Abdulaziz Al-Rasheed

Effect of Cigarette Smoking on the Clinical Outcomes of Periodontal Surgical Procedures

Introduction:Experimental studies have revealed that nicotine upregulates the expression of receptors of advanced glycation end products and retards fibroblastic cell migration in the gingiva of smokers compared with nonsmokers, thereby inducing a proinflammatory effect. The aim of this study was to review the effect of cigarette smoking on the clinical outcomes of periodontal surgical procedures. Methods:To address the focused question, “What is the effect of cigarette smoking on clinical outcomes after periodontal surgical interventions?”, databases were searched from 1968 to May 2010 using various combinations of the following key words: inflammation, mucoperiosteal flap, periodontal surgery, smoking and tobacco. The inclusion criteria included all levels of available evidence. Articles published only in the English language were evaluated, and unpublished data were not sought. Results:Twenty-four clinical studies were included. The duration of smoking habit ranged from at least 5 years to 27.8 years. Sixteen studies showed that reductions in probing depth and gains in clinical attachment levels were compromised in smokers in comparison with nonsmokers. Three studies showed residual recession after periodontal surgical interventions to be significantly higher in smokers compared with nonsmokers. Three case reports showed periodontal healing to be uneventful in smokers. Conclusion:Cigarette smoking has a negative effect on periodontal wound healing after surgical interventions.

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.

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.

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.

Characteristics of newly-formed cementum following Emdogain application.

Periodontal regenerative techniques have been proposed; however, the outcomes remain debatable. The present investigation assessed the regenerated cementum following enamel matrix derivative application in dehiscence‐type defects. Buccal osseous dehiscences were surgically created on the maxillary cuspid, and the second and fourth premolars in five female beagle dogs. The treatment group (n=15 sites) received the enamel matrix derived application, whereas the control groups (n=15) did not. The dogs were sacrificed 4 months following treatment and the specimens were histologically and histometrically examined. The newly formed cementum was uneven in thickness and mineralization, overlapped the old cementum and exhibited functional orientation, cementocyte lacunae and collagen fibril bundles. Most of the histological specimens showed the presence of a gap between the newly formed cementum and the underlying dentin. Control sites did not exhibit any cementum formation. The present study concluded that newly formed cementum is of cellular type and exhibits multiple characteristics.

Study of the osseointegration of dental implants placed with an adapted surgical technique

OBJECTIVE To study the osseointegration of dental implants placed with a modified surgical technique in Beagle dogs and to compare it with the conventional method. MATERIALS AND METHODS Dental implants were placed bilaterally in the mandible of Beagle dogs using the press-fit as well as undersized implant bed preparation technique. Micro computer tomography (micro-CT) and histometric methods were used to analyze the bone implant contact and bone volume (BV) around the implants. RESULTS The bone-to-implant contact percentage (BIC: expressed as %), first BIC (1st BIC: expressed in mm), sulcus depth (SD: expressed in mm) and connective tissue thickness (CT: expressed in mm) were analyzed for both groups. The BIC percentage was significantly higher for the undersized installed implants (P=0.0118). Also, a significant difference existed between the undersized and press-fit installed implants for the first screw thread showing bone contact (P=0.0145). There were no significant differences in mucosal response (SD and CT) for both installation procedures. Also, no significant difference was found in the BV, as measured using micro-CT, between the implants placed with an undersized technique (59.3 ± 4.6) compared with the press-fit implants (56.6 ± 4.3). CONCLUSION From the observations of the study, it can be concluded that an undersized implant bed can enhance the implant-bone response.

Effect of enamel matrix derivative protein on the healing of standardized epithelial wounds: a histomorphometric analysis in vivo.

The enamel matrix derivative (EMD) is a preparation of the enamel matrix proteins secreted by the Hertwigs epithelial root sheath. It has been shown that EMD promotes periodontal wound healing; however, the significance of the protein in repairing skin wounds is insufficiently addressed. The aim of this in vivo histomorphometric investigation was to analyse the effect of EMD protein on the healing of standardised epithelial wounds. Dorsal skin of 22‐week‐old female guinea pigs (n = 33) was scarified and divided into test‐ (topical application of EMD) and control‐sites (sutured and allowed to heal). Animals were euthanised at specific time intervals and the specimens were then evaluated histomorphometrically. The mean widths of the external wound gaps (WGs) in the test‐ and control‐sites at the 5th, 20th and 35th day of healing were 5·89, 3·6 and 1·01 mm and 6·41, 5·02 and 3·43 mm, respectively. Histomorphometric analysis showed a statistically significant difference in the WGs between the test‐ and control‐sites. A significant increase in the formation of organised connective tissue matrix, collagen fibres and early muscle formation was observed in the test‐sites as compared with the control‐sites. Within the limits of this study, it is concluded that topical application of the EMD on standardised epithelial allows early wound closure and promotes healing as compared to when the defects are merely sutured.

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.

Histomorphometric Analysis of Bone Regeneration Using a Dual Layer of Membranes (dPTFE Placed Over Collagen) in Fresh Extraction Sites: A Canine Model

In untreated extraction sockets, buccal bone remodeling compromises the alveolar ridge width. The aim of this study was to histologically assess the efficacy of using a dual layer of membranes (high-density polytetrafluoroethylene [dPTFE] placed over collagen) for ridge preservation in fresh extraction sites. Eight beagle dogs were used. After endodontic treatment of mandibular bilateral second (P2), third (P3), and fourth (P4) premolars, mandibular bilateral first premolars and distal roots of P2, P3, and P4 were extracted atraumatically. Animals were randomly divided into 4 treatment groups. group 1, the control group, received no treatment; in group 2, allograft was placed in the alveolum and the socket covered with dPTFE membrane; in group 3, allograft was placed in the alveolum, the buccal plate was overbuilt with allograft, and the socket was covered with dPTFE membrane; in group 4, allograft was placed in the alveolum and covered with dual layer of membranes (dPTFE placed over collagen). No intent of primary closure was performed for all groups. After 16 weeks, the animals were sacrificed and mandibular blocks were assessed histologically for buccolingual width of alveolar ridge, percentage of bone formation and bone marrow spaces, and the remaining bone particles. The buccolingual width of the alveolar ridge was significantly higher among sockets in group 4 than in group 1 (P < .05). the amount of newly formed bone in each socket was higher in extraction sockets in group 4 than in groups 1, 2, and 3 (P < .001). A significant difference was found in the percentage of bone marrow spaces among all groups (P < .001). No significant difference was found in the number of nonresorbed bone particles among the groups. Using a dual layer of membrane was more effective in ridge preservation than conventional socket augmentation protocols.

Guided Bone Regeneration in Standardized Calvarial Defects in Rats Using Bio-Oss and β-Tricalcium Phosphate with Adjunct Platelet-Derived Growth Factor Therapy: A Real-Time In Vivo Microcomputed Tomographic, Biomechanical, and Histologic Analysis.

The objective of the present real-time in vivo experiment was to assess guided bone regeneration (GBR) in standardized calvarial defects using particulate graft material (Bio-Oss) and β-tricalcium phosphate (β-TCP) with adjunct recombinant human platelet-derived growth factor (rhPDGF) therapy. Eighteen female Sprague-Dawley rats with a mean age and weight of 8 ± 0.53 weeks and 250 ± 0.49 g, respectively, were used. Following surgical exposure, a full-thickness standardized calvarial defect was created on the parietal bone using a trephine drill with an outer diameter of 4.6 mm. For treatment, rats were randomly divided into three groups (six rats per group): (1) control; (2) rhPDGF + Bio-Oss, and (3) rhPDGF + β-TCP. Volume of newly formed bone (NFB), bone mineral density (BMD) of NFB, volume of remnant bone particles, and BMD of remnant bone particles were assessed using in vivo microcomputed tomography. Measurements were made at baseline and at 2, 4, 6, and 10 weeks after the surgical procedures. At 10 weeks, all animals were sacrificed and calvarial tissues were assessed histologically. In the control group, a significant increase in BMD of NFB was observed at 6 weeks (mean ± standard deviation [SD], 0.32 ± 0.002 g/mm(3)) (P < .01) from baseline, and the defect did not regenerate completely. In the rhPDGF + Bio-Oss group, mean ± SD volume (2.40 ± 0.25 mm(3)) (P < .01) and BMD (0.13 ± 0.01 g/mm(3)) of NFB significantly increased at 4 weeks and 6 weeks, respectively, from baseline (P < .001). In the rhPDGF + β-TCP group, mean ± SD volume (2.01 ± 0.7 mm(3)) and BMD (0.12 ± 0.02 g/mm(3)) of NFB significantly increased at 4 weeks from baseline (P < .01). In the rhPDGF + Bio-Oss and rhPDGF + β-TCP groups, mean ± SD BMD of remnant bone particles (0.31 ± 0.11 g/mm(3) and 0.23 ± 0.01 g/mm(3)) showed significant reduction at 6 and 10 weeks, respectively, compared with baseline values (1.12 ± 0.06 g/mm(3) and 0.92 ± 0.01 g/mm(3), respectively) (P < .001). Histologic results at 10 weeks showed NBF in the rhPDGF + Bio-Oss and rhPDGF + β-TCP groups. In real time assessment, when rhPDGF was added to β-TCP, BMD and bone hardness significantly increased compared with the other two groups.