牙种植体周软组织的处理

牙种植体(以下简称种植体)周软组织形成的"袖口"、附着龈宽度、唇侧软组织丰满度和牙龈乳头状况都可影响种植体骨整合和美学效果.通过游离牙龈移植、带蒂牙龈移植、黏膜培养细胞移植法、异体脱细胞真皮基质移植法和正畸助萌法可增加种植体周附着龈宽度.美学区通常具有充足的附着龈,但其软组织形态和龈乳头高度等都可影响软组织整体美观效果,通过软组织切口设计、个别临时冠引导法、种植体牙龈乳头重建法和不翻瓣技术可保存或改善美学区软组织,实现种植美学修复.     

A technique for standardized evaluation of soft and hard peri-implant tissues in partially edentulous patients

BACKGROUND: There is a growing need to evaluate the esthetics of implant-supported crowns and bridges. An important tool for such an evaluation is standardized assessment of the soft and hard peri-implant tissue levels. METHODS: A simple acrylic device has been developed for reliable and reproducible assessment of soft and hard peri-implant tissues using standardized color slides and standardized dental x-rays. With this device, changes in both the soft and hard tissues around implant-supported crowns can be evaluated as a function of time. The reproducibility of the technique was tested on color slides as well as on dental x-rays in a series of implant-supported crowns and their neighboring teeth. RESULTS: The reproducibility of this technique was excellent. The measuring errors for repeated measurements of the soft and hard tissues were 0.14 +/- 0.02 mm and 0.13 +/- 0.01 mm, respectively. CONCLUSIONS: The device is a reliable tool to assess changes in both soft and hard tissues around crowns and implants over time. Likewise, it is suggested that this technique also can be used to objectively assess soft and hard tissue changes around natural teeth with or without prosthetic restorations.     

A modified impression technique for implant-supported restoration

An impression technique is proposed for construction of implant-borne restorations that uses a modified autopolymerizing resin custom tray to allow splinting of the impression copings directly to the tray. This method eliminates the use of the dental floss-autopolymerzing resin complex, thus decreasing resin distortion and simplifying the clinical procedures.     

Management of the peri-implant soft tissues

To provide a patient with an implant supported restoration that is functional and aesthetic requires effective diagnosis. Deficiencies in the bone and soft tissue can be dealt with in planning, and decisions can be made regarding what surgical corrections are indicated, and when these will be most effectively performed.     

A predictable and accurate technique with elastomeric impression materials

A method for obtaining more predictable and accurate final impressions with polyvinylsiloxane impression materials in conjunction with stock trays is proposed and tested. Heavy impression material is used in advance for construction of a modified custom tray, while extra-light material is used for obtaining a more accurate final impression.     

Management of prosthetic abutments respecting peri-implant soft tissues

Periodontal and peri-implant soft tissues are very similar in many aspects (phenotype, mucosal dimensions, biological width). In peri-implant tissue, the mucosal seal is localized apically to the gap existing between the fixture and the prosthetic abutment. This is due to mechanical trauma created by screwing and unscrewing the prosthetic components, to mechanical deformation produced under functional stress and to bacterial colonization. To reduce the effects of this gap on peri-implant soft tissues stability several options are available: supracresta fixture positioning, reduction of the fixture-abutment gap, and minimizing the prosthetic steps. A clinical case was illustrated. Abutments (Gingi-hue 3I with a fixture-abutment gap less than 2 mm and a fixture abutment angle rotation of 0.4 degrees ) were screwed on the fixtures after the second stage surgery and used as impression transfer. These abutments were prepared in the laboratory and definitively screwed after the impression session. The use of definitive abutments as transfer reduces the session number and allows the peri-implant soft tissues to heal without beeing troubled by screwing and unscrewing of the prosthetic components.     

Different types of inflammatory reactions in peri-implant soft tissues

Abstract The aim of the present study was to analyze some features of the peri-implant mucosa at sites in the dog model which had been exposed to plaque accumulation for periods up to 9 months. The experiment was carried out in 5 labrador dogs. The mandibular right and left 2nd, 3rd and 4th premolars (2P2, 3P3, 4P4) and the 1st molars (1M1) were extracted. Following a 3–month healing period, 3 titanium fixtures (Nobelpharma AB. Göteborg, Sweden) were installed in the edentulous premolar/molar regions. Abutment connection was performed 3 months later and a meticulous plaque control period of 3 months was initiated. A clinical examination was performed at the end of this preparatory period and a main study period of 9 months continued. During this period, the plaque control regimen was maintained in the mesial and central (left: L1, 2 and right: R1, 2) implant segments, whereas plaque was allowed to accumulate on the distal implants, i.e., L3 and R3. At the end of the main study period, i.e., 12 months after abutment connection, the clinical examination was repeated, the animals perfused and biopsies obtained. Semi-thin sections were produced for histo-metric and morphometric analyses. The peri-implant mucosa at implant sites exposed to daily and comprehensive plaque control at biopsy was clinically non-inflamed and the connective tissue lateral to a junctional epithelium was devoid of accumulations of inflammatory cells. On the other hand, termination of the plaque control program resulted in the accumulation of large amounts of plaque and calculus at the titanium abutments and the biopsies harvested from the implant sites after 9 months of plaque formation demonstrated an infiltrate which resided in the marginal portion of the peri-implant mucosa. The histological analysis of the biopsy material also revealed that an inflammatory cell infiltrate was consistently present at the level of borderline between the abutment and the fixture part of the implant. This infiltrate, called abutment ICT, occurred both at sites which had been exposed to plaque control and at sites at which plaque had been allowed to form during a 9–month interval. The histometric determinations disclosed that (i) the bone crest consistently was located about 1–1.5 mm “apical” of the abutment/fixture level, (ii) there was a zone, about 1 mm wide, of a normal non-infiltrated connective tissue that separated the apical portion of the abutment ICT and the bone crest. It is suggested that this infiltrate represents the efforts by the host to close off bacteria present within the implant system and that the establishment of an abutment ICT may explain the 1 mm bone loss observed during the course of the 1st year after bridge installation.     

A combination impression and occlusal registration technique for extension-base removable partial dentures.

The ultimate goal of a prosthodontic service is the placement and maintenance of prostheses which are in biologic and functional harmony with the supporting tissues and remaining teeth. The combination impression and occlusal registration technique minimizes clinical and technical procedures which might introduce errors. If accurately managed, this technique will provide optimum occlusion and mucosal support for extension-base removable partial dentures.     

Esthetic tunnel exposure: A combination technique for peri-implant soft tissue development at second-stage surgery

An esthetically pleasing result is the product of both prosthetic excellence and the health and quality of the soft tissue that frames the restoration. Management of the peri-implant coronal soft tissue is key to the ultimate success of treatment. This technique report describes an alternative, novel approach, combining established concepts and methods into a single technique to improve esthetic results.     

An accurate system of serially recording anterior open bite using a modified technique for impression taking and study model construction

A simple impression technique is described that enables the clinician to record an anterior open bite, to provide accurate study model construction, and to monitor the anterior open bite. A case is presented that illustrates this technique with subsequent monitoring over an 8-year period     

A modified technique to determine the tear energy of impression materials

A modified method to determine tear energy of impression materials is described. Trousers-shaped specimens were prepared between two platens. They are different from those used before in that a V-shaped line is created so as to guide tear growth, and the thickness gradually increases, then remains constant and, ultimately, decreases instantaneously. The specimens were tested at ten different rates between 0.2 and 50 cm/min. lambda can be computed from the force-time diagram. Six different materials were tested: two condensation silicones, Xantopren regular (Bayer, FRG) and Xantopren light; a polyvinylsiloxane, Reprosil regular (DeTrey, Switzerland); a polysulphide Coeflex regular (Coe, USA); a polyether, Impregum (Espe, FRG); and an alginate, Cavex, Fast Set, Dust Free (Keur & Sneltjes, The Netherlands). Tear strength (in kJ/m2) variations at rates between 0.2 and 50 cm/min are as follows: Xantopren regular, 0.37-0.64; Xantopren light, 0.29-0.46; Coeflex, 1.10-5.29; Reprosil, 0.66-1.07; Impregum, 0.62-1.04; Cavex, 0.22-0.37. These values are consistent with those reported before. It might be concluded that the new test method gives reliable tear energy values.     

Histological analysis of the Ankylos peri-implant soft tissues in a dog model

PURPOSE: The importance of the soft tissue-implant interface is enhanced by the presence of a microgap between the implant and the abutment, which represents a contamination site for bacteria. The aim of this study was to investigate the interface between the Ankylos gap-free implant system and the surrounding soft tissues in a dog model. MATERIALS AND METHODS: Six Labrador dogs were included in the study and two Ankylos implants were inserted per dog. The dogs were killed 6 months after abutment placement without functional loading and without plaque control. The implants were analysed histologically by scanning electron microscopy, light microscopy, and histomorphometry. RESULTS: Some sections exhibited histologic signs of a mild inflammation. The connective tissue between the most apical epithelial cells of the junctional epithelium and the alveolar crest was characterized by collagen fibers running from the periosteum and the alveolar crest toward the oral epithelium and, in front of the cone-shaped abutment, by a narrow zone of extracellular matrix with a few collagen fibers. CONCLUSION: Compared with results obtained in other studies using different types of implant (Astra, Br?nemark, ITI), the Ankylos implant showed a higher length and a larger width of connective tissue contact as well as a shorter epithelial downgrowth. The absence of a microgap in the Ankylos system could explain the histologic mild inflammation in the connective tissue.