Bone morphology changes around two types of bone-level implants installed in fresh extraction sockets--a histomorphometric study in Beagle dogs.

BACKGROUND: Minimizing crestal bone loss following immediate implant placement is considered the most challenging aspect in implant therapy. Implant surface topography and chemical modifications have been shown to influence the success of Osseointegration. The Straumann Bone Level implant, featuring SLActive surface, has been introduced with the aim of enhancing bone apposition. Similarly, the OsseoSpeed implants from Astra Tech claim to have an enhanced osseointegration. Because of the specific features in the implant design, both companies claim that crestal resorption is minimal with these implants. OBJECTIVE: To evaluate the osseointegration and crestal bone level following immediate placement of Straumann Bone Level implant and OsseoSpeed implants in fresh extraction sockets in Beagle dogs. METHOD: The distal roots of the second, third and fourth premolars were extracted in both sides of the mandible. The distal roots were removed using a dental elevator. A total of 60 fixtures were installed in 10 Beagle dogs. Two types of implants were used: Straumann Bone-Level implants, which were 8 × 3.3 mm in size, and Astra Tech OsseoSpeed 3.5 S MicroThread implants, which were 8 × 3.5 mm in size. The histomorphometrical evaluation was performed at the end of 4- and 12-week healing. The implant-bone contact and bone volume percentage were assessed. RESULTS: The bone-to-implant contact (BIC) and the bone volume did not show any significant changes for both types of implants. The OsseoSpeed™ implants showed 67.4% and 65.3% BIC, respectively, at 4 and 12 weeks compared with 71.7 and 73.1 for the Straumann Bone-Level implants. The bone volume around both types of implants did not differ significantly at both time periods. The crestal bone resorption was observed for both types of implants. The first BIC at buccal side and lingual side of the implants also did not differ significantly for both implant systems. CONCLUSIONS: This study showed that Straumann Bone Level and OsseoSpeed implants induced similar bone response after immediate implantation at 4 and 12 weeks. The immediate implant placement resulted in peri-implant crestal bone-level changes for both types of implants.

Healing of peri-implant tissues after flapless and flapped implant installation.

AIM: The aim of this study was to investigate the consequences of different flapless procedures for the installation of dental implants on peri-implant bone response. MATERIALS AND METHODS: After bilateral extraction of the mandibular second and third premolars and a 3-month healing period, 30 SLActive(®) implants were installed for 3 months in 10 Beagle dogs according to three different surgical approaches, i.e.: (1) flapped (F), (2) tissue punch flapless (P), and (3) direct flapless (DF). RESULTS: At harvesting, 29 implants were analysed. Micro-computed tomography and histomorphometrical evaluation (which also included the mobile implants) showed comparable results in bone volume (F=55 ± 9, P=51 ± 4, DF=54 ± 5) and crestal bone level (F=3420 ± 762, P=5358 ± 1681, DF=3843 ± 433). However, the implants inserted using the punch approach revealed a significantly lower first bone contact (F=3420 ± 762, P=5358 ± 1681, DF=3843 ± 433) and bone-to-implant contact percentage (F=70 ± 12, P=48 ± 23, DF=73 ± 12). Considering the gingival response, the barrier epithelium was also significantly deeper around the implants installed using the punch approach (F=1383 ± 332, P=2278 ± 1154, DF=1107 ± 300). CONCLUSIONS: The results indicate that a flapless surgical technique can be used for the installation of oral implants. In addition, using a tissue punch wider than the implant diameter should be avoided, as it can jeopardize the outcome of the implantation procedure.

Dental implant primary stability in different regions of the Jawbone: CBCT-based 3D finite element analysis.

AIM: This study aimed to analyze the primary stability of dental implant in maxillary and mandibular anterior and posterior regions using a finite element analysis. MATERIALS AND METHODS: CBCT images of maxillary and mandibular regions were collected from patients' radiographic data and transformed to 3D models. A Straumann Dental implant was inserted in each bone model and then pulled-out, where amount von-Mises stress was obtained and analyzed for each. A comparison between the insertion and the pull-out was evaluated. RESULTS: Twenty-four images were randomly selected for analysis from 122 scans. In both the insertion and the pull-out of the dental implant, von-Mises stress was high in cortical as compared to the cancellous bone (p < 0.0001). Maxillary posterior region had a low von-Mises stress (p < 0.001). Bone plastic deformation was higher in cancellous than the cortical bone in all bone regions and was the lowest in maxillary posterior region (p < 0.001). Bone displacement decreased from Type I to type IV bone. CONCLUSION: Evaluation of von-Mises stress showed different measurements in maxillary and mandibular regions. Bone deformation was low in the maxillary posterior region.

Assessment of lipid profile in Saudi type 2 diabetic and non-diabetic periodontal patients.

OBJECTIVE: To study the extent of periodontal disease in diabetic and non-diabetic periodontitis patients, and to investigate the relationship of dyslipidemia and periodontal disease, in diabetic and non-diabetic periodontitis patients. METHODS: This is a cross-sectional study at the Department of Preventive Dental Sciences (College of Dentistry) and Department of Physiology (College of Medicine), King Saud University, Riyadh, Kingdom of Saudi Arabia, from February 2003 to June 2004. A total of 90 patients was recruited, and divided into 3 equal groups of 30 subjects, with age and gender matched, and divided as follows: group 1 healthy group: periodontally and systemically healthy subjects, group 2 periodontitis group: chronic periodontitis patients with no systemic disease, group 3 diabetic group: chronic periodontitis patients with type 2 diabetes mellitus. Plaque index, bleeding on probing, probing pocket depth (PPD), and clinical attachment level (CAL) were measured at the time of initial examination. The glycated hemoglobin, total cholesterol, low density lipoprotein (LDL), triglyceride, high density lipoprotein were also measured. RESULTS: Periodontal parameters (PPD and CAL) were of significantly higher value in the diabetic patients, when compared to the periodontitis patients (p<0.05). The total cholesterol, LDL, and triglyceride were also found to be significantly higher among the periodontitis patients than the healthy subjects (p<0.05). CONCLUSION: This study indicated that type 2 diabetic patients had a higher risk to develop advanced periodontal disease than the non-diabetic subjects. It also highlighted the association of dyslipidemia in periodontitis patients.

Efficacy of Mucograft vs Conventional Resorbable Collagen Membranes in Guided Bone Regeneration Around Standardized Calvarial Defects in Rats: An In Vivo Microcomputed Tomographic Analysis.

The aim of this in vivo microcomputed tomographic (µCT) study was to compare the efficacy of Mucograft (MG) vs resorbable collagen membranes (RCMs) in facilitating guided bone regeneration (GBR) around standardized calvarial defects in rats. Forty female Wistar albino rats with a mean age and weight of 6 to 9 weeks and 250 to 300 g, respectively, were used. With the rats under general anesthesia, the skin over the calvaria was exposed using a full-thickness flap. A standardized calvarial defect with a 4.6-mm diameter was created in the left parietal bone. For treatment, the rats were randomly divided into four groups (n = 10 per group): (1) defects covered with MG (MG group); (2) defects covered with an RCM (RCM group); (3) defects filled with xenograft bone particles and covered by MG (MG + bone group); and (4) defects filled with xenograft bone particles and covered by an RCM (RCM + bone group). Primary closure was achieved using interrupted resorbable sutures. The animals underwent high-resolution, three-dimensional µCT scans at baseline and at 2, 4, 6, and 8 weeks after the surgical procedures. Data regarding volume and bone mineral density (BMD) of newly formed bone (NFB) and bone particles revealed an increase in the volume of NFB in all the groups from baseline to 8 weeks. The MG group had the lowest volume of NFB (mean ± standard deviation [SD], 1.32 ± 0.22 mm(3)). No significant differences in mean ± SD values for volume of NFB were observed between the RCM (3.50 ± 0.24 mm(3)) and MG + bone (3.87 ± 0.36 mm(3)) groups, but their values were significantly lower than that of the RCM + bone group (2.95 ± 0.15 mm(3), F = 131.91, dfN = 2, dfD = 27, P < .001). Significant differences in BMD of NFB between the groups (F = 332.46, dfN = 3, dfD = 36, P < .001) and during different data collection periods (F = 97.04, dfN = 3, dfD = 36, P < .01) were observed, with the RCM group having the highest mean ± SD BMD of NFB (0.42 ± 0.05 g/mm(3)). Significant differences in the bone particle volume between the RCM + bone and MG + bone groups (F = 91.04, dfN = 1, dfD = 18, P < .05) and at different data collection periods (F = 314.12, P < .01) were observed, with the RCM + bone group displaying greater reduction in both volume (36.8%) and BMD (19.7%) of bone particles. The present in vivo µCT study demonstrated that RCM is better than MG in enhancing new bone formation in rat calvarial standardized defects when used in combination with mineralized particulate graft material.

Efficacy of Mucograft vs Conventional Resorbable Collagen Membranes in Guided Bone Regeneration Around Standardized Calvarial Defects in Rats: A Histologic and Biomechanical Assessment.

Guided bone regeneration (GBR) using a porcine-derived collagen matrix (Mucograft [MG], Geistlich) has not yet been reported. The aim of this histologic and biomechanical study was to compare the efficacy of MG versus resorbable collagen membranes (RCMs) in facilitating GBR around standardized rat calvarial defects. Forty female Wistar albino rats with a mean age and weight of 6 to 9 weeks and 250 to 300 g, respectively, were used. With the rats under general anesthesia, the skin over the calvaria was exposed using a full-thickness flap. A 4.6-mm-diameter standardized calvarial defect was created in the left parietal bone. For treatment, the rats were randomly divided into four groups (n = 10 per group): (1) MG group: the defect was covered with MG; (2) RCM group: the defect was covered with an RCM; (3) MG + bone group: the defect was filled with bone graft particles and covered by MG; and (4) RCM + bone group: the defect was filled with bone graft particles and covered by an RCM. Primary closure was achieved using interrupted resorbable sutures. The animals were sacrificed at 8 weeks after the surgical procedures. Qualitative histologic analysis and biomechanical assessment to identify hardness and elastic modulus of newly formed bone (NFB) were performed. Collected data were statistically analyzed using one-way analysis of variance. Histologic findings revealed NFB with fibrous connective tissue in all groups. The quantity of NFB was highest in the RCM + bone group. Statistically significant differences in the hardness (F = 567.69, dfN = 3, dfD = 36, P < .001) and elastic modulus (F = 294.19, dfN = 3, dfD = 36, P < .001) of NFB were found between the groups. Although the RCM + bone group had the highest mean ± standard deviation (SD) hardness of NFB (531.4 ± 24.9 MPa), the RCM group had the highest mean ± SD elastic modulus of NFB (18.63 ± 1.89 GPa). The present study demonstrated that RCMs are better than MG at enhancing new bone formation in standardized rat calvarial defects when used along with mineralized particulate graft material.

Histologic assessment of alveolar bone remodeling around immediate implants placed in single and multiple contiguous extraction sites.

The aim of this study was to histologically assess alveolar bone remodeling around immediate implants placed in single and multiple contiguous extraction sites. Ten dogs were divided into three groups (with six sites per group) on the basis of premolar teeth extraction: group 1 = one tooth extracted, group 2 = two contiguous teeth extracted, and group 3 = more than two contiguous teeth extracted. Immediate implants were placed in each group. Histologic assessment of arches showed no evidence of vertical bone loss (VBL) around implants in group 1 compared with groups 2 (P < .001) and 3 (P < .001). Buccal and lingual bone thicknesses and bone-to-implant contact (BIC) were higher around implants in group 1 compared with groups 2 (P < .001) and 3 (P < .05). Buccal and lingual bone thicknesses, BIC, and VBL are compromised around implants in multiple contiguous extraction sites compared with those in a single extraction site.

Microcomputed tomographic analysis of the alveolar ridge alteration around extraction sites with and without immediate implants placement: in vivo study.

BACKGROUND: The aim was to assess the alveolar ridge alteration around extraction sites with and without immediate implants according to extraction socket classification (ESC) using microcomputed tomography (micro-CT). MATERIAL AND METHODS: Ten beagle dogs (mean age and weight: 24 ± 0.83 months and 13.8 ± 0.49 kg, respectively) were randomly divided into three groups according to the ESC. In Group 1 (ESC-I), bilateral first and third premolars were extracted and replaced with immediate implants. In Group 2 (ESC-II), two adjacent premolars were extracted with one immediate implant placement in the mesial socket in the maxilla and in the distal socket in the mandible. In Group 3 (ESC-III), three adjacent teeth were extracted and an immediate implant was placed in the central socket. Primary closure was achieved using resorbable sutures. Buccal sites with dehiscence defects were excluded. After 4 months, subjects were sacrificed and alveolar ridge widths were measured at 1 mm interval in axial and sagittal views, using micro-CT in sites with and without immediate implants. RESULTS: In sites without immediate implant placement, alveolar ridge width was significantly higher in Group 1(6.1 ± 1.35mm) than Group 3 (4.14 ± 1.53 mm) (p <.05). In sites with immediate implant placement, the alveolar ridge width was higher among sites in Group 1 (6.4 ± 3.8 mm) than Group 2 (4.8 ± 0.46 mm) (p < .05) and Group 3 (5.02 ± 0.84 mm) (p <.05). Overall, between each corresponding group in both sites with and without immediate implant placement at 1 mm thickness, there was no significant difference in the alveolar ridge widths. CONCLUSION: With the exception of Group 1 (ESC-I), immediate implant placement did not prevent or minimize bone remodeling in extraction sites according to ESC.

Efficacy of using PDGF and xenograft with or without collagen membrane for bone regeneration around immediate implants with induced dehiscence-type defects: a microcomputed tomographic study in dogs.

BACKGROUND: Use of collagen membrane (CM) with xenograft and recombinant human platelet-derived growth factor (rhPDGF) in guided bone regeneration (GBR) is debatable. The aim of this microcomputed tomographic experiment was to assess the efficacy of using PDGF and xenograft (with or without CM) for GBR around immediate implants with dehiscence defects. METHODS: Ten beagle dogs underwent atraumatic bilateral second and fourth premolar extractions from both arches. A standardized dehiscence defect (6 × 3 mm) was created on the buccal bone and immediate implants were placed in distal sockets in each site. Animals were randomly divided into three groups: 1) group 1, xenograft with rhPDGF was placed and covered with CM; 2) group 2, xenograft with rhPDGF was placed over the defects; and 3) group 3, four immediate implants were associated with dehiscence (controls). After 16 weeks, animals were sacrificed and jaw segments were assessed for buccal bone thickness (BBT), buccal bone volume (BBV), vertical bone height (VBH), and bone-to-implant contact (BIC) using microcomputed tomography. RESULTS: BBT was higher in group 2 (1.533 ± 0.89 mm) than group 1 (0.745 ± 0.322 mm) (P <0.001) and group 3 (0.257 ± 0.232 mm) (P <0.05). BBV was higher in group 2 (67.87 ± 19.83 mm(3)) than group 1 (42.47 ± 6.78 mm(3)) (P <0.05) and group 3 (19.12 ± 4.06 mm(3)) (P <0.001). VBH was higher in group 2 (6.36 ± 1.37 mm) than group 3 (0.00 ± 0.00 mm) (P <0.001). VBH was higher in group 1 (3.91 ± 2.68 mm) than group 3 (0.00 ± 0.00 mm) (P <0.05). BIC was higher in group 2 (67.25% ± 13.42%) than group 1 (36.25% ± 12.78%) (P <0.05) and group 3 (30.25% ± 7.27%) (P <0.01). CONCLUSION: GBR around immediate implants with dehiscence defects using PDGF and xenograft alone resulted in higher BBT, BBV, VBH, and BIC than when performed in combination with CM.

Comparison of self-perceived oral health, periodontal inflammatory conditions and socioeconomic status in individuals with and without prediabetes.

INTRODUCTION: The aim was to compare the self-perceived oral health, periodontal inflammatory conditions and socioeconomic status (SES) in patients with and without prediabetes. METHODS: Thirty-nine individuals [19 patients with prediabetes (test group) and 20 control individuals (control group)], at least 20 years old were included. Plaque index, bleeding on probing, probing depth (4 to <6 mm and ≥6 mm) and number of missing teeth were recorded. Fasting blood glucose levels were recorded, and marginal bone loss was measured on radiographs. SES, education status, self-perceived oral health, family history of diabetes and tobacco habits were also investigated. RESULTS: Mean ages of individuals in the test and control groups were 40.6 and 42.3 years, respectively. Plaque index, bleeding on probing, probing depth (4 to <6 mm and ≥6 mm) and number of missing teeth were higher in the test group as compared with the control group (P < 0.05). Premolar and molar marginal bone loss was higher in the test group as compared with the control group (P < 0.001). Self-perceived bleeding gums was more often reported by individuals in the test group as compared with the control group. A poor SES and education status was higher among individuals in the test group as compared with the control group (P < 0.001). CONCLUSIONS: Self-perceived gingival bleeding and clinical periodontal inflammation were severe in patients with prediabetes as compared with controls. An underprivileged SES aggravated periodontal conditions in patients with prediabetes.

Alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification: a three-dimensional microcomputed tomography analysis.

BACKGROUND: Previous studies assessed bone remodeling after a single tooth extraction; however, the effect of multiple contiguous teeth extractions around immediate implant remains unknown. The aim of this microcomputed tomographic investigation is to analyze the alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification (ESC). METHODS: Under general anesthesia, 10 beagle dogs underwent atraumatic tooth extractions. Animals were randomly divided into three groups, with 16 sites per group: 1) ESC-1, single tooth extraction; 2) ESC-2, two contiguous teeth extraction; and 3) ESC-3, more than two contiguous teeth extractions. Immediate implants were inserted in each socket, and postoperative plaque control measures were undertaken. After euthanasia, the jaw segments were evaluated for bone thickness, marginal bone loss (MBL), and bone-to-implant contact (BIC) using microcomputed tomography. RESULTS: The mean buccal bone thickness (P <0.05) and MBL (P <0.05) was compromised in jaws in ESC-3 compared to those in ESC-1 and ESC-2. The BIC was significantly higher among jaws in ESC-1 compared to those in ESC-2 and ESC-3 (P <0.05). There was no significant difference in the buccal bone thickness, MBL, and BIC among the groups in the maxilla and mandible. Lingual bone remodeling did not reveal any significant differences among the groups in either jaw. CONCLUSION: Buccal bone remodeling is significantly more extensive around immediate implants placed in multiple contiguous tooth extraction sites compared to immediate implants placed in single tooth extraction sites.

The effect of locally delivered doxycycline as an adjunctive therapy to scaling and root planing in smokers.

BACKGROUND: Locally delivered doxycycline is found to be effective in managing periodontitis as an adjunct to scaling and root planing. AIM: To evaluate the effect of locally delivered doxycycline (10%) with scaling and root planing in the periodontal treatment of smokers and to compare it with scaling and root planing alone. METHODS: Twelve smokers with chronic periodontitis and a pocket depth (⩾5 mm) on posterior teeth that bleed on probing were selected. Patients were randomly assigned to scaling and root planing (SRP) or scaling and root planing followed by local application of doxycycline (SRP-D). Plaque, bleeding on probing, gingival recession, clinical attachment level (CAL), and probing depth (PD) were recorded at the baseline, 6 and 12 weeks. RESULTS: Both groups showed a significant reduction in Plaque, Bleeding on Probing and pocket depth at 6th and 12th week from the baseline. A statistically significant gain of attachment was observed in both groups after treatment. Even though the doxycycline group showed slightly higher attachment gain it was not statistically significant compared to the control group. CONCLUSION: The observations of the study reveal that the additional benefit of topical application of doxycycline as an adjunct to scaling and root planing in smokers is not convincing. However, further clinical studies may be necessary to substantiate the present observations.

Surgical management of gingival recession: A clinical update.

Gingival recession is defined as the apical migration of the junctional epithelium with exposure of root surfaces. It is a common condition seen in both dentally aware populations and those with limited access to dental care. The etiology of the condition is multifactorial but is commonly associated with underlying alveolar morphology, tooth brushing, mechanical trauma and periodontal disease. Given the high rate of gingival recession defects among the general population, it is imperative that dental practitioners have an understanding of the etiology, complications and the management of the condition. The following review describes the surgical techniques to treat gingival recession.

The use of povidone-iodine and hydrogen peroxide mixture as an adjunct to non-surgical treatment of slight to moderate chronic periodontitis.

OBJECTIVE: The aim of this study was to evaluate the clinical effects of the adjunctive use of povidone-iodine with or without hydrogen peroxide as coolant and disinfectant during ultrasonic scaling and root planing in the treatment of chronic periodontitis. MATERIALS AND METHODS: Sixteen patients initially participated in the study. Thirteen patients (8 males and 5 females) completed the 3-month follow-up period. Their mean (±SD) age was 42.92 ± 7.55 years. In each experimental subject, the mouth was split into four quadrants. A randomly selected quadrant was chosen to receive one of the three treatment group modalities which were: Group 1 - ultrasonic scaling and root planing plus irrigation with 1% povidone-iodine and 3.0% hydrogen peroxide mixture; Group 2 - ultrasonic scaling and root planing plus irrigation with 1% povidone-iodine; Group 3 - ultrasonic scaling and root planing plus irrigation with normal saline. The fourth quadrant served as a control group. RESULTS: At the 3-month evaluation, there was no significant difference between the three treatment groups in terms of probing depth reduction, clinical attachment gain, gingival recession increase, reduction in the bleeding upon probing or plaque score reduction (P > 0.05). However, the three treatment groups had statistically significant higher mean reduction in the probing depth, gain in the clinical attachment level and reduction in the bleeding upon probing than the control group (P < 0.05). CONCLUSION: There were no added benefits of using a mixture of povidone-iodine and hydrogen peroxide or povidone-iodine as disinfectants during ultrasonic scaling and root planing in the treatment of chronic periodontitis.

Attachment of human gingival fibroblasts to periodontally involved root surface following scaling and/or etching procedures: a scanning electron microscopy study / Adesão de fibroblastos gengivais humanos em raízes periodontalmente comprometidas após raspagem e/ou condicionamento: estudo no microscópio eletrônico de varredura

This study evaluated, in vitro, fibroblast attachment to periodontally involved root surfaces which were either root planed or acid/chelated by diferents agents. Specimens were divided into 3 groups of 12 specimens each. The root surfaces were root planed with a Gracey 7/8 curette, an EMS or an Amdent piezo-electric scaler and treated with saline, citric acid, tetracycline hydrochloride or EDTA to produce different surface textures. They were then cultured with fibroblasts for 72 h and examined by scanning electron microscopy. There was a significantly greater number of fibroblasts attached to specimens treated with citric acid, tetracycline and EDTA than to those root planed only. Furthermore, fibroblasts were more likely to attach to rough-surfaced than to smooth-surfaced specimens.