Use of 4 Immediately Loaded Zygomatic Fixtures for Retreatment of Atrophic Edentulous Maxilla After Complications of Maxillary Reconstruction

This article reports the 20-month clinical outcome of the use of 4 zygomatic implants with immediate occlusal loading and reverse planning for the retreatment of atrophic edentulous maxilla after failed rehabilitation with autogenous bone graft reconstruction and maxillary implants. The intraoral clinical examination revealed mispositioned and loosened implants underneath a maxillary complete denture. The panoramic radiograph showed 6 maxillary implants. One implant was displaced into the right maxillary sinus, and the implant anchored in the region of tooth 21 was fractured. The other implants presented peri-implant bone loss. The implants anchored in the regions of teeth 21 to 23 and 11 to 13 were first removed. After 2 months, the reverse planning started with placement of 4 zygomatic fixtures, removal of the implants migrated into the sinus cavity and anchored in the region of tooth 17, and installation of a fixed denture. After 20 months of follow-up, no painful symptoms, peri-implant inflammation or infection, implant instability, or bone resorption was observed. The outcomes of this case confirm that the zygoma can offer a predictable anchorage and support function for a fixed denture in severely resorbed maxillae.

Color alteration in teeth subjected to different bleaching techniques

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chlorhexidine increases the longevity of in vivo resin-dentin bonds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dens invaginatus type III: report of a case and 10-year radiographic follow-up

Aim the purpose of this article is to report the 10-year follow-up of a right mandibular central incisor with 'dens invaginatus' that was root filled.Summary 'Dens invaginatus ' is a rare malformation of teeth, probably resulting from an infolding of the dental papilla during tooth development. It has alternatively been called 'dens in dente' and 'dilated composite odontome'. Radiographic examination may clearly demonstrate this feature, although no signs may be recognized clinically. If no entrance to the invagination can be detected and there are no signs of pulp pathosis, then no treatment is required other than fissure sealing of the invagination. In deep invaginations, it is likely that root-canal treatment may be required. Occasionally, when the tooth has an immature root, apexification is necessary. Root-canal treatment of a right mandibular central incisor with 'dens invaginatus ' is described along with 10-year follow-up.Key learning pointsBoth clinical and radiographic examinations are necessary to determine morphological features of teeth before root-canal treatment.Sensibility testing to determine the pulp condition is critical prior to treatment.

The Ability of Different Nickel-Titanium Rotary Instruments To Induce Dentinal Damage During Canal Preparation

The purpose of this study was to compare the incidence of dentinal defects (fractures and craze lines) after canal preparation with different nickel-titanium rotary files. Two hundred sixty mandibular premolars were selected. Forty teeth were left unprepared (n = 40). The other teeth were prepared either with manual Flexofiles (n = 20) or with different rotary files systems: ProTaper (Dentsply-Maillefer, Ballaigues, Switzerland), ProFile (Dentsply-Maillefer), SystemGT (Dentsply-Maillefer), or S-ApeX (FKG Dentaire, La Chaux-de-Fonds, Switzerland) (n = 50 each). Roots were then sectioned 3, 6, and 9 mm from the apex and observed under a microscope. The presence of dentinal defects was noted. There was a significant difference in the appearance of defects between the groups (p < 0.05). No defects were found in the unprepared roots and those prepared with hand files and S-ApeX. ProTaper, ProFile, and GT preparations resulted in dentinal defects in 16%, 8%, and 4% of teeth, respectively. Some endodontic preparation methods might damage the root and induce dentinal defects. (J Endod 2009;35:236-238)

Aspects of the reproductive biology of the shortfin mako, Isurus oxyrinchus (Elasmobranchii Lamnidae), in the Southeastern region of Brazil

Quatro úteros provenientes de quatro fêmeas prenhas e dois indivíduos recém-nascidos de anequim, Isurus oxyrinchus, foram coletados na região Sudeste do Brasil durante os meses de setembro a novembro de 1993 e 1994. Todos os embriões estavam bem desenvolvidos, próximos ao estágio de nascimento, apresentando a dentição e órgãos internos bastante desenvolvidos. O comprimento total desses embriões variou entre 64,5 e 72,0 cm, e o maior número de embriões observado no interior de uma única fêmea foi 20. As observações aqui realizadas confirmam a oofagia como forma de nutrição dos embriões dessa espécie e sua periodicidade. A presença de dentes no estômago dos embriões sugere que a substituição dos dentes se inicia na fase uterina.

In vitro effects of calcium hydroxide and polymyxin B on endotoxins in root canals

Objectives. To evaluate the effects of intracanal medicaments on endotoxins in root canals.Methods. Seventy-five freshly extracted maxillary incisors were used in this study. The crowns of teeth were sectioned near the CEJ in order to standardize the root length to 14 mm. The root canals were instrumented to an apical size #50 file and irrigated with 1% sodium hypochlorite solution and sterilized with 60 Co gamma irradiation. Standardized suspension containing Escherichia coli endotoxin was inoculated into the 60 root canals. The specimens were randomly assigned to 5 groups (n=15), according to the intracanal medicament used: (G1) calcium hydroxide; (G2) polymyxin B; (0) combination neomycin-potymyxin B-hydrocortisone; (G4) positive control (no intracanal medicament); (G5) negative control (no endotoxin and no intracanal medicament). After 7 days, the detoxification of endotoxin was evaluated by Limulus lysate assay and antibody production in B-tymphocytes culture.Results. Groups 1, 2 and 5 presented the best results by Limulus lysate and were significantly different to groups 3 and 4 (p<0.05). Stimulation of antibodies production in cell culture by groups 1 and 6 was smaller and statistically different than groups 2, 3, 4 and 5 (p<0.05). Groups 2 and 5 induced a small increase in the antibodies production in relation to the groups 1 and 6. Groups 3 and 4 induced a significant increase of antibodies production (p<0.05).Conclusions. The calcium hydroxide and polymyxin B intracanal medicaments detoxified endotoxin in root canals and altered the properties of LPS to stimulate the antibody production by B-Lymphocytes. The combination neomycin-polymyxin B-hydrocortisone did not detoxified endotoxin. (C) 2004 Elsevier Ltd. All rights reserved.

IN VITRO INCIDENCE of ROOT CANAL BIFURCATION IN MANDIBULAR INCISORS BY RADIOVISIOGRAPHY

Objective: The aim of this study was to verify, in vivo and in vitro, the prevalence of root canal bifurcation in mandibular incisors by digital radiography. Material and Methods: Four hundred teeth were analyzed for the in vivo study. Digital radiographs were taken in an orthoradial direction from the mandibular incisor and canine regions. The digital radiographs of the canine region allowed visualizing the incisors in a distoradial direction using 20 degrees deviation. All individuals agreed to participate by signing an informed consent form. The in vitro study was conducted on 200 mandibular incisors positioned on a model, simulating the mandibular dental arch. Digital radiographs were taken from the mandibular incisors in both buccolingual and mesiodistal directions. Results: The digital radiography showed presence of bifurcation in 20% of teeth evaluated in vitro in the mesiodistal direction. In the buccolingual direction, 17.5% of teeth evaluated in vivo and 15% evaluated in vitro presented bifurcation or characteristics indicating bifurcation. Conclusions: Digital radiography associated with X-ray beam distally allowed detection of a larger number of cases of bifurcated root canals or characteristics of bifurcation.

Evaluation of two morphometric methods of bone loss percentages caused by periodontitis in rats in different locations

Objective: The present study evaluated morphometrically bone loss percentages in experimental periodontitis in rats, comparing different locations (lingual mandible, palatal maxilla and buccal maxilla) and two evaluation methods (distance and area methods). Material and Methods: Ligatures were placed around the maxillary right second molar and around the mandibular right first molar in 14 female Wistar rats. The contralateral molars served as intragroup control. After 4 weeks, the rats were sacrificed and their mandible and maxilla were removed. The specimens were dissected and stained with methylene blue dye. Bone loss was evaluated by two different methods on the surfaces of the defleshed jaw. In the first method, the distance from the cementoenamel junction (CEJ) to the alveolar bone crest was measured in the roots of teeth associated with ligature. In the second method, the area of bone loss was determined using the alveolar tissue bone, CEJ and the proximal region of roots associated with the ligature as reference. The data were converted to bone loss percentages caused by ligature: (ligated - unligated) x 100/ligated. Results: When comparing the distance and area methods, no statistically significant difference was observed (p>0.05). Both methodologies indicated that the maxilla presented greater bone loss than the mandible and it was more accentuated on the buccal side than on the palatal side (p<0.05). Conclusions: The findings of this study show that both the area and the distance methods can be used to evaluate bone loss caused by ligature placement in rats, and suggest applying the morphometric methodology to the maxilla on the buccal side.

Cementum, apical morphology and hypercementosis: a probable adaptive response of the periodontal support tissues and potential orthodontic implications

Information about orthodontic movement of teeth with hypercementosis is scarce. As cementum deposition continues to occur, cementum is expected to change the shape of the root and apex over time, but this has not yet been demonstrated. Nor has it ever been established whether it increases or decreases the prevalence of root resorption during orthodontic treatment. The unique biological function of the interconnected network of cementocytes may play a role in orthodontic movement and its associated root resorptions, but no research has ever been conducted on the topic. Unlike cementum thickness and hypercementosis, root and apex shape has not yet been related to patient age. A study of the precise difference between increased cementum thickness and hypercementosis is warranted. Hypercementosis refers to excessive cementum formation above and beyond the extent necessary to fulfill its normal functions, resulting in abnormal thickening with macroscopic changes in the tooth root, which may require the delivery of forces that are different from conventional mechanics in their intensity, direction and distribution. What are the unique features and specificities involved in moving teeth that present with hypercementosis? Bodily movements would be expected to occur, since inclination might prove difficult to achieve, but would the root resorption index be higher or lower?

Influence of root canal dressings and sealers on repair of apical periodontitis after endodontic treatment

Objective. The objective of this study was to evaluate the histopathologic response of periapical tissues after root canal treatment of necrotic dog teeth with chronic apical periodontitis by using 2 calcium hydroxide-based root canal dressings and 2 root canal sealers.Study design. Seventy-eight root canals were instrumented by using 5.25% sodium hypochlorite as the irrigating solution, after which a calcium hydroxide paste (Calen/PMCC or Calasept) was placed for 30 days as a dressing. The root canals were then filled by using cold lateral gutta-percha condensation and an enclodontic sealer (Sealapex or AH Plus). After 360 days, the animals were killed by anesthetic overdose; then, the teeth were histologically prepared, sectioned, and stained with hematoxylin and eosin for optical microscopic analysis of apical and periapical tissue repair.Results. Statistical analysis showed that the poorest histopathologic results were observed in the Calasept/AH Plus group and that the Sealapex sealer overall resulted in better apical repair than the AH Plus sealer. The histopathologic results of Calen/PMCC paste with both AH Plus and Sealapex and Calasept paste with only Sealapex were statistically similar but were different from the results of Calasept with AH Plus.Conclusions. The results of this study in the dog showed differences in apical and periapical tissue repair of teeth with chronic apical periodontitis by using 2 calcium hydroxide root canal dressings and 2 sealers. More research is necessary to determine the best combination of dressings and sealers.

Effect of a calcium hydroxide-based root canal dressing on periapical repair in dogs: a histological study

Objective. To compare the periapical repair of teeth with periapical lesion following root canal treatment by using a calcium hydroxide-based intracanal dressing for several time periods or filling in a single visit.Study design. After induction of periapical lesions in 4 dogs, the root canals were prepared using 5.25% sodium hypochlorite for irrigation, and animals were separated into 4 experimental groups; in group I, root canals were filled in a single session; in groups II, III, and IV, a calcium hydroxide-based dressing was kept in place for 15, 30, or 180 days, respectively. Root canals from groups I, II, and III were filled with gutta-percha cones and AH Plus sealer. After 180 days, animals were killed and histological sections were stained with hematoxylin-eosin to evaluate periapical repair.Results. Periapical repair was better in groups II, III, and IV (intracanal dressing) compared with group I (single session; P <.05).Conclusion. The use of a calcium hydroxide-based intracanal dressing was important for periapical repair in teeth with periapical lesion. Dressing with calcium hydroxide paste results in better periapical repair than when the root canal is filled in a single-session treatment.

Clinical evaluation of tinnitus in patients with sleep bruxism: prevalence and characteristics

Evaluation of the prevalence and characteristics of tinnitus in a Brazilian series of sleep bruxism patients. In this descriptive study, 100 patients (80 women and 20 men) were selected through the self-report of grinding teeth during sleep, confirmed by room mate or family member. They were evaluated according to a systematized approach: a questionnaire for orofacial pain and the Portuguese version of the Research Diagnostic Criteria for Temporomandibular Disorders. The patients were divided into two groups: group A, 54 patients with complaint of tinnitus and group B, 46 patients without tinnitus complaint. The mean age was 37.85 (13-66 years) and 34.02 years (20-59 years), respectively, for groups A and B (P = 0.1164). There was statistically significant difference between the two groups, with higher prevalence for the group A, in relation to: presence of chronic facial pain (P = 0.0007); number of areas painful to palpation in the masticatory and cervical muscles (P = 0.0032); myofascial pain in the masticatory muscles (P = 0.0003); absence of teeth without prosthetic replacement (P = 0.0145) and indices of depression (P = 0.0234). Structural alterations of the TMJ, like disc displacement and vertical dimension loss did not differ for the two groups. Tinnitus frequency was higher in patients with sleep bruxism and chronic facial pain. Myofascial pain, number of areas painful to palpation in the masticatory and cervical muscles, higher levels of depression and tooth absence without prosthetic replacement were more frequent in the group with tinnitus.

Incidence of sleep bruxism among children in Itanhandu, Brazil

Sleep bruxism (SB) in children may be related to headaches and causes extensive damage of primary teeth. This paper evaluates the incidence of SB in children from Itanhandu, MG, Brazil.The presence of teeth wear facets was verified through clinical examinations on a sample of children, whose parents answered a questionnaire about their children's behavior and habits. Analysis of variance and chi-square tests (p = 0.05) were applied to identify possible correlations between the presence of SB and the parents' responses to the questionnaire.The sample comprised of 170 children, 51.76% (n = 88) of which were girls, while the average age was 4.37 (+/- 1.69) years. A total of 15.29% (n = 26) had been diagnosed as bruxers, 46.47% displayed restless behavior, and only 10% used medication. The average duration of breastfeeding was 4.4 (+/- 0.25) months. A positive correlation was found between restless behavior and the presence of SB (p < 0.001). No correlation was found between SB and medication (p = 0.573), or between the duration of breastfeeding and restless behavior (p = 0.102), SB (p = 0.565) and medication (p = 0.794).Restless behavior was positively correlated with SB, although no correlation was found between SB and medication or duration of breastfeeding.

Natal teeth: Case report

The natal teeth are defined as the presence of teeth at birth and the etiology is rather obscure. Clinically, the teeth show normal size and shape, although they reveal an immature appearance. The histological aspect show enamel with the possibility of presenting normal mineralization or being hypoplastic. The dentin may show alterations. The incidence of natal teeth varies greatly, with a predisposition for the female sex. This paper relates a case report of two partially erupted natal teeth in a female baby 9 days-old. The presence of teeth made the parents anxious. In their mind, that meant the child was abnormal. On the radiograph the erupted teeth showed little radioopacity, without a radicular formation. The therapy utilized was the keeping of the teeth and a periodic monitoring, cleaning and daily topical applications sodium fluoride. The case was monitored by monthly consultations. At 9 months of age the primary central lower did not present mobility. On the radiograph examination incomplete radicular formation was observed.