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Guided bone regeneration (GBR) is considered as a prerequisite in some cases of implant dentistry. For this purpose, bone materials are commonly used. Calcium compounds and Ca-P based materials like hydroxyapatite (HA, Ca10 (PO4)6(OH)2), due to their similarity with the human bone, can be used as graft materials for bone regeneration. This study aimed to evaluate biocompatibility of antler xenograft and compare the osteoconduction effects of antler xenograft with Cerabone in regeneration of calvarium bony defects of rabbits.Five defects with a diameter of 6 mm and a depth of 3 mm were prepared in the calvarium of four rabbits. Thereafter, two defects were randomly grafted with antler xenograft, two defects were filled with Cerabone, and one defect remained as the untreated group. Histological evaluations, including measuring percentage of new regenerated bone and the amounts of osteoblast, osteoclast, and osteocyte cells, were also performed. To do statistical analyses, paired t-test, chi-square, and Fisher tests were applied.The percentage of new bone formation was significantly higher in antler xenograft (73.33%) and in Cerabone (48.91%) compared to the untreated group (18.91%). The amounts of osteocytes and osteoblasts were obtained as 3.52 ± 0.17 and 2.41 ± 0.24 in the Antler xenograft and as 2.57 ± 0.29 and 2.31 ± 0.32 in the Cerabone group, respectively. Bone marrow formation were significantly higher in antler xenograft (6.66 ± 5.34) and Cerabone (1.99 ± 3.17) compared to the untreated group.According to this pilot study, results of using antler xenograft as an osteoconductive materials in regeneration of rabbit calvarial defects are comparable with Cerabone. Although more clinical studies are needed.

This study sought to compare the thickness of hard and soft tissues between edentulous and contralateral tooth sites. This split-mouth study evaluated 153 partially edentulous patients. The measurements were made on cone-beam computed tomography (CBCT) scans. The soft tissue thickness was measured at the cementoenamel junctional (CEJ) level, and at 2, 4, and 6 mm apical to the CEJ in the facial and palatal aspects. The bone thickness of the opposite quadrant was also recorded at 2, 4, and 6 mm apical to the CEJ. The Mann–Whitney U test and the Spearman's rank correlation coefficient were applied for further statistical analyses. At the edentulous sites, significant soft tissue loss was noted at the CEJ level (p

This retrospective study was aimed to compare the clinical and radiographic outcomes of implants with the same body design but different collar surface (laser-microtextured vs. not laser-microtextured) after functional loading. Forty-three patients (29 females, 14 males) with 139 implants (60 laser-microtextured and 79 without laser microtexturing) were included in this study. Patients were consecutively included, and the data were collected during their implant maintenance visit. Clinical and radiographic parameters including probing depth (PD), bleeding on probing (BoP), and marginal bone loss (MBL) were recorded. In addition, the implant success index (ISI) score was determined. Statistical analysis was performed using the Mann–Whitney U test, the Kruskal–Wallis rank test, or the Pearson χ2 test, along with binary logistic regression (p

Background Improvement in implant design has made implant dentistry a challenging treatment modality worldwide. Objectives This study aimed to investigate the efficacy of a xenogeneic collagen matrix in managing 3-4-millimeter gaps in flapless immediate implant placement. Material and methods Twenty-two patients received 39 immediate implants via the flapless approach. Patients with intact bony walls, buccal bone thickness ≥2 mm and a jumping distance of 3-4 mm were included in this study. The gap between the implant and the socket walls was filled with a xenogeneic collagen matrix (Collacone®). The final clinical and radiographic evaluations were performed at least 24 months following functional loading. Results There was no early or late failure, and the implants showed a 100% survival rate. The mean mesial (0.28 ±0.39 mm) and distal (0.28 ±0.39 mm) marginal bone loss (MBL) at the site of incisors was not significantly different from the values at the site of premolars and molars (0.30 ±0.42 mm and 0.34 ±0.48 mm, respectively). The evaluation of the implant success index (ISI) score revealed no difference between the mandible and the maxilla (p = 0.700), or incisors compared with premolars and molars (p = 0.420). The only significant difference was in terms of distal MBL, which was higher in the maxilla (0.39 ±0.49 mm) than in the mandible (0.12 ±0.23 mm) (p = 0.040). Conclusions Within the limitations of this study, it seems that the application of a xenogeneic collagen matrix to manage 3-4-millimeter gaps in carefully selected cases may bring promising outcomes.

Peri-implantitis is a biofilm-induced pathological condition, and different approaches have been proposed to manage this condition. This study introduces a surgical technique in accordance with the concept of guided bone regeneration for implants with extensive peri-implant defects. This pilot study was conducted on 7 patients with 11 implants (4 females and 3 males; 32 to 61 years). In this technique, we used a titanium mesh, a combination of autogenous bone, allogenic graft material, and acellular dermal matrix to reconstruct the peri-implant defects. All implants were placed submerged, and the second-stage surgery was conducted after 8 months. Soft tissue augmentation and vestibuloplasty were performed in the second-stage surgery, if required. The mean function time of implants was 60.5 ± 29.4 months. The mean baseline probing pocket depth was 5.7 ± 1.4 mm, and soft tissue recession was observed at two sites (18%). The mean recession and keratinized tissue width (KTW) values were 0.4 ± 0.8 mm and 3 ± 1.6 mm, respectively. The mean marginal bone loss and bone gain were 4.4 ± 1.2 mm and 2.9 ± 0.9 mm, respectively, which showed a significant improvement. Our preliminary evaluations showed favorable results in terms of radiographic defect fill and soft tissue condition. It appears that this technique may lead to promising outcomes in cautiously selected patients seeking to retain their failing implants. However, long-term results following functional loading are required before recommending this technique for daily practice.

This study aimed to assess the quantity and quality of available bone to provide the autologous bone graft from mandibular ramus. CBCT scans were collected and mandibular ramus was evaluated by measuring a variety of parameters including volume, bone height, cortical, and cancellous bone thickness. Data analysis was performed using descriptive statistics and inferential statistics. We used the Kolmogorov–Smirnov test for the evaluation of data normality. We then applied Pearson correlation and independent t-test for normal variables, and Spearman and Mann–Whitney correlation tests for abnormal variables. Statistical analysis was performed using SPSS version 19 and P value

Background. This study aimed to assess the association of haptoglobin (HP) and natural resistance-associated macrophage protein 1 (NRAMP1) alleles with the presence of heme-consuming periodontal pathogens in a group of Iranian patients with chronic periodontitis and peri-implantitis. Methods. This cross-sectional study evaluated 69 eligible chronic periodontitis and peri-implantitis patients selected from Shahid Beheshti Dental School. The periodontally diseased individuals had at least three teeth with clinical attachment loss of ≥3 mm and a probing pocket depth (PPD) of ≥3 mm in at least two quadrants. Peri-implant PPD of at least one site was ≥5 mm with or without suppuration and bleeding on probing. A plaque index of >20% and a radiographic crestal bone loss was present in at least one site around the implant. The paper point method was used for sampling from the deepest periodontal/peri-implant pocket of each tooth or implant for the DNA checkerboard hybridization technique. Statistical analyses were performed with PASW Statistics 18.0. The variables were presented as absolute and relative frequencies (%). Results. An Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) score of 1–2 was 5.8 times more frequent in HP 2, rs1723540 G, and rs2276631 G alleles. A Porphyromonas gingivalis (P. gingivalis) score of 1–2 was 4.8 times more common in the subjects carrying HP 2, rs1723540 G, and rs2276631 G alleles compared with HP 1, rs1723540 A, and rs2276631 A alleles. Conclusion. Within the limitations of this study, it seems that there was a relationship between HP and NRAMP1 allele frequencies and the presence of heme-consuming periodontal pathogens in the Iranian patients with chronic periodontitis and peri-implantitis evaluated in the present study.

Introduction Endovascular treatment of high-flow vascular lesions with onyx may be very dangerous due to premature occlusion of the vein resulting from high flow-induced migration of this embolic substance without occlusion of the feeding vessels and the nidus. It is also dangerous because of the risk of occlusion of the normal vessels around the lesion. Inducing temporary cardiac arrest using adenosine may be helpful in limiting and minimizing these risks. However anaesthetic management of this procedure in children suffering from high-flow vascular lesions is difficult and challenging. Methods We report three paediatric patients with high-flow cerebrospinal vascular lesions that underwent endovascular treatment under general anaesthesia and temporary cardiac arrest with adenosine. Adenosine was administered in escalating doses to induce a few seconds of cardiac standstill and the onyx injection was synchronized with the onset of adenosine-induced cardiac standstill, the fistula being occluded by onyx. Results There were no complications in peri-procedural treatment in all three cases. Post-embolization angiography revealed complete obliteration of the lesion, and the patients’ neurological status progressively improved at follow-up. Conclusion Adenosine-induced temporary cardiac standstill was successfully used to facilitate safe and controlled endovascular onyx embolization of high-flow central nervous system vascular lesions.

Introduction: Free gingival grafting is among the most foreseeing procedures for increasing the zone of keratinized attached gingiva and enhancing soft tissue around the teeth and dental implants. Nowadays low-level laser therapy (LLLT) is a promising approach in providing patients with more pleasing results in terms of esthetics and comfort. This study aims to investigate the effects of LLLT on gingival recessions treated with free gingival graft (FGG). Methods: This case series was conducted on 12 individuals requiring a bilateral gingival graft in the mandibular region. There was a 30-day interval between the two operations. The test side was selected randomly and irradiated by a low-level laser (LLL) just before surgery. The patients did not know which side was irradiated. LLLT was applied to the donors’ as well as recipients’ site immediately after the operation and 48 hours later. The patients were instructed to record their post-operative pain in a visual analogue scale (VAS) 3 and 24 hours and 7 days after the surgical procedure. The clinical photographs were taken immediately and 30 days after surgical treatment were graded by three experienced periodontists for color matching to adjacent tissues. Results: Ten individuals could finish the study. The test group presented significantly better shade matching and wound healing at the palatal donor site on days 7, 14 and 21. There was a significant reduction in post-operative pain after 24 hours (P=0.007). No statistically significant difference was found between both groups in terms of clinical periodontal indices. Conclusion: LLLT could reduce post-operative pain 24 hours after surgical treatment. Furthermore, the application of LLLT could improve the donors’ site healing and the recipients’ site color matching.

Statement of problem Immediate implant placement provides a popular therapeutic option. However, compromised sockets may jeopardize the treatment outcome. Purpose The purpose of this systematic review and meta-analysis was to investigate the treatment outcome in terms of the implant survival rate and success parameters of immediate implant placement in compromised extraction sockets. Material and methods An electronic search was conducted in PubMed, Embase, Cochrane Library, and ISI Web of Science up to January 2021. Studies evaluating implant survival rate and main success parameters were included for a qualitative and quantitative analysis (risk ratio and mean difference). Results In total, 43 studies with analysis of 4825 sockets were included. Compared with the noncompromised sockets, the compromised group showed no significant differences in implant survival rates (risk ratio=0.992; 95% confidence interval (CI)=0.979 to 1.005; P=.246). No significant statistical differences were found in marginal bone level at ≤12 months (mean difference [MD]=0.033; 95% CI=-0.012 to 0.078; P=.154) or esthetic parameters. Conclusions Immediate implant placement in compromised sites does not appear to decrease the survival and success rates. However, randomized clinical trials with large sample sizes should be conducted to draw a definite conclusion about the efficacy and safety of this treatment protocol in compromised sockets.

Objectives - Aphthous stomatitis is one of the most common ulcerative lesions in the oral cavity. The aim of this study was to report the characteristics of patients with aphthous stomatitis after dental implantation. Patients and Method - The study included 14 patients who were diagnosed with aphthous stomatitis. The subjects were analyzed with the respect to age, sex, patient's general health status, type, number, location, and duration of the ulcers and the number of dental implants. Results - Of the 14 cases, 64.3% were female and 35.7% were male. The mean age of patients was 57.7. In terms of general health status, 64.3% of patients did not have a remarkable disease; however, 14.3%, 14.3%, and 7.1% of cases had diabetes, hypothyroidism, and cardiac disease, respectively. The majority of the lesions have been presented as minor type (85.7%) and the mean number of the ulcers was 2.5. Labial mucosa has been affected more frequently (71.4%), followed by tongue and floor of the mouth. The most lesions (42.8%) were occurred one day after dental implant surgery. The mean number of dental implants was 3.1. Conclusion - Presence of apthous ulcers should be considered by dentists as a potential postoperative complication of dental implantation.

Background Bone volume plays a pivotal role in the success of dental implant treatment. Autogenous bone grafts should be harvested from reliable sites in the maxillofacial region. This study sought to assess the quantity and quality of bone in the mandibular symphysis for autogenous bone graft harvesting using cone-beam computed tomography (CBCT). Methods This cross-sectional study evaluated the CBCT scans of 78 adults presenting to three oral and maxillofacial radiology centers. The vertical (VD) and horizontal (HD) alveolar bone dimensions, cortical thickness (CT), and cancellous to cortical bone ratio (C/C) were measured in the interforaminal region of the mandible at the sites of central incisor to first premolar teeth. The interforaminal distance (ID) and the anterior loop length were also measured. Nonparametric statistical tests were used to analyze the data with respect to sex, age, and tooth position. Results The median VD, HD, and CT of the symphysis were 20.21 (3.26), 4.13 (0.37), and 2.25 (0.23) mm, respectively. The median C/C was 1.51 (0.11). The median ID was 52.24 (8.24) mm, and the median anterior loop length was 1.82 (1.06) mm. Significant differences were observed in all parameters among different teeth. Most of the measured parameters were greater in males compared with females. There were significant differences in ID, VD, and CT between different age groups. Conclusions The quantity and quality of the available bone in the mandibular symphysis for bone graft harvesting vary by gender, age, and harvesting site, necessitating careful preoperative evaluation.

This study aimed to assess the viability, distribution and penetration of human gingival fibroblasts (HGFs) into three types of acellular dermal matrix (ADM) membranes. HGFs (HGF1-PT1 cell line) were seeded and cultured onto three types of ADM membranes, namely medium-thickness and thick Regen, SureDerm and one collagen matrix (Mucoderm). Viability and proliferation of HGFs on membranes were assessed at 24, 48 and 72 h and seven days using the methyl thiazolyl tetrazolium assay. Distribution and morphology of cells were assessed qualitatively at 24 h and seven days using a scanning electron microscope (SEM). Penetration of HGFs on day seven was assessed using a transmission electron microscope (TEM). Data were analyzed using two-way ANOVA. Viability of HGFs was not significantly different on the four types of membranes at 24 or 48 h (P > 0.05). At seven days, viability on SureDerm was higher than that in other groups and cell viability on thick Regen was less than that in other groups (P

Objective Contemporary implantology is moving toward less invasive approaches. To date, several techniques have been proposed for maxillary sinus lift surgery. In this article, we introduce a new technique for maxillary sinus floor elevation that is less invasive than the osteotome technique. Methods and materials In the vertical expander screw (VES) technique, which uses a combination of drilling and bone-expander screws; a primary implant hole is created. Bone expander screws are used in lateral and vertical dimensions to elevate the sinus membrane. Results The results at the two-year follow-up revealed bone formation around the implant body in the bony sinus cavity for three patients. Accordingly, 100% survival and success rates were reported for implants placed with VES technique. Conclusion The maxillary sinus floor can be elevated to the desired height with a VES technique with minimal invasion. The VES technique can be used as an alternative to elevate the sinus floor with less invasion than the osteotome technique.

This randomized controlled clinical trial with a 1-year follow-up evaluated gingival thickness changes around teeth after use of dermal allograft and xenograft matrix. A total of 116 teeth (19 patients) were separated into two groups. One group received xenogeneic collagen matrix (n = 48), while the other received allogeneic acellular dermal matrix (n = 68) via a coronally advanced flap (CAF). Gingival thickness (GT), keratinized gingival width (KGW), pocket depth (PD), and clinical attachment loss (CAL) were measured on the day of surgery (baseline) and at 3 weeks, 2 months, 6 months, and 1 year postoperative. The two groups were compared using repeated-measures ANOVA (P .05). The GT increased in all cases treated with allogeneic and xenogeneic enriched collagen matrix. Both soft tissue substitutes were equally effective in acheiving optimal GT.

Due to advances in interventional techniques, the transvenous approach may present an effective treatment option for embolization of brain arteriovenous malformations (AVMs). Contrary to the transarterial method, the transvenous approach can only be utilized in a specific subset of patients and is not suitable as a standard procedure for all AVM lesions. While this technique can be helpful in certain patients, careful patient selection to ensure patient safety and favorable clinical outcomes is important. However, especially in high-flow AVMs, targeted deposition of embolic materials through a transvenous access can be challenging. Therefore, a temporary flow arrest may prove helpful. Transient cardiac arrest by use of adenosine has been applied in cerebrovascular surgery but is not common for endovascular embolization. Adenosine-induced arrest and systemic hypotension may be a feasible, safe method to reduce flow and help endovascular transvenous embolization of certain AVMs. Our study evaluated the efficiency and safety of adenosine-induced circulatory arrest for transvenous embolization of cerebral AVMs.

Leukocyte platelet-rich fibrin (L-PRF) has the potential to accelerate wound healing. Here, we assess clinical and radiographic outcomes of socket preservation using L-PRF. For this single-blind, randomized, split-mouth clinical trial, we selected 22 patients (15 males and seven females), who required extraction of single-rooted teeth. Subjects were randomly assigned to two groups. We used L-PRF in the extraction socket on one side and no material on the contralateral side. We obtained cone-beam computed tomographic images and diagnostic casts from tooth extraction sockets before surgery and 3 mo after the procedure. Changes in buccolingual diameter and height of bone at 3 mo after tooth extraction (compared to baseline) were determined and digitized data statistically analyzed using Statistical Package for the Social Sciences software, ver. 25.0 (IBM, Armonk, NY) via the paired t-test. In tooth sockets with/without L-PRF application 3 mo after extraction, bone buccolingual diameter significantly decreased at socket center to 0, 1, and 3 mm from the ridge crest, compared to baseline. A significant reduction occurred in sockets with/without L-PRF application in buccal and lingual bone height at the bony socket midbuccal portion of and mesial and distal septa (p < 0.0001). However, the Mann-Whitney U test showed changes to be significantly greater in controls than the case group (p < 0.0001). Taking into account study limitations, application of L-PRF in tooth extraction sockets significantly decreased reductions in bone height and buccolingual diameter compared to control sockets.

This study sought to histologically and histomorphometrically assess and compare application of xenograft bone substitute and synthetic nonceramic hydroxyapatite for tooth-socket preservation in dogs. This split-mouth clinical trial was conducted in five hybrid dogs, using four tooth sockets in each dog, with a total of 20 sockets for evaluation. Group 1 received xenografts, and group 2 received synthetic nonceramic hydroxyapatite in the sockets. In group 3 (positive controls), sockets remained empty. All sockets were covered with collagen resorbable membrane, and the flap was stitched using nonresorbable sutures. In group 4 (negative control), sockets were without membrane, left empty, and sutured. After 12 wk, 8-mm-high bone core biopsies were harvested from inside the sockets, using a trephine bur with an internal diameter of 2 mm. We assessed the tissue in terms of percentage of newly formed viable bone, percentage of remaining particles, degree of inflammation, and type of connective tissue. Data were statistically analyzed. The percentage of newly formed viable bone was 34.98% in group 1 and 41.30% in group 2, and this difference was not statistically significant (p = 0.710). The percentage of remaining particles was 15.95% in group 1 and 14.14% in group 2; this difference was also not statistically significant (p = 0.902). Both synthetic nonceramic hydroxyapatite and xenograft bone substitute showed similar efficacy, histologically and histomorphometrically, when used with resorbable collagen membrane for tooth-socket preservation in dogs.

Background. Visfatin (pre-B-cell colony-enhancing factor) is a salivary biomarker secreted from a variety of cells and is thought to have some proinflammatory and immune-modulating effects. This study compared salivary concentrations of visfatin in patients with chronic periodontitis and periimplantitis and healthy individuals. Methods. In this cross-sectional and descriptive trial, patients were selected on the basis of inclusion and exclusion cri-teria. The whole saliva samples were collected; then according to the measured clinical parameters the patients were cate-gorized to peri-, chronic periodontitis and periodontally healthy individuals. The concentrations of visfatin were evaluated using a standard ELISA kit. The salivary concentrations of visfatin were statistically analyzed using Kruskal-Wallis test. A probability value of less than 0.05 was considered significant. Results. A total of 40 participants (21 females and 19 males) were enrolled in this study. The mean salivary visfatin con-centrations in the periodontally healthy individuals, periimplantitis patients and chronic periodontitis patients were 23.97 ng/mL, 12.83 ng/mL and 11.95 ng/mL, respectively. However; visfatin levels were higher in healthy individuals compared to other groups No significant differences were found in salivary visfatin concentrations between the three groups. Conclusion. Under the limitations of this study, no significant relationships were found regarding salivary concentrations of visfatin among periimplantitis and chronic periodontitis patients as compared to healthy individuals; however, more studies are required in this regard. Key words: Visfatin, saliva, periimplantitis, chronic periodontitis.

The maxillary canines rank second after the third molars in terms of the frequency of impaction. The permanent canine teeth play a fundamental role in a functional occlusion and a balanced smile. This study aimed to review the literature and introduce clinical guidelines for surgical canine exposure techniques. The choice of treatment is influenced by several factors such as canine location, severity of impaction, patient’s age, and other considerations. There are three treatment options, namely observation, exposure and extraction. Based on the location of the impacted canine, the amount of keratinized gingiva and distance from the gingival margin, a flow diagram is introduced for decision-making to choose an appropriate surgical technique.

Background. Despite successful results of implant therapy, complications occasionally occur in challenging situations.Apart from academic courses for implantology, dental associations also offer training courses for general practitioners.We sought to assess dentists' attitude towards peri-implant diseases. Methods. The subjects in thisquestionnaire-based cross-sectional study consisted of dentists participating in the annual congress of the Iranian Dental Association in 2013, whose knowledge and attitudes towards peri-implant diseases were assessed using a five-section questionnaire (implant therapy training, peri-implant soft tissue assessment, peri-implant diseases and treatment planning for peri-implant diseases). Data were analyzedwith SPSS 22, using descriptive and analytical methods. Results. The results showed that due to extensive placement of implants and high prevalence of complications, academic and organized training courses are essential. Conclusion. The results showed that due to extensive placement of implants and high prevalence of complications, academic and organized training courses are essential.

Background and aims. The aim of this study was to evaluate the intra- and inter-examiner reliability and reproducibility of linear measurements on cone-beam computed tomography (CBCT) images made by calibrated radiologists and periodontists. Materials and methods. The alveolar ridge dimensions were measured on selected CBCT images by two calibrated radiologists and two periodontists. Intra- and inter-examiner reliability was evaluated by intra-rater and intra-class correlation coefficients (ICCs). Results. Intra- and inter-examiners ICCs obtained with the different methods showed almost perfect matches. The results demonstrated high examiner reproducibility for linear parameters of alveolar ridges on CBCT images in presurgical implant site assessments. Conclusion. The alveolar ridge dimensions provided by the radiologists might be useful for the periodontists. The measurements with small differences were related to the experience and skills of the examiner, inclination measurement, selection of the exact level of the alveolar crest and the ability to detect the exact anatomic borders on CBCT images.

Background and aims. The goal of this study was to evaluate the clinical efficacy of a standard oral hygiene routine (daily tooth brushing and flossing) along with cetylpyridinium chloride (CPC) mouthwash in comparison to the same protocol without mouthwash in chronic periodontitis patients during a 14-day period. Materials and methods. This comparative study was carried out or 50 non-smoking patients with chronic periodontitis; 25 patients followed an oral hygiene regimen using a toothbrush and dental floss (control group) and the remaining 25 used the mentioned protocol along with CPC mouthwash (test group) for 14 days. The plaque index (PI), modified gingival index (MGI) and probing pocket depth (PPD) were assessed. Wilcoxon and Mann-Whitney U tests were used to evaluate and compare the prevalence of indices between the two groups. Statistical significance was set at P

Background. Thisstudy aimed to compare the effect of one and two sessions of antimicrobial photodynamic therapy (aPDT) as an adjunct to scaling and root planing (SRP) on clinical and microbial parameters in patients with chronic periodontitis. Methods. This study was conducted on 20 patients. The dental quadrants of patients were randomly assigned to SRP at baseline (group 1), SRP at baseline and one month (group 2), SRP plus aPDT at baseline (group 3) and SRP plus aPDT at baseline and one month (group 4). Probing depth (PD), clinical attachment level (CAL) gain, and bleeding on probing (BoP) were measured at baseline, and one and three months later. F. nucleatum counts were determined by PCR. ANOVA was used for the comparison of these variables between the groups. Results. In all the groups, PD reduction and CAL gain increased significantly at 1- and 3-month intervals compared to baseline (P=0.001). At three months, the difference in PD between groups 1 and 3 was statistically significant (P=0.014). CAL gain between groups 2 and 4 at one month (P=0.016) and three months (P=0.001) wasstatistically significant. Reduction in F. nucleatum counts was not significant between the four study groups (P>0.05). Conclusion. A combination of two sessions of aPDT and SRP could improve CAL gain; however, further long-term studies are necessary in this regard.

Background The finite element method (FEM) has been used to analyze stress and strain distributions around 3 suggested dental implants with newly-designed thread parameters and the optimal shape of the implant was introduced considering the response surface optimization method sensitivity analysis. Experimental tests seemed necessary to confirm the results of the FEM. Objectives The aim of this study was to use experimental tests to prove the results of a finite element analysis of 3 dental implants with different thread designs under axial loads. Photoelastic stress analysis was chosen due to the similarity of analysis with FEM. Material and methods Two-dimensional models of 3 dental implants were built of grade 4 titanium to be tested in the polariscope. Model 1: A tapered implant with V-shaped threads; Model 2: A tapered implant with micro-threads in the upper area and V-shaped threads in the rest of the body; Model 3: A tapered implant with reverse buttress threads in all areas. Axial loading of 100 N was applied to the top of the implants and stress patterns and the maximum stress were evaluated for each implant. Results The minimum Huber-Mises-Hencky stresses of cortical bone were recorded in model 2, a tapered implant with micro-threads in the upper area and V-shaped threads in the rest of the body. The value for 100 N loading was 15.25 MPa, which was in agreement with the FEM. Conclusions Considering the stress patterns and values obtained from experimental tests of photoelasticity, the tapered implant with micro-threads in the upper area and V-shaped threads in the rest of the body has the most uniform and desirable stress distribution in the surrounding cortical bone and is preferred to be used in future applications.

Introduction: Peri-implantitis is a common complication of dental implant treatment. A cause-and-effect relationship has been previously documented between microbial plaque and peri-implantitis and implant failure. A difference has been reported in the disinfection efficacy of erbium laser irradiation and air-flow abrasion for contaminated titanium surfaces. Also, the surface changes caused by lasers and air-flow abrasion have not been well studied. Thus, the purpose of this study was to compare the surface changes of contaminated titanium discs following decontamination by erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and air-flow abrasion. Methods: Twenty-eight intact, sandblasted, and acid-etched (SLA) titanium discs were used. Twenty-four titanium discs were contaminated with Escherichia coli. Then, they were decontaminated by using Er:YAG laser irradiation and air-flow abrasion. Four discs remained intact. The mean and standard deviation of the contact angle and the weight percentage of aluminum, titanium, oxygen, carbon, phosphorus, and calcium were measured. Qualitative changes in surface topography of titanium discs were assessed by scanning electron microscopy (SEM). Results: The mean weight percentage of carbon in the air-flow abrasion group (4.98%) experienced a significant reduction compared with the contaminated (positive control) group (P=0.035). The contact angles were 46.54° and 38.67° in the laser and air-flow abrasion groups respectively, which were significantly lower than the value in the positive control group (75.15°) (P ≤0.001). SEM micrographs showed no significant change in the surface area in either technique. Conclusion: Air-flow abrasion was more successful in improving the surface characteristics of titanium discs with no alteration in surface topography or elements, compared with Er:YAG laser irradiation. Further studies regarding the safety of the Er:YAG laser for the decontamination of titanium surfaces are recommended.

Background. This study aimed to assess Aggregatibacter actinomycetemcomitans (Aa) and Prevotella intermedia (PI) counts in gingival crevicular fluid (GCF) around healthy implants, diseased implants and sound teeth. Methods. Eight patients (four males and four females), who had healthy implants, implants with peri-implantitis and sound teeth, were selected. Samples (GCF) were analyzed using real-time polymerase chain reaction (RT-PCR). The above-mentioned bacteria were detected and counted. Data analysis in RT-PCR was carried out based on the standard curve using Prism software to compare Pi and Aa counts between the three areas (GCF around sound teeth, healthy implants and implants with peri-implantitis). Results. Pi counts were significantly higher in GCF around implants with peri-implantitis (8 implants) than around healthy implants (8 implants) (P

Application of surgical stents for implant placement via guided flapless surgery is increasing. However, high cost, need for some professional machines, and not taking into account the soft-tissue parameters have limited their application. We sought to design and introduce a technique named in-office guided implant placement (iGIP) to decrease the cost by using available devices in office and enhance the applicability of surgical stents. A customized surgical stent was fabricated based on prosthetic, soft- and hard-tissue parameters by taking into account the amount of available bone (using the computed tomographic [CT] data), soft-tissue thickness and contour (using a composite-covered radiographic stent), and position of the final crown (by diagnostic cast wax up and marking the final crown position with composite). The efficacy of iGIP, in terms of the accuracy of the three-dimensional position of the implant placed in the study cast and in patient's mouth, was confirmed by direct observation and postoperative CT. The iGIP can enhance implant placement in the prosthetically desired position in various types of edentulism. Using this technique minimizes the risk of unwanted consequences, as the soft-tissue thickness and contour are taken into account when fabricating a surgical stent.

This study sought to assess the relationship between facial gingival and bone dimensions in maxillary anterior teeth region using cone beam computed tomography (CBCT).This study assessed 621 maxillary anterior teeth in 144 patients. In the sagittal plane, facial bone thickness (BT) and gingival thickness (GT) were measured at the crestal level and at 2, 4 and 6mm apical to the cementoenamel junction (CEJ). The dentogingival complex (DGC) dimensions and the distance from the CEJ to bone crest were also measured on CBCT scans. To determine the gingival biotype, GT at 2mm apical to the gingival margin was measured and GT1.5mm was categorized as thin while GT ≥1.5mm was categorized as thick. The data were analyzed using SPSS version 21 via repeated measures ANOVA and the Cochrane's Q, chi-square and independent samples t-tests.The BT around the maxillary central and lateral incisors and canine teeth at 4 and 6mm apical to the CEJ was significantly different in thick and thin gingival biotypes (P0.05). The mean GT at 2 and 4mm apical to the CEJ was significantly different around central and lateral incisors (P0.05). Thickness of crestal bone was significantly different between the two gingival biotypes around central and lateral incisors (P0.05).The two gingival biotypes had significantly different mean BT; different biotypes and their relationship to BT varied around anterior maxillary teeth.

COVID-19 has imposed tremendous burden on the healthcare systems and healthcare professionals worldwide. As periodontitis and peri-implantitis are chronic diseases, regular recall visits play a critical role in management of these conditions; however, the current situation may stop patients from attending their regular maintenance. Therefore, it may be necessary to reconsider and revise the treatment protocols.

Background. It is crucial to maintain periodontal health in patients undergoing orthodontic treatment. Biotype is a critical factor to be considered in this regard. This systematic review investigated the scientific evidence on the relationship between gingival biotype and marginal periodontal alterations induced by orthodontic interventions. Methods. An electronic search was conducted for pertinent studies in three databases: PubMed, Scopus, and Cochrane up to August 1, 2019 based on a detailed protocol according to the PRISMA statement. The authors also completed a hand search in six dental journals and the bibliographic lists of the relevant studies. Results. Of 1512 citations retrieved through the electronic search, 602 were duplicate entries. By evaluating titles, abstracts, and full texts, eight articles conformed to the inclusion criteria; however, no relevant studies were found through hand searching. The evidence suggested that recession was inversely related with the thickness of the facial margin. These findings were more evident in proclined teeth and patients using fixed appliances. Conclusion. The existing evidence suggests that orthodontic therapy might result in mild detrimental effects on the periodontium, especially in patients with thin biotype. However, due to the limited investigations and their inconsistent methodology, further well-designed prospective studies are necessary.

This study was conducted to investigate one-piece narrow-diameter implants installed in maxillary lateral and mandibular incisor sites using immediate nonfunctional loading.In this 10-year clinical trial study, 42 narrow-diameter (3.0-mm) one-piece implants for 35 patients were inserted. Clinical and radiographic measurements were recorded in 10 years and analyzed statistically using t test.A total of 26 patients (20 females and 6 males) with 30 implants were available for the 10-year follow-up. The 10-year implant survival rate was 100%. A statistically significant mean marginal bone loss was observed between 12 months and 10 years (0.18 ± 0.29 mm). The mean pocket depth increase was statistically significant (0.68 ± 0.83 mm). No bleeding on probing was observed around 90% of the implants. Full-mouth plaque index was registered at 20% of the implants.The results obtained in this analysis suggest that modest marginal bone loss was observed around the implants. One-piece narrow-diameter implants (Maximus 3.0; BioHorizons) can predictably restore missing maxillary lateral incisors and mandibular incisors in cases of careful patient selection.

This study was conducted on 87 patients with chronic periodontitis (CP), 50 patients with peri-implantitis and 90 periodontally healthy individuals referring to the Department of Periodontics for evaluating the association between Fc gamma-receptor genes polymorphisms with CP and peri-implantitis. After obtaining consent, venous blood samples (5cc) were obtained from patients and DNA was extracted using Miller's salting-out method. Polymerase chain reaction (PCR)-restriction fragment length polymorphism and tetra-primer amplification refractory mutation system-PCR methods were used to assess the polymorphisms of FcγRs IIa, IIIa, and IIIb genes. Analyzing showed a significant association between specific genotypes with increasing CP and peri-implantitis risks in codominant and dominant models. For FcγR IIIa, analyzing revealed a significant association between specific genotypes with increasing CP and peri-implantitis risks in codominant, dominant, and recessive models. For FcγR IIIb, we also detected a significant association between specific genotypes with increasing CP and peri-implantitis risks in codominant, dominant, and recessive models ( P

Background and Aim: Splinting of teeth is performed for effective distribution of loads in mobile teeth and to lower the stress applied to compromised teeth. Biomechanics cannot adequately explain load distribution around natural teeth. This study aimed to compare the distribution pattern and magnitude of stress and strain around splinted and non-splinted teeth with compromised periodontium using three-dimensional (3D) finite element analysis (FEA). Materials and Methods: Six mandibular anterior teeth were scanned and the data were entered into CATIA® and then SolidWorks® software programs. The jawbone was also designed. In the second model, the teeth were splinted with fiber reinforced composite (FRC). The models were then entered into ANSYS® software and after meshing and fixing, 100 and 200 N loads were applied at zero and 30° angle. The magnitude and distribution of stress and strain in the periodontal ligament (PDL) and the surrounding cortical bone were determined. Results: A significant reduction in stress was noted in cortical bone around central and lateral incisors while an increase in stress was noted around the canine tooth after splinting. All these changes were more significant under 100 N load compared to 200 N load and greater differences were noted in response to the application of oblique loads compared to vertical loads. Conclusion: Splinting decreases the magnitude of stress and strain in teeth close to the center of splint and increases the stress and strain in teeth far from the center of splint. Adequate bone support of canine teeth must be ensured prior to selection of splinting as the treatment plan for the anterior mandible since it increases the longevity of all teeth. Keywords: Stress; Strain; Finite Element Analysis; Periodontal Splinting

The aim of this study was to assess stress and strain patterns in cortical and cancellous bones surrounding newly designed dental implants with different thread patterns. Static loading of dental implants has been well studied, but studies on dynamic loading and fatigue analysis of dental implants are scarce. This study analyzed the static, dynamic, and fatigue behaviors of dental implants using finite element analysis (FEA). Two models of dental implants were analyzed in this study. Model A was a tapered implant with V-shaped threads and model B was a tapered implant with microthreads in the uppermost region and V-shaped threads in the rest of the body. Two types of loading conditions were simulated in an FEA model and stress and strain patterns in the surrounding bone were analyzed. Dynamic loading increased the level of stress by 5-10% compared with static loading. Both implants showed acceptable results under static and dynamic loadings, but the second implant with microthreads caused lower stress and strain in cortical and cancellous bones. Dynamic and fatigue analyses can provide a more realistic understanding of the function of dental implants. Replacing the uppermost threads with microthreads can lead to more desirable stress patterns in bone, as well as a higher safety factor and longevity.

Short implants can be used as alternatives to standard implants to prevent invasive surgical procedures. However, due to concerns about complications caused by less bone-implant contact area, researchers have focused on biomechanical properties of short implants and methods to promote them. Splinting has been suggested to decrease the limitation of short implants. This study compared the pattern of stress and strain distribution in bone supporting splinted standard and short implants positioned at crestal and subcrestal levels. An edentulous posterior mandible was made using computer-aided design. Five models of different combinations of splinted short (4 × 6 mm) and standard (4 × 10 mm) implants placed at the level of crestal bone or subcrestally mesial and distal to the edentulous region with a pontic between them were designed using the CATIA software program. ANSYS software was used for finite element analysis (FEA). In each model, 100 and 300 N loads at zero (parallel to the long axis of implants) and 30° angles were applied to implants. Maximum stress and strain for each of the five models, including equivalent stress, shear stress, and strain in peri-implant cortical and cancellous bone, were calculated and stress distribution pattern in different models were recorded. The highest stress was caused by the 300 N load applied at a 30° angle, followed by the 300 N load applied axially and the 100 N load applied at 30°. This order changed in model 1, where the highest stress was noted under the 300 N load at 30°, followed by the 100 N load at 30°. Maximum stress in peri-implant bone occurred under oblique (30°) load. Maximum stress was noted when two splinted short implants were placed subcrestally. In addition, stress in bone around crestal-level splinted short implants was lower than that around standard implants. Combination of short and standard implants had no biomechanical advantage. Application of load parallel to the long axis can significantly decrease stress in peri-implant bone. Although the combination of short and standard implants has no biomechanical advantage, crestal-level placement of splinted short implants is a suitable treatment plan.

Objectives Chronic periodontitis is a common inflammatory disease of the oral cavity that causes destruction of periodontal tissues and bone around the teeth. Sclerostin is a protein encoded by the SOST gene. In this study, gingival crevicular fluid (GCF) levels of sclerostin in patients with chronic periodontitis were compared with those of healthy subjects. Materials and Methods In this case-control study, a total of 40 subjects were enrolled and divided into the healthy group (n=23) and chronic periodontitis group (n=17). GCF samples were collected, and the concentration of sclerostin was evaluated using enzyme-linked immunosorbent assay. Comparison of significance between groups was assessed using Mann-Whitney U test. Results Sclerostin concentration was significantly higher in the chronic periodontitis group compared with the healthy group (P

Objectives The purpose of the present study was to compare the cytotoxicity of Reso-Pac and Coe-Pak periodontal dressing. Material and Methods According to ISO-10993-12:2012, 1-, 3- and 7-day extracts of the two periodontal dressings were prepared in cell culture medium and exposed to the two cultured cell lines. Cell viability and proliferation at 24 h and 72 h following exposure were evaluated using quantitative MTT assay. Results The results showed a significant (P < 0.05) reduction in the viability of cells exposed to the 3- and 7-day Coe-Pak extracts at 24 h and 72 h compared to the control group (no exposure to the extract). Reso-Pac extracts slightly decreased cell viability compared to the control group. Understudy materials showed greater cytotoxicity against human osteoblast-like compared to the human gingival fibroblast cells. No significant (P > 0.05) difference was found in the viability of cells exposed to undiluted (100%) one-day extract and diluted (50%) extract of both understudy materials at 24 h and 72 h after exposure. Conclusions Based on the results, Reso-Pac periodontal dressing has less cytotoxicity than Coe-Pak.

Periodontitis is an infectious disease of the tooth-supporting tissues. Specific periodontal pathogens trigger inflammatory responses and result in progressive bone loss, which eventually leads to exfoliation of teeth. Periimplantitis is the destructive inflammatory process affecting the soft and hard tissues surrounding dental implants. The periodontal pathogens found around failing implants are very similar to those associated with various forms of periodontal diseases. Genetic susceptibility has been known to be an important risk factor for periodontitis and periimplantitis and there have been numerous studies evaluating this in different populations. Many gene polymorphisms may influence individual susceptibility to periodontitis and peri-implantitis. We conducted a review of the literature for gene polymorphisms associated with periodontitis and peri-implantitis susceptibility in the Iranian population. A comprehensive search of the literature on human studies in English, published from January 2004 to February 2015 in PubMed database and Google scholar was performed using the key words "periodontitis," "peri-implantitis," "gene polymorphisms," and "Iranian population." Sixty-six studies were identified; 33 articles were excluded based on review of titles and abstracts. Thirty articles were eligible and had the full text evaluated. Further studies are needed to get more inclusive perception of the influence of gene polymorphisms in periodontitis and peri-implantitis.

Background and aims. The aim of this study was to assess the opening torque of grooved and non-grooved screws made of shape memory alloys (SMA) for fixation of mandibular fractures. Materials and methods. In this in vitro study the opening torques of ten SMA screws with grooves and ten SMA screws without grooves were compared in 20 holes (10 holes for grooved screws and 10 holes for non-grooved screws) placed in the bovine mandible. Statistical significance was set at P < 0.05. Results. The mean opening torque was 2.27 ± 0.43 nm for screws in the control group and 2.05 ± 0.45 nm for screws in the grooved group (P < 0.05, P = 0.08). Conclusion. This study revealed that the torque needed for opening the grooved screws was higher in comparison with current fixation screws; however, the difference was not statistically significant.

Background: Mechanical oral hygiene procedures are the most effective means of plaque removal and toothbrush is the most commonly used tool for mechanical plaque removal worldwide. There is an array of available manual and electric toothbrushes in the market. Thus, choosing the best one for dental plaque removal can be of great help for patients. Objectives: This study aimed at compare the efficacy of dental plaque removal using a manual and an electric toothbrush. Materials and Methods: This experimental, single-blinded sequential clinical trial was conducted on 12 patients (ten females and two males) who aged 21 to 30 years old. The tested manual toothbrush was 35-mm soft Oral-B Pulsar and the electric one was Oral-B Professional Care 8500 DLX chargeable D18. Patients’ dental plaque score was set as zero through scaling, root planning, and polishing. Subjects were avoided tooth cleaning for three days and on day four, plaque accumulation was assessed using Tureskey's modification of Quigley and Hein plaque index. Results: The mean of plaque index was 2.13 ± 0.83 and 2.11 ± 1.01 in the manual and electric toothbrush groups, respectively. No significant difference was detected between the study toothbrushes in terms of plaque removal (P = 0.374); however, with the manual tooth brushing, plaque removal was significantly greater in the buccal than in lingual surface and in the maxilla than in the mandible (P = 0.03 and P = 0.015, respectively). Conclusions: Similar to previous studies, this study could not show the superiority of electric toothbrush over manual in plaque removal. After 72 hours, the mean of plaque index was greater in buccal than in lingual surface, which may be attributed to the natural cleansing action of the tongue.

Objective RANK/OPG/RANKL pathway plays a significant role in osteoclastogenesis, osteoclast activation, and regulation of bone resorption. The aim of this study was to investigate the association of RANKL gene polymorphisms (rs9533156 and rs2277438) with chronic periodontitis and peri-implantitis in an Iranian population. Design 77 patients with chronic periodontitis, 40 patients with peri-implantitis and 89 periodontally healthy patients were enrolled in this study. 5cc of blood was obtained from the cephalic vein of subjects arms and transferred into tubes containing EDTA. Genomic DNA was extracted using Miller's Salting Out technique. The DNA was transferred into 96 division plates, transported to Kbioscience Institute in United Kingdom and analyzed using the Kbioscience Competitive Allele Specific PCR (KASP) technique. Differences in the frequencies of genotypes and alleles in the disease and control groups were analyzed using Chi-square and Fisher's exact statistical tests. Results Comparison of frequency of alleles in SNP rs9533156 of RANKL gene between the chronic periodontitis group with the control and peri-implantitis groups revealed statistically significant differences ( P = 0.024 and P = 0.027, respectively). Comparison of genotype expression of SNP rs9533156 on RANKL gene between the peri-implantitis group with chronic periodontitis and control groups revealed statistically significant differences ( P = 0.001); the prevalence of CT genotype was significantly higher amongst the chronic periodontitis group. Regarding SNP rs2277438 of RANKL gene, comparison of prevalence of genotypes and frequency of alleles did not reveal any significant differences ( P = 0.641/ P = 0.537, respectively). Conclusions The results of this study indicate that CT genotype of rs9533156 RANKL gene polymorphism was significantly associated with peri-implantitis, and may be considered as a genetic determinant for peri-implantitis.

Immediate implantation related to socket and vital anatomy of the maxillary sinus area requires careful consideration. One major complication that may occur during immediate replacement of posterior teeth is maxillary sinus membrane perforation. To date, no specific technique has been proposed to manage this problem so that implant insertion remains possible during the same surgery. In this paper, we introduce a method to manage this type of perforation and while performing simultaneous implantation. We used sinus-socket osteotomy (SSO), a modified osteotomy technique for socket preparation that blocks sinus perforation with autogenous bone. A 12-month follow-up showed that this technique was clinically successful and reduced the overall treatment time. However, this advanced method requires a skillful surgeon.

AIM: MicroRNAs (MiRs) are small noncoding RNAs that are involved in protein translation, osteoclastogenesis, and immunoregulation. Peri-implantitis and chronic periodontitis are multifactorial diseases. They are the consequence of complex interactions among host response, genetics, and environment. In the present study, we aimed to investigate the possible association between MiR146a/MiR499 gene polymorphisms and periodontitis/peri-implantitis as a first report in oral implantology. METHODS: From 197 individuals referred to Periodontology Department of Shahid Beheshti Dental School, three groups were enrolled in the assessment: 75 patients in the chronic periodontitis (CP) group, 38 patients in the peri-implantitis (PI) group, and 84 healthy subjects. DNA was extracted from fresh blood samples from the arm veins of participants and transferred to KBiosience Institute (Hoddesdon, United Kingdom) for genotyping. Chi-squared and Kruskal-Wallis tests were performed using SPSS software v.19 for statistical analyses. P-value < 0.05 was considered significant. RESULTS: The genotype frequencies in MiR 146a and MiR 499 were significantly different among the three groups. CONCLUSIONS: MiR146a (rs2910146) and MiR499 (rs3746444) gene polymorphisms may be genetic determinants for increased risk of chronic periodontitis and peri-implantitis in Iranians. More studies with larger sample sizes in different populations are necessary for determining the effect of these SNPs.

Purpose: The effects of magnetostrictive and piezoelectric devices on tooth surfaces seem to differ with regard to the root surface roughness they produce. This study aimed to compare the results of scaling using magnetostrictive and piezoelectric devices on extracted teeth. Methods: Forty-four human extracted teeth were assigned to four study groups (n = 11). In two groups (C100 and C200), the teeth were scaled using a magnetostrictive device and two different lateral forces: 100 g and 200 g, respectively. In the other two groups (P100 and P200), the teeth were scaled with a piezoelectric device with 100 g and 200 g of lateral force, respectively. The teeth were scaled and the data on the duration of scaling and the amount of surface were collected and analyzed using the t-test. Results: The mean time needed for instrumentation for the piezoelectric and magnetostrictive devices was 50:54 and 41:10, respectively, but their difference was not statistically significant (P = 0.171). For root surface roughness, we only found a statistically significantly poorer result for the C200 group in comparison to the P200 group (P = 0.033). Conclusions: This study revealed that applying a piezoelectric scaler with 200 g of lateral force leaves smoother surfaces than a magnetostrictive device with the same lateral force.

The aim of this study was to use intra-oral radiographs to evaluate changes in marginal bone levels around three different implant designs after 1 year.Three implant designs; two with a straight and one with a conical design, were placed adjacent to each other in the partially edentulous areas of 25 patients. The patients received 46 implants with a straight design (All fit SSO and SPI-element) and 29 implants with a conical design (SPI-contact). Two-way repeated analysis of variance (ANOVA) was used to evaluate the marginal bone changes in each group at 12 months follow-up (p0.05).None of the implants had failed by the end of this study. After 12 months, significant differences were noted in the amount of alveolar bone loss recorded between the All fit SSO and SPI implants (p0.05). Mean crestal bone loss was 0.88 ± 0.43 mm for the All fit, 0.61 ± 0.34 mm for the SPI contact and 0.54 ± 0.27 mm for the SPI element implants.The results of this study demonstrate that straight (cylindrical) implants with shorter high polish surface displayed less bone resorption.

AIMS The present study aimed at evaluating the acceptability of the Implant Success Index (ISI) in comparison with the conventional classification system. MATERIALS AND METHODS A comparative questionnaire was designed to evaluate 10 criteria that were reported to be important for acceptance of a new classification system. We asked 20 experts who had at least 5 years of clinical experience in implant dentistry to complete a questionnaire based on a visual analog scale. Data were analyzed by a blinded statistician using a Wilcoxon non-parametric rank test. RESULTS Measuring all 10 criteria, the acceptability level of ISI was significantly higher than that of the Misch classification (70.90 and 54.90, respectively; P < 0.05). The most significant differences were found in the system's ability to detect early lesions, its lack of overestimation, its quantitative base, and its comprehensiveness. The simplicity and compatibility of the two understudy classification systems were not significantly different. CONCLUSIONS ISI seems to be a proper scoring system with a high level of acceptability for determining the success rate of dental implants and for selection of procedures used for improving the status of peri-implant tissue.

Cigarette smoking and tobacco consumption are serious hazards threatening the health of human beings. Several strategies have been proposed for smoking cessation in patients presenting to medical centers to seek treatment. Some believe that the dental profession plays a key role in quit smoking programs due to its extensive and long-term relationship with patients. Use of known strategies to create motivation for quitting smoking among patients has yielded relatively optimal results. However, it seems that patients' attitudes toward smoking can be changed if we enhance their knowledge about the hazards of tobacco consumption and its adverse effects on dental and oral health and especially the health of dental implants' surrounding structures. This study reports smoking cessation in two patients requiring dental implant treatment. Twenty-eight months after loading of implants, treatment success was confirmed by use of clinical and radiographic indices. No sign of peri-implant disease was detected and the patients were eagerly following the smoking cessation program. It seems that contemporary dental treatments, especially dental implant therapy, can provide a good opportunity to create the motivation required for lifestyle changes in patients.

Objectives This study aimed to optimize the thread depth and pitch of a recently designed dental implant to provide uniform stress distribution by means of a response surface optimization method available in finite element (FE) software. The sensitivity of simulation to different mechanical parameters was also evaluated. Materials and Methods A three-dimensional model of a tapered dental implant with micro-threads in the upper area and V-shaped threads in the rest of the body was modeled and analyzed using finite element analysis (FEA). An axial load of 100 N was applied to the top of the implants. The model was optimized for thread depth and pitch to determine the optimal stress distribution. In this analysis, micro-threads had 0.25 to 0.3 mm depth and 0.27 to 0.33 mm pitch, and V-shaped threads had 0.405 to 0.495 mm depth and 0.66 to 0.8 mm pitch. Results The optimized depth and pitch were 0.307 and 0.286 mm for micro-threads and 0.405 and 0.808 mm for V-shaped threads, respectively. In this design, the most effective parameters on stress distribution were the depth and pitch of the micro-threads based on sensitivity analysis results. Conclusion Based on the results of this study, the optimal implant design has micro-threads with 0.307 and 0.286 mm depth and pitch, respectively, in the upper area and V-shaped threads with 0.405 and 0.808 mm depth and pitch in the rest of the body. These results indicate that micro-thread parameters have a greater effect on stress and strain values.