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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., (© 2023 Wiley Periodicals LLC.)

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.

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., (© 2021 The Korean Academy of Prosthodontics.)

Background: Bone tissues may undergo remodeling under functional mechanical stimuli., Purpose: This prospective study on implant-supported fixed complete dentures (IFCDs) evaluated the radiographic trabecular bone changes in density by means of gray levels and texture analysis variables after up to 3-year loading., Materials and Methods: The sample consisted of digital periapical radiographs of 63 distal implants of hybrid IFCDs installed in 30 patients (22 women, mean age of 62 ± 7.8 years). Digital periapical radiographs were taken after prosthesis installation, and 1 and 3 years after IFCD loading. Longitudinal images of each implant were superimposed, and the same regions of interest were selected for measurement of gray levels statistics (mean gray levels, SD, and coefficient of variation [CV]) and texture parameters (correlation, contrast, entropy, and angular second moment). Data were analyzed by mixed regression models., Results: Mean gray levels increased for 1 year (P < .05), for 3 years (P < .01) and for maximum bite force (P < .01). The interaction between bruxism and time in 1 year was significant (P < .01) for a decrease in CV. No significant effect of texture analysis variables was found (P > .05)., Conclusions: The results suggest an increase of radiographic bone density as measured by an increase in mean gray levels and a decrease in CV in IFCD distal implants up to 3 years of loading., (© 2019 Wiley Periodicals, Inc.)

This clinical study evaluated the early effect of oral rehabilitation with dental implants and nocturnal bruxism on maximum occlusal force (MOF), before sensorimotor adaptation. A consecutive sample consisted of 127 patients divided into three groups according to their dental state: G1- implant-supported fixed complete denture (IFCD) opposing to a small fixed prosthesis or natural dentition; G2- IFCD opposing to a complete denture; and G3- small fixed prosthesis or natural dentition in both arches. Clinical data were collected after prosthesis installation: systemic and oral health conditions, MOF, self-reported bruxism, and bruxism severity (low, moderate, severe). Data were analysed by ANOVA and Tukey-Krammer tests. Dental state and the interaction sex-bruxism had significant effect on MOF. G1 had higher MOF than G3, but G2 was not significantly different from G1 and G3. Men with bruxism had the highest MOF. The levels of bruxism severity did not have a significant effect on MOF. The results suggest that MOF varies as a function of dental state and the interaction sex-bruxism. However, presence and severity of bruxism alone does not affect MOF., (Copyright© 2019 Dennis Barber Ltd.)

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.

Purpose: To investigate whether the inclination of the most distal implant and the cantilever length influence marginal bone loss in implant-supported fixed complete dentures (ISFCDs)., Materials and Methods: A novel method using computed tomography images was developed to measure the mesiodistal implant inclination. The cantilever length was measured during ISFCD fabrication. Radiographs were obtained after ISFCD installation at 1 and 3 years after loading., Results: A total of 30 subjects with 62 implants were included. Accumulated marginal bone loss was 0.35 ± 0.49 mm. No significant association was found between marginal bone loss and cantilever length or implant inclination., Conclusion: Implant inclination and cantilever length do not seem to affect marginal bone loss.

Objectives: This prospective cohort study estimated the effect of technical and clinical factors on mechanical complications in implant-supported fixed complete dentures (IFCDs). The patient's perception of the impact of oral rehabilitation on quality of life was assessed., Material and Methods: A non-probabilistic sample consisted of 88 consecutive patients treated with 94 screw-retained, metal-acrylic IFCDs. Data collection included sociodemographic variables, presence and intensity of bruxism, maximal occlusal force, opposing arch, design of the metallic framework, distribution of occlusal contacts, and quality of life (OHIP-14). IFCD-level data were analyzed using Kaplan-Meier survival analysis and Cox regression model. Quality of life data were analyzed by paired Student t test., Results: During a mean follow-up of 35.1 ± 18.3 months, 16/94 IFCDs (17%) had repairable mechanical complications because of loosening/fracture of artificial teeth (n = 15) and screw loosening (n = 1). Framework design (retention pins <4 mm) was a significant risk factor for complications (HR = 11.038; p = 0.027) when adjusted for sex. Mechanical complications were not associated with sex, body mass index, thickness of the acrylic resin veneering, type of opposing arch, distribution of occlusal contacts and force, protrusion interference, presence/intensity of bruxism or maximal occlusal force. OHIP-14 total scores decreased after IFCD treatment for both patients with or without complications., Conclusions: Within the limitations of this study, the results suggest that clinical success is associated to framework design with retention pins equal or longer than 4 mm. Quality of life improved with IFCD treatment, even in patients with mechanical complications., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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.

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., (© 2017 Wiley Periodicals, Inc.)

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.

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.

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.

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.