The prevalence of second canals in the mesiobuccal root of maxillary molars in a South African subpopulation : a cone beam computed tomography study

Introduction: Endodontic therapy is a global routine dental therapeutic procedure. Despite recent and present advances in dentistry and particularly with the popularity of implant dentistry, it remains biologically and aesthetically advantageous for retention of one�s original dentition. Tooth extraction followed by surgical placement of dental implants should remain a last resort in management. Treatment success depends on intricate knowledge and a thorough understanding of the anatomy of the root canal system, in order to adequately debride, disinfect, and obturate teeth affected by irreversible pulpitis or pulp necrosis. High endodontic failure rates are frequent in the maxillary molar tooth owing to the complexity of their root canal anatomy, and variations in the number of mesiobuccal (MB) roots. Conventional radiographic imaging techniques are unreliable for the detection of multiple canals, whereas cone beam computed tomography (CBCT) has proven to be effective for visualization of additional canals of root canal systems. There is little published data on the prevalence of second canals in the MB roots (MB2) of permanent maxillary first and second molars in a South African subpopulation. The aim of this study is to detect the prevalence of MB2 canals by analysing axial views of CBCT scans of adult patients. Methodology: A total number of 200 patient CBCT scans, from 100 male and 100 female patients respectively, were enrolled in the study. A total of 800 teeth were analysed in-vivo on CBCT scans, comprising 200 right maxillary first molar teeth (tooth 16), 200 left maxillary first molar teeth (tooth 26), 200 right maxillary second molar teeth (tooth 17), and 200 left maxillary second molar teeth (tooth 27). Teeth displaying radiological evidence of an additional mesiobuccal canal (MB2) were identified. Results: First maxillary molar teeth showed a high prevalence of MB2 canals, 92% and 87%, for the 16 and 26 respectively. Second maxillary molar teeth showed a lower, but still significant, prevalence of MB2 canals, 69% and 65%, for the 17 and 27 respectively. An association between patient age, gender and the prevalence of MB2 canals was not noted in the study sample. Conclusion: Root morphology and anatomy of permanent maxillary first and second molar teeth is highly variable. The prevalence of additional canals in the MB roots is a frequent finding which has previously been underreported. The presence of these variations significantly impact endodontic therapy success, longevity, and retention of the natural dentition. The prevalence of these canals requires documentation for dissemination of this knowledge and greater cognizance thereof with respect to more accurate endodontic outcomes and success.Mini Dissertation (MChD)--University of Pretoria, 2018.ProsthodonticsMChDUnrestricte

Morphological Aspects And Cox-2 Expression After Exposure To 780-nm Laser Therapy In Injured Skeletal Muscle: An In Vivo Study

Background: The effectiveness of low-level laser therapy in muscle regeneration is still not well known. Objective: To investigate the effects of laser irradiation during muscle healing. Method: For this purpose, 63 rats were distributed to 3 groups: non-irradiated control group (CG); group irradiated at 10 J/cm² (G10); and group irradiated at 50 J/cm² (G50). Each group was divided into 3 different subgroups (n=7), and on days 7, 14 and 21 post-injury the rats were sacrificed. Results: Seven days post-surgery, the CG showed destroyed zones and extensive myofibrillar degeneration. For both treated groups, the necrosis area was smaller compared to the CG. On day 14 post-injury, treated groups demonstrated better tissue organization, with newly formed muscle fibers compared to the CG. On the 21st day, the irradiated groups showed similar patterns of tissue repair, with improved muscle structure at the site of the injury, resembling uninjured muscle tissue organization. Regarding collagen deposition, the G10 showed an increase in collagen synthesis. In the last period evaluated, both treated groups showed statistically higher values in comparison with the CG. Furthermore, laser irradiation at 10 J/cm2 produced a down-regulation of cyclooxygenase 2 (Cox-2) immunoexpression on day 7 post-injury. Moreover, Cox-2 immunoexpression was decreased in both treated groups on day 14. Conclusions: Laser therapy at both fluencies stimulated muscle repair through the formation of new muscle fiber, increase in collagen synthesis, and down-regulation of Cox-2 expression.185395401Minamoto, V.B., Bunho, S.R., Salvini, T.F., Regenerated rat skeletal muscle after periodic contusions (2001) Braz J Med Biol Res, 34 (11), pp. 1447-1452. , http://dx.doi.org/10.1590/S0100-879X2001001100012, PMid:11668355Baptista, J., Martins, M.D., Pavesi, V.C., Bussadori, S.K., Fernandes, K.P., Pinto, D.S., Jr., Influence of laser photobiomodulation on collagen IV during skeletal muscle tissue remodeling after injury in rats (2011) Photomed Laser Surg, 29 (1), pp. 11-17. , http://dx.doi.org/10.1089/pho.2009.2737, PMid:20701543Renno, A.C., Toma, R.L., Feitosa, S.M., Fernandes, K., Bossini, P.S., De Oliveira, P., Comparative effects of low-intensity pulsed ultrasound and low-level laser therapy on injured skeletal muscle (2011) Photomed Laser Surg, 29 (1), pp. 5-10. , http://dx.doi.org/10.1089/pho.2009.2715, PMid:21166589Pinheiro, A.L., Soares, L.G., Aciole, G.T., Correia, N.A., Barbosa, A.F., Ramalho, L.M., Light microscopic description of the effects of laser phototherapy on bone defects grafted with mineral trioxide aggregate, bone morphogenetic proteins, and guided bone regeneration in a rodent model (2011) J Biomed Mater Res A, 98 (2), pp. 212-221. , http://dx.doi.org/10.1002/jbm.a.33107, PMid:21548072Amaral, A.C., Parizotto, N.A., Salvini, T.F., Dose-dependency of low-energy HeNe laser effect in regeneration of skeletal muscle in mice (2001) Lasers Med Sci, 16 (1), pp. 44-51. , PMid:11486338Cressoni, M.D., Dib Giusti, H.H., Casarotto, R.A., Anaruma, C.A., The effects of a 785-nm AlGaInP laser on the regeneration of rat anterior tibialis muscle after surgicallyinduced injury (2008) Photomed Laser Surg, 26 (5), pp. 461-466. , http://dx.doi.org/10.1089/pho.2007.2150, PMid:18800950Pires, D., Xavier, M., Araújo, T., Silva, J.A., Jr., Aimbire, F., Albertini, R., Low-level laser therapy (LLLT780 nm) acts differently on mRNA expression of antiand pro-inflammatory mediators in an experimental model of collagenaseinducel tendinitis in rat (2011) Lasers Med Sci, 26, pp. 85-94. , http://dx.doi.org/10.1007/s10103-010-0811-zAlves, A.N., Fernandes, K.P.S., Melo, C.A.V., Yamaguchi, R.Y., França, C.M., Teixeira, D.F., Modulating effect of Low-level laser therapy on fibrosis in the repair process of the tibialis anterior muscle in rats (2014) Lasers Med Sci, 29 (2), pp. 813-821. , http://dx.doi.org/10.1007/s10103-013-1428-9, PMid:23982721Almeida, P., Lopes-Martins, R.A.B., De Marchi, T., Tomazoni, S.S., Albertini, R., Correa, J.C.F., Red (660nm) and infrared (830nm) low-level laser therapy in skeletal muscle fatigue in humans: What is better? (2012) Lasers Med Sci, 27, pp. 453-458. , http://dx.doi.org/10.1007/s10103-011-0957-3Brunelli, R.M., Rodrigues, N.C., Ribeiro, D.A., Fernandes, K., Magri, A., Assis, L., The effects of 780-nm low-level laser therapy on muscle healing process after cryolesion (2014) Lasers Med Sci, 29 (1), pp. 91-96. , http://dx.doi.org/10.1007/s10103-013-1277-6, PMid:23407900Rodrigues, N.C., Brunelli, R., De Araújo, H.S., Parizotto, N.A., Renno, A.C., Low-level laser therapy (LLLT) (660nm) alters gene expression during muscle healing in rats (2013) J Photochem Photobiol B, 120, pp. 29-35. , http://dx.doi.org/10.1016/j.jphotobiol.2013.01.002, PMid:23416710Shefer, G., Partridge, T.A., Heslop, L., Gross, J.G., Oron, U., Halevy, O., Low-energy laser irradiation promotes the survival and cell cycle entry of skeletal muscle satellite cells (2002) J Cell Sci, 115, pp. 1461-1469. , PMid:11896194Bossini, P.S., Renno, A.C., Ribeiro, D.A., Fangel, R., Peitl, O., Zanotto, E.D., Biosilicate(R) and low-level laser therapy improve bone repair in osteoporotic rats (2011) J Tissue Eng Regen Med, 5 (3), pp. 229-237. , http://dx.doi.org/10.1002/term.309, PMid:20925130Silveira, P.C., Silva, L.A., Fraga, D.B., Freitas, T.P., Streck, E.L., Pinho, R., Evaluation of mitochondrial respiratory chain activity in muscle healing by low-level laser therapy (2009) J Photochem Photobiol B, 95 (2), pp. 89-92. , http://dx.doi.org/10.1016/j.jphotobiol.2009.01.004, PMid:19232497Tim, C.R., Pinto, K.N., Rossi, B.R., Fernandes, K., Matsumoto, M.A., Parizotto, N.A., Low-level laser therapy enhances the expression of osteogenic factors during bone repair in rats (2014) Lasers Med Sci, 29 (1), pp. 147-156. , http://dx.doi.org/10.1007/s10103-013-1302-9, PMid:23515631Rizzi, C.F., Mauriz, J.L., Freitas Correa, D.S., Moreira, A.J., Zettler, C.G., Filippin, L.I., Effects of low-level laser therapy (LLLT) on the nuclear factor (NF)-kappaB signaling pathway in traumatized muscle (2006) Lasers Surg Med, 38 (7), pp. 704-713. , http://dx.doi.org/10.1002/lsm.20371, PMid:16799998Carmeli, E., Moas, M., Reznick, A.Z., Coleman, R., Matrix metalloproteinases and skeletal muscle: A brief review (2004) Muscle Nerve, 29 (2), pp. 191-197. , http://dx.doi.org/10.1002/mus.10529, PMid:14755482Matsumoto, M.A., Ferino, R.V., Monteleone, G.F., Ribeiro, D.A., Low-level laser therapy modulates cyclo-oxygenase-2 expression during bone repair in rats (2009) Lasers Med Sci, 24 (2), pp. 195-201. , http://dx.doi.org/10.1007/s10103-008-0544-4, PMid:18309458Albertini, R., Aimbire, F., Villaverde, A.B., Silva, J.A., Jr., Costa, M.S., COX-2 mRNA expression decreases in the subplantar muscle of rat paw subjected to carrageenan-induced inflammation after low level laser therapy (2007) Inflamm Res, 56 (6), pp. 228-229. , http://dx.doi.org/10.1007/s00011-007-6211-6, PMid:17607546Byrnes, K.R., Wu, X., Waynant, R.W., Ilev, I.K., Anders, J.J., Low power laser irradiation alters gene expression of olfactory ensheathing cells in vitro (2005) Lasers Surg Med, 37 (2), pp. 161-171. , http://dx.doi.org/10.1002/lsm.20202, PMid:16037971Moore, P., Ridgway, T.D., Higbee, R.G., Howard, E.W., Lucroy, M.D., Effect of wavelength on low-intensity laser irradiation-stimulated cell proliferation in vitro (2005) Lasers Surg Med, 36 (1), pp. 8-12. , http://dx.doi.org/10.1002/lsm.20117, PMid:15662631Demidova-Rice, T.N., Salomatina, E.V., Yaroslavsky, A.N., Herman, I.M., Hamblin, M.R., Low-level light stimulates excisional wound healing in mice (2007) Lasers Surg Med, 39 (9), pp. 706-715. , http://dx.doi.org/10.1002/lsm.20549, PMid:17960752 PMCid:PMC293579

Cambridge Colour Test: reproducibility in normal trichromats

This study evaluated reproducibility of the Trivector subtest of the Cambridge Colour Test. Data for normal trichromats were obtained in Brazil (N=111) at T0, six (T1), and 12 months later (T2), and in the United Kingdom (N=79), with test directly followed by a retest. Coefficients of repeatability – Bland-Altman indices – for Protan, Deutan, and Tritan vectors were similar for both datasets. Intraclass correlation coefficients (ICCs) – measures of reliability – were low or moderate for these relatively homogeneous datasets; for a heterogeneous dataset, comprising color-normal and abnormal observers, ICCs were 0.80–0.98, indicating high discriminative accuracy of the Trivector subtest

The longevity of restorations - a literature review

Dentists need to consider various factors when choosing restorative materials, with the longevity of restorations being one of the most important criteria. Replacement of failed restorations constitutes over 60% of operative procedures, leading to high annual costs. This literature review compares the survival rates of different restorative materials used for both direct and indirect restorations. A literature search was carried out using Pubmed to identify all articles on restorative materials published from 1974 to 2014, of which 22 were included in this review. For direct restorations, amalgam showed the highest survival rates (22.5 years), with an average survival rate of 95% over 10 years, followed by composite resins (90% over 10 years), and glass ionomer cements (65% over 5 years). For indirect restorations, gold restorations are still the “gold standard” with a 96% over 10 years survival rate, followed by porcelain-fused-to-metal crowns (PFM) (90% over 10 years), and all ceramic crowns (75-80% over 10 years). Amongst the ceramic restorations, eMax shows the longest survival rate (90% over 10 years), and Zirconia the lowest (88% over five years). The longevity of restorations depends on many factors, including: materials used, type of restorative procedure, patient parameters, operator variables, and local factors.https://www.sada.co.za/the-sadjam201

Immediate implant placement and provisionalization following tumor-resective surgery in the midfacial region : a case series

Surgical and prosthodontic restoration of the midfacial region following tumor resection has always posed a considerable challenge, as this area serves crucial functional and esthetic roles. Being diagnosed and subsequently treated for facial tumors can have an immense psychosocial impact on a patient, as the resulting defects are often disfiguring, and lead to an inability to masticate, swallow, and speak clearly. Provision of an immediate facial and dental prosthesis at the time of surgery can limit these side effects and help reduce mental duress on these patients and their families, as well as aid in the process of rehabilitation. Rapid prototyping (RP) and 3D printing, as this paper shows, assists presurgical planning of the tumor resection, as well as the manufacture of maxillofacial and dental prostheses. Often these defects are extensive, so prosthesis retention is aided by zygomatic implants placed at the time of surgical resection. When placed at this time, and prior to radiation therapy, these craniofacial implants have improved survival rates. Thus, this treatment modality can improve postoperative recovery considerably, while at the same time allowing for cleaning and monitoring of the resected site for tumor recurrence.http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1532-849X2019-06-01hj2017Prosthodontic

Comparison of alveolar osteitis with post implant removal osteitis (can a “dry socket” occur after implant removal?)

The introduction of dental implants spawned an exponential growth in the number of fixtures being placed to meet the increasing functional and aesthetic demands of patients. In response, manufacturers have flooded the market with new, cheaper systems, and many general practitioners have begun placing implants to support restorations. Enhanced life expectancy means that implants placed in younger people are expected to function effectively over many years. Studies have shown that a certain low percentage of implants will develop early or late complications,1 and that the risks are greater with increased usage.2 It is thus anticipated that practitioners will be faced with increasing numbers of implant-related complications that will require appropriate management, or even implant removal.1 Hence the majority of complications will be in older persons where healing may be compromised due to physiological ageing, systemic medication, or other age-related factors.https://www.sada.co.za/the-sadjam2018Prosthodontic

Nasal reconstruction of a patient with complete congenital arhinia : a clinical report

Complete congenital arhinia is a rare embryonic disorder of unknown etiology. This is a clinical report of prosthetic nasal rehabilitations done in the early childhood and adolescent stages of a patient with complete congenital arhinia. Additive manufacturing techniques for creating pre-surgical planning models to assist in the creation of new nasal passages is also described. These rare cases can be successfully rehabilitated if patients are sufficiently motivated and there is meticulous planning and collaboration from a multidisciplinary team.http://www.journals.elsevier.com/journal-of-prosthetic-dentistry2017-12-31hb2016Prosthodontic

Reconstruction of an extensive midfacial defect using additive manufacturing techniques

Malignant peripheral nerve sheath tumours are extremely rare tumours arising in peripheral nerves. Only 17 cases involving the trigeminal nerve have ever been reported. These tumours have a very poor prognosis and very high rates of recurrence and metastases. Their recommended treatment involves complete tumour resection followed by radiation. This can be problematic in the head and neck region. We present a clinical case involving a 33 year old female patient presenting with a slow growing exophytic mass of the anterior maxilla. Incisional biopsy and subsequent histological examination revealed a diagnosis of a malignant peripheral nerve sheath tumour. Surgical resection involved a complete maxillectomy, rhinectomy, and resection of the upper lip and aspects of the left and right cheeks. Reconstruction of the subsequent defect incorporated the placement of 4 zygomatic oncology implants to aid in retention of a facial prosthesis. These implants, however, were subsequently lost so it was decided to manufacture an anatomical model of the hard tissues via 3D printing. This model was used to design and manufacture a titanium frame (customised implant) for the patient, which was then fixated and secured intra-operatively with 21 cortical screws. A maxillary denture and silicone facial prosthesis were also made to fit onto this frame. This is the first known case where additive manufacturing, via the use of rapid prototyping and 3D printing, was employed to manufacture a facial prosthesis.The South African National Research Foundation and Materialise (Leuven, Belgium).http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1532-849X2017-10-31hb2016Maxillo-Facial and Oral SurgeryProsthodontic