6 mm short versus 11 mm long inter-foraminal implants in the full-arch rehabilitation of edentulous non-atrophic mandibles: 5-year results from a multicenter randomized controlled trial.

OBJECTIVE: The aim of this multicenter parallel-group randomized controlled trial is to compare, in the same clinical scenario, 6 mm short with 11 mm long implants for the rehabilitation of completely edentulous non-atrophic mandibles. MATERIALS AND METHODS: Thirty patients in three study centers received a fixed full-arch mandibular rehabilitation supported by five inter-foraminal implants, with no need for bone augmentation procedures. Patients were randomly allocated (1:1 ratio), at the time of surgery, to test (6 mm implants) or control group (11 mm implants). After 3 months, a screw-retained full-arch prosthesis was positioned (baseline). Peri-implant marginal bone level change (MBLc, primary outcome) together with implant and prosthesis survival rate, and biological/technical complications (secondary outcomes) were evaluated up to 5 years. RESULTS: Twenty seven patients were controlled at 5 years (3 drop-outs). No implant or prosthesis loss occurred. No significant intergroup difference for biological/technical complications (p > .05, Fisher's exact test) and no significant intragroup and intergroup difference in the MBLc values were registered (test -0.03 ± 0.17 mm and control -0.13 ± 0.32 mm at 5-years; p > .025, one-sided Mann-Whitney U-test). CONCLUSIONS: When used in comparable anatomic, surgical, and prosthetic conditions, no difference in the clinical and radiographic outcomes between 6-mm and 11-mm implants was observed at 5 years of follow-up. Short implants showed to be a reliable option for the rehabilitation of completely edentulous non-atrophic mandibles. There is growing clinical evidence supporting the use of short implants, even in the case of non-atrophic sites.

Occurrence of complications in patients restored with implants.

OBJECTIVES: To determine the occurrence and clustering of complications in subjects restored with fixed implant-supported prostheses. METHODS: In the present retrospective case series, 241 subjects treated at one clinical centre and provided with 729 implants were included. A clinical and radiographic examination was performed after a mean follow-up period of 4.8 ± 2.0 years. Additional information on occurrence of technical (chipping, loss of retention, fracture of components) and biological complications (marginal bone loss, implant loss) during follow-up was extracted from patient records. For each type of complication and complications overall, regression analyses were performed to identify potential risk factors. Cox regression analyses were used to evaluate time to event for implant loss and technical complications. RESULTS: In all, 30% of the 241 patients presented with at least one complication of technical and/or biological character during the follow-up period. Technical complications affected 19.5% of subjects, while 14.1% presented with marginal bone loss >2 mm. Implant loss occurred in 4.6% of subjects. While technical complications were noted already early during the maintenance period (<1200 days), implant loss typically occurred during a later phase. A small subgroup of subjects (7.9%) experienced more than one type of complication. CONCLUSIONS: Complications occurred frequently and the most common type of complication was of technical character. Technical and biological complications occurred independently of each other.

Fixed full-arch maxillary prostheses supported by four versus six implants with a titanium CAD/CAM milled framework: 3-year multicentre RCT.

OBJECTIVES: This RCT compares marginal bone level (MBL) change and the clinical parameters after a 3-year function in maxillary implant-supported fixed complete dentures (FCDs) treated with four-implants (4-I) or six-implants (6-I). MATERIAL AND METHOD: Three centres treated 56 patients with 280 implants allocated to the 4-I or 6-I group. Radiographic and clinical examinations were performed. The primary outcome was to investigate MBL change between the groups. RESULTS: Implant survival rates were 100% and 99% in the 4-I and 6-I groups, respectively. Considering the clustering effects, the MBL change was not significantly different between the groups over the 3-year follow-up. The MBL in the 4-I group was 0.30 ± 0.50 mm at baseline, 0.24 ± 0.31 mm at 1 year and 0.24 ± 0.38 mm at 3 years. In the 6-I group, MBL was 0.14 ± 0.32 mm at baseline, 0.16 ± 0.35 mm at 1 year and 0.12 ± 0.26 mm at 3 years. There was a statistically significant difference between the groups at BL and 3Y. No significant differences between the groups were reported for clinical parameters at each time point as well as in between the visits. The technical and biological complications rates were 1.6% and 6.0%, respectively. Prosthetic complications affected 25 FCDs (47.2%). CONCLUSION: Marginal bone level change revealed a stable condition in the 3-year period in the two groups. Few technical and biological complications occurred apart from the chipping/fracture of the prosthetic teeth. Four-implant is a feasible solution if the rehabilitation is oriented towards the most cost-effective treatment and towards avoiding bone augmentation procedures. Clinicians have to consider the potential required visits for prosthetic maintenance.

CAD/CAM Implant Abutments: Peri-implant Hard and Soft Tissue Response with Up to 4 Years of Follow-up- A Retrospective Cohort Study Evaluation.

This retrospective study evaluated hard and soft tissue response and reported mechanical and technical complications around computer-aided design/computer-assisted manufactured (CAD/CAM) abutments. A total of 123 patients restored with titanium, gold-hue titanium, and zirconia CAD/CAM abutments were included (N = 291). Each patient was followed up for at least 2 years. Clinical and radiographic parameters were assessed annually and complications were recorded. No implant or reconstruction failures were reported. One fracture of a zirconia abutment occurred. The prosthetic survival rate after 4 years of function for restorations and abutments was 100% and 99.66%, respectively. No significant differences in biologic and radiographic indices were found. The bleeding on probing index was positive at 42% of implant sites, and it had no significant correlation with the overall change in marginal bone level (0.02 mm) of bone gain. The short-term survival of CAD/CAM abutments was reliable, no matter of the material used for manufacturing.

6-mm-short and 11-mm-long implants compared in the full-arch rehabilitation of the edentulous mandible: A 3-year multicenter randomized controlled trial.

OBJECTIVE: The aim of this multicenter parallel-group randomized controlled trial is to compare 6-mm-short with 11-mm-long implants in the rehabilitation of totally edentulous mandible in a completely comparable clinical situation, from anatomical, surgical, and prosthetic point of view. MATERIAL AND METHODS: Thirty patients were selected in three study centers to receive a fixed full-arch mandibular rehabilitation supported by five inter-foraminal implants. Patients were randomly allocated, at the time of surgery, half to the test group (6-mm-long implants) and half to the control group (11-mm-long implants). No bone augmentation procedure was performed. After 3 months, a screw-retained full-arch prosthesis with distal cantilevers was positioned (baseline). Peri-implant marginal bone level change (MBLc), implant and prosthesis survival rate, and biological/technical complications were evaluated after 1 and 3 years. RESULTS: Thirty subjects (150 implants) were evaluated after 1 year and 28 (140 implants) after 3 years. No implant or prosthesis loss occurred. No significant inter-group difference for biological/technical complications was registered. No statistically significant (p > .025) intra-group or inter-group difference in the mean MBLc values was registered. The mean MBLc was 0.01 ± 0.19 mm and -0.04 ± 0.21 mm at 1 year, and -0.10 ± 0.24 mm and 0.02 ± 0.25 mm at 3 years (test and control groups, respectively). CONCLUSIONS: 6-mm-short implants may be a reliable option when used in the rehabilitation of total edentulous mandibles. These results need to be confirmed by longer follow-up data from well-designed randomized controlled clinical trials.

Patient satisfaction and clinical outcomes in implant-supported overdentures retained by milled bars: Two-year follow-up.

OBJECTIVES: This observational clinical study evaluated the patient satisfaction and the clinical outcomes of edentulous arches rehabilitated with overdentures retained by CAD-CAM milled titanium bars. MATERIALS AND METHODS: Edentulous patients were treated with a full-arch removable overdenture anchored on two milled bars based on a friction retention system. Patient satisfaction was tested using the validated Oral Health Impact Profile (OHIP-14) questionnaire at the pre- and post-treatment visits, up to two years after prosthesis delivery (possible score range: 0-56. Best: 0). The prosthodontist satisfaction was also assessed through a designed questionnaire (best possible range 0-4. Best:0). Radiographic and clinical examinations were performed at baseline and after 2 years of function. Implant and prostheses complications were recorded. RESULTS: Forty (25 mandible) edentulous patients, mean age 69 ± 9.5 (SD) (52% males, 10% smokers), were treated with a total of 185 implants. The mean difference between pre- and post-treatment OHIP-14 score was 20.6 ± 8.0 (P < 0.0001) showing a high level of satisfaction for aesthetics, functional and psychological outcomes. This perception was not influenced by patient's age or gender. The clinicians' mean score was 3.4 ± 4.0. There was a marginal bone level (MBL) gain of 0.02 ± 0.22 mm between the two time points. Minor complications were reported in five patients. CONCLUSIONS: This procedure may lead to satisfaction regarding aesthetics and mastication function. One of the most relevant aspects is the versatility, which allows selection of the most suitable treatment option according to patient needs. The prosthodontist satisfaction questionnaire showed that this procedure met the clinical expectations.

Clinical Evidence of OsseoSpeed EV Implants: A Retrospective Study and Characterization of the Newly Introduced System.

This retrospective study sought to compare a new implant (Astra Tech OsseoSpeed EV) with its predecessor (Astra Tech OsseoSpeed TX) by scanning electron microscopy and interferometry. Radiographic data from 19 patients who underwent implant restoration with EV (n = 49) with a median follow-up of 16 months were evaluated for mean bone level (MBL) changes from delivery of the definitive prosthesis. EV and TX did not differ in surface roughness, and both systems had a tight seal at the implant-abutment interface. The median MBL change of the EV was -0.02 mm mesiodistally after a median follow-up period of 16 months. Greater maintenance of MBL was found in the screw-retained restorations (n = 17) compared to cemented (0.35 ± 0.33 mm and -0.38 ± 0.76 mm, respectively; P = .03). The data suggest that EV shows minimal levels of bone loss and high implant survival.

Effect of socket grafting with deproteinized bone mineral: An RCT on dimensional alterations after 6 months.

OBJECTIVE: To examine if (i) characteristics of the fresh extraction socket site influenced subsequent dimensional alterations and (ii) placement of deproteinized bovine mineral in the socket affected volumetric change during healing. MATERIALS AND METHODS: Twenty seven subjects and 28 extraction sites were included. Immediately after the removal of the tooth and after 6 months of healing, stone and virtual models of the jaw were produced. A cone beam computerized tomography scan was obtained immediately after extraction and the thickness of the buccal bone wall at the extraction site was measured. Extraction sites were randomly assigned to test or control group. In the test group, extraction sockets were filled with deproteinized bone mineral and covered with a collagen membrane. In the control group, only a collagen membrane was placed. RESULTS: The thickness of the buccal bone wall at the extraction site influenced the amount of volume reduction that occurred. Socket grafting influenced the degree of ridge diminution only at sites where the buccal bone wall was thin (≤ 1 mm). CONCLUSION: A graft comprised of collagen-enriched deproteinized bovine bone mineral, placed to fill extraction sockets failed to influence the overall diminution of the ridge that occurred during healing. The thickness of the buccal bone wall apparently had a significant influence on volumetric alterations of the edentulous ridge following tooth extraction.

Bone loss at implants and teeth in the same inter-proximal unit: A radiographic study.

OBJECTIVE: This study was performed to determine whether the distance between an implant and a tooth present in an inter-proximal unit influenced the amount of marginal bone loss that occurred at the two facing (adjacent) surfaces. MATERIALS AND METHODS: One hundred and eighty patients with a total of 278 inter-proximal units were included. Radiographs of implants that also included adjacent (facing) natural tooth/teeth were digitalized, and various linear measurements were performed using a software program. The marginal bone level and the bone level change that had occurred during a mean of 5.8 years were assessed as well as distance between the implant and the adjacent tooth/teeth. RESULTS: The mean amount of additional marginal bone loss that took place during the observation period was about 0.4 mm at both implants and adjacent tooth surfaces. The horizontal distance between an implant and the facing tooth did not influence the amount of marginal bone loss that had occurred. In most inter-proximal units, more advanced bone loss (>1 mm, >2 mm) had ensued either at the implant or at the facing tooth surface. Advanced additional bone loss occurred at both the implant and the tooth in only about 3% of the examined subjects. CONCLUSION: Bone loss at implants and teeth appears to be a site-specific phenomenon and not dependent on the inter-proximal distance.

Clinical Considerations of Adapted Drilling Protocol by Bone Quality Perception.

PURPOSE: To evaluate insertion torque value (ITV) and marginal bone loss (MBL) of an implant system after a clinically perceived bone quality-adapted drilling. MATERIALS AND METHODS: This multicenter retrospective study included patients treated with implants, conventionally loaded, in completely healed sites. Operators customized the osteotomy preparation according to radiographic assessment and their perception of bone quality. Drilling sequence, bone quality, and ITV were recorded at the time of surgery. Radiographs were taken at the time of implant placement and permanent restoration. MBL between implant placement and permanent restoration was calculated. The implant was used as the statistical unit. Demographic and implant characteristics were shown by means of descriptive statistics. Outcome values were compared using analysis of variance (ANOVA) and Kruskal-Wallis tests. Multiple regression models were used to test the effect of independent variables on ITV and MBL. RESULTS: One hundred eighty-eight implants placed in 87 patients were included in the analysis. The mean observation period was 144 ± 59 days. The mean ITV was 30.8 ± 15.1 Ncm. ITV differed significantly based on arches (mandible/maxilla) (P = .001), bone quality (P < .001), implant diameter (P = .032), and drilling protocol (P = .019). Median MBL was 0.05 mm (0.00; 0.24). A significant difference was found between the mandible and maxilla (P = .008) and between drilling protocols (P = .011). In particular, significantly higher MBL was found in the undersized drilling protocol. Multiple regression analysis showed that ITV was influenced by bone quality and implant diameter. MBL was influenced by bone quality, implant diameter, ITV, and the interaction between bone quality and ITV. It was estimated that MBL was greater with increased bone density and ITV. CONCLUSION: Excessive ITV in dense bone can cause negative marginal bone responses. A presurgical radiographic assessment and the perception of bone quality are necessary to select an optimal drilling protocol and to minimize surgical trauma.

Bone loss at implants and teeth in the same segment of the dentition in partially dentate subjects.

BACKGROUND: Some studies have indicated that marginal bone loss at implants and at teeth are similar, while results from other studies showed that implants lost more bone than teeth in the same dentition. AIM: To determine the amount of progressive marginal bone loss that had occurred at implants and teeth in the same segment of the dentition following implant placement in partially dentate subjects. MATERIAL AND METHODS: A total of 217 patients with a total of 573 implants and 318 teeth present in the same segments of the dentition were included. Radiographs were available from 1 year (baseline) and ≥3 years after loading. RESULTS: The mean bone loss that occurred between the two examinations was at implants 0.42 ± 0.68 mm and at teeth 0.44 ± 0.52 mm. Thirty-eight subjects (18%) had ≥1 implant exhibiting >1 mm bone loss. Bone loss at the 148 implants in this category of patients was 1.30 ± 1.04 mm with a corresponding loss at the 69 teeth of 0.53 ± 0.62 mm. Eighteen subjects (8%) had ≥1 tooth that exhibited >1 mm bone loss. The mean amount of bone loss in this sample was 1.37 ± 0.87 mm (38 teeth) and 0.29 ± 0.31 mm (56 implants). CONCLUSIONS: This study showed that marginal bone loss at implants and teeth in many partially dentate subjects might be independent phenomena.

The effect of placing a bone replacement graft in the gap at immediately placed implants: a randomized clinical trial.

OBJECTIVE: To assess the added value of using a bone replacement graft in combination with immediate implants in reducing the bone dimensional changes occurring in the residual ridge. MATERIAL AND METHODS: Randomized parallel controlled clinical trial to study the efficacy of grafting with demineralized bovine bone mineral with 10% collagen (DBBM-C) in the gap between the implant surface and the inner bone walls when the implants were immediately placed in the anterior maxilla. The changes between implant placement and 16 weeks later in the horizontal and vertical crestal bone changes in relation to the implant were evaluated through direct bone measurements using a periodontal probe. Mean changes were compared between the experimental and control sites using parametric statistics. RESULTS: A total of 86 implant sites in 86 subjects were included in the analysis (43 in the test group and 43 in the control group). The horizontal crest dimension underwent marked changes during healing mainly at the buccal aspect of the alveolar crest where this reduction amounted to 1.1 (29%) in the test group and 1.6 mm (38%) in the control group, being these statistically significant (P = 0.02). This outcome was even more pronounced at sites in the anterior maxilla and with thinner buccal bone plates. CONCLUSIONS: In conclusion, the results from this clinical trial demonstrated that placing a DBBM-C bone replacement graft significantly reduced the horizontal bone resorptive changes occurring in the buccal bone after the immediate implantation in fresh extraction sockets.

Biomechanical, Biologic, and Clinical Outcomes of Undersized Implant Surgical Preparation: A Systematic Review.

PURPOSE: To compile the current evidence on biomechanical, biologic, and clinical outcomes of undersized surgical preparation protocols in dental implant surgery. MATERIALS AND METHODS: An electronic search using three different databases (PubMed, Web of Science, and Cochrane Library) and a manual hand search were performed including in vitro, animal, and clinical studies published prior to October 2015. Studies in which an undersized drilling protocol was compared with a nonundersized drilling protocol were included. RESULTS: From an initial selection of 1,655 titles, 29 studies met the inclusion criteria, including 14 biomechanical, 7 biologic, 6 biologic and biomechanical, and 2 clinical. Due to methodologic variation, meta-analysis was not performed. Several studies showed that implants inserted with an undersized drilling approach reached a significantly higher insertion torque value than conventional drilling in low-density substrates, while this effect is less evident if a thick cortical layer is present. Similar results in terms of boneto-implant contact (BIC) were achieved in the longer term between implants inserted with undersized and nonundersized protocols. Results in the short term were inconclusive. Clinical studies did not show negative outcomes for undersized drilling, although clinical evidence was sparse. No data are available on marginal bone loss. CONCLUSION: From the biomechanical standpoint, an undersized drilling protocol is effective in increasing insertion torque in low-density bone. Biologic response in long-term healing after undersized implant placement is comparable to that in the nonundersized surgical drilling protocol. Clinical studies indicate that performing an undersized drilling protocol on low-density bone is a safe procedure; however, more extensive studies are needed to confirm these data.

Multicenter Clinical Randomized Controlled Trial Evaluation of an Implant System Designed for Enhanced Primary Stability.

PURPOSE: This intention-to-treat (ITT) non-inferiority multicenter study was performed to evaluate implant system design, surgical and prosthetic aspects, and the effect on marginal bone levels of two related implant systems. Implant design alterations consisted of modifications in implant body shape and abutment connections. Drilling procedures and drill design were adapted to the implant design. MATERIALS AND METHODS: Five clinics participated in this study; all had institutional review board approval. Two versions of the implant system were used: test and predicate. One hundred twenty partially dentate subjects with healed sites were randomized to either test or predicate implants. Fifty-nine subjects received 79 test implants and 61 received 87 predicate implants. Bone classification, insertion torque values (ITV), and the surgeon's perception of primary stability were recorded. Definitive restorations with a titanium abutment were made approximately 6 to 8 weeks following implant placement. All restorations were cement retained. Marginal bone levels were evaluated on radiographs at implant placement, at restoration, and at 6 and 12 months postloading. RESULTS: Most subjects received one implant placed in the premolar or molar area (95% of sites). Fifty-three percent of the implants were placed in the maxilla. Median ITV at placement was 31 ± 13 Ncm for the test system and 22 ± 9 Ncm for predicate system, respectively. Time to loading was similar (test, 63.1 ± 24.8; predicate, 62.9 ± 26.9 days). Mean marginal bone loss 12 months after functional loading was 0.07 ± 0.73 mm in the test group and 0.03 ± 0.84 mm in the predicate group, with no statistically significant difference (P = .6895). Five implants were lost (four test, one predicate) from implant placement, all within the first 8 weeks following placement; none were restored. The 1-year postloading cumulative implant survival rate was 94.9% (73 implants at risk) for the test system and 98.9% (84 implants at risk) for the predicate system. CONCLUSION: Treatment with the test implant system, utilizing its bone classification for guidance regarding drilling protocol, resulted in enhanced implant stability. Marginal bone levels were stable 12 months after functional loading.

Soft tissues stability of cad-cam and stock abutments in anterior regions: 2-year prospective multicentric cohort study.

AIM: Aim of this study was to verify if the type of implant abutment manufacturing, stock or cad-cam, could influence the maintenance of stable gingival margins around single restorations in anterior areas. METHODS: After 16 weeks of healing, implants (Osseospeed, Astra Tech Dental Implant) were positioned. Depending on the different fixture inclination and the thickness of buccal peri-implant soft tissue, abutment selection resulted in four groups: Group 1 (patients with zirconia ZirDesign(®) stock abutments), Group 2 (titanium stock TiDesign(®) abutments), Group 3 (zirconia cad-cam abutments), and Group 4 (titanium cad-cam abutments). The following parameters were assessed: buccal gingival margin modification (BGM). The modification of the implant gingival margin was followed at 1 and 2 years of follow-up. A computerized analysis was performed for measurements. Differences between soft tissue margin at baseline and after 2 years measured the gingival margin recession. A general linear model was used to evaluate each group in relation to gingival recession after two years. Tukey's post hoc test was used to compare the mean REC indexes of each group of abutments. RESULTS: Seventy-two healthy patients (39 males and 33 females; mean age of 46 years) scheduled for single gap rehabilitation in anterior areas were enrolled. A 100% of implant survival rate was observed after 24 months of function. One failure occurred due to fracture of a Zirconia cad-cam abutment. Moreover, two abutment screw unscrewing were observed. Both for zirconia and titanium stock abutments (Group 1 and 2), the mean recession of implant buccal soft tissue was of 0.3 mm (SD of 0.3 and 0.4 mm, respectively). Soft tissue mean recession of zirconia and titanium cad-cam abutments (Group 3 and 4) was of 0.1 and -0.3 mm, respectively (SD of 0.3 and 0.4 mm, respectively). REC values of cad-cam titanium abutments (Group 4) were significantly lower than that of Group 1 (-0.57 mm), Group 2 (-0.61 mm), and Group 3 (-0.40 mm), respectively (Table 4). CONCLUSION: In the anterior area, the use of cad-cam abutments is related to a better soft tissue stability. Such a relationship is significant if cad-cam titanium abutments are compared to both titanium and zirconia stock abutments.

A prospective, randomized, controlled study using OsseoSpeed™ implants placed in maxillary fresh extraction socket: soft tissues response.

PURPOSE: The aim of this work was to study the peri-implant soft tissues response, by evaluating both the recession and the papilla indexes, of patients treated with implants with two different configurations. In addition, data were stratified by tooth category, smoking habit and thickness of buccal bone wall. MATERIALS AND METHODS: The clinical trial was designed as a prospective, randomized-controlled multicenter study. Adults in need of one or more implants replacing teeth to be removed in the maxilla within the region 15-25 were recruited. Following tooth extraction, the site was randomly allocated to receive either a cylindrical or conical/cylindrical implant. The following parameters were studied: (i) Soft tissue recession (REC) measured by comparing the gingival zenith (GZ) score at baseline (permanent restoration) with that of the yearly follow-up visits over a period of 3 years (V1, V2 and V3). (ii) Interdental Papilla Index (PI): PI measurements were performed at baseline and compared with that of the follow-up visits. In addition, data were stratified by different variables: tooth category: anterior (incisors and canine) and posterior (first and second premolar); smoking habit: patient smoker (habitual or occasional smoker at inclusion) or non-smoker (non-smoker or ex-smoker at inclusion) and thickness of buccal bone wall (TB): TB ≤ 1 mm (thin buccal wall) or TB > 1 mm (thick buccal wall). RESULTS: A total of 93 patients were treated with 93 implants. At the surgical re-entry one implant was mobile and then removed; moreover, one patient was lost to follow-up. Ninety-one patients were restored with 91 implant-supported permanent single crowns. After the 3-year follow-up, a mean gain of 0.23 mm of GZ was measured; moreover, 79% and 72% of mesial and distal papillae were classified as >50%/ complete, respectively. From the stratification analysis, not significant differences were found between the mean GZ scores of implants with TB ≤ 1 mm (thin buccal wall) and TB > 1 mm (thick buccal wall), respectively (P < 0.05, Mann-Whitney U-test) at baseline, at V1, V2 and V3 follow-up visits. Also, the other variables did not seem to influence GZ changes over the follow-up period. Moreover, a re-growth of the interproximal mesial and distal papillae was the general trend observed independently from the variables studied. CONCLUSIONS: Immediate single implant treatment may be considered a predictable option regarding soft tissue stability over a period of 3 years of follow-up. An overall buccal soft tissue stability was observed during the GZ changes from the baseline to the 3 years of follow-up with a mean GZ reduction of 0.23 mm. A nearly full papillary re-growth can be detectable over a minimum period of 2 years of follow-up for both cylindrical and conical/cylindrical implants. Both the interproximal papilla filling and the midfacial mucosa stability were not influenced by variables such as type of fixture configuration, tooth category, smoke habit, and thickness of buccal bone wall of ≤ 1 mm (thin buccal wall).

Dimensions of the healthy gingiva and peri-implant mucosa.

OBJECTIVE: To determine the dimensions of the soft tissue cuff present at various aspects of teeth and to compare these dimensions to those of the mucosa surrounding single implants. MATERIAL AND METHODS: Fifty volunteers were recruited that were ≥25 years of age and exhibited no signs of (i) untreated caries; (ii) loss of periodontal tissue support in the incisor, canine, and premolar regions; (iii) systemic or local disease. Furthermore, among the 50 patients recruited (iV), 27 had one single implant in the maxilla with teeth present mesial and/or distal to the implant. Probing pocket depth (PPD) and transmucosal sounding depth (TS) were assessed by five experienced, carefully calibrated examiners and with the use of a periodontal probe at the proximal (mesial, distal) and flat (facial, buccal and palatal/lingual) surfaces of all teeth/implants. The width of the keratinized mucosa (KM) was also determined. RESULTS: It was demonstrated that (i) PPD and TS were greater at proximal than at flat surfaces at both tooth and implant sites. In addition, both PPD and TS were deeper at implant than at tooth sites. The TS values documented that the cuff of healthy soft tissue that surrounded a tooth varied between 2 mm at flat surfaces and 4 mm at proximal surfaces, while at implant sites, the mucosa at proximal as well as flat surfaces was 1-1.5 mm greater. CONCLUSION: The probing pocket depth (PPD) and the transmucosal sounding depth (TS) values were greater at proximal than at flat, that is, facial/palatal (lingual) surfaces at tooth sites and frequently also at implant sites. Furthermore, the PPD and the TS dimensions were greater at implant than at adjacent tooth sites.

Mucosal inflammation and incidence of crestal bone loss among implant patients: a 10-year study.

OBJECTIVE: The objective of this prospective study was to determine the prevalence and incidence of marginal bone loss and, in addition, peri-implantitis in subjects and implant sites after 10 years in function. MATERIAL AND METHODS: One hundred and thirty-three subjects with a total of 407 implants that had been in function for about 5 years attended a follow-up visit in 2007 (visit 2; V2). 100 of the 133 subjects returned for a new clinical and radiographic examination in 2012 (visit 3; V3). The clinical examination included assessment of "bleeding on probing" (BoP+) and "probing pocket depth." Subjects with implant sites that in the radiograph exhibited crater-shaped marginal bone loss of >0.5 mm were identified as losers. RESULTS: During the interval between V2 and V3 (about 5 years), 13 implants in 7 subjects exhibited progressive bone loss and were removed. The overall amount of crestal bone loss that had occurred at the remaining implants between visit 1 (V1; ≥1 year of loading) and V3 (10 years) was small (0.36 ± 1.4 mm). The bone-level reduction was twice as great between V2 and V3 as between V1 and V2. Forty subjects and 75 (26%) implant sites exhibited marginal bone loss of >0.5 mm between V1 and V3. In the interval between V2 and V3, 37 new implant sites lost significant amounts of bone. During the entire 10-year period (V1-V3), 12% of patients and 5% of implants displayed signs of peri-implantitis (bone loss >0.5 mm, BoP+, PPD ≥6 mm), while in the V2-V3 interval, the corresponding numbers were 10% (patients) and 4% (implant sites). CONCLUSION: Sites with marginal bone loss of ≥1 mm were not common among implant patients. Peri-implantitis occurred in about 10% of patients and 4% of implant sites.

Ridge preservation with the use of deproteinized bovine bone mineral.

OBJECTIVE: The aim was to examine the tissue composition of extraction sockets that had been grafted with deproteinized bovine bone mineral and allowed to heal for 6 months. MATERIAL AND METHODS: Twenty-five subjects with one tooth each scheduled for extraction and replacement with dental implants were recruited. The assigned teeth were carefully removed. The site/patient was thereafter allocated to a test or a control group. In the test group patients, Bio-Oss(®) Collagen was placed to fill the fresh extraction socket while in the controls no grafting was performed. After about 6 months of healing, a biopsy was sampled from the center of the extraction site. The specimens were decalcified, embedded in paraffin, sectioned, and stained in HTX. The proportions occupied by mineralized bone, osteoid, bone marrow, fibrous tissue, and Bio-Oss(®) particles were determined by morphometric point counting. RESULTS: Mineralized bone made up 57.4 ± 12.4% of the control sites (C) and 48.9 ± 8.5% of the T1 sites (graft material not included). The amount of bone marrow (C: 7.1 ± 6.1%, T1: 2.1 ± 3.1%) and osteoid (C: 7.3 ± 4.9%, T1: 1.9 ± 2.1%) was about five times greater in the control than in the test sites. Fibrous tissue comprised 23.1 ± 16.3% (C) and 40.0 ± 11.9% (T1). I n the T2 sites (graft material included), the percentage mineralized bone was 39.9 ± 8.6 while the proportions of bone marrow and osteoid were 1.8 ± 2.5% and 1.6 ± 1.8%. Fibrous tissue occupied 32.4 ± 9.2% and Bio-Oss(®) particles 19.0 ± 6.5% of the T2 sites. CONCLUSION: Placement of the biomaterial in the fresh extraction socket retarded healing. The Bio-Oss(®) particles were not resorbed but became surrounded by new bone. This may explain why grafted extraction sites may fail to undergo dimensional change.

Implants placed in fresh extraction sockets in the maxilla: clinical and radiographic outcomes from a 3-year follow-up examination.

AIM: The aim of this prospective, randomized, controlled multicenter study was to determine the 3-year efficacy and stability of the soft and hard tissues at implants with a different geometry that were placed in fresh extraction sockets. MATERIAL AND METHODS: Implants with two different configurations, cylindrical (Group A) or conical/cylindrical (Group B) were installed, and healing abutments were attached. Sixteen weeks after implant placement, subjects returned for a re-entry procedure. Prosthetic restorations were delivered 22 weeks after implant placement. Each subject was placed in a 3-year follow-up program, including examinations at yearly visits including various soft tissue and bone level parameters. RESULTS: The percentage of sites that were considered inflamed during the follow-up period was stable and varied between 8.8% and 10.2%. The radiographic examinations documented improved bone levels at the final examination and the mean improvement from baseline (placement of permanent restoration; PR) amounted to 0.17 ± 0.67 mm. More than 70% (54 of 76) of the implants monitored in this study suffered no bone loss during the maintenance period. Moreover, there was an obvious "gain" of interproximal soft tissue volume and at the 3-year examination around 25% of all embrasure gaps were completely filled with "papillae". CONCLUSIONS: Both conical/cylindrical and cylindrical implants placed in fresh extraction sockets allowed proper soft and hard tissue healing to occur. At both types of implants, mucosal inflammation was infrequent, marginal bone levels were maintained, and soft tissue volume increased gradually after the placement of the permanent restoration.