Buccal Marginal Bone Research Articles

Allogeneic Demineralized Dentin Matrix as rhBMP-2 Carrier: A Retrospective Clinical Study.

To compare the clinical outcomes of autogenous and allogeneic demineralized dentin matrices loaded with recombinant human bone morphogenetic protein-2 (rhBMP-2; auto- and allo-DDM/rhBMP-2) by measuring the buccal marginal bone resorption around dental implants. This retrospective study included patients who underwent dental implant placement with auto-DDM/rhBMP-2 as the control group and allo-DDM/rhBMP-2 as the experimental group. The primary outcome was buccal marginal bone resorption on CBCT. The resorption was calculated during T0 (from surgery to prosthetic loading), T1 (during the first year after loading), and T2 (during the second year after loading). The secondary outcome was the histologic analysis of five specimens of each group, obtained during the prosthetic procedure. Among the 103 implants, 61 and 42 implants were placed with auto- and allo-DDM/rhBMP-2 matrices, respectively. The resorptions of all periods were similar between the groups (T0: 0.65 ± 0.71 and 0.67 ± 0.81 mm, T1: 0.55 ± 0.60 and 0.59 ± 0.81 mm, and T2: 0.29 ± 0.45 and 0.20 ± 0.30 mm with auto- and allo-DDM/rhBMP-2, respectively). The histologic and histomorphometric analysis revealed similar osteoinductive aspects and proportions of new bone between the groups. Allo-DDM/rhBMP-2 showed comparable outcomes in terms of buccal marginal bone resorption to auto-DDM/rhBMP-2 during the second year after loading.

Clinical and radiographic study to evaluate marginal bone level around one piece and two piece of immediate loaded implants

Objective: The present study evaluated marginal bone level around immediate loaded implants using one piece and two piece implants. Subjects and methods: A group of 22 patients were divided into two groups; Group 1: 11 Patients received immediate loaded implant placement using one piece implants. Group 2: 11 Patients received immediate loaded implant placement using two piece implants. According to clinical evaluation; plaque Index, gingival Index and peri-implant probing depth were recorded and measured at three and six months and nine months, also implant quality score was measured. Radiographically, marginal bone level was measured and bone density and compared in three months, six months, nine months. Results: Group 1 showed a significant decrease in the peri-implant probing depth compared to Group 2. Group 1 showed significant buccal marginal bone loss than Group 2 allover the time intervals. There is no significant difference in the palatal or mesial or distal surface between the two groups. Also no significant difference between the two groups including plaque index or gingival index or bone density. Concerning the implant quality scale; 100% of group 2 were scale 1 , while 50% of group 1 were considered scale 1. Conclusion: immediate loading of two piece dental implants appeared significantly superior than one piece type.

Allogeneic Demineralized Dentin Matrix Graft for Guided Bone Regeneration in Dental Implants

Autogenous and allogeneic demineralized dentin matrices (Auto-DDM and Allo-DDM, respectively) are currently used for guided bone regeneration (GBR). Buccal marginal bone (BMB) resorption is critical for successful implant integration. This study analyzed BMB resorption around dental implants for GBR between the control group (Auto-DDM graft) and experimental group (Allo-DDM graft). From 2014 to 2019, we enrolled 96 patients (59 males, 37 females, average 57.13 years) who received GBR (52 and 44 using Allo-DDM and Auto-DDM, respectively,) without a barrier membrane and a simultaneous single dental implantation (54 in the maxilla and 42 in the mandible). BMB height was measured immediately after GBR, at prosthetic loading, and 12 months after loading. BMB resorption was classified as initial resorption (between GBR and prosthetic loading) and functional resorption (during 12 months after prosthetic loading). The differences in the BMB levels of Auto-DDM and Allo-DDM were analyzed between the initial and functional resorption stages by independent sample t-test. Auto-DDM and Allo-DDM showed similar BMB changes in initial resorption (0.73 ± 0.97 and 0.72 ± 0.77 mm, respectively) and functional resorption (0.69 ± 0.81 and 0.48 ± 0.58 mm, respectively) without a significant difference between the maxilla and mandible. For GBR, Allo-DDM is comparable to Auto-DDM in terms of BMB resorption.

A modified surgical approach for hard and soft tissue reconstruction of severe periimplantitis defects: laser-assisted periimplant defect regeneration (LAPIDER)

BackgroundThe main problem in periimplantitis is often the combination of severe periimplant bone loss with a contaminated implant surface and an insufficient soft tissue situation. Classic surgical concepts with crestal access to the bony defect and debridement of the surface most often lead to partial defect regeneration and a soft tissue recession. An incision directly above the pathologic bony lesion is contrary to general surgical treatment rules.AimTo overcome this problem, a new surgical concept was developed which allows to clean the implant surface, reconstruct the bony defect, and improve soft tissue height and thickness without cutting the papilla complex. This publication presents the innovative regenerative treatment approach for severe periimplantitis defects.Material and methodsAfter diagnosis and non-surgical pre-treatment of a severe periimplantitis lesion, the following treatment protocol was applied: horizontal mucosal incision 5 mm apical to marginal mucosa, supraperiosteal preparation in apical direction, cutting through periosteum at the level of the implant apex, subperiosteal coronal flap elevation, exploration and cleaning of the periimplant defect, thorough debridement of the implant surface with the Er:YAG laser, subperiosteal grafting with connective tissue, grafting of the bony defect with autogenous bone chips from the mandibular ramus, and bilayered suturing of periosteum and mucosa. Implant survival, marginal bone levels, periimplant probing depths, recession, and facial mucosa thickness (PIROP ultrasonic measurement) were evaluated in a pilot case at 1-year follow-up examination.ResultsInter-proximal, oral, and buccal marginal bone levels increased significantly to the level of the implant shoulder from pre-operative to 1-year follow-up examination. No signs of suppuration or periimplant infection were present. Probing depths and recession decreased significantly, while the facial mucosa thickness improved from pre-operative to final examination.ConclusionsMarginal bone levels and soft tissue improvement suggest feasibility for the regeneration of severe periimplant hard and soft tissue deficiencies by this new treatment approach. With the use of this concept, the simultaneous implant surface cleansing and improvement of hard and soft tissue seem to be possible and unfavorable postoperative exposition of titanium surface might be prevented. Comparative studies are planned to quantify the effects of this new surgical protocol.

Histologic Analyses of Immediate Implant Placement in Infected and Noninfected Sockets: An Experimental Pilot Study in Beagle Dogs.

To investigate the histologic differences between immediate implants placed in chronically infected sites and noninfected sites in a canine model. The histologic results of immediate implant placement also were evaluated on the basis of healing time and implant surface modification. Chronic endodontic-periodontic combined lesions were induced on the second, third, and fourth premolars of the hemimandible in six dogs, with the contralateral teeth as controls. Implants were immediately placed following the infected and noninfected tooth extractions using implants with a machined surface, sandblasted with alumina and acid-etched surface, and chemically modified sandblasted with alumina and acid-etched with calcium solution surface. After 1 and 3 months, three dogs were euthanized and the bone-to-implant contact, bone area fraction occupied, buccal and lingual first bone-to-implant contact from the implant platform, and buccal and lingual marginal bone loss were calculated. On histologic evaluation, no inflammation was observed around implants placed in the infected or noninfected sockets. At 1 month, no statistically significant differences were observed between the infected and noninfected sockets in buccal marginal bone loss in the machined implant group (P = .046), lingual first bone-to-implant contact from the implant in the sandblasted with alumina and acid-etched group (P = .046), lingual marginal bone loss in the sandblasted with alumina and acid-etched implant group (P = .028), buccal first bone-to-implant contact from the implant platform in the chemically modified sandblasted with alumina and acid-etched with calcium solution group (P = .028), and lingual first bone-to-implant contact from the implant platform in the chemically modified sandblasted with alumina and acid-etched with calcium solution group (P = .046). At 3 months, no statistically significant differences were observed in parameters between the infected and noninfected sockets for three implant surfaces. Differences between the infected and noninfected sockets were observed between the machined and sandblasted with alumina and acid-etched implant at 1 month (P = .023). Immediate implant placement in an infected socket did not lead to any differences when compared with placement in a noninfected socket when sufficient healing time was provided.

Buccal bone resorption around posterior implants after surgery: a 1-year prospective study.

This prospective study aimed to examine postoperative dimensional changes in the buccal bone and mucosa around single-stage implants placed in the posterior region. The dimensions of peri-implant tissue around screw-type implants placed in the posterior region were examined at surgery (baseline) and 6 months and 1 year after surgery. The lateral contour of the buccal bone and mucosa was horizontally measured at five vertical heights at 1-mm intervals (+1 to -3 mm from the implant platform) using custom-designed instruments. Bone resorption on the proximal sides was assessed on radiographs. Mucosal recession was measured on plaster casts of the dentition. Sixty-six implants placed in 30 patients were examined. All implants were clinically osseointegrated and stable throughout the study period. The buccal bone exhibited horizontal resorption throughout the study period, even at the most apical height measured. Assessed at each height, thicker bone (> 2 mm thick) tended to exhibit horizontal resorption during the first 6 months after surgery. However, the bone resorbed horizontally by approximately 0.4 mm during the final 6 months, irrespective of its contour. Vertical resorption of the buccal marginal bone was approximately 1 mm during the period from 6 months to 1 year. The bone-retaining group at the 1-year time point was found to have thicker bone walls at baseline compared with the bone-loss group. The thickness of the buccal mucosa showed little change. There was no obvious correlation between buccal bone resorption and mucosal recession. The buccal bone exhibited both horizontal and vertical resorption over the year after surgery. The initial contour of the bone was significantly associated with bone retention or loss at 1 year. However, mucosal recession was not directly affected by buccal bone resorption.

Influence of presence or absence of keratinized mucosa on the alveolar bony crest level as it relates to different buccal marginal bone thicknesses. An experimental study in dogs

To investigate the influence of the presence or absence of keratinized mucosa on the alveolar bony crest level as it relates to different buccal marginal bone thicknesses. In six beagle dogs, the mandibular premolars and first molars were extracted bilaterally. In the right side of the mandible (test), flaps were elevated, and the buccal as well as part of the lingual masticatory mucosa was removed. The flap was released coronally to allow a primary wound closure. In the left side, the wounds were left unsutured with the keratinized mucosa remaining (control). After 3months of healing, a complete absence of keratinized mucosa was found at the test sites. Two recipient sites were prepared at each side of the mandible, one in the premolar and one in the molar region. A buccal bony ridge width of approximately 1 and 2mm was obtained at the premolar and molar region, respectively. Implants were installed with the shoulder flush with the buccal alveolar bony crest, and abutments were connected to allow a nonsubmerged healing. At least 2mm of keratinized mucosa was surrounding the control sites, while at the test sites, the implants were bordered by alveolar mucosa. After 3months, the animals were euthanized and ground sections obtained. A higher vertical bony crest resorption was observed at the test compared with the control sites both at the premolar and molar regions, the differences being statistically significant. The top of the peri-implant mucosa was located more coronally at the control compared with the test sites. The horizontal resorption measured 1mm below the implant shoulder was similar at the test and control sites. Only limited differences were found between premolar and molar sites, with the exclusion of the horizontal resorption that was higher at the test compared with the control sites. A higher alveolar buccal bony crest resorption and a more apical soft tissue marginal position should be expected, when implants are surrounded with thin alveolar mucosa at the time of installation, independently of the thickness of the buccal bony crest.

CBCT assessment of alveolar buccal bone level after RME

To evaluate the maxillary alveolar buccal bone levels after expansion with banded and bonded expanders, using cone-beam computed tomography (CBCT). The population sample consisted of 22 patients who required expansion during their comprehensive treatment; 10 patients (five males and five females) with a mean age of 13.5 years (CVMS 3) had bonded hygienic expanders, and 12 (six males and six females) with a mean age of 12.6 years (CVMS 3) had banded hyrax expanders. CBCT was taken both before (T1) and 6 months after last activation (T2). Measurements were made for buccal bone thickness (BT), buccal marginal bone level (MBL), and bone thickness level (BTL) at the right first molar (M(Rt)), left first molar (M(Lft)), right first premolar (PM(Rt)), and left first premolar (PM(Lft)). A mixed-design analysis of variance assessed differences between and within the groups. Post hoc t-tests were completed on significant analysis of variance results to determine where differences occurred. Analysis of variance revealed no significant differences between or within the two groups. BT significantly decreased horizontally following rapid maxillary expansion. The amount of bone lost was -0.59 mm M(Rt), -0.72 mm PM(Rt), -0.50 mm M(Lft), and -0.57 mm PM(Lft) (P < .003). There was no significant difference between or within the two groups. Buccal bone loss in the vertical dimension (MBL) only showed significance in the banded group for M(Rt) (0.63 mm) and PM(LFt) (0.37 mm) as evidenced by the paired t-test (P < .05).

Healing at Implants Placed in an Alveolar Ridge with a Sloped Configuration: An Experimental Study in Dogs

To study healing around implants placed in an alveolar ridge with a sloped lingual-buccal configuration. Six Labrador dogs were used. Buccal bone defects were prepared in the mandible after extraction of premolars. Three months later, two test implants with a sloped marginal design and two control implants were placed in the chronic defect area with a sloped lingual-buccal configuration of each premolar region. The test implants were placed in such a way that the buccal margin of the implant coincided with the buccal bone crest. The lingual margin of the control implants was placed to a similar depth as the lingual margin of the test implants. Abutments were connected to the implants in the right mandibular premolar region and flaps were sutured around the neck of the abutments. In the left side of the mandible, cover screws were placed and the flaps were sutured to cover the implants. Biopsies were obtained 4 months later and prepared for histological examination. It was demonstrated that healing around implants placed in an alveolar ridge with a sloped lingual-buccal configuration resulted in the preservation of a vertical discrepancy between the lingual and buccal marginal bone levels around implants with either a regular cylindrical outline or a modified marginal portion that matched the slope of the alveolar ridge. As the marginal buccal portion of the control implants with a regular design had no bone support, it is suggested that implants with a modified marginal portion may be considered in recipient sites with a sloped lingual-buccal configuration.

Marginal Bone Stability Using 3 Different Flap Approaches for Alveolar Split Expansion for Dental Implants—A 1-Year Clinical Study

Width augmentation for the alveolar process using alveolar split procedures has not been studied in a comparative study with regard to marginal bone stability. Most research in this regard has used implant osseointegration as an endpoint for the success of the bone grafting procedure. The purpose of the present clinical trial was to retrospectively evaluate the stability of the buccal crestal bone around dental implants placed into alveolar split graft sites using 3 different approaches: a minimal flap, a partial-thickness flap, and a full mucoperiosteal flap. Implants were placed simultaneously or delayed to alveolar split grafting. The aim of the present study was to do a comparative analysis of these 3 techniques by clinical detection for the presence or absence of marginal bone using a periodontal probe 1 year after implant restoration. The working hypothesis was that detachment or disturbance of the blood supply of the buccal plate would be influenced by the flap procedure used and would therefore affect the late marginal bone stability around the implants. A total of 40 consecutive patients were treated in 2 different practice locations (20 at each office) with alveolar split procedures and simultaneous implant placement, using 3 different flap approaches and were seen again after 1 year at the 2 private office locations. The patients were in general good health, without active periodontal disease. All patients were nonsmokers. Patients with diabetes mellitus were excluded from the study. The aim of the present study was to establish the stability of the mobilized buccal bone plate, which could only be observed indirectly. The method used to detect the presence or absence of buccal marginal bone was a blunt periodontal probe used in the sulcus on the facial surface of the restored implant or a sharp explorer used transgingivally to detect marginal bone presence. However, the bone thickness could not be established using either of these methods. This was done in both practice locations by the surgeon who had performed the procedure (in a few cases, open flap procedures were done up to 1 year after grafting, which permitted direct observation of the original treatment site). The 3 different flap approaches studied were full-thickness flap reflection, partial-thickness flap reflection, and minimal flap reflection of the osteoperiosteal flap approach to crestally split and then widen the alveolus. A total of 40 consecutive patients treated with 65 alveolar split expansion procedures done in 2 practice locations during a 2-year period were statistically analyzed retrospectively for buccal bone augmentation presence and implant restorability after 1 year of healing. Facial bone loss of 2 mm or more was seen in 11 sites, 10 of which were full flap reflections and 1 an osteoperiosteal flap site. Implant osseointegration was 92.5% for the osteoperiosteal flaps, 93.3% for the partial-thickness flaps, and 94.4% for the full-thickness flaps. The 3 flap approaches to alveolar widening by crest splitting with implant placement had a sustained increased alveolar width after 1 year. However, most full flap alveolar split cases had facial bone loss and gingival recession. The osteoperiosteal flaps (book flap) and partial-thickness flaps showed stable buccal bone patterns. The results of the present clinical study of relatively early osseous remodeling suggest that full mucoperiosteal flaps should not be reflected when an alveolar split is done. However, to further elucidate the marginal bone vitality, a longer study period must be undertaken to more fully validate the alveolar split procedure and verify the best flap approach.

Factors affecting buccal bone changes of maxillary posterior teeth after rapid maxillary expansion

The purpose of this study was to use cone-beam computed tomography (CBCT) images to determine the factors that might affect buccal bone changes of maxillary posterior teeth after rapid maxillary expansion (RME). Thirty consecutive patients (17 boys, 13 girls; mean age, 13.8 +/- 1.7 years) who required RME as part of their orthodontic treatment and had the pre-RME (T1) and post-RME (T2) CBCT images available were included in the study. The T1 and T2 measurements of interdental distance, interdental angle (IA), buccal bone thickness (BBT), and buccal marginal bone levels (BMBL) of the first premolar (P1), the second premolar (P2), and the first molar (M1) were compared with the Friedman and the Wilcoxon signed rank tests. To determine which variables were associated with the changes in IA, BBT, and BMBL, the Spearman rank correlation analysis was performed (alpha = .05). The results suggest that buccal crown tipping, and reduction of BBT and BMBL of the maxillary posterior teeth are the expected immediate effects of RME. There were no significant differences in dental expansion among P1, P2, and M1 (P >.05). P2 had clinically more buccal crown tipping (P = .116) but statistically less reduction in BBT and BMBL (P <.0001 and P = .001) than P1 and M1. Buccal bone changes and dental tipping on P2 were not affected by any other variables. Factors that showed significant correlation to buccal bone changes and dental tipping on P1 and M1 were age, appliance expansion, initial buccal bone thickness, and differential expansion (P <.05), but rate of expansion and retention time had no significant association (P >.05).

Towards the limit of quantifying low-amplitude strains on bone and in coagulum around immediately loaded oral implants in extraction sockets

The purpose of this study was to quantify strains in coagulum around immediately loaded oral implants in extraction sockets at the ex vivo level. Bilateral maxillary premolar teeth of two fresh human cadavers were extracted and psi 4.1 x 12 mm Straumann TE implants were placed in the sockets of first and second premolars by utilizing mesio-distal and palatal anchorage, respectively. Installation torque value (ITV) of each implant was measured by a custom-made torque wrench and resonance frequency analyses (RFAs) were undertaken to determine intraosseous stability. Upon abutment connection, a gold coping allowing the placement of a miniature load cell to contact the underlying solid abutment was fabricated. A linear strain gauge was connected to the coping at a distance for strain measurements in coagulum around the implant neck in the extraction socket. Linear strain gauges were also bonded on the labial marginal bone of each extraction socket. Strain measurements were performed at a sample rate of 10 kHz simultaneously monitored from a computer connected to data acquisition system and under a maximum load of 100 N on each implant with or without human coagulum in the extraction socket. Low-amplitude strains were measured around immediate implants. The increase in load increased strains on labial marginal cortical bone around implants (P < 0.05). Bone strains were higher on the implant loaded, when coagulum was present in the bone defects (P < 0.05). Strains within coagulum around mesiodistally anchored implants were higher than palatally anchored implants (P < 0.05). The type of implant on anchorage and presence of coagulum has an impact mechanotransduction to buccal marginal bone around immediate implants.

Rationale for the Lingual Approach to Mandibular Osseous Surgery

The definitive treatment of periodontitis for pocket elimination and the establishment of periodontal architecture that can be effectively maintained with daily personal oral hygiene techniques is sometimes an elusive goal. Performing osseous reduction, primarily from the lingual aspect of the posterior mandible, definitely helps in accomplishing such a goal. This paper should not be interpreted to mean that osseous correction of bony defects should be approached strictly from the lingual, since almost all cases require some buccal recontouring if a satisfactory soft and hard tissue architectural form is to be achieved. Clinical observation and experience have shown that the anatomical patterns, seen in relation to the mandible, have a powerful effect on normal periodontal architecture as well as the types and locations of bony defects encountered. Tooth to bone relationships deserve attention. The buccal housing of the alveolar bone is frequently thin in the premolar region and occasionally on the first molar, while the external oblique ridge causes thicknened bone over the second molar. The vestibular depth on the buccal of the molars is often quite shallow, meaning that only a very limited amount of osteoplasty-osteoectomy can be performed from the buccal. The lingual housing of the alveolar bone is normally thickened and shelf-like from the distal of the third molars to the mesial aspect of the premolar region. Because the posterior teeth are inclined lingually from the second premolar distally, the buccal marginal bone height is higher occlusally than the lingual bone margins, with the interproximal bone therefore sloping somewhat apically and lingually. Interdental craters are the most common defect seen with the onset of periodontitis. Such defects in the lower arch tend to occur beneath the contact areas of the teeth, which are much further to the lingual than in the maxilla. The highest percentage of interproximal craters are shallow and not amenable to grafting techniques in the hands of most clinicians. These shallow craters are prime candidates for osseous reduction techniques. With the progression of periodontitis, the interproximal defects frequently extend to include infrabony lingual defects. Although obtaining lingual access for osseous reduction techniques is often difficult, osteoectomy-osteoplasty techniques performed primarily from the buccal of the posterior mandible frequently result in compromise of the lingual and over treating the buccal in terms of osteoectomy procedures. The lingual embrasure spaces are usually wider than on the buccal, and with adequate reduction of the mylohyoid ridge, greater access for oral hygiene procedures is provided.