Long-term clinical performance of short 6-mm implants supporting single crowns in the posterior region: A 10-year cohort study.

INTRODUCTION: Long-term clinical success of non-splinted, posterior, and short implants still is unclear. This prospective cohort study reports the 10-year follow-up of 6-mm implants supporting single crowns in the posterior region, and patient-reported outcomes. METHODS: Baseline sample comprised 20 patients treated with 46 screw-retained crowns supported by 6-mm implants with moderately rough implant surface. Participants were recalled for a 10-year clinical follow-up to assess survival rates, biologic and mechanic conditions, quality of life (OHIP-14), and treatment satisfaction. Data were collected with clinical-radiographic exams and analyzed using descriptive and inferential statistics. RESULTS: Fourteen patients with 35 implant-crown units were examined after 127.6 ± 11.8 months. For the entire cohort period, 7/46 implants were lost (survival estimate: 77.7% at 133 months), and mechanic complications occurred in 14/46 units (survival estimate: 66.4% at 116 months). In the Cox models, "maximum occlusal force" had a significant effect for implant loss (p = 0.038) and for prosthetic screw loosening (p = 0.038); "arch" and "bruxism" were not significant. Peri-implant bone loss was 0.4 ± 0.6 mm at 10 years. For peri-implant bone level, "crown-to-implant ratio" (p < 0.001) and "time" (p = 0.001) were significant. Bone levels differed from baseline to 12, 48, and 120 months. Satisfaction VAS was 94.0 ± 7.9 mm and OHIP-14 was 2.3 ± 2.2. CONCLUSION: Single screw-retained crowns supported by 6-mm implants have an acceptable long-term clinical performance, with stable peri-implant bone levels after 10 years of function.

Biomechanical variables affect peri-implant bone loss in implant-supported fixed complete dentures: A methodological and prospective study.

PURPOSE: Implant-supported fixed complete dentures (IFCD) experience failures and complications related to biological and technical risk factors. This study investigated the effect of biomechanical variables of IFCD on 1-year peri-implant bone loss at the buccal, palatal/lingual, mesial, and distal implant sides. A new method was used to measure the geometric biomechanical variables of IFCD using cone beam computed tomography (CBCT). METHODS: The study sample consisted of 246 external hexagon implants supporting 48 hybrid IFCD in 44 patients. CBCT images obtained immediately (T0) and 1 year (T1) after prosthesis installation were used to measure the support polygon area, clinical crown/implant (C/I) ratio (vertical lever), anteroposterior power and resistance arms, anterior and posterior cantilevers (horizontal levers), and peri-implant bone remodeling (T1-T0). Data were analyzed using multilevel multivariable models. RESULTS: The average total bone loss in the mandible and maxilla were 0.88 mm, with a loss of 0.62 mm in the mandible and 1.08 mm in the maxilla. The C/I ratio had a significant effect on bone loss on the mesial, distal, and palatal/lingual sides (P <.05). The anterior cantilever had a protective effect on the lingual side of the anterior implant. No effect on bone loss was found for the support polygon area, posterior cantilever, resistance arm, or power arm (P >.05). CONCLUSIONS: The results suggest that the C/I ratio and anterior cantilever in IFCD affect peri-implant bone loss according to the implant side and position in the arch.

Impacto Biopsicosocial de la Rehabilitación Oral Soportada por Implantes: Revisión Analítica de Instrumentos de Investigación

Este trabajo ha realizado una revisión narrativa de la literatura para analizar los instrumentos usados en la investigación clínica para los resultados centrados en el paciente en rehabilitación oral soportada por implantes. La búsqueda ha sido realizada en bases indexadoras de periódicos nacionales e internacionales, sin restricción temporal, en los idiomas portugués e inglés, utilizando las palabras-clave: implantes dentales, investigación clínica, resultados reportados por pacientes, cualidad de vida. Actualmente, los estudios clínicos deben incluir resultados obtenidos por relatos autorales de percepció n de los beneficios del tratamiento cuanto a los aspectos funcionales, sicológicos y sociales. La mayoría de los estudios utiliza instrumentos que añaden diferentes dimensiones de cualidad de vida, tales como GOHAI (Geriatric Oral Health Assessment Index), DIDL (Dental Impacton Daily Living), OHIP (Oral Health Impact Profile), OHQoL-UK (W), OIDP (Oral Impactson Daily Performances). En general, los ítems de estos cuestionarios han sido formulados de manera negativa, con el enfoque en los problemas, siendo el OHIP-14 lo más utilizado por ser sencillo, validado para varios idiomas y consolidado para las diferentes situaciones clínicas. Otros instrumentos de sicología positiva, como los cuestionarios de Rosenberg y McCullough, han sugestionado evaluar la percepción de la autoestima y de la gratitud, con el enfoque en el bienestar y en la satisfacción del pacien te a largo plazo. Estudios cualitativos o con métodos mistos pueden fornecer también más comprensión de los resultados centrados en los pacientes en rehabilitación soportada por implantes. Con base en la literatura observada se concluye que el estudio de resultados centrados en los pacientes puede ser enriquecido con el uso de diversos métodos para capturar la percepción del paciente de los beneficios de la rehabilitación soportada por implantes. Se sugestiona el uso del OHIP-14, aunque, su uso presente limitaciones que en parte pueden ser reprimidas por la aplicación de los cuestionarios relacionados a la sicología positiva como lo de la gratitud y lo de la autoestima, los cuales presentan dominios positivos.

This study aimed to conduct a narrative review of the literatura to analyze the instruments used in clinical research for patient-reported outcomes measures in implant-supported oral rehabilitation. The search was conducted in index data bases of national and international journals without time restriction, in Portuguese and English, using the key words: dental implants, clinical research, patient-reported outcomes measures, quality of life. Currently, clinical studies should include results obtained through self- reporting of the perceived benefits of treatment in functional, psychological and social aspects. Most studies use instruments that add different dimensions of quality of life, such as GOHAI (Geriatric Oral Health Assessment Index), DIDL (Dental Impacton Daily Living), OHIP (Oral Health Impact Profile), OHQoL-UK (W), OIDP (Oral impacts in daily presentations). In general, the itens in these questionnaires were formulated in a negative way, with a focuson problens, with OHIP-14 being the most used because it is simple, validated for several languages and consolidated for different clinical situations. Other positive psychology tools, such as the Rosenberg and McCullough questionnaires, have been suggested to assess the perception of self-esteen and gratitude, with a focus on long-term well-being and patient satisfaction. Qualitative or mixed method studies can also provide a better understanding of the results centered on patients undergoing rehabilitation with implants. Based on the observed literature, it is concluded that the study of patient-centered results can be enriched with the use of various methods to capture the patient's perception of the benefits of implant-supported rehabilitation. It is suggested the use of the OHIP-14, however, their use has limitations that can be partially met by the application of questionnaires related to positive psychology, as gratitude and self-esteen, which have positive fields.

A within-subject comparison of short implants in the posterior region: retrospective study of up to 10 years.

PURPOSE: This intra-patient retrospective study of up to 10 years evaluated the clinical success and risk factors of 6- and 8-mm long implants and their respective prostheses. MATERIALS AND METHODS: The sample consisted of patients treated at a Military Polyclinic dental service, who received both 6- and 8-mm long tissue level implants in the posterior region of the same arch. Data were collected from the dental charts, clinical and radiographic exams, self-report of sleep bruxism, measurement of maximum occlusal force, and clinical crown-to-implant (C/I) ratio. Data were analyzed by descriptive and inferential statistics with univariate and hierarchical multivariate models, at the 0.05 significance level. RESULTS: The 30 patients (27 women) had 85 implants and 83 prostheses. Two implants were lost before prosthesis installation (implant survival: 97.6%). Ten events of prosthetic complication (screw tightening loss) occurred in five patients (success rate: 87.9%) in a single moment. Only the variable C/I ratio had a significant effect for repairable prosthesis complication (P<.05). CONCLUSION: The results suggest that 6- and 8-mm long implants have similar long-term clinical success for implants and prostheses.

Relation between insertion torque and tactile, visual, and rescaled gray value measures of bone quality: a cross-sectional clinical study with short implants.

BACKGROUND: This study assessed the relationship between insertion torque and bone quality evaluated during surgery and in preoperative computed tomographic (CT) images analyzed either visually or by rescaled mean gray values (MGVs). The study also tested the correlation between the clinical and radiographic measures of bone quality. METHODS: The consecutive sample was composed of 45 short implants (4.1 × 6 mm) placed in the posterior region of 20 patients. Intra-surgical tactile bone quality, based on the classification of bone types by Lekholm and Zarb, and insertion torque were recorded during the implant placement. Visual bone quality and normalized MGV were assessed in standardized axial, coronal, and sagittal sections of preoperative CT images. Data were analyzed by ANOVA and Spearman correlation (alpha = 0.05). RESULTS: Insertion torque was associated with all assessment methods of bone quality (tactile, CT visual, MGV). A moderate correlation was found among all methods of bone quality, except for CT visual assessment and tactile evaluation. MGVs varied as a function of arch, dental region, insertion torque, and bone types. CONCLUSIONS: The results suggest that bone quality measures affect primary stability as recorded by insertion torque, and the assessment methods are consistently related.

Volumetric Bone Measurement Around Dental Implants Using 3D Image Superimposition: A Methodological and Clinical Pilot Study.

PURPOSE: This study describes the development of a methodology for using three-dimensional (3D) image superimposition to measure volumetric changes in bone level around dental implants in comparison with linear measures. MATERIALS AND METHODS: The sample was comprised of 46 dental implants of 6-mm length and 4.1-mm diameter placed in the posterior maxilla and posterior mandible in 20 patients. All implants received screw-retained single crowns. Radiographic images were taken using cone beam computed tomography (CBCT) and digital periapical radiography after implantation and after 12 and 24 months of functional loading (after crown installation). Tridimensional reconstructions of the bone perimeter closest to the implant were developed, superimposed, and volumetrically measured. Linear measures of bone levels were recorded in periapical radiography images. A multilevel regression model tested volumetric and linear bone loss. RESULTS: The mean peri-implant linear bone loss for the first and second years was 0.2 ± 0.4 mm and 0.1 ± 0.2 mm, respectively, and the mean volumetric bone loss for the first and second years was 7.2 ± 6.1 mm³ and 6.4 ± 7.8 mm³, respectively. It was estimated that an increase of 1 mm of linear bone loss was associated with a mean volumetric bone loss of approximately 14 mm³ (P < .001). CONCLUSION: The findings showed that linear and volumetric bone loss measures are related. Measuring volumetric bone changes around implants is possible provided that the CBCT images have proper contrast and sharpness, particularly around the implant outline. Improvements in image quality and in the filters for bone tissue detection would be important for this methodology to be made faster and used clinically.

Risk factors for single crowns supported by short (6-mm) implants in the posterior region: A prospective clinical and radiographic study.

BACKGROUND: The use of short implants is still not a consensus for challenging clinical situations, such as unfavorable crown-to-implant (C/I) ratio. PURPOSE: This prospective study evaluated the rates of prosthetic complications and implant failure, the mean marginal bone loss of 6-mm dental implants with single crowns in posterior regions and the potential risk factors. MATERIALS AND METHODS: Forty-six dental implants, 6-mm long and 4.1-mm wide, were placed in the posterior region in 20 patients. Patients were clinically and radiographically examined after the restoration with single crowns and on a yearly basis. Potential risk factors (arch, bruxism, maximum bite force, anatomical and clinical C/I ratios, and occlusal table area) were analyzed according to the following outcomes: implant survival, bone loss, and prosthetic complications. RESULTS: The mean follow-up time was 45 ± 9 (16-57) months. There was no early loss of implants. After prosthetic loading, 4 implants were lost (2 in the mandible and 2 in the maxilla; 91.3% survival), and there were 13 prosthetic complications (28.3%), yielding a 65.2% success rate. The frailty term showed a 95% greater chance of loss in the mandible than the maxilla. Mean peri-implant bone loss was of 0.2 ± 0.4 mm, 0.1 ± 0.2 mm, 0.1 ± 0.3 mm, and 0.2 ± 0.4 mm in the first, second, third, and fourth years, respectively, with a mean cumulative loss of 0.3 ± 0.5 mm at 48 months. In the multilevel model, the effects of the clinical C/I ratio and time were significant for bone loss (P < .001). It was estimated that a mean bone loss of 0.1 mm is associated with both a one-unit increase in time (12 months) and a 0.1 increase in the clinical C/I ratio. The other potential risk factors showed no significant relationship with the outcomes. CONCLUSIONS: The 6-mm implants supporting single crowns performed well, but the mandible shows a higher risk of failure. The time and clinical C/I ratio are predictors for bone loss.

The effect of a positioning index on the biomechanical stability of tapered implant-abutment connections.

The biomechanical stability of the implant-abutment connection is critical for the success of implant-supported restorations. This study investigated the effect of a positioning index on the abutment screw preload values of tapered connection implants. Twenty Morse taper implants presenting an internal locking hex received 10 solid and 10 straight screw retained abutments for cemented single-crown restorations. Ten abutments had a positioning index to fit the internal locking hex of the implant (straight), and 10 were locked only by the implant taper (solid). The preload values for each abutment screw after a tightening torque were registered by strain gauges. Prosthetic crowns were placed on each abutment and subjected to mechanical cycling. Detorque forces were applied to each abutment and compared with the initial torque values. Data were statistically analyzed using Kolmogorov-Smirnov and Student t tests. The nonindexed group presented higher initial preload (6.05 N ± 0.95 N) compared with the indexed group (4.88 N ± 0.92 N; P < .05). After cycling, the nonindexed group exhibited less reduction of preload (13.84% ± 6.43%) compared with the indexed group (52.65% ± 14.81%; P < .01). Indexed tapered abutments for single-crown restorations might represent greater biomechanical risk under function.

Efficacy of an ionic toothbrush on gingival crevicular fluid--a pilot study.

The aim of this study was to compare the efficacy of an ionic and a conventional toothbrush in reducing gingival inflammation measured by gingival crevicular fluid (GCF) volume. Twenty dental students participated in this randomized crossover clinical trial. Quigley-Hein (QH) Plaque Index was assessed in six sites per tooth. GCF was measured in 3 teeth. Two experimental periods of 28 days with a 14-day washout were set. Mean values of GCF were calculated and tested by paired sample t-test. Correlations between % QH = O and alterations in GCF were performed. No significant differences were observed between conventional and ionic toothbrushes respectively neither at baseline (.62 +/- .19 vs. .55 +/- .18) nor at 28 days (.44 +/- .12 vs. .47). A negative correlation (-.33) was detected between the increase in % of QH = O and GCF for both brushes. It may be concluded that the performance of an ionic toothbrush does not differ from that of a conventional brush.

Nuclear changes in tongue epithelial cells following panoramic radiography.

This study aimed to investigate the effect of radiation from panoramic radiographs on the cells of the lateral border of the tongue by evaluating nuclear changes. Forty-two patients were included: 22 had one radiograph (Group I), and 20 required a repeat radiograph due to error in the first exposure (Group II). Material for the cytopathologic evaluation was collected before radiographs and 10 days later. Smears were stained with the Feulgen reaction and micronuclei, buds, broken eggs, karyorrhexis and binucleate cells were scored. The comparison of nuclear changes before and after radiation exposure in both groups revealed a statistically higher number of broken eggs, buds, karyorrhexis and binucleate cells 10 days after exposure (P=0.01). The number of karyorrhexis and binucleate cells was greater in group II (P=0.01). There was no change in the frequency of micronuclei before and after the radiographs. Radiation emitted during panoramic radiographs increased the number of nuclear anomalies (except micronuclei) in exfoliated cells of the lateral border of the tongue. This effect was more pronounced when the patients were exposed to a repeat radiograph, without however implying increased risk of irreversible tissue damage.

A clinical trial testing the efficacy of an ionic toothbrush for reducing plaque and gingivitis.

OBJECTIVE: This study was designed to assess the efficacy of an ionic toothbrush on reducing plaque and gingivitis. METHODOLOGY: Twenty first-year dental students were included in the study. Ten individuals were randomly assigned to use either an ionic or a conventional toothbrush. Two periods of 28 days each were used with each brush, with a wash-out period of 14 days. A calibrated examiner used the Quigley-Hein Plaque Index (QHI) and Gingival Bleeding Index (GBI) on six sites per tooth, on all teeth, both pre- and post-brushing. The examiner was unaware of the toothbrush used by the subjects. Means were calculated, and for intra and inter-group comparisons a paired sample t-test was used (alpha = 0.05). RESULTS: On buccal-lingual surfaces, both toothbrushes significantly reduced plaque; there was no statistically significant difference between the two toothbrushes (1.56 and 1.52 for ionic and conventional toothbrushes, respectively). In interdental spaces, an increase of QHI was detected for both brushes, but without significant differences between them. For the GBI on buccal/lingual surfaces, no significant differences were detected between toothbrushes. The GBI did not significantly change for either toothbrush on interdental surfaces during the study period. CONCLUSION: The ionic and the conventional toothbrushes did not present statistically significant differences on plaque and gingival bleeding reductions.