Prospective 1-Year Study of Immediately Loaded Implants: 8-Patient Case Series Report.

The goal of this case series report is to demonstrate the predictability of providing immediate restorations with an implant specifically designed to achieve high primary stability, and to report on 12-month survival outcomes. Twenty-nine implants were placed in eight patients with various tooth-replacement needs, from single teeth to partially edentulous spans to fully edentulous mandibles. A new tapered-implant system (The Marc Nevins, Little Implant) was utilized that incorporates a self-tapping thread design with a thread pitch and thread lead to improve primary stability at insertion. All implants were placed with a minimum insertion torque of 45 Ncm. Four immediate implants and two early placements at extraction sites were included in the cohort. Twenty-seven implants were clinically successful at 1 year. Two implants in a healed ridge were found to have failed at 6 weeks postoperative in one patient wearing an ill-fitting removable partial denture. The radiographic crestal marginal bone levels were recorded in millimeters from the top of the implant platform to the first bone-to-implant contact. The mean crestal marginal bone level change was -0.57 ± 0.82 mm. This case series report demonstrates the ability of an implant designed for high primary stability to achieve successful integration in the presence of an immediate restoration for various clinical presentations, including single-tooth, multi-unit, and edentulous cases.

Platform switching versus conventional technique: a randomized controlled clinical trial.

In this controlled prospective study, 53 patients treated at four study centers were randomly assigned to receive either (test) implants with platform switching built into their design or similar nonplatform-switched controls (same manufacturer, surface treatment, etc) for treatment of single and multiple edentulous sites in all four quadrants. Radiographs taken at the time of implant placement, definitive restoration delivery, and 1-year follow-up found significantly less crestal bone loss around the test implants (0.25 mm) compared to the controls (0.65 mm). Notably, bone loss around the control implants had declined by the 1-year follow-up point.

Human histologic assessment of a platform-switched osseointegrated dental implant.

This case report examined crestal bone level maintenance surrounding a platform-switched implant that was retrieved due to prosthetic difficulty. The retrieved platform-switched implant threads demonstrated tight contact with the surrounding bone and demonstrated both radiographic and histologic features that were indicative of successful osseointegration. Very high bone-to-implant contact (BIC) without epithelial downgrowth to the implant thread was noted. The BIC consisted of a combination of newly formed bone and native bone. The buccal and lingual bone levels coincided with the original platform position noted at the time of the surgery, and did not appear to resorb at all. The result of the present investigation confirms the maintenance of the crestal bone level for platform-switched implants.

Recombinant human platelet-derived growth factor BB for reconstruction of human large extraction site defects.

This study investigated the ability of growth factor-enhanced matrices combined with a tenting screw scaffolding system and resorbable membrane to regenerate large alveolar extraction site defects. Eight patients were randomized to treatment either with a bovine or equine matrix mixed in a ratio of 1.0 mL (0.3 mg/mL) recombinant human platelet-derived growth factor BB (rh-PDGF-BB) per gram of xenograft and allowed to absorb for 10 minutes. Tenting screws were used to provide additional support, and the growth factor-enhanced particulate matrix was incrementally placed and condensed into the defect and covered by a resorbable membrane. Reentry surgery after 5 months allowed for trephine core biopsies and implant placement. All sites healed well with evidence of bonelike hard tissue that was confirmed histologically as vital bone around the remaining graft particulate in both treatment groups. The results of this study demonstrate the capability of growth factor-enhanced matrices combined with tenting screws and a resorbable membrane to support the reconstruction of large extraction site defects.

A prospective 9-month human clinical evaluation of Laser-Assisted New Attachment Procedure (LANAP) therapy.

This investigation was designed and implemented as a single-center, prospective study to evaluate the clinical response to the Laser-Assisted New Attachment Procedure (LANAP). Eight patients with advanced periodontitis were enrolled and treated with full-mouth LANAP therapy and monitored for 9 months. Fullmouth clinical measurements, including clinical attachment level (CAL), probing depth (PD), and recession, were provided at baseline and after 9 months of healing by a single calibrated examiner, including a total of 930 sites and 444 sites with initial PD equal to or greater than 5 mm. Clinical results for the 930 sites measured pre- and postoperatively revealed that mean PD was reduced from 4.62 ± 2.29 mm to 3.14 ± 1.48 mm after 9 months (P < .05). CAL decreased from 5.58 ± 2.76 mm to 4.66 ± 2.10 mm (P < .05) and recession increased from 0.86 ± 1.31 mm to 1.52 ± 1.62 after 9 months (P < .05). For the subset of 444 sites with initial PD greater than or equal to 5 mm, the PD decreased from 6.50 ± 2.07 mm to 3.92 ± 1.54 mm (P < .05) and CAL decreased from 7.42 ± 2.70 mm to 5.78 ± 2.06 mm (P < .05). As demonstrated by the clinical evaluation, the majority of treated sites demonstrated clinical improvement. LANAP therapy should be further investigated with long-term clinical trials to compare the stability of clinical results with conventional therapy.

Ridge preservation with and without primary wound closure: a case series.

The purpose of this study was to determine the clinical and histologic efficacy of the combination of alloplastic biphasic calcium phosphate composed of 30% hydroxyapatite and 70% Β-tricalcium phosphate (Osteon II) and a cross-linked collagen membrane used to reconstruct an extraction socket with new bone formation. Twelve patients, from two private dental practices, requiring extraction of maxillary and mandibular nonmolar teeth (n = 30) received both Osteon II (0.5- to 1.0-mm particle size) and the collagen membrane. The primary healing intention group (group A, n = 12) received primary flap closure over the membrane, while in the secondary healing intention group (group B, n = 18), the membrane was left exposed. Early wound healing seemed to be slower in group B when compared to group A, but the difference was not noticeable after 4 weeks. Clinical reentry revealed that the dimensions of the ridge appeared to be maintained in both groups, and internal socket bone fill was evident. The grafted area appeared to be well vascularized, but clinically visible graft particles were noted in some cases. Light microscopic analysis revealed the formation of new bone directly apposing the surfaces of graft particles and bridging the space between them, indicating that the graft material behaved as an osteoconductive scaffold. The mean amount of vital bone in group A was 40.3% ± 7.8%, while the remaining graft was 6.0% ± 4.0%. The mean amount of vital bone in group B was 47.3% ± 11.3%, while the remaining graft was 18.0% ± 20.0%. The absence of primary flap closure did not affect the percentage of vital bone formation or residual graft.

Alveolar ridge reconstruction with a composite alloplastic biomaterial.

The purpose of this case report was to analyze the outcome of alveolar ridge reconstruction procedures with composite alloplastic biomaterial (biphasic calcium phosphate composed of 30% hydroxyapatite and 70% Β-tricalcium phosphate) for the treatment of large alveolar ridge defects. The clinical and histologic findings demonstrated that this alloplastic biomaterial can be used to potentially regenerate large alveolar ridge defects. This composite biomaterial appears to be safe, biocompatible, and osteoconductive.

Human clinical and histologic evaluation of laser-assisted new attachment procedure.

This investigation was designed to evaluate the healing response to the laser-assisted new attachment procedure (LANAP). Eight patients presenting with 12 teeth predetermined to be surgically extracted were enrolled and consented to treatment with full-mouth LANAP therapy. LANAP surgical therapy consisted of a first pass with a 360-Μm fiber diameter, laser settings with verified output of 4.0 W and energy density of 1,965 mJ/mm2, 100-Μs pulse duration, and 20 Hz applied from the gingival margin to the base of the pocket parallel to the root surface and moved laterally and apically to remove the diseased pocket epithelium. The teeth were aggressively scaled and root planed with piezo ultrasonic instrumentation. A second pass was performed with a 360-Μm fiber diameter, laser settings with verified output of 4.0 W and energy density of 1,965 mJ/mm2, 650-Μs pulse duration, and 20 Hz applied from the apical extent of the bone defect to the gingival margin. After 9 months of healing, en bloc biopsy extractions were provided. Ten teeth were analyzed histologically to assess the periodontal wound healing. Five teeth evidenced a degree of periodontal regeneration with new cementum, periodontal ligament, and alveolar bone. One tooth had new attachment with new cementum and inserting collagen fibers, and four teeth healed via a long junctional epithelium. LANAP therapy should be further investigated with long-term clinical trials to compare the stability of clinical results to conventional therapy. This report provides evidence that LANAP therapy can induce periodontal regeneration.

Connective tissue attachment to laser-microgrooved abutments: a human histologic case report.

Previous preclinical and clinical studies have demonstrated the effectiveness of precisely configured laser-ablated microgrooves placed on implant collars to allow direct connective tissue attachment to the implant surface. A recent canine study examining laser-ablated microgrooves placed in a defined healing abutment area demonstrated similar findings. In both instances, direct connective tissue attachment to the implant-abutment surface served as an obstacle to the apical migration of the junctional epithelium, thus preventing crestal bone resorption. The current case report examines the effectiveness of abutment-positioned laser-ablated microgrooves in human subjects. As in the preclinical trial, precisely defined laser-ablated microgrooves allowed direct connective tissue attachment to the altered abutment surface, prevented apical migration of the junctional epithelium, and thus protected the crestal bone from premature resorption.

Reattachment of connective tissue fibers to a laser-microgrooved abutment surface.

This report presents human evidence of reattachment of the connective tissue when a laser-microgrooved healing abutment was replaced with a laser-microgrooved cylindric definitive abutment. No additional bone loss was noted 15 weeks after placement of the laser-microgrooved cylindric definitive abutment. Dense connective tissue was in intimate contact with the laser-microgrooved surface to the point of the soft tissue separation, and clear evidence of the junctional epithelium ending at the coronal-most position of the laser-microgrooved zone was identified.

Growth factor-mediated combination therapy to treat large local human alveolar ridge defects.

The purpose of this case report is to demonstrate the effectiveness of a matrix consisting of recombinant human platelet-derived growth factor BB (rhPDGF-BB)-hydrated cancellous allogenic block graft in the reconstruction of large local human alveolar ridge defects. The results suggest improved bone regeneration when combining rhPDGF-BB with the allogenic block graft. The clinical and histologic evidence of new bone formation as well as bone remodeling supports the clinical potency of this growth factor-mediated therapy.

Treatment of gingival recession defects with xenogenic collagen matrix: a histologic report.

The connective tissue graft (CTG) in conjunction with a coronally advanced flap is still regarded as the gold standard treatment for gingival recession defects. Increased surgical morbidity as well as limited tissue availability continues to spur interest in alternatives to the CTG. The current case report examines a porcine-derived, double-layer collagen matrix as an alternative to the CTG in managing Miller Class I and II recession defects. A long junctional epithelial attachment as well as connective tissue adhesion were noted when collagen matrix was used in conjunction with a coronally advanced flap in recession treatment protocols. The results suggest that it is possible to obtain root coverage without harvesting connective tissue.

Human histologic evaluation of the use of the dental putty for bone formation in the maxillary sinus: case series.

A proof-of-principle study was conducted to assess the safety and efficacy of dental putty as an alternative sinus augmentation biomaterial. Six healthy patients requiring a total of 10 sinus augmentations received sinus augmentations. All patients volunteered and signed an informed consent based on the Helsinki declaration of 1975, as revised in 2000. The sinus augmentation was performed under local anesthesia with a mucoperiosteal flap elevated to expose the buccal wall of the maxillary sinus. The space was then filled with the dental putty in several increments, and the window was covered with an absorbable collagen membrane. Biopsies were harvested from all 10 treated sinuses using a 3-mm trephine bur at the time of implant placement at either 6 or at 9 months after sinus augmentation. All patients completed the study without complications, except for 1 patient who reported fistulas at 1 and 2 months after the surgery. Clinical reentry revealed that regenerated bone on the osteotomy site was soft and immature. The ground sections of the biopsied cores revealed minimum amounts of trabeculation surrounded by an abundant array of irregular-shaped residual alloplastic particles embedded in loose connective tissue. The present study's findings revealed inadequate bone formation, although the material appears to be bioinert as there is no elicitation of inflammatory response.

Human buccal plate extraction socket regeneration with recombinant human platelet-derived growth factor BB or enamel matrix derivative.

The objective of this study was to assess the osseous healing of buccal plate extraction socket defects. There were four cohorts: group A (mineral collagen bone substitute [MCBS] scaffold alone), group B (MCBS with recombinant human platelet-derived growth factor BB [rhPDGF-BB; 0.3 mg/mL]), group C (MCBS with enamel matrix derivative [EMD]), and group D (combination of EMD with bone ceramic). The primary outcome of bone quality was evaluated using light microscopy, backscatter scanning electron microscopy, and histomorphometrics. Reentry surgery provided an opportunity for clinical observation of the healed ridge morphology. Sixteen patients with buccal wall extraction socket defects were randomized into four treatment groups of equal size. Grafting was provided at the time of extraction with advancement of the buccal flap for primary closure. A trephine core biopsy of the implant site preparation was performed after 5 months for implant placement. Histologic examination identified new bone healing around the biomaterial scaffolds. Statistically significant differences in new bone formation were not observed among the treatment groups. There was a histomorphometric trend toward more new bone for the rhPDGF-BB-treated group (group B). This group had the most favorable ridge morphology for optimal implant placement.

The clinical and histologic efficacy of xenograft granules for maxillary sinus floor augmentation.

The objective of this study was to investigate the potential of xenograft (cancellous bovine bone) granules to form vital bone in non-natural bone-forming areas of maxillary sinuses. Fourteen sinus augmentations were performed in 14 patients. Surgical outcomes were uneventful, and sufficient radiopaque volume was present radiographically to place dental implants in all sites. Clinical reentry at 6 months revealed bone formation at the osteotomy site. Histologic evaluation of the obtained bone cores revealed that xenograft granules were integrated and surrounded by woven bone and lamellar bone that were in close contact with the particles. The average percentage of newly formed bone at 6 months was 27.5% ± 8.9%. Vital bone formation using the xenograft granules was supported by both clinical and histologic evidence.

Pilot clinical and histologic evaluations of a two-piece zirconia implant.

An investigation was conducted to evaluate the clinical and histologic results of bone and soft tissue healing around a two-piece zirconia dental implant in a human model. A healthy female patient requiring tooth replacement with dental implants received a two-piece zirconia implant together with conventional titanium implants to be implemented in a prosthesis. Clinical and radiographic evaluations at 6 months revealed stable osseointegrated zirconia and titanium dental implants. Light microscopy and backscatter scanning electron microscopic analyses confirmed the biocompatibility and achievement of osseointegration, in addition to maintenance of the crestal bone level. The findings suggest that the bone-to-implant contact with a zirconia implant surface is sufficient to provide clinical and histologic evidence of osseointegration. The biopsied two-piece zirconia dental implant with platform switching demonstrated osseointegration occlusal to the implant-abutment junction, eliminating the significance of the microgap.

The feasibility of demineralized bone matrix and cancellous bone chips in conjunction with an extracellular matrix membrane for alveolar ridge preservation: a case series.

An investigation was conducted to test the feasibility of demineralized bone matrix and cancellous bone chips in a reverse-phase medium carrier (DynaBlast) in concert with an extracellular matrix membrane (DynaMatrix) to provide hard and soft tissue regeneration for the purpose of a ridge preservation procedure. Nine patients requiring extraction of 30 maxillary teeth were grafted with DynaBlast and DynaMatrix. Twenty sites attained primary flap closure over the grafted area (primary healing intention group), while 10 sites were assigned randomly to the secondary healing intention group, in which primary flap closure over the membrane was not achieved. Clinical and radiographic evaluations at 6 months revealed comparable bone formation for both groups. Histologic analyses of 21 harvested soft and hard tissue core biopsies revealed absence of the remnant membrane and consistent patterns of new bone formation. The efficacy and safety of DynaBlast and DynaMatrix have been validated clinically and histologically to preserve the dimensions of the alveolar process.

The clinical efficacy of DynaMatrix extracellular membrane in augmenting keratinized tissue.

This study was conducted to compare the efficacy and feasibility of an extracellular matrix membrane (DynaMatrix) with that of an autogenous gingival graft in increasing the width of attached keratinized tissue. Six patients with an inadequate amount of attached keratinized gingiva on the bilateral facial aspect of the mandibular posterior teeth were recruited for this study. The defect sites were randomly subjected to receive either test (DynaMatrix membrane) or control (autogenous gingival graft) treatment. Both test and control sites achieved a clinically significant increase in the amount of keratinized gingiva, and the DynaMatrix membrane-treated sites blended well with the surrounding tissue, with a better appearance when compared to the autogenous gingival grafted sites. The biopsy specimens of both test and control sites appeared to be similar histologically, with mature connective tissue covered by keratinized epithelium. The results of both clinical and histologic evaluations have suggested a potential application of an extracellular matrix membrane in achieving gingival augmentation.

Minimally invasive alveolar ridge augmentation procedure (tunneling technique) using rhPDGF-BB in combination with three matrices: a case series.

This study investigated a minimally invasive surgical procedure for alveolar ridge augmentation that combined recombinant human platelet-derived growth factor BB (rhPDGF-BB) and three different matrices. The minimally invasive tunneling ridge augmentation procedure was applied to 12 patients randomized into three groups: rhPDGF-BB (0.3 mg/mL) was combined with freeze-dried bone allograft (FDBA; group A), anorganic bovine bone graft (ABBG; group B), or anorganic bovine bone graft/mineralized collagen bone substitute (ABBG/MCBS; group C). Computed tomography (CT) scans were obtained presurgically and prior to 14-week re-entry surgery. Clinical reentry revealed adequate bone volume to place implants in all patients in groups A and B and two of four patients in group C. Trephine core biopsies were obtained and evaluated by microCT, backscatter scanning electron microscopy (BE-SEM), and light microscopy. New bone formation was consistently observed with BE-SEM and histologic analysis for group A and B specimens. Newly formed woven and lamellar bone were in close contact with graft particles. The ABBG/MCBS specimens (group C) had more variable results, with fibrous encapsulation of graft particles and limited histologic evidence of new bone formation. Within the limits of this study, the FDBA and ABBG carriers appear to be appropriate scaffolds to deliver rhPDGF-BB for ridge augmentation via minimally invasive surgical techniques.

The efficacy of demineralized bone matrix and cancellous bone chips for maxillary sinus augmentation.

Demineralized bone matrix and cancellous bone chips in a reverse-phase medium carrier (DynaBlast, Keystone Dental) were used to augment the maxillary sinuses in 8 patients requiring 10 sinus augmentations. Clinical reentry after 6 to 7 months (mean, 6.2 months) and computed tomographic scan evaluation at 5 months demonstrated new bone formation as well as sufficient radiopaque volume to place implants in all sites. Microcomputed tomographic evaluation and histomorphometric analysis of sinus core biopsies confirmed the formation of new bone and demonstrated three distinctive mineralization patterns that have been previously described. DynaBlast can be considered a viable alternative to the use of autogenous bone or other types of grafting materials.