Soft tissue development around abutments with a circular macro-groove in healed sites of partially edentulous posterior maxillae and mandibles: a clinical pilot study.
ABSTRACT The aim of this study was to evaluate soft tissue development at concave circular macro-grooved titanium abutments in healed sites.
In a split-mouth pilot study 10 patients received two implants each at healed posterior sites in contralateral maxillary or mandibular jaw quadrants. Either circular macro-grooved concave study abutments or conventional convex control abutments were immediately provisionalized and received permanent crowns 3 months postimplantation. Marginal bone level, papilla index, modified plaque and bleeding index were recorded. The esthetic outcome was evaluated with standardized perpendicular pictures according to the Pink Esthetic Score (PES). Statistical analysis included the description of all variables by mean value, standard deviation and range. PES values were compared using the Wilcoxon signed rank test for paired data.
Cumulative survival rate for all 20 implants was 100%. At the 1-year follow-up, there was no statistical significant difference of marginal bone levels between sites restored with the study (-0.11 ± 0.77 mm) vs. the control (-0.34 ± 0.53 mm) abutments (P>0.05). Esthetic evaluation (PES) revealed statistically significant differences in scores between the study group [study abutment group] (7.2 ± 2.82, 8 ± 1.89) and the control group [control abutment group] (9.5 ± 1.58, 10.5 ± 1.72) at the time of prosthetic delivery and the 1-year follow-up. Whereas PES scores for mesial papilla at control sites at the 1-year follow-up demonstrated statistically significant higher values, both soft tissue level and soft tissue contour at control sites revealed statistically significantly higher PES values (P<0.05) at time of prosthetic delivery and at 1-year follow-up when compared with study sites.
Concave macro-grooved abutments in healed posterior maxillary and mandibular sites did not exhibit a superior soft tissue development compared with standard convex abutments.
- [show abstract] [hide abstract]
ABSTRACT: The objective of the present study was to determine the dimension of the mucosal-implant attachment at sites with insufficient width of the ridge mucosa. 5 beagle dogs were used. Extractions of all mandibular premolars were performed and 3 months later, 3 fixtures of the Branemark System were installed in each side. Following 3 months of healing, abutment connection was carried out. On the right or left side of the mandible, abutment connection was performed according to the Branemark System manual (control side). On the contralateral side (test side), an incision not extending through the periosteum was made at the crest of the ridge. The soft tissue was dissected and a critical amount of connective tissue on the inside of the flap was excised. The periosteum was subsequently incised, abutment connection performed, and the trimmed flaps sutured. The sutures were removed after 10 days. After a 6-month period of plaque control, the animals were sacrificed, biopsies sampled and processed for light microscopy. The length of the junctional epithelium varied within a rather narrow range; 2.1 mm (control side) and 2.0 mm (test side). The height of the suprabony connective tissue in this model varied between 1.3+/-0.3 mm (test side) and 1.8+/-0.4 mm (control side). At sites where the ridge mucosa prior to abutment connection was made thin (< or = 2 mm), wound healing consistently included bone resorption. This implies that a certain minimum width of the periimplant mucosa may be required, and that bone resorption may take place to allow a stable soft tissue attachment to form.Journal Of Clinical Periodontology 10/1996; 23(10):971-3. · 3.69 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The oral, oral sulcular, and junctional epithelia of the natural gingiva each possess distinct patterns of differentiation that are demonstrable both ultrastructurally and by their individual patterns of macromolecular synthesis. The supracrestal tissues reformed around oral implants structurally resemble those of natural gingiva but little is known about phenotype changes occurring in the epithelia. To investigate whether peri-implant epithelia acquire similar patterns of differentiation to those of natural gingiva, biopsies from the supracrestal regions of five oral implants were examined by immunofluorescent methods using a panel of monoclonal antibodies with specificities for individual cytokeratins and ICAM-1, macromolecules which act as markers of the three gingival epithelial phenotypes. The observed staining patterns indicated the formation of oral, oral sulcular, and junctional epithelia which were phenotypically indistinguishable from those of natural gingival epithelia. This degree of reprogramming of epithelial gene expression is a surprising observation and the potential mechanisms leading to the development of those new epithelial phenotypes are discussed in the context of what is known about the development of natural gingiva, in terms of the possible effects of inflammation, and in relation to the known connective tissue influences on epithelial differentiation.Journal of Periodontology 12/1995; 66(11):933-43. · 2.40 Impact Factor
- [show abstract] [hide abstract]
ABSTRACT: The aim of this study was to longitudinally evaluate alterations in the position of the periimplant soft tissue margin, occurring during a 2-year period after insertion of fixed prostheses. 41 patients, subjected to treatment with partial or full-arch implant supported fixed prostheses based on a total of 163 standard Brånemark oral implants, were included in the study. A baseline examination was performed at time of insertion of the prosthetic construction and involved assessments of plaque, mucositis, probing depth, bleeding on probing marginal soft tissue level, width of masticatory mucosa and marginal soft tissue mobility. All patients were re-examined after 6 months, and after 1 and 2 years, respectively. A regression analysis was performed to evaluate if alterations, occurring in the position of the periimplant soft tissue margin during the 2 years, could be predicted by various variables recorded at time of the installation of the fixed prosthesis. The descriptive analysis showed a slight decrease in mean probing depth (0.2 mm) and width of masticatory mucosa (0.3 mm) during the follow-up period. Apical displacement of the soft tissue margin mainly took place during the first 6 months of observation. Lingual sites in the mandible showed the most pronounced soft tissue recession, decrease of probing depth, and decrease of width of masticatory mucosa. The statistical analysis revealed that lack of masticatory mucosa and mobility of the periimplant soft tissue at time of bridge installation were poor predictors of soft tissue recession occurring during the 2 years of follow-up, but indicated in greater amount of recession in women than men, in the mandible than in the maxilla, at lingual than at facial sites and with increased initial probing depth. It was suggested that the recession of the periimplant soft tissue margin mainly may be the result of a remodelling of the soft tissue in order to establish "appropriate biological dimensions" of the periimplant soft tissue barrier, i.e., the required dimension of epithelial-connective tissue attachment in relation to the faciolingual thickness of the supracrestal soft tissue.Clinical Oral Implants Research 01/1997; 7(4):303-10. · 3.43 Impact Factor