bluuebunny/crossref_metadata_2025 huggingface dataset:
Tissue inhibitor of metalloproteinases‐1, matrix metalloproteinases‐1 and ‐8, and collagenase activity levels in peri‐implant crevicular fluid after implantation
Authors: Nomura Takashi , Ishii Ayato , Shimizu Hiroshi , Taguchi Naoyuki , Yoshie Hiromasa , Kusakari Haruka , Hara Kohji
Published: March 2003

The integrity of connective tissues surrounding dental implants may be influenced by a balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). The purpose of this study was to provide an overall assessment of TIMP‐1, MMP‐1 and ‐8 levels as well as collagenase activities during the wound healing process after implantation and in peri‐implantitis lesions. Peri‐implant crevicular fluid (PICF) was sampled with sterile paper strips from 10 osseointegrated implants of 6 subjects. Ten implants from 6 patients affected with peri‐implantitis were also assessed. Gingival crevicular fluid (GCF) from 11 periodontitis‐affected patients and 10 healthy volunteers served as controls. TIMP‐1 and MMP‐1 and ‐8 protein levels in the PICF were measured by ELISA, and active and APMA‐activatable collagenase activities were determined by functional assays using image‐analysis after SDS‐PAGE. The experiment showed a significant increase in the TIMP‐1 level at 1 week after implantation as compared with that in GCF from healthy periodontium. Four weeks after implantation it had reached the same level as that in the GCF of healthy subjects. The data has also disclosed a higher post‐implantation collagenase activity level at 1 week than at weeks 2, 4, and 12. This may be due to the increase in MMP‐1 and ‐8. Furthermore, peri‐implantitis and periodontitis were shown to be similar inflammatory lesions in respect to MMP‐1 and ‐8 and collagenase activities, even though the TIMP‐1/MMP‐1+MMP‐8 ratio was significantly lower in peri‐implantitis than in periodontitis. In conclusion, the over‐production of TIMP‐1 in the wound area after implantation could, to some extent, inhibit excessive tissue destruction and degradation of the neo‐matrix in wound repair due to MMPs.
An in vitro study on compensation of mismatch of screw versus cement‐retained implant supported fixed prostheses
Authors: Pietrabissa Riccardo , Gionso Luca , Quaglini Virginio , Di Martino Elena , Simion Massimo
Published: March 2003

In common practice a perfect fit of the prosthetic framework with the implant abutments is almost impossible to achieve. The mismatch, which is principally induced by the technological process adopted to manufacture the fixed prostheses, strains the framework thus generating constraint reactions. These are static forces that load the implant components and the bone at the implant–bone interface and may cause the bone remodelling. Depending on the magnitude of such forces, i.e. depending on the magnitude of the mismatch, the bone remodelling may lead to the loosening of the screws and of the implant–bone interface and hence cause implant failure. The present study shows an in vitro comparison of 3 different connecting abutments (standard, EsthetiCone and CerAdapt, Nobel Biocare AB, Göteborg, Sweden) with relation to the mechanical stresses induced by geometrical mismatches (technology induced errors). Two experimental devices were purposely realized and used to assess the ability of the different abutments to compensate errors. One was designed for translation errors and the other for rotation errors. The experimental apparatus set‐up includes 2 freestanding implants supporting a prosthetic structure and the connecting abutments. The implants and the abutments were used as delivered by the manufacturer, while the prostheses were purposely realized and instrumented with strain gauges. The data obtained with the error devices do not give quantitative information on what happens in clinical applications where the implants are connected to living bone, which is a tissue much more deformable than the steel used for the error devices. Results allow direct comparisons of the behaviour of the different investigated abutments with respect to position errors. The CerAdapt system (cement retained ceramic abutments) showed the least strain in presence of translation errors. The standard system (screw retained abutments) showed the least strain in presence of rotation errors.
Bone classification: an objective scale of bone density using the computerized tomography scan
Authors: Norton Michael R. , Gamble Carole
Published: March 2003

Abstract: Dental implants are subject to masticatory loads of varying magnitude. Implant performance is closely related to load transmission at the bone‐to‐implant interface where bone quality will be highly variable. The type and architecture of bone is known to influence its load bearing capacity and it has been demonstrated that poorer quality bone is associated with higher failure rates. To date, bone classifications have only provided rough subjective methods for pre‐operative assessment, which can prove unreliable. The results of an extensive analysis of computerized tomography scans using SimplantTM software (Columbia Scientific Inc., Columbia, MD, USA) demonstrate that an objective scale of bone density based on the Houndsfield scale, can be established and that there is a strong correlation between bone density value and subjective quality score (P=0.002) as well as between the bone density score and the region of the mouth (P<0.001).
Bisphosphonate inhibits alveolar bone resorption in experimentally‐induced peri‐implantitis in dogs
Authors: Shibutani Toshiaki , Inuduka Akihiro , Horiki Itaru , Iwayama Yukio , Luan Qingxing
Published: March 2003

Abstract: The purpose of this study was to determine the effect of bisphosphonate on alveolar bone resorption in experimentally‐induced peri‐implantitis in beagle dogs. Experimental peri‐implantitis was induced by ligation around the abutments, 6 months after placement of a fixture. Pamidronate (0.6 mg/kg) was injected intramuscularly every 3 days into each of 5 dogs. Another 5 dogs served as the control group and were injected with saline only. Peripheral blood and urine samples were collected every week up to 12 weeks after placement of the ligature. Standard X‐rays were taken every week. Urinary deoxypyridinoline (DPD) and serum osteocalcin (OC) were evaluated by ELISA as markers of alveolar bone remodeling. X‐ray films were analyzed with a computer image analyzer. After 12 weeks, the bone level was measured after removal of the gingival flap. The distance between the top surface of the fixture and the fundus of the defect was significantly lower in the Pamidronate group (1.59±0.55 mm, mean±SD) than in the control group (2.41±0.48 mm). Bone density analyzed from the X‐ray films was significantly higher in the bisphosphonate group (69.2±8.7%, mean±SD) than in the control group (50.3±12.8%) after 2 to 8 weeks compared with the baseline value (100%). OC and DPD levels fluctuated during the experimental period. These findings suggest that bisphosphonate inhibits the progression of alveolar bone resorption during ligature‐induced peri‐implantitis in dogs.
Inter‐abutment and peri‐abutment mucosal enlargement with mandibular implant overdentures
Authors: Payne Alan G. T. , Solomons Yvette F. , Tawse‐Smith Andrew , Lownie John F.
Published: March 2003

Abstract: A variety of terms have been used to describe changes in the oral mucosa around abutments underneath fixed and removable implant prostheses such as mucosal inflammation, peri‐implant mucosal hyperplasia, gingival hyperplasia, hyperplastic tissue, mucosal proliferation, proliferative gingivitis and peri‐implant mucositis. Although such terms have become part of the evidence‐based literature, there is no histological evidence to support the descriptive terminology used by authors. The use of the alternative term mucosal enlargement for clinical observations underneath mandibular implant overdentures is proposed. Prospective and retrospective reports have failed to use similar criteria to measure periodontal parameters in relation to these mucosal changes, both in keratinized or non‐keratinized tissues. Therapeutic remedies for mucosal enlargement are dictated by authors’ opinions on the possible aetiology. This literature review, coupled with clinical observations during a 5‐year prospective study, prompts this proposal of the term mucosal enlargement underneath splinted and unsplinted mandibular implant overdentures.
Retrospective assessment of clinical and microbiological factors affecting periimplant tissue conditions
Authors: Rutar Alexandra , Lang Niklaus P. , Buser Daniel , Bürgin Walter , Mombelli Andrea
Published: March 2003

Abstract: An increasing number of studies point to the detrimental effect of plaque bacteria on periimplant tissue health. The purpose of this retrospective study was to explore a possible relationship between the clinical and microbiological periimplant conditions of osseointegrated oral implants after several years of service and the dental and medical history, as well as the conditions of the residual dentition. 45 partially edentulous patients (mean age: 51 years, range: 27–83 years), with a total of 64 implants participated in this retrospective analysis. The time between examination and the last dental visit ranged from 6 to 24 months (mean: 13 months) and the time since the last maintenance therapy appointment with a dental hygienist ranged between 3 and 24 months (mean 7 months). During 5 to 10 years between implant installation and examination, 9 implants experienced one episode and an additional 6 implants two episodes of periimplantitis. As a consequence of extensive bone loss associated with these infections, one of these implants, in a patient who had a history of diabetes, was lost. With this exception, the other episodes of periimplantitis were successfully treated employing the principles of the Cumulative Interceptive Supportive Therapy (CIST) protocol. At examination, 42 implants (66%) showed a probing pocket depth exceeding 4 mm. Of the periimplantitis sites, four implants showed cultural evidence for presence of Porphyromonas gingivalis, and 2 implants were positive for Actinobacillus actinomycetemcomitans. Statistical analysis revealed a significant relationship between periimplant probing depth and the total anaerobic cultivable microbiota as well as the frequency of detection of P. gingivalis.
The influence of static and dynamic loading on marginal bone reactions around osseointegrated implants: an animal experimental study
Authors: Duyck Joke , Naert Ignace , Rønold Hans Jacob , Ellingsen Jan Eirik , Van Oosterwyck Hans , Vander Sloten Jos
Published: March 2003

Abstract: Although it is generally accepted that adverse forces can impair osseointegration, the mechanism of this complication is unknown. In this study, static and dynamic loads were applied on 10 mm long implants (Brånemark System®, Nobel Biocare, Sweden) installed bicortically in rabbit tibiae to investigate the bone response. Each of 10 adult New Zealand black rabbits had one statically loaded implant (with a transverse force of 29.4 N applied on a distance of 1.5 mm from the top of the implant, resulting in a bending moment of 4.4 Ncm), one dynamically loaded implant (with a transverse force of 14.7 N applied on a distance of 50 mm from the top of the implant, resulting in a bending moment of 73.5 Ncm, 2.520 cycles in total, applied with a frequency of 1 Hz), and one unloaded control implant. The loading was performed during 14 days. A numerical model was used as a guideline for the applied dynamic load. Histomorphometrical quantifications of the bone to metal contact area and bone density lateral to the implant were performed on undecalcified and toluidine blue stained sections. The histological picture was similar for statically loaded and control implants. Dense cortical lamellar bone was present around the marginal and apical part of the latter implants with no signs of bone loss. Crater‐shaped bone defects and Howship’s lacunae were explicit signs of bone resorption in the marginal bone area around the dynamically loaded implants. Despite those bone defects, bone islands were present in contact with the implant surface in this marginal area. This resulted in no significantly lower bone‐to‐implant contact around the dynamically loaded implants in comparison with the statically loaded and the control implants. However, when comparing the amount of bone in the immediate surroundings of the marginal part of the implants, significantly (P<0.007) less bone volume (density) was present around the dynamically loaded in comparison with the statically loaded and the control implants. This study shows that excessive dynamic loads cause crater‐like bone defects lateral to osseointegrated implants.
Early loading of sandblasted and acid‐etched (SLA) implants: a prospective split‐mouth comparative study
Authors: Roccuzzo Mario , Bunino Marco , Prioglio Fabrizio , Bianchi Silvio D.
Published: March 2003

Abstract: Sandblasted and acid‐etched (SLA) implants were recently introduced to reduce the healing period between surgery and prosthesis. In this split‐mouth study, SLA implants were compared to titanium plasma‐sprayed (TPS) implants under loaded conditions one year after placement in 32 healthy patients, with comparable bilateral edentulous sites and no discrepancies in the opposing dentition. The surgical procedure was performed by the same operator and was identical at 68 SLA (test) and 68 TPS (control) sites. Tapping was never performed and primary stability was always achieved. Abutment connection was carried out at 35 Ncm 6 weeks postsurgery for test sites and 12 weeks for the controls, by the same dentist blind to the type of surface of the implant. In 4 of the 68 test sites the implant rotated slightly, patients reported minor pain and connection was not completed. Provisional restoration was fabricated and a new tightening was performed after six weeks. Similar gold‐ceramic restorations were cemented on the same type of solid abutments on both sites. No implant was lost. Clinical measures and radiographic changes were recorded by the same operator, blind to the type of surface of the implant, 1 year post surgery. No significant differences were found with respect to presence of plaque (24% vs. 27%), bleeding on probing (24% vs. 31%), mean pocket depth (3.3 mm vs. 2.9 mm) or mean marginal bone loss (0.65 mm vs. 0.77 mm). The results suggest that SLA implants are suitable for early loading at 6 weeks. Limited implant spinning may occasionally be found but, if properly handled, it produces no detrimental effect on the clinical outcome.
Resonance frequency assessment of dental implant stability with various bone qualities: a numerical approach
Authors: Huang Haw‐Ming , Lee Sheng‐Yang , Yeh Ching‐Ying , Lin Che‐Tong
Published: March 2003

Abstract: Resonance frequency analysis (RFA) has been used by several investigators to assess the boundary conditions of dental implants. The goal of the current study was to determine the vibrating behavior of a dental implant under various surrounding bone conditions. A 3D finite element (FE) model of a cylinder‐type titanium implant was developed. In this model, the implant was embedded into a cubic section of bone. The model was first validated using a series of modal testing experiments. The effects of bony conditions on the resonance frequencies of the implant were computed with different bone types and bone densities. Our results show that the resonance frequency of the implant with type III surrounding bone decreased linearly (r=−0.996, P<0.01) from 17.9 kHz (without loss in bone density) to 0.6 kHz (90% loss in bone density) when the bone densities were decreased. On the other hand, without bone loss, the highest resonance frequency value (36.1 kHz) was found when the implant was placed into type I surrounding bone. In contrast, the resonance frequency of the implant with type IV bone quality was found to be 9.9 kHz, which is almost four‐fold less than that found in the type I model. These results suggest that RFA could serve as a non‐invasive diagnostic tool for detecting the stability of dental implants during the healing stages and in subsequent routine follow‐up care after treatment.
Alveolar ridge augmentation by combining autogenous mandibular bone grafts and non‐resorbable membranes
Authors: Donos Nikolaos , Kostopoulos Lambros , Karring Thorkild
Published: March 2003

Abstract: The aim of the present study was to evaluate the effect of using mandibular cortical bone grafts covered with e‐PTFE membranes for maxillary alveolar ridge augmentation, in comparison with the use of mandibular cortical grafts alone. The experiment was carried out in 20 rats. At one side of the maxillary jaw, the edentulous alveolar ridge between the incisor and the first molar was augmented by means of an autogenous mandibular bone graft, which was fixed with a titanium microimplant and covered with a Teflon membrane. The contralateral side, serving as control, was treated the same way, except for the placement of a membrane. Histological analysis at 15, 30, 60 and 90 days after surgery demonstrated that, in situations where the membrane was not exposed to the oral cavity during healing, the mandibular bone grafts presented no resorption and were in continuity with the maxillary bone at the recipient site. In situations where the membrane had become exposed, however, the bone grafts presented extensive resorption and lack of continuity with the bone at the recipient site. These latter findings were similar to those made at the non‐membrane‐treated side. The results indicate that the volume of autogenous bone graft used for alveolar ridge augmentation can be retained by covering the graft with a membrane, provided that the membrane is properly adapted and is kept covered with mucosa during healing.
Injectable calcium phosphate cement as a filler for bone defects around oral implants: an experimental study in goats
Authors: Comuzzi Luca , Ooms Edwin , Jansen John A.
Published: March 2003

Abstract: The aim of this study was to evaluate the clinical applicability and biological behavior of a newly developed injectable calcium phosphate (Ca‐P) cement as bone filler for gaps around oral implants. Twenty‐four step‐like implants, creating gaps of 1 and 2 mm, were inserted into the trabecular bone of the medial femoral condyles of six goats. Four different situations were tested: (1) implant + gaps; (2) implant + gaps, but covered with a polylactic acid membrane; (3) implant + gaps that were filled with Ca‐P cement; and (4) implant + gaps that were filled with Ca‐P cement and covered with a membrane. All implants were left in place for 12 weeks. Histological and quantitative histomorphometrical measurements demonstrated that implants + gaps had generally poor bone contact at the implant base. Furthermore, fibrous encapsulation was observed in the gap part. In contrast, the presence of a membrane promoted bone ingrowth into the gap and also the bone contact at the implant base. Injection of Ca‐P cement resulted in an almost complete filling of the gaps around the implant. The cement surface was completely covered by bone. Active resorption and remodeling of cement particles was observed, suggesting a pattern of slow resorption associated with full replacement with newly formed bone. Additional use of a membrane did not result in adjunctive benefits. Bone‐to‐implant contact at the implant base was comparable with the implants provided only with a membrane. In conclusion, the Ca‐P cement used here showed excellent clinical handling properties combined with a superior bone behavior. On the other hand, the degradation rate of the material was still very slow. This current characteristic can hamper the final clinical applicability of the material as gap filler for periimplant or periodontal defects.
Food selection and perceptions of chewing ability following provision of implant and conventional prostheses in complete denture wearers
Authors: Allen Finbarr , McMillan Anne
Published: March 2003

Abstract: The loss of natural teeth compromises chewing efficiency, and edentulous patients often have a diet that is deficient in fibre and vitamins. Prostheses that are retained on implants offer the possibility of overcoming some of the limitations of conventional dentures in terms of chewing efficiency. The aim of this study was to test the hypothesis that improvement in satisfaction with oral prostheses would result in improved food selection in edentulous patients. This prospective study involved three groups, namely (i) subjects who requested and received implants to stabilise a complete fixed or removable prosthesis (IG, n = 26), (ii) edentulous subjects who requested implant prostheses, but received conventional dentures (CDG1, n = 22), and (iii) edentulous subjects who requested and received conventional dentures (CDG2, n = 35). Data were collected using validated questionnaires pre‐ and postoperatively. Prior to treatment, all subjects were asked whether they ate a variety of hard and soft foods, to indicate the degree of difficulty they experienced when chewing these foods, and to rate their satisfaction with various aspects of their maxillary and mandibular complete dentures. Following the completion of treatment, subjects completed the questionnaires again. Pre‐ and postoperative data were compared. Subjects who received implant prostheses reported significant improvement in chewing hard and soft foods. CDG2 subjects also reported improvement, but CDG1 subjects reported no change or even deterioration following treatment. Despite reported improvement in satisfaction with comfort and ability to chew food, 30–50% of IG and CDG2 subjects still avoided eating foods such as carrot and apple. This suggests that, in the absence of tailored dietary advice, apparently successful prosthetic rehabilitation does not necessarily result in a satisfactory diet.
Quality of life assessment in patients with implant‐supported and resin‐bonded fixed prosthesis for bounded edentulous spaces
Authors: Sonoyama Wataru , Kuboki Takuo , Okamoto Soichiro , Suzuki Hidenori , Arakawa Hikaru , Kanyama Manabu , Yatani Hirofumi , Yamashita Atsushi
Published: March 2003

Abstract: Objectives: Dental implants have become increasingly popular in the prosthetic rehabilitation of patients with bounded edentulous spaces. Oral condition‐related quality of life (QOL) levels have rarely been assessed in these patients.

Material and methods: Two groups of subjects with bounded edentulous spaces were studied: an implant‐supported fixed prosthesis group (11 patients) and a resin‐bonded fixed prosthesis group (33 patients). The two groups were well matched in terms of sex, age, missing units and location of missing units. The patients were requested to answer a self‐administered QOL questionnaire with two major subscales − oral condition‐ and general condition‐related QOL scores. The test–retest reliability of each question was pre‐examined and found acceptable (mean Spearman rank correlation coefficient was 0.55 ± 0.16). Mean QOL score differences between the two groups were analyzed by the Mann–Whitney U‐test.

Results: Mean oral condition‐related QOL scores of the implant‐supported and resin‐bonded fixed prosthesis groups were 87.8 ± 9.5 and 87.1 ± 12.3% (P = 0.85), and mean general condition‐related QOL scores were 73.8 ± 14.8 and 71.6 ± 15.2% (P = 0.95), respectively. No significant QOL differences between the two groups were observed in the two subscales.

Conclusion: In patients with bounded edentulous spaces, multidimensional QOL levels of patients with an implant‐supported fixed prosthesis do not exceed those of patients with a resin‐bonded fixed prosthesis in a short follow‐up period.
Organization of the connective tissue barrier around long‐term loaded implant abutments in man
Authors: Schierano Gianmario , Ramieri Guglielmo , Cortese MariaGrazia , Aimetti Mario , Preti Giulio
Published: March 2003

Abstract: The study aimed to investigate the connective tissue seal and the spatial organization of collagen fibers around long‐term loaded implants in man. Block specimens containing smooth titanium implant abutments and the surrounding supracrestal connective tissue were obtained from patients rehabilitated for at least 1 year with implant‐retained overdentures or implant‐supported fixed prostheses and were histologically investigated. The histological features of the connective tissue around long‐term loaded titanium abutments were specific: the tissue was rich in collagen fibers, organized in bundles, presenting a constant spatial arrangement, similar to that reported in animal studies. Circular fibers, the most numerous, were located externally, and longitudinal fibers internally. Radial fibers inserted on the abutment surface, similar to those of the periodontal system, were not observed in any case. No histological differences were found between tissue sampled around implants supporting a fixed restoration and those anchoring an overdenture.
Conventional and early loading of unsplinted ITI implants supporting mandibular overdentures
Authors: Payne Alan G. T. , Tawse‐Smith Andrew , Duncan Warwick D. , Kumara Rohana
Published: March 2003

Abstract: The aim of this study was to compare the success rates after 1 and 2 years of conventionally and early loaded pairs of unsplinted ITI implants supporting mandibular overdentures in edentulous patients. Twenty‐four participants (age range 55–80 years) were randomly allocated with maximum concealment to two treatment groups. In the first group, the implants were allowed to heal for 12 weeks before being functionally loaded (control) and the second group had 6 weeks of healing with identical loading. All participants had new conventional complete maxillary and mandibular dentures prior to the study. Two sandblasted large‐grit acid‐etched (SLA) surface ITI implants were placed in the mandibular interforaminal area, following a standardized nonsubmerged surgical protocol. After 6 or 12 weeks of healing, matrices were processed into the fitting surface of the pre‐existing mandibular dentures and the implants loaded. Implant success was determined using mobility tests and radiographs taken at baseline and 52 and 104 weeks after surgery. Clinical peri‐implant parameters were also documented. Results showed all implants successfully osseointegrated, according to accepted criteria, after 2 years. Mean loss of crestal bone height after 1 year was 0.35 ± 0.22 mm (control) vs. 0.27 ± 0.18 mm (test). After 2 years this reduced to 0.09 ± 0.06 mm (control) vs. 0.12 ± 0.17 mm (test). The mean Periotest® value after 1 year was −4.9 (control) vs.−3.78 (test). After 2 years, the mean resonance frequency value for the control implants was 6797 Hz [mean implant stability quotient (ISQ) = 64.77] and for the test implants 6670 Hz (mean ISQ = 62.0). Shortened loading periods for these ITI implants did not cause any statistically significant differences in osseointegration or peri‐implant parameters. We conclude that pairs of unsplinted SLA‐surface ITI implants can be successfully loaded with mandibular overdentures 6 weeks after surgery.
The relative impact of local and endogenous patient‐related factors on implant failure up to the abutment stage
Authors: Van Steenberghe Daniel , Jacobs Reinhilde , Desnyder Mandy , Maffei Gaia , Quirynen Marc
Published: March 2003

Abstract: The aim of the present study was to assess the influence of endogenous and local factors on the occurrence of implant failure up to the abutment stage. The study comprised a group of 399 consecutive patients, which represented the total of patients who had been treated from 1995 to 1997 (with a total of 1263 Brånemark Brån‐system® implants) at the Department of Periodontology of the University Hospital, Catholic University Leuven. For each patient, the medical history was carefully examined. Data collection and analysis were mainly focused on endogenous factors such as hypertension, osteoporosis, hypo‐ or hyperthyroid function, chemotherapy, diabetes type I or II, Crohn's disease, some local factors (e.g. bone quality, reason for tooth loss) and breach of sterility during surgery. The reason for tooth loss, smoking habits, radiotherapy and other local bone factors (bone quality and quantity) were also recorded. Implant failures were recorded up to the abutment connection. The present study indicated a success rate until this stage of 97.8%. General factors such as heavy smoking, chemotherapy plus poor bone quality increased implant failure rate. Radiotherapy, limited bone volume and claustrophobia, which led to breaching the strict preoperative rules of asepsis, appeared to be the most relevant local factors for early implant failures.
Comparative analysis of collagen membranes for the treatment of implant dehiscence defects
Authors: Oh Tae‐Ju , Meraw Stephen J. , Lee Eun‐Ju , Giannobile William V. , Wang Hom‐Lay
Published: March 2003

Abstract: Guided bone regeneration (GBR) evolved from the concept of guided tissue regeneration (GTR) and has been used for reconstructing sites with bone deficiencies associated with dental implants. For GBR, the use of absorbable collagen membranes has been increasing, but, at present, scientific information on the use of collagen membranes for GBR is limited. This study was aimed to clinically and histomorphometrically compare two collagen membranes, Bio‐Gide® and BioMend ExtendTM, for the treatment of implant dehiscence defects in eight mongrel dogs. Implant dehiscence defects were surgically created in edentulous ridges, followed by the placement of three endosseous implants bilaterally in the mandible. Each implant dehiscence defect was randomly assigned to one of three treatment groups: (1) control (no membrane), (2) porcine dermis collagen barrier (Bio‐Gide) or (3) bovine tendon collagen barrier (BioMend Extend). Dogs were sacrificed at 4 and 16 weeks (four dogs each) after treatment. Histomorphometric analysis included percentage linear bone fill (LF), new bone‐to‐implant contact (BIC) and area of new bone fill (BF). The results of the study revealed no significant differences among groups for any parameter at 4 weeks. However, at 16 weeks, more LF, BIC, and BF were noted in the membrane‐treated groups than controls. BioMend Extend‐treated defects demonstrated significantly greater BIC than control (P < 0.05) at this time point. BIC at 16 weeks was significantly greater than 4‐week BIC (P < 0.05). Membrane exposure occurred in 9 out of 15 sites examined, resulting in significantly less LF and BIC than the sites without membrane exposure (P < 0.05). The results of this study indicate that: (1) GBR treatment with collagen membranes may significantly enhance bone regeneration, manifested at late stage (16 weeks) of healing; and (2) space maintenance and membrane coverage were the two most important factors affecting GBR using bioabsorbable collagen membranes.
Biomechanical stress in bone surrounding an implant under simulated chewing
Authors: Ishigaki Shoichi , Nakano Tamaki , Yamada Shinichi , Nakamura Takashi , Takashima Fumio
Published: March 2003

Abstract: The concept of reducing nonaxial loading of dental implants has been widely regarded as the standard procedure. The aim of this study was to reveal the biomechanical stress distribution in supporting bone around an implant and a natural tooth under chewing function. Three‐dimensional finite element models of the mandibular first molar and the titanium implant both with the mandible in the molar region were constructed. The directions of displacement constraints were determined according to the angles of the closing pathways of chopping type and grinding type chewing patterns. The tooth model showed smooth stress distribution in the supporting bone with low stress concentration around the neck of the tooth. The implant model showed stress concentration in the supporting bone around the neck of the implant, especially in the buccal area. The grinding type model of the implant showed higher tensile stress concentration than the chopping type model at the lingual neck of the implant. The results of this study suggested the importance of considering occlusion under chewing function for understanding the biomechanics of oral implants.
Patient satisfaction and quality of single‐tooth restorations
Authors: Vermylen Katrien , Collaert Bruno , Lindén Ulf , Björn Anna‐Lisa , De Bruyn Hugo
Published: March 2003

Abstract: This retrospective study focuses on patient opinion and professionally assessed quality of single‐tooth restorations of Brånemark fixtures. Patients were treated by periodontists for fixture installation and/or abutment connection and by referring general practitioners for prosthetic rehabilitation. Seventy‐eight consecutively treated patients were sent a questionnaire regarding aesthetics, phonetics and overall satisfaction. Forty‐eight patients (52 fixtures) returned the questionnaire. Forty were able to attend a clinical examination by an independent examiner. The quality of 43 single implant crowns was evaluated according to the modified guidelines for assessment of quality and professional performance used for evaluation of design, fit, occlusion/articulation and aesthetics. Bone to implant level was assessed radiographically. Patients were very positive about aesthetics, phonetics, eating comfort and overall satisfaction. Nevertheless, 6/40 patients would not undergo the same treatment again, yet all of them would recommend it to others. The professionally rated quality of the crowns was perfect in 17 and acceptable in 25 cases. One crown needed modification to prevent future complications. Two crowns had already been replaced as a result of porcelain fracture; one restoration showed abrasion and one was damaged. With a mean loading time of 33 months (range: 3–89 months), none of the patients returning the questionnaire had encountered fixture loss. All except five fixtures showed bone remodelling at or above the first implant thread. It is concluded that single Brånemark fixtures installed by periodontists and restored by general practitioners are of an acceptable clinical quality to satisfy the patient.
Within‐subject comparisons of maxillary fixed and removable implant prostheses
Authors: Heydecke Guido , Boudrias Pierre , Awad Manal A. , De Albuquerque Rubens F. , Lund James P. , Feine Jocelyne S.
Published: March 2003

Abstract: Dental implants provide patients with restorative options for the edentulous maxilla. Both fixed and removable prostheses can be attached to the edentulous maxilla, but the efficacy of different designs has not been determined. In this two‐session within‐subject crossover trial we compared maxillary implant retained fixed prostheses with removable implant overdentures opposed by mandibular implant‐supported overdentures. Sixteen patients, who had previously received mandibular implants, entered the study and received four to six maxillary implants. After dropouts as a consequence of a lack of osseointegration and general health problems, 13 remained. Of these, five received the removable prosthesis first and eight the fixed prosthesis. After 2 months, the prostheses were exchanged and the second was also worn for 2 months. Psychometric measurements of general satisfaction with the prostheses as well as comfort, ability to speak, stability, esthetics, ease of cleaning and occlusion were obtained once each prosthesis had been worn for 2 months. Chewing ability was assessed for seven types of food. Removable long‐bar overdentures received significantly higher ratings of general satisfaction than fixed prostheses (P = 0.003). Patients also rated their ability to speak and ease of cleaning significantly better with the removable overdentures. Nine patients chose to keep the removable prosthesis and four preferred to keep the fixed prosthesis. The results suggest that maxillary removable overdentures on multiple implants may provide patients with better function than fixed prostheses.

Heydecke G, Boudrias P, Awad MA, de Albuquerque Jr RF, Lund JP, Feine JS. Within subject comparisons of maxillary fixed and removable implant prostheses: Patient satisfaction and choice of prosthesis.
Exposure to tobacco smoking and periodontal health
Authors: Bergström Jan , Eliasson Sören , Dock Jan
Published: March 2003

Background: The influence of smoking behavior on the periodontal health condition was clinically and radiographically studied in 257 dentally aware adults in the age range 20–69 years, including 50 current smokers, 61 former smokers and 133 non‐smokers.

Aims:

The clinical variables to be investigated were frequency of diseased sites ≥4 mm, frequency of gingival bleeding sites and plaque index. In addition, the periodontal bone height was radiographically assessed as a % of the dental root length.

Methods: All variables were based on full‐mouth examinations including all teeth and periodontia.

Results: The observations indicated an inferior periodontal health condition associated with smoking. This was evidenced by a significantly greater frequency of diseased sites and a significantly greater reduction of periodontal bone height in current smokers as compared to non‐smokers. The condition of former smokers was intermediate between current smokers and non‐smokers, suggesting that former smokers who have quit smoking have a better periodontal health condition than current smokers, although worse than that of non‐smokers. The finding that former smokers exhibited less disease than current smokers suggests that smoking cessation may be beneficial and mitigate the untoward effects inflicted by smoking, allowing a normalization towards non‐smoker conditions. Heavy exposure was consistently associated with more severe a condition than light exposure, suggesting that the relationship between smoking exposure and periodontal morbidity is dose‐dependent.

Conclusions: Altogether, the present observations identify a negative impact from smoking on periodontal health and provide further evidence that tobacco smoking is an avoidable risk for periodontal disease.
Lack of antimicrobial effect on periodontopathic bacteria by ultrasonic and sonic scalers in vitro
Authors: Schenk Günther , Flemmig Thomas F. , Lob Sibylle , Ruckdeschel Gotthard , Hickel Reinhard
Published: March 2003

Background: The purpose of this study was to assess the antimicrobial effects of a sonic and ultrasonic scaler generally used for subgingival scaling on gram‐negative and gram‐positive periodontopathic bacteria.

Method: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Campylobacter rectus, or Peptostreptococcus micros were suspended in Schaedler's broth medium and treated by a sonic or a magnetostrictive ultrasonic scaler for 30 s and 150 s in vitro. Bacterial suspensions treated by an ultrasonic cell disruptor served as a positive control and untreated bacterial suspensions served as a negative control. Following sonication, samples were serially diluted, streaked on blood agar plates and incubated for 2–5 days at 37°C.

Results: Treatment by the sonic or ultrasonic scaler for up to 150 s did not reduce the viability of any of the tested periodontal pathogens. Compared to untreated controls, the viability of A. actinomycetemcomitans and P. gingivalis was significantly (p<0.05) reduced only following ultrasonication with the cell disruptor after 30 s (0.72 and 0.54 log CFU/ml, respectively) and of A. actinomycetemcomitans, P. gingivalis, C. rectus, and P. micros after 150 s (1.98, 1.34, 1.95 and 1.98 log CFU/ml, respectively).

Conclusion: The data of the study may indicate that the assessed sonic and ultrasonic scaler used for subgingival debridement do not result in killing of the tested periodontal pathogens.
Relationship of the substance P to indicators of host response in human gingival crevicular fluid
Authors: Hanioka Takashi , Takaya Keiko , Matsumori Yukiko , Matsuse Ryoichi , Shizukuishi Satoshi
Published: March 2003

Backgound: The substance P (SP) level in human gingival crevicular fluid (GCF) was studied in relation to clinical periodontal variables and to various indicators of host response in the GCF.

Methods: GCF was collected from periodontal sites with gingival inflammation and shallow or moderately deep pocket in 48 subjects. The total amount of SP and the substances based on host response factors in a 30‐s sample were determined by ELISA and enzymatic methods.

Results: Significant correlation was found between SP and probing depth (r=0.637, p<0.001), while correlation was weak between SP and either gingival (r=0.177, p=0.23) or plaque index (r=0.008, p=0.96). SP also showed significant correlation with the indicators of host response: prostaglandin E2, aspartate aminotransferase, alkaline phosphatase, myeloperoxidase, interleukin‐1β, tumor necrosis factor‐α, interleukin‐8 and monocyte chemoattractant protein‐1 (r=0.434–0.867, p<0.01–0.001).

Conclusion: These results indicate that neuropeptide SP in GCF may have a potential as an indicator of periodontal inflammation and the host response.
Healing following GTR treatment of intrabony defects distal to mandibular 2nd molars using resorbable and non‐resorbable barriers
Authors: Karapataki Sofia , Hugoson Anders , Falk Hanne , Laurell Lars , Kugelberg Carl F.
Published: March 2003

Aims: The objectives of the present, randomised clinical trial were (i) to evaluate the healing of periodontal intrabony defects at the distal aspect of mandibular 2nd molars using a resorbable polylactic acid (PLA) barrier and a non‐resorbable polytetrafluoroethylene (e‐PTFE) barrier and (ii) to compare the therapeutic effect of the bioresorbable versus the non‐resorbable barrier.

Method: 19 patients with intrabony defects distal to mandibular 2nd molars 4 mm (on radiographs) were included in the study. The defects all remained 5 years after surgical removal of impacted 3rd molars. Following flap elevation and defect debridement, the defects were randomly covered with, either a resorbable PLA or a non‐resorbable e‐PTFE barrier. Flaps were repositioned and sutured to completely cover the barriers. Treatment was evaluated clinically after 1 year by measurements of probing depth (PD), probing attachment level (PAL), and probing bone level (PBL) and radiographically by measurements of bone levels on computer digitised images of radiographs taken immediately before and 1 year post‐surgery.

Results: Both treatments resulted in significant PD reduction, PAL gain, and bone fill. The total PD reduction was 5.3±l.9 mm for the PLA treated sites and 3.7±l.7 mm for the e‐PTFE treated sites (p<0.05). The corresponding values for PAL gain were 4.7±0.7 mm and 3.6±1.7 mm (p<0.05) and for PBL gain 5.1±1.2 and 3.3±2.0 mm (p<0.05). Radiographic bone fill averaged 3.4±l.2 for the PLA and 2.0±1.6 mm for the e‐PTFE barriers (p<0.05). Radiographic bone level measurements were significantly smaller than the corresponding clinical measurements, indicating that radiographs tend to underestimate bone fill.

Conclusions: GTR treatment of deep intrabony defects distal to mandibular second molars using resorbable PLA barriers resulted in significant PD reduction, PAL gain and bone fill at least equivalent to the results obtained using non‐resorbable e‐PTFE barriers.
The validity and reproducibility of an oral rating index as a measurement of gingival health care and oral hygiene level in adults
Authors: Kawamura Makoto , Fukuda Setsuko , Inoue Chiaki , Sasahara Hisako , Iwamoto Yoshifumi
Published: March 2003

The purpose of this study was to investigate the validity and reproducibility of an oral rating index (ORI) as a conceptual measurement of “gingival health care” level in adults. The study was conducted on 163 patients who received medical examinations and attended for dental checkups at a hospital. The score of the ORI was recorded as excellent (+2), good (+1), questionable (0), poor (−1) or very poor (−2). The validity of the ORI was investigated by comparing it with: Jackson's gingivitis index (GI); Greene & Vermillion's debris index (DI) and calculus index (CI); probing pocket depth (PPD); and percentage of bleeding on probing (%BOP). The intra‐ and inter‐examiner reproducibility of the ORI was assessed on a flat screen using patients' color transparencies of the mouth. The ORI had significantly negative correlations with the GI, DI, CI, and PPD (p<0.001). The κ values were 0.604–0.672 for intra‐examiner reproducibility, and 0.441–0.449 for inter‐examiner reproducibility. The present study suggests that the ORI has moderate to good intra‐examiner and inter‐examiner reproducibility. Mouth examination using the ORI appears to provide useful information that will enable a dental professional or health educator to make sensible decisions on the type and level of oral health instruction according to adults' gingival health care level.
Plasma lipid and blood glucose levels in patients with destructive periodontal disease
Authors: Lösche Wolfgang , Karapetow Frank , Pohl Andreas , Pohl Carmen , Kocher Thomas
Published: March 2003

Hyperlipidaemia and hyperglycaemia are major risk factors for cardiovascular disease. In recent years, some evidence has been presented that periodontal disease is associated with an increased risk of cardiovascular disease. To further elucidate this association, we have studied standard blood chemistry variables known as risk markers for cardiovascular disease in periodontally diseased and healthy subjects. We have measured levels of plasma lipids and fasting blood glucose in 39 subjects with moderate periodontal disease (age 50–60 years) and compared the results with those obtained in 40 age‐ and sex‐matched controls. Both groups were systemically healthy according to their medical history. Total cholesterol, low density lipoprotein cholesterol and triglycerides were significantly higher in periodontally diseased subjects by about 8% (p<0.03), 13% (p<0.003) and 39% (p<0.001), respectively, when compared to controls. Although subjects with diabetes were excluded from the study, we found significantly higher blood glucose levels in the patient than in the control group (85±25 versus 73±17 mg/dl; p<0.02). There was also a significantly higher frequency of pathological plasma lipid profiles in the patient than in the control group. The results indicate that hyperlipaemia and pre‐diabetes may be associated with periodontal disease in systemically healthy subjects. These data do not allow us to decide, whether periodontal disease causes an increase in hyperlipaemia and in a prediabetic state or whether periodontal disease and cardiovascular disease share hyperlipidaemia and the prediabetic state as common risk factors.
Comparison of treatments of infrabony defects with enamel matrix derivative, guided tissue regeneration with a nonresorbable membrane and Widman modified flap
Authors: Silvestri Maurizio , Ricci Giano , Rasperini Giulio , Sartori Stefano , Cattaneo Vitaliano
Published: March 2003

Background, aims: The purpose of the present study was to compare the efficacy of 3 different surgical procedures in the treatment of infrabony defects: guided tissue regeneration (GTR) with non‐resorbable membranes, Widman modified flap (WMF) and enamel matrix derivative (EMD).

Method: 30 patients with an infrabony component 4 mm were selected. 10 were treated with expanded polytetrafluorethylene (ePTFE (Gore – Tex W. L. Gore and Associates, Flagstaff, AZ, USA)) membranes, 10 with WMF and 10 with enamel matrix derivatives (Emdogain® (Û Biora AB Malm, Sweden)). The efficacy of each treatment modality was investigated through regression analysis. Probing attachment level (PAL) gain, probing depth (PD) reduction and gingival recession (REC) variation were analyzed.

Results: Both Emdogain® (enamel matrix derivative) and ePTFE treatment show significant better results as compared to the WMF procedure in which there were no significant changes in PAL gain and PD reduction at baseline and 1 year after surgery.

Conclusions: Results from our analysis suggest that there is no statistically significant difference in PAL gain between GTR and EMD. The clinical outcomes of this pilot study may be of little significance, considering the small number of patients, but it has provided an important base for a controlled clinical trial (with a larger number of patients) which is currently in progress.