Orthodontic tooth extrusion to regenerate missing papilla adjacent to maxillary anterior single implants: A 2- to 7-year retrospective study.

INTRODUCTION: Regeneration of the missing papilla adjacent to single implants in the esthetic zone has always been challenging, despite advances in vertical hard and soft tissue regeneration. Orthodontic tooth extrusion has been shown to effectively gain alveolar bone and gingival tissue. This retrospective study evaluated the effectiveness of orthodontic tooth extrusion on regenerating missing papilla between existing maxillary anterior single implant and its adjacent tooth. METHODS: Patients who underwent orthodontic tooth extrusion to regenerate missing papilla adjacent to a single implant in the esthetic zone were included in this study. The gingival phenotype, orthodontic extrusion movement, proximal bone level, dento-implant papilla level, facial gingival level, mucogingival junction level, and keratinized tissue width, of the extruded tooth were recorded at pre-orthodontic extrusion (T0 ), post-orthodontic extrusion and retention (T1 ), and latest follow-up (T2 ). RESULTS: A total of 17 maxillary single tooth had orthodontic tooth extrusion to regenerate missing papilla adjacent to 14 maxillary anterior single implants in 14 patients. After a mean follow-up time of 48.4 months, implant success rate was 100% (14/14), with none of the orthodontically extruded teeth being extracted. After a mean extrusion and retention period of 14.3 months, a mean orthodontic extrusion movement of 4.62 ± 0.78 mm was noted with a mean proximal bone level gain of 3.54 ± 0.61 mm (77.0% efficacy), dento-implant papilla level gain of 3.98 ± 0.81 mm (86.8% efficacy), and facial gingival tissue gain of 4.27 mm ± 0.55 mm (93.4% efficacy). A mean keratinized tissue width gain of 4.17 ± 0.49 mm with minimal mean mucogingival junction level change of 0.10 ± 0.30 mm were observed. The efficacy of orthodontic eruption movement on dento-implant papilla gain was less in the thin (80.5%) phenotype group when compared with that in the thick (91.5%) phenotype group. CONCLUSIONS: Within the confines of this study, orthodontic extrusion is an effective, noninvasive method in regenerating mid-term stable proximal bone and papilla adjacent to maxillary anterior single implants. CLINICAL SIGNIFICANCE: This retrospective study presents a mid-term result on orthodontic extrusion as a mean to regenerate dento-implant papilla defect. The extended retention period following orthodontic extrusion showed stable and efficacious proximal bone and papilla gain.

Proposal regarding horizontal and vertical positioning of single implants placed in healed sites: Effect on cervical crown form and the need for bone grafting.

STATEMENT OF PROBLEM: When single implants are placed in healed sites, guidelines are lacking on the horizontal and vertical implant positions that optimize cervical crown form and the implant locations that would require bone grafting to develop the optimal crown form. PURPOSE: The purpose of this clinical study was to evaluate the cervical contour of wax patterns formed on casts of single implants placed in healed sites and to determine which horizontal and vertical implant positions produced the best cervical crown form and which indicated the need for bone grafting. MATERIAL AND METHODS: Fifty-eight wax patterns were fabricated on casts where implants had been placed in healed sites without bone grafting. The wax patterns were subjectively assessed by 5 dental faculty members and 5 graduate students as having good, fair, or poor cervical crown form. Horizontal measurements were made between the facial surface of the implant and a round metal wire connecting the gingival zeniths of the adjacent teeth. Vertical measurements were also made between the wire and implant platform. The subjective assessments along with the horizontal and vertical implant position measurements were used to propose guidelines for optimal implant placement in healed sites. RESULTS: Horizontal distances of 2.0 to 3.0 mm produced good cervical crown contours, with distances >3.0 mm and <2.0 mm resulting in fair or poor assessments. Vertical distances of 3.0 to 4.0 mm were judged to have good cervical crown contour, whereas depths of 1.0 mm or less were assessed as poor. CONCLUSIONS: Based on the subjective assessment of wax patterns formed on casts of single implants placed in healed sites, a guideline of 2.0 to 3.0 mm is proposed for the horizontal distance between a line connecting the adjacent gingival zeniths and the facial surface of the implant. A vertical distance guideline of 3.0 to 4.0 mm is proposed between the adjacent gingival zeniths and the implant platform.

Facial implant gingival level and thickness changes following maxillary anterior immediate tooth replacement with scarf-connective tissue graft: A 4-13-year retrospective study.

OBJECTIVE: A scarf-shaped connective tissue graft can be placed at the facial and proximal aspect of the peri-implant soft tissue zone during immediate implant placement and provisionalization (IIPP) procedures in the esthetic zone to optimize implant esthetics without the need of flap reflection. This retrospective study evaluated soft tissue stability after scarf-connective tissue graft (S-CTG) in conjunction with IIPP procedures in the esthetic zone. MATERIALS AND METHODS: Patients who received IIPP with S-CTG with a minimum 1-year follow-up were evaluated. Mid-facial gingival level (MFGL) change and mid-facial gingival thickness (MFGT) change were measured and compared at the pre-op (T0), IIPP + S-CTG surgery (T1), follow up appointment with MFGT measurement (T2), and latest follow-up appointment (T3). Implant success rate and graft necrosis were also recorded. RESULTS: A total of 22 IIPP and S-CTG procedures in 20 patients were evaluated in the study. After a mean follow-up of 8.2 years (3.9-13.4) (T3), all implants remained osseointegrated (22/22 [100%]), with statistically insignificant mean midfacial gingival level change of -0.19 mm (-1.5 to 0.8). Statistically significant difference in midfacial gingival thickness (MFGT) was noted (2.5 mm [1.8-3.5 mm]) after a mean follow-up time (T2) of 2.3 years (1-8.6) when compared with MFGT at baseline (1.1 mm [0.6-1.3 mm]) (T1). Necrosis of S-CTG during initial healing phase was noted in 9% (2/22) of the sites. CONCLUSIONS: Within the confines of this study, scarf-connective tissue graft at time of immediate implant placement and provisionalization can thicken the gingiva and maintain the gingival level at the critical soft tissue zone. CLINICAL SIGNIFICANCE: Managing the soft tissue zone is as important as that of the hard tissue zone for peri-implant esthetics. Connective tissue graft is one of the methods that can enhance the final esthetic outcomes. This retrospective study has demonstrated that Scarf-CTG technique is an effective treatment modality to maintain soft tissue stability.

Effects of cyclic loading on loss of abutment screw torque of angled screw channel single implant crowns on narrow diameter implants.

STATEMENT OF PROBLEM: Screw access channels that emerge on the facial aspect of anterior screw-retained implant crowns can compromise esthetics. Recently, angled screw channels (ASCs) have been developed that can alter screw access channel angulations to improve esthetics. While ASCs can be used on narrow-diameter implants, information is limited on the loss of abutment screw torque on narrow-diameter implants with ASCs. PURPOSE: The purpose of this in vitro study was to compare the loss of abutment screw torque after thermocycling and the cyclic loading of ASCs from 3 different companies connected to narrow-diameter implants. MATERIAL AND METHODS: A total of 40 narrow-diameter implants (NobelReplace Conical Connection 3.5×11.5 mm) were mounted individually in acrylic resin blocks and divided equally into 4 groups. The first group, NB-0 (Control), consisted of screw-retained zirconia crowns fabricated on ASCs at 0-degree angulation (n=10). The other 3 groups consisted of a total of 30 screw-retained zirconia crowns fabricated on ASCs at 20-degree angulation: NB-20 (Angulated Screw Channel Solutions), ATL-20 (Atlantis Custom Base Solution with angulated screw access), and DA-20 (Dynamic TiBase). Each crown was secured on the mounted implant with its corresponding titanium base insert and screw and then tightened to the manufacturer's recommended torque with a digital torque gauge. The initial reverse torque value (RTVI) was obtained and recorded at baseline. Subsequently, a new set of screws were tightened to recommended values, and each specimen underwent thermocycling and then cyclic loading at 0 to 100 N at 10 Hz for 1 million cycles to simulate 1year of functional loading. After cyclic loading, the final reverse torque values (RTVF) were recorded and compared with the RTVI to evaluate the percentage torque loss (PTLF). Statistical analysis was performed using the Kruskal-Wallis analysis, Rank base analysis of covariance (ANCOVA), and the Tukey HSD post hoc comparisons (α=.05). RESULTS: Significant differences were found for the PTLF among all groups after cyclic loading (P<.001). The PTLF in ATL-20 (51.4%) was significantly higher than in NB-0 (22.2%) (P<.001) and NB-20 (29.2%) (P=.010). No significant difference was found in the PTLF among other groups (P>.05). CONCLUSIONS: The abutment screw torque loss after cyclic loading of the ASCs on narrow diameter implants among the 4 groups did not perform comparably. The largest percentage torque loss was recorded for the ATL-20 group. The NB-20 group demonstrated the lowest percentage torque loss. DA-20 showed percentage torque loss less than ATL-20; however, its RTVF was the lowest.

Facial Contour Preservation of Anterior Immediate Single-Tooth Replacement With the Socket Shield Technique Versus Connective Tissue Graft: A Case Report.

The socket shield technique and subepithelial connective tissue graft following immediate implant placement with provisionalization had been advocated for peri-implant facial contour and gingival architecture preservation. This case report used three-dimensional volumetric analysis to longitudinally assess the peri-implant facial contour change before and after these procedures. The results demonstrated comparable and acceptable preservation of peri-implant facial contour between the two procedures after 2 years of function.

Complications Associated with Metal Resin Fixed Complete Dentures Based on Implant Distribution.

PURPOSE: To compare prevalence and type of complications associated with metal resin fixed complete dentures based on implant distribution. MATERIALS AND METHODS: This retrospective study included data collected for a period of 12 years for patients treated with maxillary and mandibular implant-supported fixed complete dentures at Loma Linda University School of Dentistry. In total, 223 patient's charts were reviewed which included 100 maxillary and 123 mandibular fixed complete dentures. Implant distribution and prevalence of complications associated with each implant-supported fixed complete denture were documented. Tooth delamination, the most common complication associated with fixed complete dentures, was compared between 2 implant distribution groups in each arch. Covariates including age, sex, opposing arch, cantilever occluding units, and number of implants were evaluated to determine their association with tooth delamination. Data and hypotheses were statistically analyzed using descriptive statistics along with logistic regression model. All tests of hypotheses were considered statistically significant at an alpha level of 0.05. RESULTS: In the maxillary arch, some effect of the prevalence of tooth delamination was seen for the group that had implants placed posterior to canine eminence but it was not statistically significant. Denture tooth delamination had the highest prevalence among complications irrespective of implant distribution. Significant denture tooth delamination was seen for patients with opposing fixed complete dentures in comparison to patients with removable opposing arch prostheses. CONCLUSIONS: Implant distribution is not a significant factor related to metal resin fixed complete dentures. Opposing fixed complete dentures have a significantly higher association with denture tooth delamination.

Exposure of Barriers Used in Guided Bone Regeneration: Rate, Timing, Management, and Effect on Grafted Bone-A Retrospective Analysis.

The purpose of this study is to compare the exposure rate of 3 different barrier types after a guided-bone regeneration procedure as well as to compare the percentage grafted bone dimensional loss with and without exposed barriers. Patient records from September 2007 to May 2015 were reviewed to identify subjects who had received a bone graft followed by implant placement procedure after the graft had completely healed. The subjects were divided into 3 groups: (1) resorbable barrier, (2) nonresorbable barrier, and (3) titanium-mesh barrier. Incidences of barrier exposure were recorded. Cone-beam computerized tomography images before treatment (T0), right after grafting (T1), and after healing (T2) were used to determine the percentage of grafted bone dimensional loss and am quantitative amount of grafted bone remaining (mm2). Three cross-sectioned areas, at 1-mm apart, of preplanned implant positions at the grafted site were measured using cone-beam computerized tomography to calculate the remaining grafted bone and grafted bone dimensional change. The exposure rate of all guided bone regeneration was 36.9%. The exposure rate of the resorbable barrier (23.3%) was significantly lower than titanium mesh (68.9%) and nonresorbable (72.7%; χ2, P < .001). The results of this study revealed that barrier types have a significant effect on the exposure rate. There was also a significant difference in grafted bone dimensional loss between sites with barrier exposure (58.3%) and sites with no barrier exposure (44.1%) during the healing period (Mann-Whitney U test, P = .008).

Heat and Sound Generation During Implant Osteotomy When Using Different Types of Drills in Artificial and Bovine Bone Blocks.

The purpose of this study was to compare heat and sound generated during implant osteotomy when different types of drill were used in artificial bone and bovine bone blocks. A total of 80 implant osteotomies were formed using 4 implant drilling systems: N1 (OsseoShaper) (Nobel), NobelActive (Nobel), V3 (MIS), and BLX (Straumann) in both artificial bone and bovine bone blocks. Thermocouple probes were used to record temperature change at the depths of 5.0 mm and 13.0 mm of each implant osteotomy formed by the final drill. In addition, thermographic images, drilling sound, and drilling time were recorded and evaluated. Statistical analyses were performed at α = 0.05. The mean temperature changes as recorded by thermocouple probes and thermocamera were significantly lower in OsseoShaper than most other drill-bone combinations (P < .05). The mean drilling times and sound generation for OsseoShaper were significantly higher and lower than most other drill-bone combinations (P < .05), respectively. Minimal heat and sound generation can be expected when implant osteotomies are performed using OsseoShaper at a low rotational speed (50 rpm) even without irrigation. However, extended drilling time is required.

Scanning accuracy with splinted and unsplinted implant scan bodies for the edentulous arch at implant level: an in vitro study.

Accuracy of completely edentulous arch scanning with implant scan bodies has not been completely validated for intraoral scanners. For desktop laboratory scanners validations were found in the literature. The aim of this in vitro study was to compare the dimensional accuracy of scanning with splinted and unsplinted scan bodies on a completely edentulous maxillary arch with 6 implants. A maxillary edentulous master cast with 6 implants was used as control for all implant level impressions. 6 implants were digitally planned and placed at different angulation of 0, 0  17° and 30°. A contact coordinate measuring machine (CMM) was used to generate baseline linear measurements of the master cast. Four test groups included: 2 intraoral scanners Trios (3shape, Copenhagen, Denmark) and True Definition (3M ESPE, St Paul, MN), one industrial scanner Atos (Core optical 3D scanner) and one conventional impression group scanned with laboratory scanner Dental Wings 7 Series. Each scan recording was made with splinted and unsplinted scan bodies. Digital datasets of all measurements were compared with the CMM baseline values using PolyWorks® InnovMetric Software in order to assess the linear and angular deviations and determine the accuracy of complete arch digital impression. Factorial ANOVA showed significant effect with splinting, scanner type, inter-implant distance and implant angulation for linear deviations. Splinted scan bodies revealed elevated linear and angular deviation values for all scanners with significantly highest deviations for True Definition scanner. Significant correlation was found between inter-implant distance and linear deviation (r =0.45, P =<0.001) with increased linear deviations among all scanners, regardless of splinting. ( P <0.05). Significant effect on accuracy was seen for angular deviation with splinting, scanner type and implant angulation; significant difference was found between 0° and 30° implant angulation ( P =0.035) with more deviation with 30° implant angulation. The accuracy of the complete arch implant digital impression using splinted scan bodies was significantly reduced for measurements that crossed the arch midline. The digital impression technique using a broad splint design to connect scan bodies was not found to improve the scan accuracy for intraoral scanners.

Long-term crestal bone changes in implants placed in augmented sinuses with minimal or moderate remaining alveolar bone: A 10-year retrospective case-series study.

OBJECTIVES: To evaluate long-term clinical and radiographic outcomes of dental implants placed after lateral window sinus augmentation utilizing the sagittal sandwich technique. MATERIALS AND METHODS: Patients treated with sinus augmentation were included in this retrospective case-series study. The surgical procedure was performed with particulate autogenous bone- and anorganic bovine bone-derived mineral (3:7 ratio). Implants were grouped based on baseline residual alveolar ridge height: group S (residual alveolar ridge height of 0.1-3.5 mm), group M (height of 3.5-7mm), and group C (native bone). Radiographs were taken at baseline (abutment installation) and annually throughout the 10-year follow-up. RESULTS: A total of 86 patients (92 sinus lifts) and 209 implants were included. Ten sinus membrane perforations were recorded (11% incidence), and graft infections occurred in 3 cases (3.2% incidence). During the 10-year follow-up, 3 implants (1.4%) failed. No significant differences in the mean implant marginal bone loss (MBL) between the three groups were found after 1-, 2-, and 5-year follow-up (p > .05). At 10 years, group C exhibited more MBL than group M with a mean difference of -0.53 mm (p = .01). After 10 years, MK III implants displayed significantly more bone loss in native bone than those in augmented bone with a mean difference of 0.48 mm (p = .02). Five patients and 7 implants developed peri-implantitis with no significant differences between the groups (p = .570). CONCLUSION: Implant placement after two-stage sinus grafting utilizing the sagittal sandwich technique is a relatively safe and predictable procedure with minimal complications and MBL after 10-year follow-up.

Abutment screw torque changes with straight and angled screw-access channels.

STATEMENT OF PROBLEM: Angle-correcting options allow the use of screw-retained implant prostheses in situations where an implant has been placed with a facial inclination. However, manufacturers have different recommended torque values, and it is unclear whether the performance of these designs is equivalent to that of the traditional screw-retained crowns (SRCs) when subjected to cyclic loading forces. PURPOSE: The purpose of this in vitro study was to compare torque differences between conventional straight-line screw access and angulated access SRCs before and after simulated functional loading. MATERIAL AND METHODS: Five groups consisting of 10 SRCs and implants were formed: Nobel Biocare zirconia crowns with 20-degree access channels (NB-20); Dynamic Abutment Solution zirconia crowns (DA-20) with 20-degree access channels; Core3dcentre angle correction zirconia crowns with 20-degree access channels (C3D-20); Nobel Biocare zirconia crowns with 0-degree access channels (NB-0); and gold alloy crowns cast to Nobel Biocare Gold-Adapt abutments (GA-0). Each specimen underwent thermocycling before cyclic loading. A preload torque based on the manufacturer's recommendation was applied to each crown placed on an implant. Reverse torque measurements were obtained for each specimen before cyclic loading. Each implant-abutment assembly was then cyclic loaded at 0 to 100 N at 10 Hz for 1 million cycles. Reverse torque measurements were obtained after cyclic loading and the percentage difference calculated. RESULTS: No significant percentage torque loss differences were observed between the 0-degree and 20-degree SRCs after cyclic loading. No significant differences were seen among the angulated access channel crowns. DA-20 and C3D-20 specimens had significantly higher torque loss compared with the NB-0 group. The C3D-20 group reported the largest percentage torque loss (34.5%) among the angulated access screw channel groups. The GA-0 group reported the largest percentage torque loss of all the groups (35.9%). No crown mobility or other complications were observed in any of the groups after cyclic loading. CONCLUSIONS: Angulated access channel crowns performed comparably with conventional straight-line screw access SRCs with regard to percentage torque values after cyclic loading. Angulated access channel crowns with lower manufacturer recommended torque values had higher percentage torque differences.

Facial Gingival Changes With and Without Socket Gap Grafting Following Single Maxillary Anterior Immediate Tooth Replacement: One-Year Results.

This 1-year prospective study evaluated horizontal and vertical facial gingival tissue changes after immediate implant placement and provisionalization (IIPP) with and without bone graft in the implant-socket gap (ISG). During IIPP, 10 patients received bone graft material in the ISG (G group), while the other 10 patients did not (NG group). The implants were evaluated for implant stability quotient (ISQ), modified plaque index (mPI), modified bleeding index (mBI), marginal bone level (MBL), facial gingival level (FGL), and facial gingival profile (FGP) changes. The mean ISQ value at 9-month follow-up was statistically significantly greater than on the day of implant surgery (P < .05). The mPI and mBI scores demonstrated that patients were able to maintain a good level of hygiene. There were no statistically significant differences in the mean MBL changes between the G and NG groups (P > .05). There were statistically significant differences in FGL changes between the G (-0.77 mm) and NG (-1.35 mm) groups (P = .035). There were no statistically significant differences in FGP changes between the G and NG groups (P > .05). However, statistically significant differences were noted in FGP change between the 3-12 and 0-12 month intervals in both groups (P < .05). Within the limitations of this study, although no significant differences were noted in FGP changes between groups, G group experienced significantly less FGL changes than NG group. Bone graft material placement into ISG seems to be advantageous for tissue preservation during IIPP. However, future long-term studies, with larger sample size, are needed to validate the efficacy of such procedure.

Accuracy of 3D Printed Models Created by Two Technologies of Printers with Different Designs of Model Base.

PURPOSE: To evaluate the accuracy of three-dimensional (3D) printed models manufactured using two different printer technologies with different model base designs. MATERIALS AND METHODS: A maxillary typodont was scanned using a desktop scanner to generate the Standard Tessellation Language (STL) file as a reference scan. After the scanning procedure, the STL file was exported to Model Builder™ for designing the following two types of the model bases: a solid base design and a hollow base design with a 2.0 mm thickness of the external shell. Each design was printed to produce 10 models using a Continuous Liquid Interface Production (CLIP) printer and a Digital Light Processing (DLP) printer. The following four groups were tested: CLIP with solid base (CS); CLIP with hollow base (CH); DLP with solid base (DS); and DLP with hollow base (DH). A total of 40 models were scanned using the same desktop scanner to generate the STL files for evaluation of the accuracy by evaluation of trueness and precision. All STL files were superimposed with the control STL file via surface matching software and a comparison was performed using the 3D color mapping function and a 2D comparison of 48 points selected on the tested model. The data were collected by measuring the deviation between the tested model and the reference scan. Trueness was calculated by using the comparison among four tested groups. The Kruskal-Wallis analysis was conducted to assess the overall statistical significance of differences among the tested groups (α = 0.05). For precision measurement, the evaluation was conducted using Intraclass Correlation Coefficient (ICC) value at 95% confident interval to determine the deviation within the same tested groups. RESULTS: The median values for the deviated distance of the four tested groups were 0.045 (CH), 0.035 (CS), 0.077 (DH), and 0.077 mm (DS). There were no statistically significant differences between the trueness of the two groups when using the same printers regardless of the designs of model base (p > 0.05). However, when comparing the two printers using the same model base design and the two different designs of model base, there were statistically significant differences in trueness (p < 0.05). The 3D printed models created using CLIP technology had higher trueness than the DLP technology printer. Precision of the 3D printed model was displayed in ICC value. The ICC values of four tested groups were 0.968 (CH), 0.981 (CS), 0.969 (DH), and 0.983 (DS). All tested groups were classified as exhibiting an excellent level of precision based on 95% confident interval of the ICC estimation. CONCLUSIONS: The accuracy of 3D printed models was affected by the printer technology regardless of whether the model base was solid or hollow. The CLIP technology printer produced significantly less variation from the reference model than the DLP printer. However, all of the 3D printed models were determined to exhibit a clinically acceptable level of accuracy based on the recorded dimensions being less than 100 µm different than the reference model.

A 3D-printed guide for lateral approach sinus grafting: A dental technique.

Lateral approach sinus grafting has become a routine and predictable surgical method of augmenting the pneumatized sinus for implant placement. Outlining the lateral window access can be a challenging task for the clinician to envision and execute. Improper extension and access to the maxillary sinus can prevent proper placement of graft materials and lead to complications. The purpose of this report was to demonstrate a technique that will allow the precise planning of the lateral approach using radiographic information and 3-dimensional (3D) software to 3D-print a surgical guide.

Combining guided alveolar ridge reduction and guided implant placement for all-on-4 surgery: A clinical report.

Immediate restoration with the all-on-4 concept has become an established treatment option. The technique involves alveoloplasty before implant placement to provide space for the prosthetic components and to provide a platform on which dental implants can be placed in clinical situations where a knife-edge alveolar ridge is present. Guided implant surgery involves the fabrication of a guide by using data from cone-beam computed tomography (CBCT) and implant surgery performed without flap reflection. In the presented technique, a printed cast based on a CBCT is used to fabricate a guide for both alveolar ridge reduction and guided implant surgery. The alveolar ridge reduction and implant surgery are virtually simulated in the laboratory to provide space for the restorative components and to avoid critical anatomic landmarks (mental nerve or perforation of the lingual mandibular plate). The described surgical guide enables guided alveolar ridge reduction and guided implant placement where the implant placement performed in the laboratory can be duplicated clinically during implant surgery.

Marginal bone response of implants with platform switching and non-platform switching abutments in posterior healed sites: a 1-year prospective study.

OBJECTIVES: This 1-year prospective study evaluated the implant success rate and marginal bone response of non-submerged implants with platform and non-platform switching abutments in posterior healed sites. MATERIAL AND METHODS: Nineteen patients (9 male, 10 female) with posterior partially edentulous spaces, between the ages of 23 and 76 (mean = 55.4 years), were included in this study. A total of 30 implants (15 implants restored with platform switching [PS] abutments [control] and 15 implants restored with non-platform switching [NPS] abutments [test]) were assigned between two groups using a randomization procedure. The definitive abutments with conical connections were placed at the time of surgery, and the definitive restorations were placed at 3 months. All patients were evaluated clinically and radiographically using standardized radiographs at time of implant placement (0), 3, 6 and 12 months after implant placement. Data were analyzed using Friedman test with post hoc pairwise comparisons, Mann-Whitney U-test, and Pearson's chi-square test at the significance level of α = 0.05. RESULTS: At 12 months, all 30 implants remained osseointegrated corresponding to a 100% success rate. The overall mean marginal bone level change at 12 months was -0.04 ± 0.08 mm for PS group and -0.19 ± 0.16 mm for NPS group. Statistically significant difference in the marginal bone level change was observed between groups at 0 to 12 months and 3 to 12 months (P < 0.05). CONCLUSIONS: This 1-year randomized control study suggests that when a conical implant-abutment connection is present, similar peri-implant tissue responses can be achieved with platform switching and non-platform switching abutments.

Severe mandibular atrophy treated with a subperiosteal implant and simultaneous graft with rhBMP-2 and mineralized allograft: a case report.

A 71-year-old patient was successfully rehabilitated by means of a 3D model-derived, hydroxyapatite-coated titanium subperiosteal mandibular implant. The implant was specifically designed to allow bone augmentation. The deficient bone was simultaneously grafted with mineralized bone allograft and recombinant bone morphogenetic protein -2 (rhBMP-2). The 32-month postoperative cone beam computerized tomography follow-up showed vertical bone augmentation beneath the implant frame.

Teeth versus implants: mucogingival considerations and management of soft tissue complications.

Soft tissue complications around dental implants occur with an incidence between 1 and 7 percent, and the treatments for these have not been as well studied, understood or as predictable as with similar complications associated with teeth. These complications include recession, fenestration/dehiscence defects, gingival inflammation/proliferation and fistulas. This paper compares and contrasts important mucogingival considerations between teeth and implants. Diagnosis, treatment and prevention of some of the more common soft tissue complications are presented.