Influência do tipo de parafuso, liga e da posição do cilindro na adaptação marginal das infra-estruturas sob implantes antes e após a soldagem a laser

Misfit at the abutment-prosthetic cylinder interface can cause loss of preload, leading to loosening or fracture of gold and titanium screws. OBJECTIVES: To evaluate the influence of screw type, alloy, and cylinder position on marginal fit of implant frameworks before and after laser welding. METHODS: After Estheticone-like abutments were screwed to the implants, thirty plastic prosthetic cylinders were mounted and waxed-up to fifteen cylindrical bars. Each specimen had three interconnected prosthetic components. Five specimens were one-piece cast in titanium and five in cobalt-chromium alloy. On each specimen, tests were conducted with hexagonal titanium and slotted gold screws separately, performing a total of thirty tested screws. Measurements at the interfaces were performed using an optical microscope with 5mm accuracy. After sectioning, specimens were laser welded and new measurements were obtained. Data were submitted to a four-way ANOVA and Tukey's multiple comparisons test (alpha=0.05). RESULTS: Slotted and hexagonal screws did not present significant differences regarding to the fit of cylinders cast in titanium, either in one-piece casting framework or after laser welding. When slotted and hexagonal screws were tested on the cobalt-chromium specimens, statistically significant differences were found for the one-piece casting condition, with the slotted screws presenting better fit (24.13µm) than the hexagonal screws (27.93 µm). Besides, no statistically significant differences were found after laser welding. CONCLUSIONS: 1) The use of different metal alloys do exert influence on the marginal fit, 2) The slotted and hexagonal screws play the exclusive role of fixing the prosthesis, and did not improve the fit of cylinders, and 3) cylinder position did not affect marginal fit values.A desadaptação na interface abutment-cilindro protético pode causar perda da pré-carga, levando ao afrouxamento ou fratura dos parafusos de ouro e titânio. OBJETIVOS: Avaliar a influência do tipo de parafuso, liga e posição do cilindro na adaptação marginal de infra-estruturas sobre implante antes e após a soldagem a laser. MÉTODOS: Após os abutments do tipo Estheticone serem aparafusados nos implantes, trinta cilindros protéticos de plástico foram montados e encerados com 15 barras cilíndricas. Cada espécime possuía três componentes protéticos interconectados. Cinco espécimes foram fundidos em monobloco com liga de titânio e liga de cobalto-crômio. Em cada espécime, os testes foram conduzidos com parafusos hexagonais de titânio e com parafusos de ouro com fenda, separadamente, num total de 30 parafusos testados. As medidas nas interfaces foram feitas com microscópio óptico com 5mm de precisão. Após o seccionamento, os espécimes foram soldados a laser e novas medidas obtidas. Os dados foram submetidos para análise com os testes ANOVA a quatro critérios e Tukey para comparações múltiplas (alfa=0,05). RESULTADOS: Os parafusos com fenda e hexágono não apresentaram diferenças significantes independente da adaptação dos cilindros fundidos em titânio, tanto em monobloco como após a soldagem a laser. Quando os parafusos com hexágono e fenda foram testados nos espécimes de cobalto-crômio, diferenças estatisticamente significantes foram encontradas na condição monobloco, com os parafusos fendidos apresentando melhor adaptação (24,13µm) do que os com hexágono (27,93 µm). Além disso, nenhuma diferença significante foi encontrada após a soldagem a laser. CONCLUSÕES: 1) O uso de diferentes ligas metálicas exerce influência nos resultados, 2) Os parafusos com hexágono e fenda somente possuem o papel de fixar a prótese, e não melhoram a adaptação dos cilindros e 3) a posição do cilindro não afetou os valores de adaptação marginal

Adaptação marginal na interface intermediário-cilindro antes e após as sobrefundições

The aim of this study was to measure marginal fit at cylinder-abutment interface, before and after overcasting procedure. A hexagonal implant was fixed to a stainless steel base and a Estheticone-like abutment used during all the experiment. Before casting procedure, gold (Group I) and Ni-Cr-Be (Group II) premachined cylinders were tightened to the abutment with gold and titanium screws (in both groups), with 10Ncm and 20Ncm torque values for the same screw type. Vertical measures were taken at the light microscope (Mitutoyo 5050, Tokyo, Japan) three times in six different parts along the abutment-cylinder interface for each torque value. Cylinders were overcast with Ag-Pd (Group I) or Ni-Cr-Be (Group II) alloy. After casting, the same measures and torque values were repeated. Intragroup differences (10 or 20Ncm torque values, before and after casting) and intergroup differences (10 and 20Ncm torque values, before or after casting) were analyzed by the Paired t Test; (pO objetivo deste estudo foi medir a adaptação marginal na interface intermediário-cilindro, antes e após a sobrefundição. Um implante do tipo hexágono externo afixado numa base de aço inoxidável e um intermediário do tipo Estheticone foram usados durante todo o experimento. Antes das fundições, cilindros pré-usinados de ouro (Grupo I) e de Ni-Cr-Be (Grupo II) foram aparafusados ao intermediário com parafusos de ouro e titânio em ambos os grupos, com torques de 10Ncm e 20Ncm para o mesmo tipo de parafuso. As medidas verticais foram feitas num microscópio óptico (Mitutoyo 5050, Tóquio, Japão) três vezes em seis locais diferentes ao longo da interface intermediário-cilindro para cada valor de torque. Os cilindros foram encerados e fundidos tanto em liga de Ag-Pd (Grupo I) ou liga de Ni-Cr-Be (Grupo II). Após as fundições, as mesmas medidas e os mesmos valores de torque foram repetidos. As diferenças intra-grupo (torques de 10 ou 20Ncm, antes e após as fundições) e as diferenças inter-grupos (torques de 10 e 20Ncm, antes ou após as fundições) foram analisadas pelo teste t pareado (

Association Between Sleep Bruxism and Myofascial Pain: a Polysomnographic Study.

Objetivos: Verificar 1) a presença de associação entre bruxismo do sono (BS) e dor miofascial (DMF); 2) se há correlação entre atividade rítmica dos músculos mastigatórios (ARMM) e os valores de limiar de dor à pressão matinais (LDP-pósPSG); 3) se maiores níveis de dor ou sensibilidade à palpação correlacionam-se com menores índices de ARMM em bruxômanos e não bruxômanos com e sem DMF e 4) avaliar a confiabilidade do exame clínico de bruxismo (ECB) Material e Métodos: Realizaram-se exame PSG (2 noites consecutivas) e ECB em 30 pacientes com DMF e 30 indivíduos assintomáticos, correspondentes em sexo e em idade. Previamente à PSG (2a noite) verificou-se o LDP (pré- PSG) da origem, corpo, inserção e porção profunda do masseter e porções anterior, média e posterior do temporal. Na manhã seguinte, verificou-se o LDP pós-PSG nos mesmos sítios musculares. Resultados: Todos os pacientes com DMF apresentaram queixa de dor nos músculos mastigatórios (temporal e/ou masseter), 90% relataram dor leve ou moderada, com duração média de 34,67 ± 36,96 meses (2 a 120). Não houve diferenças entre os grupos quanto à macroestrutura do sono. Houve associação significativa entre BS e DMF [(Quiquadrado, p = 0,039); OR 3,45 (IC 95% 1,066 - 11,194); RR:1,83 e LR+: 1,9. Apenas entre os pacientes de DMF houve correlações negativas entre ARMM e LDP pós-PSG. As correlações foram mais fortes entre os pacientes não-bruxômanos do que nos pacientes bruxômanos. Apenas entre os bruxômanos assintomáticos houve correlações positivas entre LDP pré-PSG e ARMM. Conclusões: 1) O BS associou-se com DMF; 2) a DMF parece ser fator predisponente à maior sensibilidade matinal à palpação; 3) não bruxômanos com DMF parecem responder com maior sensibilidade matinal à palpação a aumentos na intensidade da ARMM do que bruxômanos com DMF; 4) apenas entre os bruxômanos assintomáticos encontrou-se suporte à ocorrência do mecanismo de adaptação à dor e 5) o ECB apresentou valores distintos de confiabilidade para a população com DMF e assintomática, apresentando valores mais altos na população com DMF, embora não tenha atingido os níveis adequados de sensibilidade (75%) e especificidade (90%).Objectives: To test 1) the association between sleep bruxism (SB) and miofascial pain (MFP); 2) the correlation between rhythmic masticatory muscle activity (RMMA) and pressure pain threshold (PPT) at morning, 3) the influence of previous tenderness over RMMA in bruxers and non-bruxers with/without MFP, and 4) the validity of a clinical diagnostic criteria of sleep bruxism (DCSB). Materials and Methods: Polysomnographic recording (PSG) (two consecutive nights) were performed in 30 MFP patients, selected according to RDC/TMD and 30 asymptomatic controls age and gender-matched. Pre and post-PSG PPT values were verified for masseter (origin, body, insertion, and deep portion), as well as for temporal (anterior, medium, posterior) muscles. Results: All MFP patients reported pain complaints on masseter and/or temporal muscles. Most of MFP patients reported mild or moderate pain (46.67%, and 43.33%, respectively), and only 3 (10%) reported severe pain. Pain duration ranged from 2 to 120 months (mean of 34.67 ± 36.96 months). No differences in sleep architecture were observed in both groups. A significant association was observed between SB and MFP [Chi-Square=0.039, Odds Ratio=3.45 [CI 95% 1.066-11.194)]. Only in MFP patients negative correlations were seen between ARRM and morning-PPT ? indicating a dose-response gradient between ARRM and tenderness to palpation on morning. This gradient seemed more evident among MFP non-bruxers than on bruxers. There were positive correlations between pre-PSG PPT and RMMA only among asymptomatic bruxers. Conclusions: These findings indicate that: 1) Sleep bruxism is significantly associated with MFP; 2) MFP seems to be a predisposing factor that increases bruxism-related muscle sensitivity; 3) MFP non-bruxers seem to show more tenderness on palpation due to more intense RMMA than do MFP bruxers. 4) Only among asymptomatic bruxers was found some evidence of pain-adaptation model; and 5) The DCSB showed different confiability values for MFP and asymptomatic patients, presenting higher values for MFP patients, although not reaching adequate sensitivity (75%) and specificity (90%) levels

Association between sleep bruxism and temporomandibular disorders: A polysomnographic pilot study

The aim of this study was to verify the association between sleep bruxism (SB) and temporomandibular disorders (TMD) in a sample of 14 TMD patients and 12 healthy control subjects. All participants were evaluated using a clinical questionnaire, visual analog scale (VAS) for TMJ/muscle palpation, and by functional examination. The experimental group was divided into three TMD subgroups: joint sounds and pain, muscular tenderness, and mixed diagnosis. All participants underwent polysomnographic recording (PSG). A second clinical examination was then carried out to verify the relationship between rhythmic masticatory muscle activity and pain/tenderness on the following morning. e experimental and control groups presented VAS mean scores of 36.85 +/- 23.73 mm and 0 mm, respectively. The presence of SB was neither associated with TMD (p>0.05) nor with pain on palpation (p>0.05). Further research with a more representative sample of each TMD subgroup is necessary to elucidate its interaction with SB

Association between rhythmic masticatory muscle activity during sleep and masticatory myofascial pain: A polysomnographic study

Aims: To test for an association between rhythmic masticatory muscle activity during sleep, as assessed according to polysomnographic criteria for sleep bruxism (RMMA-SB), and myofascial pain (MFP), as well as the chance of occurrence of MFP in patients with RMMA-SB. Methods: Thirty MFP patients (diagnosed according to the Research Diagnostic Criteria for Temporomandibular Disorders) and 30 age- and gender-matcbed asymptomatic controls underwent a polysomnographic examination. Also, any self-reporting of daytime clenching (DC) was registered in 58 of these subjects. Results: Most MFP patients reported mild or moderate pain (46.67% and 43.33%, respectively), and only 3 (10%) reported severe pain. Pain duration ranged from 2 to 120 months (mean 34.67 +/- 36.96 months). Significant associations were observed between RMMA-SB and MFP as well as between DC and MFP. Conclusions: (1) RMMA-SB is significantly associated with MFP; (2) although RMMA-SB represents a risk factor for MFP, this risk is low; and (3) DC probably constitutes a stronger risk factor for MFP than RMMA-SB

Influence of tinnitus on pain severity and quality of life in patients with temporomandibular disorders

OBJECTIVE:The aim of this cross-sectional study was to evaluate the relationship among pain intensity and duration, presence of tinnitus and quality of life in patients with chronic temporomandibular disorders (TMD). MATERIAL AND METHODS: Fifty-nine female patients presenting with chronic TMD were selected from those seeking for treatment at the Bauru School of Dentistry Orofacial Pain Center. Patients were submitted to the Research Diagnostic Criteria anamnesis and physical examination. Visual analog scale was used to evaluate the pain intensity while pain duration was assessed by interview. Oral Health Impact Profile inventory modified for patients with orofacial pain was used to evaluate the patients' quality of life. The presence of tinnitus was assessed by self report. The patients were divided into: with or without self report of tinnitus. The data were analyzed statistically using the Student's t-test and Pearson's Chi-square test, with a level of significance of 5%. RESULTS: The mean age for the sample was 35.25 years, without statistically significant difference between groups. Thirty-two patients (54.24%) reported the presence of tinnitus. The mean pain intensity by visual analog scale was 77.10 and 73.74 for the groups with and without tinnitus, respectively. The mean pain duration was 76.12 months and 65.11 months for the groups with and without tinnitus, respectively. The mean OHIP score was 11.72 and 11.74 for the groups with and without tinnitus, respectively. There was no statistically significant difference between groups for pain intensity, pain duration and OHIP scoreS (p>;0.05). CONCLUSION: Chronic TMD pain seems to play a more significant role in patient 's quality of life than the presence of tinnitus

Palpation of the lateral pterygoid area in the myofascial pain diagnosis

Objectives. To evaluate the diagnostic value of intraoral palpation at the lateral pterygoid (LP) area as part of the physical examination to detect myofascial pain, according to modified research diagnostic criteria for temporomandibular disorders. Study design. Fouty-four women composed the myofascial pain group, and 33 symptom-free age-matched were the control group. One examiner calibrated and blinded to group distribution performed 2 intraoral bilateral palpations of the lateral pterygoid. Results. The LP area palpation showed sensitivity and specificity values of 79.55% and 77.27%, respectively, and positive and negative likelihood ratios of 3.50 and 0.26, respectively. Conclusions. Palpation at the LP area did not reach acceptable values of specificity, and care must be taken when judging positive response to this procedure

Marginal fit at cylinder-abutment interface before and after overcasting procedure Adaptação marginal na interface intermediário-cilindro antes e após as sobrefundições

The aim of this study was to measure marginal fit at cylinder-abutment interface, before and after overcasting procedure. A hexagonal implant was fixed to a stainless steel base and a Estheticone-like abutment used during all the experiment. Before casting procedure, gold (Group I) and Ni-Cr-Be (Group II) premachined cylinders were tightened to the abutment with gold and titanium screws (in both groups), with 10Ncm and 20Ncm torque values for the same screw type. Vertical measures were taken at the light microscope (Mitutoyo 5050, Tokyo, Japan) three times in six different parts along the abutment-cylinder interface for each torque value. Cylinders were overcast with Ag-Pd (Group I) or Ni-Cr-Be (Group II) alloy. After casting, the same measures and torque values were repeated. Intragroup differences (10 or 20Ncm torque values, before and after casting) and intergroup differences (10 and 20Ncm torque values, before or after casting) were analyzed by the Paired t Test; (p<0.05). Intragroup differences were observed for G-I (gold, 20Ncm, titanium screw, p=0.044) and for G-II (Ni-Cr-Be, 10Ncm, gold screw, p=0.002). Intergroup differences only were not observed in the G-II group (Ni-Cr-Be, 10 and 20Ncm, titanium screw, p=0.534). Within the limits of this study, the following conclusions can be drawn: 1) Regardless of screw type, marginal misfit was higher for Ni-Cr-Be cylinders after casting, but within acceptable levels of fit; 2) The combination of gold cylinders with gold or titanium screws was the most effective to reduce marginal misfit; 3) Both screw types did not improve marginal fit of Ni-Cr-Be cylinders after overcastting, and 4) Although a 20Ncm torque improved marginal fit in all situations, its use is not recommended due to the increased risk of prosthesis failure. Ni-Cr-Be alloys may be successfully used in single-tooth implant restorations, with no damage to the fit between abutment and prosthetic cylinder.<br>O objetivo deste estudo foi medir a adaptação marginal na interface intermediário-cilindro, antes e após a sobrefundição. Um implante do tipo hexágono externo afixado numa base de aço inoxidável e um intermediário do tipo Estheticone foram usados durante todo o experimento. Antes das fundições, cilindros pré-usinados de ouro (Grupo I) e de Ni-Cr-Be (Grupo II) foram aparafusados ao intermediário com parafusos de ouro e titânio em ambos os grupos, com torques de 10Ncm e 20Ncm para o mesmo tipo de parafuso. As medidas verticais foram feitas num microscópio óptico (Mitutoyo 5050, Tóquio, Japão) três vezes em seis locais diferentes ao longo da interface intermediário-cilindro para cada valor de torque. Os cilindros foram encerados e fundidos tanto em liga de Ag-Pd (Grupo I) ou liga de Ni-Cr-Be (Grupo II). Após as fundições, as mesmas medidas e os mesmos valores de torque foram repetidos. As diferenças intra-grupo (torques de 10 ou 20Ncm, antes e após as fundições) e as diferenças inter-grupos (torques de 10 e 20Ncm, antes ou após as fundições) foram analisadas pelo teste t pareado (p<0.05). Diferenças intra-grupo foram observadas em G-I (ouro, 20Ncm, parafuso de titânio, p=0,044) e em G-II (Ni-Cr-Be, 10Ncm, parafuso de ouro, p=0,002). As diferenças inter-grupos não foram observadas somente no grupo G-II (Ni-Cr-Be, 10 e 20Ncm, parafuso de titânio, p=0,534). Dentro dos limites deste estudo, as seguintes conclusões podem ser feitas: 1) Independente do tipo de parafuso, os valores de desadaptação marginal foram mais altos para os cilindros de Ni-Cr-Be após as fundições, mas dentro dos níveis aceitáveis de adaptação; 2) A combinação cilindro de ouro com parafuso de ouro ou de titânio foi a mais efetiva para reduzir o desajuste marginal; 3) Ambos os tipos de parafusos não melhoraram a adaptação marginal dos cilindros de Ni-Cr-Be após as fundições, e 4) Embora um torque de 20Ncm tenha melhorado a adaptação marginal em todas as situações, seu uso não é recomendado devido ao risco aumentado de falha na prótese . As ligas de Ni-Cr-Be podem ser usadas com sucesso nas restaurações unitárias sobre implantes, sem prejuízo na adaptação entre o abutment e o cilindro protético