantation. The animals were killed after a further 14 months and specimens including implant and adjacent teeth were processed for light and electron microscopy. Histological pictures of all samples showed the neck and most of the screw body to be surrounded by new bone. The soft tissue surrounding the implant post included pocket epithelium and supra-crestal connective tissue displaying collagen fiber bundles comparable to gingival ligaments. These peri-implant collagen fiber bundles arose from the neighboring alveolar crest, root cementum of adjacent teeth or, superficially, from the epithelium and followed a circular array around the implant neck.