The use of a porcine-derived collagen matrix for vertical soft tissue augmentation. A case report.

Soft tissue augmentation is a well-established procedure employed in a diverse range of applications such as soft tissue thickening, keratinized tissue augmentation, improvement of the esthetics of existing dental implants and teeth, and crestal bone preservation around implants. This case report describes a technique for the augmentation of vertically thin soft tissue in the lower jaw posterior area. At the time of the implant placement, after measuring the soft tissue thickness, soft tissues were augmented with a porcine accellular dermal matrix (Mucoderm, Botiss Biomaterials, Germany). After 2 months, during the second stage surgery, the implant was exposed and the soft tissue thickness was measured.

Bone augmentation and simultaneous soft tissue thickening with collagen tissue matrix derivate membrane in an aesthetic area. A case report.

Aesthetic implant restoration in the anterior maxilla is a challenge for clinicians. Alveolar ridge and surrounding gingiva deficiencies aggravates implant placement in the aesthetic area. This case report describes a technique for aesthetic single implant placement with simultaneous bone grafting and soft tissue thickening. At the time of implant surgery, allogenic (Maxgraft, Botiss Biomaterials, Germany) and xenogenic bone substitute (Cerabone, Botiss Biomaterials, Germany) was used for bone grafting, soft tissues were augmented simultaneously with collagen tissue matrix derivate membrane (Mucoderm, Botiss Biomaterials, Germany). After 4 months during second stage surgery the implant was exposed. Subsequently healing abutment was replaced with provisional crown for gingival contouring. An individual zirconia abutment was made and a cemented full-ceramic crown was placed for final restoration. The 12-month follow-up check-up revealed a pleasing aesthetic treatment outcome, as well as clinically healthy peri-implant soft tissues. Radiological examination showed a stable bone crest with minor bone remodelling around the implant platform. The use of an collagen tissue matrix derivate, simultaneously with GBR, in the aesthetic area can provide excellent results, by establishing and maintaining facial bone wall and thick soft tissue in aesthetic area.

Influence of Vertical Soft Tissue Thickness on Crestal Bone Changes Around Implants with Platform Switching: A Comparative Clinical Study.

BACKGROUND: Numerous studies have shown the superiority of platform-switched implants in preserving crestal bone as compared with platform-matched implants. However, the influence of initial soft tissue thickness on development of crestal bone loss has not been addressed in previous studies; thus, further research is needed. PURPOSE: To evaluate crestal bone levels around platform-switched implants placed in thin and thick mucosal tissue. MATERIALS AND METHODS: Eighty patients (38 male and 42 female, mean age 44 ± 3.34 years) received 80 bone-level implants of 4.1 mm in diameter with platform switching (Institut Straumann AG, Basel, Switzerland). Tissue thickness was measured, and cases were distributed to Group 1, with thin soft tissue (2 mm or less, n = 40), and Group 2, with thick tissue (more than 2 mm, n = 40). Implants were placed with a one-stage approach and restored with screw-retained restorations. Radiographic examination was performed after implant placement, 2 months after healing, after restoration, and at 1-year follow-up post-reconstruction. Crestal bone loss was calculated. The Mann-Whitney U-test was applied, and significance was set to p ≤ .05. RESULTS: Implants in Group 1 (thin tissue) showed 0.79 mm of bone loss after 2 months. After 1-year follow-up, bone loss was 1.17 mm. Implants in Group 2 (thick tissue) showed bone loss of 0.17 mm after 2 months of implant placement and 0.21 mm after 1-year follow-up. The differences between groups were significant (p < .001) at both time points. CONCLUSIONS: It can be concluded that platform switching does not prevent crestal bone loss if, at the time of implant placement, mucosal tissue is thin. In thick soft tissue, use of platform-switched implants maintained crestal bone level with minimal remodeling.

Clinical Factors Influencing Removal of the Cement Excess in Implant-Supported Restorations.

BACKGROUND: The depth of the cementation margin has an influence on the amount of cement remnants around implants. However, the role of other clinical factors is still not clarified. PURPOSE: The aim of the study was to evaluate the correlation between undetected cement and (i) location of the implant, (ii) implant diameter, and (iii) undercut. MATERIALS AND METHODS: Sixty-five patients were treated with single metal-ceramic restorations on implants. The undercut between the restoration and the tissue was measured. After cementation, the restoration-abutment unit was unscrewed. All quadrants of the specimens were photographed and analyzed. The ratio between total restoration area/peri-implant tissue area and area of cement remnants was calculated in pixels. Significance was set to 0.05. RESULTS: Sixty-five metal-ceramic restorations were placed on 65 implants (39 molars, 22 premolars, 4 anteriors; 21 implants had a diameter of 3.5 mm, 34 of 4.0 mm, 10 of 5.0 mm). An undercut of 1 mm was found in 118 sites, 2 mm in 96 sites, and 3 mm in 46. The percentages of soft tissue and restoration, respectively, covered by cement were as follows: molars 4% and 7%; premolars 3.8% and 7.3%; anteriors 3% and 3.4%; 3.5 mm diameter 3.3% and 7.4%; 4.0 mm 7.7% and 7.7%; 5.0 mm 3.9% and 2.1%; 1-mm undercut 3.5% and 5.4%; 2-mm 4% and 8.1%; 3-mm 4.8% and 8.4%. The relationship between amount of cement remnants and implant location was insignificant (p > 0.05) for both soft tissue and the specimen, but significant relationships with amount of cement remnants were found for diameter (p = 0.026 for soft tissue, p = 0.600 for specimen) and undercut (p = 0.004 for soft tissue, p = 0.046 for specimen). CONCLUSION: If cemented crown restoration is desired, undercuts should be reduced to a minimum for better removal of cement excess, irrespective of the diameter and location of the implants in the mouth.

The use of acellular dermal matrix membrane for vertical soft tissue augmentation during submerged implant placement: a case series.

OBJECTIVE: To evaluate the efficiency of acellular dermal matrix membrane to augment vertical peri-implant soft tissue thickness during submerged implant placement. MATERIAL AND METHODS: Forty acellular dermal matrix-derived allogenic membranes (AlloDerm, BioHorizons, Birmingham, AL, USA) and 42 laser-modified surface internal hex implants (BioHorizons Tapered Laser Lok, Birmingham, AL, USA) were placed in submerged approach in 40 patients (15 males and 25 females, mean age 42.5 ± 1.7) with a thin vertical soft tissue thickness of 2 mm or less. After 3 months, healing abutments were connected to implants, and the augmented soft tissue thickness was measured with periodontal probe. The gain in vertical soft tissue volume was calculated. Mann-Whitney U-test was applied and significance was set to 0.05. RESULTS: All 40 allografts healed successfully. Thin soft tissue before augmentation had an average thickness of 1.54 ± 0.51 mm SD (range, 0.5-2.0 mm, median 1.75 mm), and after soft tissue augmentation with acellular dermal matrix, thickness increased to 3.75 ± 0.54 mm SD (range, 3.0-5.0 mm, median 4.0 mm) at 3 months after placement. This difference between medians was found to be statistically significant (P < 0.001). Mean increase in soft tissue thickness was 2.21 ± 0.85 mm SD (range, 1.0-4.5 mm, median 2.0 mm). CONCLUSIONS: It can be concluded that acellular dermal matrix membrane can be successfully used for vertical soft tissue augmentation.

Does residual cement around implant-supported restorations cause peri-implant disease? A retrospective case analysis.

OBJECTIVES: The purpose of this study was to determine the relationship between patients with a history of periodontitis and development of cement-related peri-implant disease. MATERIALS AND METHODS: Seventy-seven patients with 129 implants for this retrospective analysis were selected from completed implant cases that were scheduled for regular maintenance or had experienced mechanical or biological complications between years 2006 and 2011 in private practice. Implants with extracoronal residual cement and implants without cement remnants were analyzed. The selected cases were further divided into two groups--implants in patients with history of periodontitis (1) and implants in periodontitis-free individuals (2). The selection of these groups was made on the basis of treatment history and orthopantomograph. As a control group, a set of 238 screw-retained implant restorations, delivered to 66 patients during the same period of time was examined. The incidence of peri-implant disease among implants in all groups was calculated. RESULTS: Peri-implant disease was evident in 62 of 73 implants with cement remnants (85%). All implants in group 1 developed peri-implantitis--4 early and 35 delayed disease cases. In the periodontally healthy group, 20 of 31 implants were diagnosed with peri-implant mucositis, 3 implants had early peri-implantitis, and 11 implants with cement remnants did not develop biological complications. In the group of implants without cement remnants, peri-implant disease was diagnosed in 17 of 56 cases (30%). In contrast, only two occurrences of peri-implant disease were registered in the control group of screw-retained restorations (1.08%). CONCLUSIONS: Implants with cement remnants in patients with history of periodontitis may be more likely to develop peri-implantitis, compared with patients without history of periodontal infection.

The influence of the cementation margin position on the amount of undetected cement. A prospective clinical study.

OBJECTIVE: To evaluate the amount of undetected cement after cementation and cleaning of implant-supported restorations. MATERIALS AND METHODS: Fifty three patients were treated with 53 single implant-supported metal-ceramic restorations. The subgingival location of the margin of each implant was measured with a periodontal probe mesially, distally, buccaly, and lingually(,) resulting in 212 measurements. The data were divided into four groups: equally with tissue level (14 samples), 1 mm subgingivally (56), 2 mm (74), and 3 mm (68) below tissues contour. Metal-ceramic restorations were fabricated with occlusal openings and cemented on standard abutments with resin-reinforced glass-ionomer. After cleaning, a radiograph was taken to assess if all cement had been removed. Then the abutment/crown unit was unscrewed for evaluation. All quadrants of the specimens and peri-implant tissues were photographed and analyzed with Adobe Photoshop. Two proportions were calculated: (1) the relation between the cement remnants area and the total area of the abutment/restoration and (2) the relation between the cement remnants and the total area of implant soft tissue contour. Significance set to 0.05. RESULTS: Excess on the crown groups: 1 (0.002 ± 0.001); 2 (0.024 ± 0.005); 3 (0.036 ± 0.004); 4 (0.055 ± 0.007). Undetected excess increased when the margin was located deeper subgingivally (P = 0.000), significant difference was found among all groups (P ≤ 0.05). Remnants in the soft tissue groups: 1 (0.014 ± 0.006); 2 (0.052 ± 0.011); 3 (0.057 ± 0.009); 4 (0.071 ± 0.012). The increase of the remnants was statistically reliable (P = 0.0045), significant difference was found between group 1 and 2 (P ≤ 0.05). Radiographic evaluation showed that cement remnants mesially were visible in four cases of 53 or 7.5%, and in six cases of 53 distally (11.3%). CONCLUSIONS: The deeper the position of the margin, the greater amount of undetected cement was discovered. Dental radiographs should not be considered as a reliable method for cement excess evaluation.

The influence of implant placement depth and impression material on the stability of an open tray impression coping.

STATEMENT OF PROBLEM: Subgingival positioning of a single dental implant may result in a less stable impression coping in a polymerized impression material. PURPOSE: The purpose of this study was to evaluate the influence of a single dental implant placement depth and different impression materials on the stability of an open tray impression coping. MATERIAL AND METHODS: Six polyvinyl chloride-based plastic models with single embedded internal hexagon implant analogs were fabricated. The implant analogs were placed equally with their surface 0, 1, 2, 3, 4, or 5 mm below the simulated gingival margin. Open tray impression copings were connected to the embedded implant analogs, and impressions were made with different vinyl polysiloxane (VPS) impression materials, polyethers, and an addition silicone-based occlusal registration material. The laboratory analogs were connected to the impression copings and the plastic trays were placed in a locking device. A measuring device, consisting of a compression force gauge connected to a platform moving at a speed of 3.2 mm/s, was fabricated. The impression trays were fixed so that the pole of the force gauge would touch the surface of the implant analog in the same place and push it 1.0 mm. Measurements of each specimen were made 5 times. Statistical analysis was performed with a 1-way ANOVA, the Tukey test, and the Pearson correlation coefficient (α=.05). RESULTS: There was a significant negative correlation between the dental implant placement depth and the force needed to move the impression coping (P<.05). In all depth groups, the impression coping was significantly more stable when the impressions were made with the occlusal registration material (P<.05). CONCLUSIONS: As the dental implant placement depth increased, the force needed to move the impression coping decreased. The coping was significantly more stable when an occlusal registration material was used to make the impression.

Influence of the temperature on the cement disintegration in cement-retained implant restorations.

The aim of this study was to estimate the average disintegration temperature of three dental cements used for the cementation of the implant-supported prostheses. One hundred and twenty metal frameworks were fabricated and cemented on the prosthetic abutments with different dental cements. After heat treatment in the dental furnace, the samples were set for the separation to test the integration of the cement. Results have shown that resin-modified glass-ionomer cement (RGIC) exhibited the lowest disintegration temperature (p<0.05), but there was no difference between zinc phosphate cement (ZPC) and dual cure resin cement (RC) (p>0.05). Average separation temperatures: RGIC - 306 ± 23 °C, RC - 363 ± 71 °C, it could not be calculated for the ZPC due to the eight unseparated specimens. Within the limitations of the study, it could be concluded that RGIC cement disintegrates at the lowest temperature and ZPC is not prone to break down after exposure to temperature.

The influence of margin location on the amount of undetected cement excess after delivery of cement-retained implant restorations.

OBJECTIVES: The aim of this study was to evaluate the amount of the residual cement excess after cementation and cleaning of implant-supported restorations with various positions of the margins. MATERIAL AND METHODS: Twenty-five casts with embedded implant analogs and flexible soft-tissue imitation were used in the study. Individual abutments with different position of the margin - from 1 mm supragingivally to 3 mm below the gingival level - were modelled and divided equally into five groups. The same amount of polished metal crowns was luted to prosthetic abutments, excess cement was cleaned and the restorations were removed for evaluation of the undetected cement remnants. All quadrants of each specimen were photographed for calculation of the ratio between the cement remnants area and the total specimen area using Adobe Photoshop. Afterwards, cement remnants were cleared from each specimen and weighed with analytical balances. RESULTS: The measurements in all the groups consisted of (1) the relation between the cement remnants area and the total area of the specimen; and (2) cement excess weight in grams after cleaning: group 1 (0.0111 ± 0.021; 0.0003 ± 0.0001 g); group 2 (0.0165 ± 0.019; 0.0008 ± 0.0003 g); group 3 (0.0572 ± 0.028; 0.0013 ± 0.0005 g); group 4 (0.1158 ± 0.054; 0.0051 ± 0.0013 g); and group 5 (0.1171 ± 0.059; 0.0063 ± 0.0021 g). Results showed significant increase of undetected cement quantity, as the restoration margins were located deeper subgingivally, using weighting (P=0) and calculation of proportion (P=0). There was a significant correlation between evaluation techniques (r=0.889; P=0). CONCLUSIONS: The amount of residual cement after cleaning increased as the restoration margins were located more subgingivally.