Analyzing the Causes and Frequency of Early Dental Implant Failure among Iranians: An Epidemiological Study.

Aim: The rate of early dental implant failure (DIF) has increased in recent years, though the risk factors associated with this primary failure remain unclear. This study aimed to determine the rate of early implant failure and identify contributing factors. It was conducted from March 2018 to 2020 in Mashhad, Iran. Method: This observational study examined the records of 983 implants from the Implant Department of Mashhad Dental School. Variables considered included age, gender, systemic diseases, smoking habits, implant type and size, and surgery-related factors. Data were analyzed using Chi-square, Mann-Whitney U, and Fisher exact tests in SPSS V22, with a p-value of 0.05 or less considered statistically significant. Result: Of the 983 implants, 42 (4.3%) experienced early failure. The study population consisted of 555 (56.5%) females and 428 (43.5%) males, with an average age of 49.34 ± 13.67 years. A significant correlation was found between surgical complications (e.g., fracture of implant fixtures and inferior alveolar nerve exposure) and implant loading time (Yes or No) with early DIF (p=0.05 and p < 0.01, respectively). However, no significant correlation was observed between early failure and factors such as age, gender, smoking habits, systemic diseases, implant dimensions, or manufacturer. Conclusion: Surgical complications and loading time may be the most critical factors contributing to early implant failure. Therefore, we suggest dentists pay attention to the mentioned factors in the surgical protocols and their relationship. Further prospective studies on risk factors that could affect early implant failure are needed.

Effect of Acellular Dermal Matrix Placement Simultaneous with Implant Placement on Vertical Soft Tissue Thickness: A Randomized Controlled Clinical Trial.

Acellular dermal matrix (ADM) is commonly used for soft tissue augmentation in root coverage, increasing the width of keratinized gingiva or vestibular depth, or filling the localized alveolar bone defects. This parallel-design randomized controlled clinical trial assessed the effect of ADM membrane placement simultaneous with implant placement on vertical soft tissue thickness. A total of 25 submerged implants were placed in 25 patients (8 men, 17 women) with vertical soft tissue thickness < 3 mm at the surgical site. Patients were randomized into two groups: The intervention group (n = 13) received ADM over the implant for soft tissue augmentation, while no augmentation was performed for the control group (n = 12). After 3 months, healing abutments were placed, and the soft tissue thickness at the surgical site was measured again with a periodontal probe in both groups. Data were analyzed using Mann-Whitney and Wilcoxon tests. All 25 patients were successfully treated. The presurgical vertical soft tissue thickness was 2 mm and 1.92 mm in the control and test groups, respectively (P > .05). These values changed to 1.83 mm and 2.69 mm, respectively, after the intervention. The mean gain in soft tissue thickness was 0.76 mm in the test group, and the difference between groups was statistically significant (P < .05). ADM membrane can be successfully used to augment vertical soft tissue thickness simultaneous with implant placement.

Using Platelet-Rich Fibrin in Combination With Allograft Bone Particles Can Induce Bone Formation in Maxillary Sinus Augmentation.

BACKGROUND: Sinus pneumatization secondary to posterior maxillary tooth extraction can hinder proper implant installation. Maxillary sinus floor augmentation is a surgical procedure that has been proposed to overcome this issue. PURPOSE: The aim of this study was to evaluate and compare the histomorphometric outcomes of sinus floor elevation using allograft bone particles with or without platelet-rich fibrin (PRF). STUDY DESIGN, SETTING, SAMPLE: This randomized clinical trial included patients scheduled for maxillary sinus floor elevation in the Implant Department of Mashhad Dental School. Healthy adults with an edentulous maxilla and residual alveolar bone height of 3 mm or less were eligible to participate and were randomly allocated to intervention (A) or control (B) groups. Bone biopsies were obtained 6 months postoperatively. PREDICTOR VARIABLE: The predictor variable was using a PRF membrane for maxillary sinus augmentation. In group A, sinus floor elevation was performed using PRF combined with bone allografts, while in group B only allograft particles were used. MAIN OUTCOME VARIABLES: The primary outcome variables were the recorded postoperative histologic parameters, as in the area of newly formed bone, new bone marrow, and residual graft particles (µm2). The secondary outcome variables were the radiographically measured postoperative bone height and width at the graft site. COVARIATES: Age and sex. ANALYSES: Independent sample t-test was employed to compare the postoperative histomorphometric parameters between groups A and B. P value ≤ .05 was considered statistically significant. RESULTS: A total of 20 patients (10 per group) completed the study. The mean rate of new bone formation was 43.25 ± 5.22% in group A and 38.25 ± 7.01% in group B. This difference was statistically insignificant (P = .087). The mean amount of newly formed bone marrow was significantly more in group A compared to group B (6.81 ± 2.19% vs 10.23 ± 4.49%; P = .044). The average amount of remaining particles was also significantly less in group A patients (9.35 ± 3.43% vs 13.18 ± 3.67%; P = .027). CONCLUSION AND RELEVANCE: Incorporating PRF as an adjunctive grafting material results in fewer residual particles of allograft and in more bone marrow formation and may serve as a treatment option for developing the atrophic posterior maxilla.

Comparison of Guided Bone Regeneration with Periosteal Pocket Flap Technique Versus Autogenous Bone Block Graft for Horizontal Bone Augmentation: A Clinical Trial Study

The aim of this study was to assess changes in the horizontal dimension of the alveolar ridge when the autogenous bone block (ABB) or periosteal pocket flap (PPF) techniques were performed prior to implant placement. This randomized trial study was conducted on 25 patients in need of horizontal bone augmentation, who were randomly divided into two groups as follows: 13 patients underwent ridge augmentation using ABB, allograft, and a collagen membrane, while the remaining 12 underwent horizontal bone augmentation via the PPF technique. For all patients, radiographic examinations via CBCT were performed both before and 26 weeks after the operation. Following the surgery, dimensional changes in the ridge width were measured both within and between the two groups in the three regions of 0, 3, and 5 mm from the top of the alveolar crest. A total of 11 patients in the ABB group and 12 patients in the PPF group successfully completed the study. Statistical analysis showed that the increase in alveolar ridge width in each group was significant, but not significantly different between the two groups at any of the measured spots (0 mm from the crest, P = .25; 3 mm, P = .38; and 5 mm, P = .73). However, more postoperative complications were observed with the ABB technique. According to the results of the present study, there was no statistically significant difference between the PPF and ABB techniques in terms of horizontal bone gain.

Correlation between gray values in cone-beam computed tomography and histomorphometric analysis.

Purpose: The aim of this study was to analyze the relationships between bone density measurements obtained using cone-beam computed tomography (CBCT) and morphometric parameters of bone determined by histomorphometric analysis. Materials and Methods: In this in vivo study, 30 samples from the maxillary bones of 7 sheep were acquired using a trephine. The bone samples were returned to their original sites, and the sheep heads were imaged using CBCT. On the CBCT images, gray values were calculated. In the histomorphometric analysis, the total bone volume, the trabecular bone volume (referred to simply as bone volume), and the trabecular thickness were assessed. Results: Statistical testing showed significant correlations between CBCT gray values and total bone volume (r=0.537, P=0.002), bone volume (r=0.672, P<0.001), and trabecular thickness (r=0.692, P<0.001), as determined via the histomorphometric analysis. Conclusion: The results indicate a significant and acceptable association between CBCT gray values and bone volume, suggesting that CBCT may be used in bone densitometry.

Treatment of a Hopeless Tooth with Combined Endodontic-periodontal Lesion Using Guided Tissue Regeneration: A Case Report with One Year Follow-up.

Endodontic-periodontal lesions have always been a challenge for treatment due to the reduced success rate in comparison to endodontic or periodontal lesions alone. This case report describes surgical/endodontic management of supra-erupted non-vital maxillary incisor with primary periodontal and secondary endodontic lesions with mobility grade III and severe horizontal and vertical loss of attachment apparatus in a 55 years old woman with aggressive periodontitis. The successful results at one-year follow-up revealed that with an appropriate case selection strategy, proper regeneration method and soft tissue enhancement, severe combined endo-perio lesions may treat.

Clinical and Histological Evaluation of Tissue Healing in Beveled or Perpendicular Vertical Releasing Incision.

OBJECTIVES: The aim of this investigation was to evaluate the clinical and histological differences in wound healing between beveled and perpendicular vertical releasing incisions in dogs. MATERIAL AND METHODS: Four male mongrel dogs were used in this investigation. In each quadrant, a vertical releasing incision was made on either the mesial or the distal aspect of the cuspid teeth of each animal all on the same day. The sites were randomly selected to either receive a beveled incision or a perpendicular incision. A sulcular muco-periosteal flap was raised, reapproximated, and then sutured using 3-0 Vicryl. The animals were evaluated daily for the first week, and then at different time intervals during this investigation. One animal was killed at each time interval of 9, 14, 21, and 28 days after surgery. One animal was killed at each time interval, and a bone block consisting of the cuspid teeth and their surrounding bone and soft tissues was harvested, formalin fixed, and paraffin embedded. Samples were sectioned serially and stained with hematoxylin-eosin. Specimens were evaluated using a microscope with magnification ranging from ×10 to ×400 by a histopathologist. Four indices were used for histologic evaluation. RESULTS: At day 9 after surgery, a visible groove was seen in the marginal tissues of both perpendicular and beveled incisions. At day 9, both of the histologic sections showed less organized connective tissue and capillary networks with no significant difference in inflammation. In the 14-day samples, a depression was still present at the perpendicular incision sites, but not in the beveled incision group, where the groove was not visualized at all. In the 21- and 28-day samples, irregular capillary arrangements were seen in the connective tissue of the perpendicular incision groups with completely healed epithelium. There were no statistically significant differences noted histologically between the beveled and perpendicular incision groups noted at 9, 14, 21, or 28 days (P > .05). CONCLUSION: Based on these findings, it appears that clinical and histologic healing of beveled or perpendicular releasing incisions are similar 28 days after surgery.

Is Impregnation of Xenograft with Caffeine Effective on Bone Healing Rate in Mandibular Defects? A Pilot Histological Animal Study.

INTRODUCTION AND AIM: The aim of this study was to evaluate the effect of two concentrations of caffeine (1.5% and 3%) powder added to Bio-Oss xenograft on bone healing rate of iatrogenic mandibular defects in dogs. MATERIALS AND METHOD: The researchers implemented a pilot study on ten male adult mongrel dogs. Two 4-mm circular critical-sized defects were trephined on each side of the mandibular body (a total of 4 defects for each dog). One of the defects remained empty as a control group. The other three defects in each case were randomly filled with 1.5% or 3% caffeinated Bio-Oss or pure Bio-Oss. The mandible specimens were sent for histological and histomorphometric assessments, 4 months postoperatively. Our predictor variable was the type of bone substitute. The study outcomes were new bone formation, angiogenesis, and fibrosis. The p value was set at 0.05 using SPSS 16. RESULTS: The histological assessment showed that the administration of 1.5% caffeinated Bio-Oss to mandibular defects caused more angiogenesis and more new bone formation as well as less fibrosis compared to the other groups (p < 0.05). CONCLUSION: This study suggested that the application of 1.5% caffeinated Bio-Oss in bone defects of dogs resulted in the higher new bone formation. However, further clinical trials are needed to support its relevancy.

Evaluating Vitality and Periodontal Sensitivity of Teeth Adjacent to the Site of Open Sinus Lift Surgery before and after Treatment: A Case Series Study.

The aim of this study was to evaluate the effect of open sinus lift surgery on dental vitality and periodontal sensitivity of teeth adjacent to a surgery area. Forty-one patients undergoing open sinus lift surgery were evaluated for dental vitality and periodontal sensitivity of adjacent teeth. Dental vitality was evaluated using an electric pulp tester and cold spray. Periodontal sensitivity of teeth in the surgery area of open sinus lift was evaluated by interview and visual analogue scale before surgery and one, three, and six weeks after surgery. In order to increase the validity of the study, one healthy tooth was considered as a control. In the experimental group, differences in periodontal sensitivity were significant between the four measured times (P < 0.001). Pretreatment compared with three weeks posttreatment, pretreatment compared with one week posttreatment, six weeks posttreatment compared with one week posttreatment, and three weeks posttreatment compared with one week posttreatment showed significant differences (P = 0.001). In the control group, the periodontal sensitivity between the four measured times did not differ significantly (P = 0.421). In the experimental group, pulpal sensitivity was significant between the four measured times (P = 0.019). It was found that the test and control groups showed significant differences in pretreatment versus six weeks posttreatment and one week posttreatment versus three weeks posttreatment (P < 0.001). Pulse sensitivity significantly changed after open sinus lift surgery, making it clear that the surgery may lead to necrosis of adjacent teeth. However, further research is needed. Also, teeth in area of the surgery may be periodontally affected, but will undergo recovery.

Tapered Versus Cylindrical Implant: Which Shape Inflicts Less Pain After Dental Implant Surgery? A Clinical Trial.

PURPOSE: Because no study has evaluated the postoperative pain caused by the shape of dental implants, this study compared the level of postoperative pain between tapered and cylindrical implants inserted in the posterior region of the maxilla. MATERIALS AND METHODS: The study was designed as a double-blinded randomized clinical trial and conducted in 50 healthy patients 20 to 60 years old who were edentulous in the posterior maxilla and were candidates for single implantation. All patients had the same surgical difficulty with appropriate bone width and height. BioHorizons (Birmingham, AL) implants (tapered vs cylindrical) with 4.5-mm platform diameter were randomly selected for each group. The visual analog scale was used to evaluate the level of pain. Pain severity in each group was measured at 30-minute, 3-hour, 6-hour, 12-hour, 24-hour, 2-day, 3-day, and 1-week intervals. The predictor variable was implant shape and the outcome was postoperative pain severity. Data were statistically analyzed with SPPS 16 (SPSS, Inc, Chicago, IL) at the significance level of a P value less than .05. RESULTS: Fifty patients (n = 25 per group) with the mean age of 43.7 ± 10.9 years were included in this study. The pain level in the 2 groups reached its maximum at the 6-hour postoperative interval. Pain severity decreased significantly over time in the 2 implant groups (P < .001). Severities of postoperative pain in the tapered group at 3-, 6-, 12-, and 24-hour intervals were statistically lower than those in the cylindrical group (P < .05). CONCLUSIONS: Implant shape had an impact on postoperative pain. It can be concluded that tapered implants lead to less postoperative pain compared with cylindrical ones.

Immediate Nonfunctional Loading of a Single Implant in the Posterior Maxillary Area: A Randomized Clinical Trial.

This study compared the clinical and radiographic outcomes of immediate nonfunctional loading of implants to conventional loading in the posterior maxilla. In this single-blind randomized clinical trial, a total of 39 implants were inserted and evaluated in 32 patients. Nineteen implants were in the control group, and 20 implants were placed in the test group. The test group received implants and immediate restoration within 72 hours after surgery; the control group was followed by a conventional loading protocol 4 months after surgery. Follow-up appointments were performed at 4, 6, and 12 months. Clinical assessment included measurement of implant stability through resonance frequency analysis (RFA), probing depth around the implant in four aspects, and survival rate. Radiographic assessment, including evaluation of crestal bone loss in the mesial and distal of the implants by parallel periapical radiography, was conducted. Twenty-nine implants were followed throughout the study period, completing the entire intended follow-up. No significant difference was seen between the test and control groups in terms of crestal bone loss at any interval either in mesial or distal aspects. Also, no significant difference was found between the two groups regarding implant stability. Probing depth did not show significant differences between groups at 6 and 12 months. Only one implant in the control group failed before prosthesis loading, and no failure was observed in the test group. Average of insertion torque in the control group and the test groups were 49 and 51 N/cm, respectively. This variable also showed no significant difference between the two groups. If appropriate primary stability is achieved, nonfunctional immediate loading of implants in the posterior maxilla may have similar results to conventional loading in this area. Using this protocol, the time of edentulousness could be minimized.

Crestal Sinus Floor Elevation with Autogenous Press-Fit Dowel Bone Harvested Using Trephine Drills: A New Method.

The aim of this study was clinical and radiographic evaluation of sinus floor lifting from the alveolar crest with trephine bur and autogenous bone graft. In this research, a press-fit dowel bone technique with application of an autogenous bone block was used for elevating the sinus floor. Ten closed sinus lift surgeries were performed on 10 patients; all patients possessed atrophic ridges in an edentulous maxilla. Bone height of the ridge ranged between 3 and 5 mm. Surgery included forming a bony cylinder with a trephine bur to reach the sinus cortical floor and then elevating the sinus floor bone with anosteotom and placing an autogenous bone block at the site and fitting it with strikes of a hand mallet. The amount of an osteotom sinus floor height gain was measured during implant placement and via radiography before surgery and four months postsurgery. Average height of the sinus floor bone after surgery was 8.33 mm with SD = 1.39 mm. Mean bone height gain after surgery in evaluated patients was 3.47 mm with SD = 1.4 mm. As a result, bone sinus floor height following surgery was significantly increased (P value = 0.044), with a significant difference between sinus floor bone height before and after surgery (P value = 0.041). No significant difference was observed between sinus floor bone height gain and sex, age, and smoking before and after the operation. The sinus floor lift method by trephine and autogenous bone graft is a practical and simple way to reduce the time needed for implantation in patients with moderate atrophy of the posterior maxilla.

Comparative evaluation of IL-17 and TGF-ß expression in tissues of patients with chronic periodontitis and healthy individuals using real-time PCR.

Background: The present study aimed to determine the association between periodontal disease and the Th17/Treg balance by examining the genetic expression of IL-17 and TGF-ß, which influence incidence and suppression of inflammation. Methods: In this case-control study, samples were collected in a randomized and task-oriented order. Thirty-seven patients referred to professional periodontology clinics in Mashhad and the Periodontology Department of the Mashhad Dentistry Faculty for periodontal (case) or crown-length (control) surgery was enrolled. IL-17 and TGF-ß gene expression indices were measured in tissue samples by real-time polymerase chain reaction. Results: The IL-17 gene expression index was higher in the case group (2.68±0.91) than in the control group (1.68±0.41), but this difference was not significant. The TGF-ß gene expression index was significantly higher in the case group (54.42±7.88) than in the control group (24.12±3.38). Conclusion: L-17 and TGF-ß expression is increased in chronic periodontitis patients, but TGF-ß plays a more important role in periodontal inflammation in patients with chronic periodontitis. Further studies of the roles of Th17 and Treg cells are warranted.

Relationship between periodontal variables and disease severity in patients with chronic obstructive pulmonary disease.

Background: The present study investigated the relationship between certain periodontal variables and severity of disease in COPD patients. Methods: The present cross-sectional study included 50 patients suffering from COPD. Lung function examination, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), FEV1/FVC, SpO2, and Modified Medical Research Council (MMRC) Dyspnea Scale were performed. Periodontal clinical examination index included probing depth (PD), attachment loss (AL), gingival index (GI) and plaque index (PI). A quality of life validated index, the COPD assessment test (CAT index), was also calculated. Results: The FEV1 and FVC indices showed a significant negative correlation with PI and AL variables only. The COPD assessment test (CAT) index showed a significant but positive correlation with PI and AL variables only. The SpO2 index presented a significant negative correlation with GI and AL variables. The FEV1/FVC ratio was found to have a negative correlation with PD and AL variables. It is worth noting that MMRC exhibited no significant relationship with any of the periodontal variables. The only variable that was significantly different (P=0.022) among the three smoking groups was the FVC index. The FVC value was significantly higher in the group of subjects who smoked more than 10 cigarettes per day versus the non-smoking group (P=0.017). Conclusion: Based on the findings of this study, in view of the relationship between periodontal variables and respiratory indices in the course of COPD, early treatment of periodontal diseases, might considerably reduce the severity of COPD.

The effect of smoking on inflammatory cell infiltrate subtypes in gingival tissue of patients with chronic periodontitis.

BACKGROUND: Examinations on blood samples and gingival crevicular fluid of subjects with chronic periodontitis showed that smoking increased production of cytokines. OBJECTIVE: To evaluate the expression of immune markers on mononuclear inflammatory cell infiltrate at periodontitis and healthy tissue among smoking and non-smoking subjects. METHODS: This case-control study was performed on 41 patients who referred to a clinic of periodontology at a Mashhad dental school in Iran in 2016. The participants were all of Iranian Khorasanian ethnicity with age range of 35-65 years. Gingival biopsies were obtained during routine periodontal flap procedure. Immunohistochemistry using markers of CD20, CD3, CD68, and CD45RO was carried out. Data was analyzed by SPSS version 15, using one-way ANOVA and Tukey HSD test. RESULTS: Nonsmoker subjects showed significantly greater numbers of CD20+, CD68+, CD3+ cells compared to smoker subjects, both at healthy and periodontitis tissue biopsies (p<0.00), whereas there was no significant difference in terms of CD45RO (p=0.120). CONCLUSION: Cigarette smoking, results in infiltrative mononuclear chronic inflammatory cells reduction in connective periodontium.

The Effects of Smoking on Expression of IL-12 and IL-1ß in Gingival Tissues of Patients with Chronic Periodontitis.

AIM: The purpose of this study was to compare IL-1ß and IL-12 gene expression in the gingival tissue of smokers and non-smokers either with healthy periodontium or with chronic periodontitis. MATERIALS AND METHODS: 41 individuals consisting of 21 healthy controls (11 non-smokers and 10 smokers) and 20 chronic periodontitis patients (10 non-smokers and 10 smokers) participated in this study. Samples were collected from papillary regions of targeted areas and cytokines were analyzed using Real Time PCR. Shapiro-Wilk, Mann-Witney and Independent T tests were employed for statistical analysis. RESULTS: IL-1ß gene expression in gingival tissue of non-smoker group with chronic periodontitis was significantly higher than non-smoker-healthy group (p=0.011). Smoker-chronic periodontitis group showed lower IL-1ß gene expression than non-smoker-chronic periodontitis group (p=0.003). IL-12 gene expression was not significantly different between analyzed groups. CONCLUSION: IL-1ß gene expression increases in gingival tissue of non-smoker-chronic periodontitis patients due to inflammatory processes but smoking reduces the expression of this cytokine in diseased periodontal tissues. On the other hand periodontal condition and smoking habits do not seem to affect IL-12 gene expressions in gingival tissues. Authors concluded that reduced levels of IL1 and in some extent IL12 in smoking patients are responsible for higher tissue and bone degenerations and less treatment responses in smokers.

Comparison of Two Regenerative Surgical Treatments for Peri-Implantitis Defect using Natix Alone or in Combination with Bio-Oss and Collagen Membrane.

The aim of this clinical trial was to evaluate 6-month clinical and radiographic outcomes after surgical regenerative therapy of peri-implantitis lesions using either porous titanium granules (Natix, Tigran Technologies, Malmo, Sweden) alone or bovine bone mineral (Bio-Oss, Giestlich, Wolhusen, Switzerland) with a collagen membrane (B&B Dental Implant Company, San Pietro, Italy). Twenty-four patients having at least one implant with a peri-implantitis lesion were involved in this study. Patients were assigned randomly into two groups and treated with two different regenerative approaches. The first group (Group 1) received Natix alone and the second group (Group 2) received Bio-Oss plus collagen membrane after debridement of the defect. Probing depth, clinical attachment level, and radiographic measurements were recorded at baseline and after 6 months of healing. One patient with one implant from Group 1 and another patient with 2 implants from the Group 2 discontinued the study. Mean pocket depth change was 1.1 ± 1.4 mm in Group 1 and 1.1 ± 2.1 mm in Group 2. Bone level changes were 0.85 ± 1.06 and 1.4 ± 1.04 mm in the two groups, respectively, over the 6-month follow-up period. Neither clinical nor radiographical differences between the two groups were statistically significant. We conclude that both application of porous titanium granules and Bio-Oss plus collagen membrane resulted in clinical improvement of peri-implantitis lesions over a period of 6 months.

Evaluation of Alveolar Crest Changes following Buccal Bone Overbuilding in Immediate Implantation.

The aim of the present study was to evaluate alveolar crest changes when using demineralized freeze-dried bone allograft (DFDBA) and resorbable membrane between flap and buccal bone in addition to filling the gap, as compared to merely filling the gap, when performing immediate implantation. In 18 patients with 24 single-root teeth, implants were placed immediately after extraction. In the test group (nine patients with 12 teeth), DFDBA and barrier membrane were placed between buccal crest and flap after implant placement. In the control group (nine patients with 12 teeth), implants were placed without buccal grafting. In addition, in both groups, if the gap width between implant and buccal crest was ≥2 mm, the gap was filled with DFDBA at the time of extraction. The height of buccal crest soft tissue and the buccolingual width of bone at 3 and 5 mm, apical to the line connecting the two cementoenamel junctions (CEJs) of adjacent teeth (CEJ line), were measured at baseline and after 4 mo. In the test group, the mean height of the buccal crest increased by 1.04 ± 0.68 mm, but in the control group, height decreased by 0.83 mm (p < 0.001). In the test group, the mean height of soft tissue increased by 0.29 mm, but in the control group, height decreased by 0.79 ± 0.72 mm (p = 0.006). The mean reduction of buccolingual width of bone in 3 and 5 mm apical to the crest in the test group was lower than that of the control group, but not significantly (p = 0.231 and 0.212, respectively). The findings of this study show that using DFDBA and membrane between buccal crest and flap in immediate implantation could increase buccal crest and soft tissue height in the midfacial region but may not significantly prevent buccolingual width reduction of bone at 3 and 5 mm from the CEJ line.

Clinical and Radiographic Evaluation of Demineralized Freeze-Dried Cancellous Block Allograft for Ridge Augmentation: A Pilot Study.

Bone resorption after tooth extraction is a common problem in implant dentistry. Allografts are one of the therapeutic techniques used to reconstruct the deficient ridge. Although this technique eliminates the need for a surgical donor site, it has yielded contradictory results. The aim of the present pilot study was to evaluate the clinical and radiographic results of the use of demineralized freeze-dried cancellous block allografts (DFDCBAs) in lateral ridge augmentation. Seven patients were included in this study. Lateral reconstruction of bone was performed using DFDCBA with stabilizing screws and resorbable collagen membranes. The ridge width was initially measured during the augmentation surgery. A second measurement was taken 6 months later at the time of implant placement. In addition, cone bean computed tomography images were used at both baseline and at 6-month reentry for measuring the width of bone by applying an acrylic stent with a radiopaque marker at the edentulous area. Paired t test was used to evaluate the statistical differences. The mean increase in the clinical and radiographic ridge widths were 1.70 ± 1.90 and 1.28 ± 1.52 mm, respectively, which were not statistically significant (P = 0.56 and P = 0.067, respectively). The results showed that the use of DFDCBAs in conjunction with resorbable membrane does not yield predictable results in the reconstruction of ridge width deficiencies.