Regeneration, Reconstruction & Restoration (Triple R)

TE is centered on the concepts of tissue formation, regeneration and sustained functional remodeling. This is in contrast to the classic, “spare part” replacement therapy of the past with its associated harvest site morbidities. TE is especially an enticing application since bone, is a dynamic, highly vascular tissue that has the unique ability to remodel without scar. There are over one million major skeletal defects requiring major bone grafts reconstructions every year. This does not account for the vast numbers of small alveolar grafts that are performed by dentists yearly in their clinics.  To grow new bone, demands the contemporary surgeon not only have a thorough knowledge of its biology but also a different perspective.

Introduction: Small molecules are active substances which are used in bone tissue engineering. They present great characteristics including induction of developmental genes, bioavailability and easy metabolism. Purmorphamine is a small molecule which has been demonstrated to exert osteogenic effects. In the present study we aimed to review present literature regarding the osteogenic effect of purmorphamine.

Materials and Methods: The MEDLINE (NCBI PubMed and PMC), Google Scholar and Scopus were searched by the following keywords “purmorphamine” AND “osteogenesis” OR “osteogenic differentiation” OR “bone formation”. According to PRISMA statement, all in vivo and in vitro studies conducted on osteogenic effect of purmorphamine were included. Search was limited to English-language studies up to February 2020.

Results: Finally, 16 studies were included and the data were extracted. Data were categorized by the studied cell type, purmorphamine dosage and treatment groups, scaffolds and results.

Conclusion: It is demonstrated that purmorphamine may be effective in osteogenic differentiation of various cells but this effect may vary by applied dosage and duration.

Introduction: The enhancement of osteogenesis by tissue engineering is a challenge in periodontal therapy. Several graft materials in conjunction with carriers, such as blood or saline, are used for this purpose. This study aimed to assess the effect of phosphate buffered saline (PBS), Hank's balanced salt solution (HBSS) and saline on the activity of MG-63 osteoblast-like cells in the presence and absence of beta-tricalcium phosphate (β-TCP).

Materials and Methods: In this in vitro experimental study, MG-63 osteoblast-like cells were cultured in 10% PBS, HBSS and saline (10%) with and without β-TCP granules for 24 and 72 h and five days. At 24 and 72 h, cell viability and proliferation were assessed. Alkaline phosphatase (ALP) activity test was used to assess bone activity. The data were analyzed using SPSS version 20 (IBM Corp. Released 2011. IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp) via one-way and two-way ANOVA (P<0.05).

Results: Pairwise comparisons showed no significant difference in the viability of MG-63 cells at 24 h in the three solutions (with equal β-TCP content) or with the negative control group (complete culture). At 72 h, significant differences were only observed in the reduction of cell proliferation between 10% saline without β-TCP and 10% saline with β-TCP , and also between HBSS without β-TCP  and HBSS with β-TCP (P<0.05).

Conclusion: The three solutions did not induce ALP activity at 24 or 72 h and did not cause the formation of any calcified nodule at three or five days in MG-63 cells.

Introduction: Pigmentation is associated with the production of melanin by melanocytes, which is a physiological state in the body. It makes an unpleasant appearance especially for those who have high aesthetic demand. Among different methods, lasers have many advantages in dentistry. Evaluation of gingival pigmentation treatment efficacy using 980 nm diode laser is the purpose of this study.

Material and Methods: 24 patients were qualified for inclusion in the study. Depigmentation was performed using a diode laser. The size of the pigmentation was measured by AutoCAD software before the intervention, 1, 3, and 6 months after the intervention in each patient. Data were analyzed using SPSS software (v.22), Paired t-test, Smirnov-Kolmogorov, and Friedman tests.

Results: The results demonstrated that the area and circumstance of the pigmentation significantly reduced after laser therapy. Also, repigmentation rate evaluation demonstrated that the rate has not changed in the first, third, and sixth months of follow up periods.

Conclusion: The outcomes demonstrated that 980 nm diode laser is effective in treating gingival pigmentation as well as restoring beauty and comfort to the patient.

Introduction: Since the early days of the discovery of dental implants, there has been a substantial paradigm shift from placing implants in edentulous ridges to rehabilitating the most complex cases in the aesthetic zone. In the initial periods the main focus was solely concentrated on the quality and quantity of the hard tissue however passing of time has evidently revealed that soft tissue has a significant importance especially in the aesthetic zone. The advent of many complications along with dental implants in this area draw attention of most clinicians regarding the importance of the soft tissue. The use of reliable techniques to improve the aesthetic outcomes in the aesthetic zone is an important clinical aid to advance the results over time. There has been many different surgical techniques in the literature, which so far there has been no adequate reason to prove one of the treatment approaches the most effective and predictable.

Case Report: Vestibular sub-periosteal tunnel access (VISTA) approach has been used in three clinical cases in order to enhance the quality and quantity of soft tissue around dental implants in the esthetic zone.

Results:  This technique had an advantage of having the incision line in a remote area from the marginal mucosa which supports preserving the integrity of this critical area during the surgical procedure.

Conclusion: VISTA technique is a viable technique for soft tissue enhancement around dental implants especially in the aesthetic zone where both the quality and quantity of the soft tissue play an important role for the long term prognosis of the implants.

Introduction: Prosthetic rehabilitation requires sufficient hard and soft tissues. In this article, a case of severe mandibular atrophic ridge is presented, which has been treated with autogenous iliac and rib bone grafts and simultaneous nerve transposition with an extraoral approach.

Case Report: The patient was a 56-year old female with severe mandibuar atrophic ridge. The prosthetic rehabilitation for this patient was performed in four stages: 1) reconstruction of mandibular atrophic ridge using autogenous iliac and rib bone graft with simultaneous inferior nerve transposition through an extraoral approach, 2) insertion of four implant fixtures in reconstructed mandibular ridge after six months, 3) buccal and lingual vestibuloplsty and free gingival graft and loading of healing abutments, three months later, and 4) prosthetic rehabilitation after two months. Following stage four, a mandibular hybrid prosthesis on four implants with a maxillary removable complete denture were delivered to the patient.

Results: Following four stages of surgical and prosthetic procedures, rehabilitation of a severe mandibular atrophic ridge was done with autogenous iliac and rib bone grafts, simultaneous inferior alveolar nerve transposition and a mandibular hybrid prosthesis on four implants. Further follow up of the patient will reveal the outcomes of this procedure.

Conclusion:  This procedure can be suggested in the case of severe mandibular atrophic ridges which need inferior border augmentation and superior border vertical and horizontal augmentation at the same time.

Introduction: Diabetes mellitus is one of the most common endocrine disorders in the world and is accompanied with many complications such as periodontal disorders as the most common complications of diabetes in the mouth. It is estimated that 1 million people worldwide are suffering from varying degrees of vitamin D deficiency, and some studies have linked it with periodontitis and diabetes. The purpose of this study is to investigate the relationship between periodontal disease in type 2 Diabetic patients and vitamin D deficiency in Iranian population.

Materials and Methods: This cross-sectional study conducted on 74 Iranian patients admitted to Baqiyatallah hospital during the years 2017-2019. The type II diabetic patients were selected and non-volunteers patients and those who did not meet the inclusion criteria were excluded. Then, Necessary tests were evaluated in all patients. Patients were divided into two groups of with and without vitamin D deficiency. A questionnaire for periodontal disorders was completed by two different blinded periodontists. The collected data was analyzed using SPSS-21 software using Chi-square and T-test.

Results: 44 males and 30 females were studied. 37 patients had vitamin D levels below 30 ng/ml. 83.8% of the patients had periodontal disorders. The frequency of periodontitis was higher in diabetic patients with vitamin D deficiency than in diabetic patients with normal levels of vitamin D. Periodontal disorders were also significantly correlated with duration of diabetes, age of patients and HbA1c.

Conclusion: Periodontal disorder is more prevalent in patients with inadequate vitamin D serum levels. Screening for diabetic patients seems to be necessary both in terms of diagnosis of periodontitis and vitamin D deficiency.

Introduction: The aim of this study was to evaluate vertical dimension of face and position of incisors following extraction of four first premolars in patients with class I malocclusion and bimaxillary dentoalveolar protrusion and/or crowding.

Materials and Methods: This study evaluated 22 patients with class I molar relationship, bimaxillary dentoalveolar protrusion and/or crowding with the treatment plan of extraction of all four first premolars. The change in U1-PP, L1-MP, IMPA, U1-SN, saddle angle, articular angle, gonial angle, and the sum of Bjork was determined by assessing the before and after-treatment cephalograms. The changes in cephalometric parameters were analyzed by ANOVA and paired t-test.

Results: The U1-SN, IMPA, U1-PP and sum of Bjork significantly changed following extraction of the four first premolars (P<0.05). However, the changes in saddle, articular and gonial angles and L1-MP were not significant (P>0.05).

Conclusion: We observed retraction and extrusion of incisors and increase of vertical dimension following extraction. Retraction of incisors will relatively retract lips. Also, it is not advisable to extract premolars to improve vertical dimension, although extrusion of incisors will facilitate the bite closure.