Jamil Awad Shibli

Composition of supra- and subgingival biofilm of subjects with healthy and diseased implants

OBJECTIVES The purpose of this study was to compare the microbial composition of supra- and subgingival biofilm in subjects with and without peri-implantitis. MATERIAL AND METHODS Forty-four subjects (mean age 48.9 +/- 13.51 years) with at least one implant restored and functional for at least 2 years were assigned to two groups: a peri-implantitis group (n=22), consisting of subjects presenting peri-implant sites with radiographic defects >3 mm, bleeding on probing and/or suppuration; and a control group (n=22), consisting of subjects with healthy implants. The clinical parameters evaluated were plaque index, gingival bleeding, bleeding on probing, suppuration, probing depth and clinical attachment level. Supra- and subgingival biofilm samples were taken from the deepest sites of each implant and analyzed for the presence of 36 microorganisms by checkerboard DNA-DNA hybridization. RESULTS Higher mean counts of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were observed in the peri-implantitis group, both supra- and subgingivally (P<0.05). The proportions of the pathogens from the red complex were elevated, while host-compatible beneficial microbial complexes were reduced in diseased compared with healthy implants. The microbiological profiles of supra- and subgingival environments did not differ substantially within each group. CONCLUSION Marked differences were observed in the composition of supra- and subgingival biofilm between healthy and diseased implants. The microbiota associated with peri-implantitis was comprised of more periodontal pathogenic bacterial species, including the supragingival biofilm.

Prevalence of Maxillary Sinus Septa in 1024 Subjects With Edentulous Upper Jaws: A Retrospective Study

Maxillary sinus floor augmentation has been routinely performed to optimize dental implant placement in the posterior maxilla. However, complications during a sinus grafting procedure, such as perforation of the Schneiderian membrane, have been reported. This complication is generally associated with the presence of maxillary septa. Therefore, the aim of this retrospective study was to evaluate the prevalence of maxillary sinus septae in completely edentulous subjects by means of panoramic radiography. A total of 1024 panoramic radiographs were evaluated by 3 calibrated examiners. From these radiographs, 307 maxillary septa were detected in 221 subjects (21.58%); 86 (8.40%) of the subjects showed maxillary septa in both maxillary sinuses. Logistic regression failed to detect any correlation between the presence of maxillary septa, age, and gender (P > .05). Within the limits of the study, the prevalence of maxillary septa in this Brazilian population was shown to be moderate, indicating that dentists must be aware of the presence of this anatomic structure during maxillary sinus elevation grafting.

Prospective Evaluation of 2,549 Morse Taper Connection Implants: 1‐ to 6‐Year Data

BACKGROUND The aim of this study is to evaluate the implant survival, the implant-crown success, and the prosthetic complications of 2,549 Morse taper interference-fit connection implants. METHODS A total of 2,549 Morse taper connection implants were inserted in 893 patients from January 2003 until December 2008. At each annual recall, clinical, radiographic, and prosthetic parameters were assessed. The implant-crown success criteria included the absence of pain, suppuration, and clinical mobility; an average distance between the implant shoulder and the first visible bone contact <2 mm from initial surgery; and the absence of prosthetic complications at the implant-abutment interface. Prosthetic restorations were fixed partial prostheses (462 units); fixed full-arch prostheses (60 units); single crowns (531 units); and overdentures (93 units). RESULTS The cumulative implant survival rate was 98.23% (97.25% maxilla, 99.05% mandible). The implant-crown success was 92.49%. A few prosthetic complications at implant-abutment interface were reported (0.37%). After 6 years, distance between the implant shoulder and the first visible bone contact was 1.10 mm (± 0.30 mm). CONCLUSION The use of Morse taper connection implants represents a successful procedure for the rehabilitation of partially and completely edentulous arches.

Receptor Activator of Nuclear Factor-Kappa B Ligand/Osteoprotegerin Ratio in Sites of Chronic Periodontitis of Subjects With Poorly and Well-Controlled Type 2 Diabetes

BACKGROUND The aim of this study is to evaluate the levels of osteoclastogenesis-related factors (soluble receptor activator of nuclear factor-kappa B ligand [sRANKL] and osteoprotegerin [OPG]) in gingival crevicular fluid (GCF) from subjects with poorly and well-controlled type 2 diabetes and chronic periodontitis before and after periodontal therapy. METHODS Eighteen subjects with well-controlled diabetes (glycated hemoglobin [HbA1c] levels ≤ 8%) and 20 subjects with poorly controlled diabetes (HbA1c levels >8%) were enrolled in this study. All subjects were submitted to non-surgical periodontal therapy. GCF sampling and clinical periodontal parameters were assessed at baseline and 3 and 6 months post-therapy. Total amounts and concentrations of sRANKL and OPG in GCF were analyzed by enzyme-linked immunosorbent assay (ELISA). RESULTS Total amounts and concentrations of sRANKL and RANKL/OPG ratios were higher in poorly controlled subjects than in well-controlled subjects at baseline and 3 and 6 months post-therapy (P <0.05). In addition, RANKL/OPG ratios decreased in well-controlled subjects (P <0.05) but not in poorly controlled subjects (P >0.05) at 3 months post-therapy. Almost all clinical parameters improved significantly for both groups post-treatment (P <0.05). CONCLUSION RANKL/OPG ratios in untreated and treated periodontitis sites may be negatively influenced by poor glycemic control in subjects with type 2 diabetes.

Early Human Bone Response to Laser Metal Sintering Surface Topography: A Histologic Report

This histologic report evaluated the early human bone response to a direct laser metal sintering implant surface retrieved after a short period of healing. A selective laser sintering procedure using a Ti-6Al-4V alloy powder with a particle size of 25-45 microm prepared this surface topography. One experimental microimplant was inserted into the anterior mandible of a patient during conventional implant surgery of the jaw. The microimplant and surrounding tissues were removed after 2 months of unloaded healing and were prepared for histomorphometric analysis. Histologically, the peri-implant bone appeared in close contact with the implant surface, whereas marrow spaces could be detected in other areas along with prominently stained cement lines. The mean of bone-to-implant contact was 69.51%. The results of this histologic report suggest that the laser metal sintering surface could be a promising alternative to conventional implant surface topographies.

Influence of direct laser fabrication implant topography on type IV bone: A histomorphometric study in humans

The aim of this histologic study was to evaluate the influence of the direct laser fabrication (DFL) surface topography on bone-to-implant contact (BIC%), on bone density in the threaded area (BA%) as well as bone density outside the threaded area (BD%) in type IV bone after 8 weeks of unloaded healing. Thirty patients (mean age 51.34 +/- 3.06 years) received 1 micro-implant (2.5-mm diameter and 6-mm length) each during conventional implant surgery in the posterior maxilla. Thirty micro-implants with three topographies were evaluated: 10 machined (cpTi); 10 sandblasted and acid etched surface (SAE) and 10 DFL micro-implants. After 8 weeks, the micro-implants and the surrounding tissue were removed and prepared for histomorphometric analysis. Four micro-implants (2 cpTi, 1 SAE and 1DLF) showed no osseointegration after the healing period. Histometric evaluation indicated that the mean BIC% was higher for the DFL and SAE surfaces (p = 0.0002). The BA% was higher for the DFL surface, although there was no difference with the SAE surface. The BD% was similar for all topographies (p > 0.05). Data suggest that the DFL and SAE surfaces presented a higher bone-to-implant contact rate compared with cpTi surfaces under unloaded conditions, after a healing period of 8 weeks.

Single-tooth Morse taper connection implants placed in fresh extraction sockets of the anterior maxilla: an aesthetic evaluation

OBJECTIVE The aim of this retrospective study was to evaluate the aesthetic outcome of single-tooth Morse taper connection implants placed in fresh extraction sockets of the anterior maxilla, by means of the pink aesthetic/white aesthetic score (PES/WES) index. MATERIALS AND METHODS Twenty-six adult patients (18 men, 8 women, aged between 20 and 62 years; average: 48.7 years) who were treated with an immediate, single-tooth Morse taper connection implant (Leone Implant System(R) , Florence, Italy) in the aesthetic area of the anterior maxilla, were enrolled in this retrospective study. An independent calibrated examiner applied the PES/WES index to 26 single-tooth implant-supported restorations, respectively, 3 months and 2 years after implant placement. RESULTS No implants were lost. All 26 anterior maxillary single-tooth implants fulfilled the established success criteria for dental implants with regard to osseointegration, including the absence of pain, suppuration, clinically detectable implant mobility, peri-implant radiolucency and prosthetic complications at the implant-abutment interface, with an overall implant-crown success of 100.0%. At the 2-year examination, the mean DIB was 0.44 ± 0.14 mm (95% CI: 0.41-0.47); the mean total PES/WES was 14.30 ± 2.78 (range 8-19); the mean PES was 7.30 ± 1.78 (range 4-10) and the mean WES was 7.00 ± 1.35 (range 4-10). CONCLUSIONS The immediate placement of single-tooth Morse taper connection implants in the anterior maxilla seems to represent a successful procedure, from an aesthetic point of view. Further studies are needed to evaluate the aesthetic outcome of single-tooth Morse taper connection implants placed in fresh extraction sockets of the anterior maxilla.

Equicrestal and Subcrestal Dental Implants: A Histologic and Histomorphometric Evaluation of Nine Retrieved Human Implants

BACKGROUND Stability of peri-implant crestal bone plays a relevant role relative to the presence or absence of interdental papilla. Several factors can contribute to the crestal bone resorption observed around two-piece implants, such as the presence of a microgap at the level of the implant-abutment junction, the type of connection between implant and prosthetic components, the implant positioning relative to the alveolar crest, and the interimplant distance. Subcrestal positioning of dental implants has been proposed to decrease the risk of exposure of the metal of the top of the implant or of the abutment margin, and to get enough space in a vertical dimension to create a harmoniously esthetic emergence profile. METHODS The present retrospective histologic study was performed to evaluate dental implants retrieved from human jaws that had been inserted in an equicrestal or subcrestal position. A total of nine implants were evaluated: five of these had been inserted in an equicrestal position, whereas the other four had been positioned subcrestally (1 to 3 mm). RESULTS In all subcrestally placed implants, preexisting and newly formed bone was found over the implant shoulder. In the equicrestal implants, crestal bone resorption (0.5 to 1.5 mm) was present around all implants. CONCLUSION The subcrestal position of the implants resulted in bone located above the implant shoulder.

Histologic Evaluation of Human Bone Integration on Machined and Sandblasted Acid-etched Titanium Surfaces in Type IV Bone

The aim of this preliminary study was to evaluate the influence of a sandblasted acid-etched surface on bone-implant contact percentage (BIC%) as well as the bone density in the threads area (BD%) in type 4 bone after 2 months of unloaded healing. Five subjects (mean age = 42.6 years) received 2 microimplants each during conventional implant surgery in the posterior maxilla. The microimplants with commercially pure titanium surface (machined) and sandblasted acid-etched surface served as the control and test surfaces, respectively. After a healing period of 2 months, the microimplants and the surrounding tissue were removed and prepared for ground sectioning and histomorphometric analysis. One microimplant with a machined surface was found to be clinically unstable at the time of retrieval. Histometric evaluation indicated mean BIC% was 20.66+/-14.54% and 40.08+/- 9.89% for machined and sandblasted acid-etched surfaces, respectively (P=.03). The BD% was 26.33 +/-19.92% for machined surface and 54.84+/-22.77% for sandblasted acid-etched surface (P=.015). Within the limits of this study, the data suggest that the sandblasted acid-etched implant surface presented a higher percentage of bone-implant contact compared with machined surfaces, under unloaded conditions in posterior maxilla after a healing period of 2 months.

Simultaneous Sinus Membrane Elevation and Dental Implant Placement Without Bone Graft: A 6-Month Follow-Up Study

BACKGROUND Previous studies have shown that simultaneous elevation of the sinus mucosal lining and placement of dental implants without graft materials can be a predictable procedure. Nevertheless, few prospective, controlled, and randomized studies have evaluated this technique. The aim of this prospective, controlled, and randomized clinical study is to evaluate whether sinus membrane elevation and simultaneous placement of dental implants without autogenous bone graft can create sufficient bone support to allow implant success 6 months post-surgically. METHODS Sinus membrane elevation and simultaneous placement of dental implants were performed bilaterally in 15 patients in a split-mouth design. The sinuses were assigned to two groups: the test group, with simultaneous sinus mucosal lining elevation and placement of dental implants without graft materials; and the control group, with simultaneous sinus mucosal lining elevation and placement of dental implants with intraoral autogenous bone graft. After 6 months of healing, abutments were connected. For each implant, length of implant protrusion into the sinus, resonance frequency analysis, and bone gain were recorded at baseline and 6 months follow-up. RESULTS Clinical complications were not observed, except for two postoperative fistulas and suppuration in both groups. Only one implant of the test group was lost, reaching a success rate of 96.4% and 100% for the test and control groups, respectively. After healing, radiographic new peri-implant bone was observed in both groups ranging between 8.3 ± 2.6 and 7.9 ± 3.6 mm for the control and test groups, respectively (P >0.05). Resonance frequency analysis values were lower for the control group compared to baseline (P <0.05). However, these values were similar at 6 months (P >0.05). A significant positive correlation was found between the protruded implant length/bone gain and implant survival/sinusitis (P <0.0001). CONCLUSION Implants placed simultaneously to sinus membrane elevation without graft material resulted in bone formation over a period of 6 months.