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Background. The maxillary palatine process (MPP) is an excellent source of autogenous bone transplants for anterior maxillary reconstruction. This research aimed to determine the quantity and quality of accessible MPP as a donor location. Methods. Cone-beam computed tomography (CBCT) scans of patients referred to the School of Dentistry were evaluated by a certified examiner. The harvestable MPP was defined as the space between the distal surfaces of maxillary first premolars. OnDemand 3D Imaging software was used to determine bone properties. SPSS software was used to investigate the following variables: Bone characteristics are correlated with age and gender, accessible volume, and palatal width and height. P

Background. The present study aimed to evaluate the osteopromoting ability of human tooth powder and compare it to a bovine xenograft, a synthetic material, and the DFDBA allograft. Methods. In this in vitro study, 30 teeth without caries, inflammation, and infection, which had been extracted for orthodontic reasons, were collected. The crowns were removed, pulpectomy was carried out, and the samples were ground to a powder with particles

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.

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.

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. 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). Methods. Six mandibular anterior teeth were scanned and data were registered in 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 transferred to ANSYS® software program and after meshing and fixing, 100- and 200-N loads were applied at zero and 30° angles. 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 decreased the magnitude of stress and strain in teeth close to the center of splint and increased 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 the teeth.

The purpose of this paper was to review the commercially available periodontal dressings, their physical and chemical properties, biocompatibility and therapeutic effects. Electronic search of scientific papers from 1956 to 2012 was carried out using PubMed, Scopus and Wiley InterScience search engines using the searched terms periodontal dressing, periodontal pack. Numerous in vitro and in vivo studies have evaluated various properties of periodontal dressings. Physical and chemical properties of dressings are directly related to their dimensional changes and adhesion properties. Their biocompatibility and therapeutic effect are among the other factors evaluated in the literature. Chlorhexidine is the most commonly used antibacterial agent in studies. In general, when comparing the advantages with the disadvantages, application of periodontal dressing seems to be beneficial. Numerous factors are involved in selection of an optimal dressing such as surgeon’s intention, required time for the dressing to remain on the surgery site and its dimensional changes.

Background and aims. The aim of this study was to determine the stress patterns within an implant and the effect of different types of connections on load transfer. Materials and methods. Three different types of implant-abutment connections were selected for this study. Sample A: 1.5-mm deep internal hex corresponding to a lead-in bevel; sample B: a tri-channel internal connection; and sample C: internal Morse taper with 110 degrees of tapering and 6 anti-rotational grooves. Four types of loading conditions were simulated in a finite element model, with the maximum von Mises stress set as output variables. Results. The maximum stress concentration at the inner surface of the fixtures was higher than the stress value in bone in all of the samples. Stress values in sample B were the lowest amongst all of the models. Any alterations in the amount and direction of the 100-N axial load resulted in an increase in fixture surfaces stress. Overall, the highest amount of stress (112 MPa) was detected in sample C at the inner surface of the fixture under a non-axial load of 300 N. Conclusion. Stress concentration decreased when the internal surface area increased. Creating three or six stops in the internal surface of the fixtures resulted in a decrease in stress.