Mandibular Dental Implants Research Articles

The sensitivity of bone conduction for dental implants.

Dental implants are connected to the alveolar bone by osseointegration. Dental implants could be used as a potential bone conduction (BC) hearing assistive device in the mouth. However, the BC threshold of dental implants has not been reported. The present study aimed to examine the pure tone auditory thresholds of normal human subjects to BC stimulation of the implants. Dental implants showed a significantly lower BC threshold than natural teeth and mastoids. Mandibular dental implants had BC sensitivity similar to that of maxillary dental implants. The BC threshold of anterior dental implants was significantly lower than that of posterior dental implants. Dental implants exhibited excellent BC properties.

Effect of Anatomical Location of Dental Implants in the Mandible on Generation of Metal Artifacts on Cone-Beam Computed Tomography Scans

Background: Metal artifacts are the major weak points of cone-beam computed tomography (CBCT) scans. This study aimed to quantify the amount of metal artifacts generated by dental implants placed in different anatomical locations in the mandible on CBCT scans. Methods: In this study, 98 CBCT scans of mandibular dental implants with prosthetic crowns were randomly selected irrespective of the age and gender of the patients. Of all 98 implants, 42 were placed in the anterior mandible and 56 were placed in the posterior mandible. The samples were divided into two groups of single and multiple implants. The CBCT scans of each implant were evaluated in apical and cervical cross-sections. The amount of metal artifacts generated around the implants was calculated. Data were analyzed using the Mann-Whitney U test at 0.05 level of significance. Results: Higher amounts of artifacts were noted in the anterior mandible compared to the posterior mandible. Additionally, the amount of artifacts was higher in the cervical cross-section than in the apical cross-section. The difference in the amount of artifacts generated in the cervical cross-section was significant between single and multiple implants (P<0.05). However, this difference was not significant in the apical cross-section (P>0.05). Conclusions: Dental implants always generate metal artifacts on CBCT scans, and the amount of generated artifacts is influenced by the anatomical location of implants in the mandibular arch.

A retrospective study in a comprehensive assessment of the various systemic factors of Iraqi patients receiving dental implants

In this study, 220 patients from different hospitals in Iraq and distribution Lost follow-up implants and Failed implants of the patient's study for four years, 300 implants. Study showed 220 participants were included, and the average age ranged between 40-60 years with a mean value and standard deviation of 48±7.8.0 This study was designed by adopting an analysis approach for all factors affecting dental implants, and the results were analysed according to the statistical analysis program IBM SPSS Soft. The quality of life (WHO QOL-BREF) was also measured for the purpose of conducting a comprehensive assessment of the various systemic factors of Iraqi patients receiving dental implants. The results which found to be distributed according to gender for 130 male patients with 59.09%, females for 90 patients with 40.09%, Implant insertion torque range achieved in no. of cases (Maxillary dental implants with No. of implants placed 30 for 30±4.9 N and 40 No. of implants placed with Implant insertion torque range achieved in no. of cases 45±7.7 N), (Mandibular dental implants with No. of implants placed for 40 (Implant insertion torque range achieved in no. of cases 34±3.4), (Mandibular dental implants with No. of implants placed 175 and Implant insertion torque range achieved in no. of cases 47±6.6) The effect of dental implants on the quality of life of patients was also identified, and a statistically significant relationship was found at a p-value < 0.05

Bone Loss Evaluation by Cone Beam Computed Tomography Postdental Implant Placement: An Original Research.

Introduction:The success of the prosthetic rehabilitation is a factor of the periodontal reactions. Hence, in the current study, we aim to assess bone loss in the osseointegrated implants posttreatment by the cone beam computed tomography (CBCT) imaging.Materials and Methods:We conducted a prospective clinical observational study among 50 subjects who received mandibular dental implants for the replacement of the single lost anterior tooth. The follow-up was done at 1 week, 2 weeks, and after 6 weeks. The bone loss around the implant was noted by imaging with CBCT. The values were compared and analyzed statistically.Results:We observed a significant variation among the genders and the age groups. The mean bone loss around the implants was statistically significant for the different time intervals (P = 0.001).Conclusion:Significant bone loss was noted in the first few weeks after implantation. Care should be focused in the initial posttreatment phase to eliminate the factors aggravating the periodontitis.

Ectopic Laryngeal Ossification after Bone Morphogenetic Protein-2.

We report two cases of ectopic bone formation in the head and neck following treatment with recombinant human bone morphogenetic protein-2 (rhBMP-2). Surgical pathologic data, laryngoscopy imaging, CT imaging, and patient medical history were obtained. First, we report osseous metaplasia in the vocal fold in a 67-year-old male following mandibular dental implants with rhBMP-2; second, a case of severe bony overgrowth of the larynx and fusion to the anterior cervical spine (ACS) in a 73-year-old male following multiple anterior cervical discectomies and fusions with rhBMP-2. Ectopic bone formation following rhBMP-2 has been previously reported. Adverse events like local swelling and edema leading to dysphagia and even airway obstruction after cervical spine application of rhBMP-2 have also been widely reported. Due to the uncommon nature of abnormal bony growth in soft tissue areas of the head and neck and the previously documented adverse effects of rhBMP-2 use, especially in the cervical spine, we consider the two unusual case presentations of ectopic bony formation highly likely to be linked with rhBMP-2. We urge awareness of the adverse effects caused by rhBMP-2, and urge caution in dosing.

Biomechanical evaluation of stress distributions at the implant-abutment complex and peri-implant bone around mandibular dental implants with different neck geometries and inclinations.

This study aimed to investigate the effects of the different dental implant neck designs, diameters, and inclinations, on the stress distributions at the mandibular crestal bone and implant-abutment complex, using three-dimensional (3D) finite element stress analysis (FEA) method. Finite element models of three-unit fixed partial dentures supported with two same length implants (10 mm), placed on the second premolar and second molar regions, were designed. Eight different models were designed according to the implants' neck designs (platform switching/traditional), diameters (4.1 mm/4.8 mm) and the tilting angles of the posterior implants (0°/15°). The anterior implants' widths were 4.1 mm and the neck design of the anterior implants matched the posterior implants. Two types of 100-N loads in vertical and 30° oblique directions were applied separately onto each central fossae and functional cusps of the fixed partial dentures crowns. Algor Fempro Software was used for the simulation and evaluation of the stress levels at the implant-abutment complex and the crestal bone. Stress levels measured at the crestal bone were found to be lower for the platform switching models. However, the platform switching design generated higher stress magnitudes within the implant-abutment complex. Inclined placement of posterior implants increased the amount of stress at the crestal bone around both implants. Biomechanically, selection of the largest diameter possible when using tilted platform switched implants may be recommended at the posterior mandible.

Clinical outcomes of flap versus flapless immediately loaded single dental implants in the mandibular posterior region: One-year follow-up results from a randomized controlled trial

Statement of problemFlapless implant placement with immediate functional loading has been reported in anterior locations. However, data on posterior locations are lacking. PurposeThe purpose of this randomized controlled trial was to determine and compare clinical outcomes of flap versus flapless surgically placed single posterior mandibular dental implants subjected to immediate functional loading. Material and methodsParticipants with missing mandibular first molar teeth were recruited and randomized into 2 groups (n=51): flapped and flapless. Dental implants were surgically placed and loaded immediately with interim restorations following implant protective occlusion. Outcome measures were implant failure, crestal bone loss, and periodontal parameters: modified plaque index, modified sulcus bleeding index, and pocket depths. Outcome data were recorded at baseline, 6-month, and 12-month follow-up visits. Cone beam computed tomography scans were used to calculate crestal bone loss, and periodontal outcomes were recorded by using a resin covered periodontal probe (α=.05). ResultsAfter 12 months, similar implant failure rates (P>.05) were found between the groups. Crestal bone loss in the flapped group was statistically higher than in the flapless group at 6 months (0.83 ±0.21 mm versus 0.75 ±0.23 mm) and at 12 months (1.04 ±0.27 mm versus 0.90 ±0.24 mm) from the baseline. The modified plaque index, modified sulcus bleeding index, and peri-implant probing depths (PDs) in both groups increased from the baseline to 6-month follow-ups (Baseline modified plaque index: 0.82 ±0.54 versus 0.79 ±0.21; Baseline modified sulcus bleeding index: 0.74 ±0.21 versus 0.70 ±0.43; Baseline PD: 1.25 ±0.37 mm versus 1.20 ±0.22 mm; 6 months modified plaque index: 1.54 ±0.70 versus 1.21 ±0.45; 6 months modified sulcus bleeding index: 1.93 ±0.54 versus 1.51 ±0.61; 6 months PD: 3.20 ±0.73 mm versus 2.80 ±0.43 mm). At 12-month follow-ups after repeated oral hygiene reinforcements, periodontal parameters had improved (decreased) significantly. ConclusionsFlapless implant insertion with immediate functional loading could be considered as an appropriate treatment option for providing functional restorations on the day of implant placement with minimal surgical intervention, reducing crestal bone loss, and periodontal complications.

Immediate implant-supported full-arch hybrid prosthesis on an edentulous patient using a bar-retained overdenture in the mandible: Case Report.

The hybrid prosthesis is a very predictable treatment option that allows patients to recover their oral functionality. It is a good alternative to conventional treatments and overdentures. The present report describes controlled an 80 year old female patient with controlled hypertension, who came for consultation with a bar overdenture with attachment holders on two external hexagonal dental implants; an immediate loading hybrid prosthesis was installed over four mandibular dental implants.

Dental implant navigation system guide the surgery future

No study has investigated the effect of learning curves on the accuracy of dental implant navigation systems. This study evaluated the accuracy of the dental implant navigation system and established the learning curve according to operation site and operating time. Each dental model was used for drilling 3 missing tooth positions, and a patient tracking module was created. The same dentist performed the drilling test for 5 sets of dental models. CT back scanning was performed on the dental models. Customized implants based on the drilled holes were inserted. The relative error between the preoperative planning and actual implant was calculated. Using the dental navigation system could help dentists position implants more accurately. Increasing the frequency with which a dentist used the navigation system resulted in shorter operations. Longitudinal and angular deviation were significantly (P < 0.0001 and P = 0.0164). We found that the same level of accuracy could be obtained for the maxilla and mandible implants. The Student's t test demonstrated that the longitudinal error, but not the total or angular error, differed significantly (P = 0.0012). The learning curve for the dental implant navigation system exhibited a learning plateau after 5 tests. The current system exhibited similar accuracy for both maxillary and mandibular dental implants in different dental locations. The one-way ANOVA revealed that the total, longitudinal, and angular errors differed significantly (P < 0.0001, P < 0.0001 and P = 0.0153). In addition, it possesses high potential for future use in dental implant surgery and its learning curve can serve as a reference for dentists.

Systemic Assessment of Patients Undergoing Dental Implant Surgeries: A Trans- and Post-operative Analysis.

Background:Procedure-related and patient-related factors influence the prognosis of dental implants to a major extent. Hence, we aimed to evaluate and analyze various systemic factors in patients receiving dental implants.Materials and Methods:Fifty-one patients were included in the study, in which a total of 110 dental implants were placed. Complete examination of the subjects was done before and after placement of dental implants. Implant surgery was planned, and osseointegrated dental implants were placed in the subjects. Postoperative evaluation of the dental implant patients was done after 3 weeks. Anxiety levels were determined using State-Trait Anxiety Inventory (STAI) questionnaire on the surgery day and after 1 week of surgery. The participant describes how they feel at the moment by responding to twenty items as follows: (1) absolutely not, (2) slightly, (3) somewhat, or (4) very much. All the results were recorded and statistical analyzed by SPSS software.Results:Out of 51, 29 patients were males while 22 were females, with ratio of 1.32:1. Female patients’ mean age was 50.18 years while male patients’ mean age was 52.71 years, with statistically nonsignificant difference between them. Functional rehabilitation was the main purpose of choosing dental implants in more than 90% of the subjects. Diameter of 3.75 mm was the shortest implants to be placed in the present study, whereas in terms of length, 8.5 mm was the shortest length of dental implant used in the present study. Tooth area in which maximum implants were placed in our study was 36 tooth region. Maximum implants were placed in Type II bone quality (n = 38). Implants installed in the mandible were clamped more efficiently than implants placed in the maxilla (P < 0.001). The difference of average STAI-State subscore before and after the surgery was statistically significant (P < 0.05; significant).Conclusion:Mandibular dental implants show more clamping (torque) than maxillary dental implants.

Radiographic Fractal and Clinical Resonance Frequency Analyses of Posterior Mandibular Dental Implants: Their Possible Association With Mandibular Cortical Index With 12-Month Follow-up.

The aim of the present study was to investigate whether the mandibular cortical index (MCI) has a relationship with fractal dimension of bone and/or implant stability, and to justify the possible association between MCI, fractal dimension, and stability. Eighty-two subjects who received dental implants to replace missing mandibular premolar/molar sites were selected. Three months after surgical placement, implants were restored with fixed ceramic fused metal crowns. MCI was evaluated at baseline; fractal dimensions were measured with fractal analysis (FA) and implant stability quotient (ISQ) with resonance frequency analysis immediately after surgery and 12-month follow-up. FA at mesial and distal regions for Class 1, Class 2, and Class 3 MCI resulted with significant increases at 12-month follow-up compared to baseline. The ISQ in patients with Class 2 and Class 3 MCI resulted with a significant decrease compared to Class 1 MCI at baseline and at 12 months. All MCI classes evaluated with ISQ and FA at baseline values resulted with significant increases at 12 months. Significant correlations were considered for all mandibular posterior implants between baseline and 12-month measurements for ISQ and FA evaluations. Fractal analysis may be a useful method for understanding the healing process around implants and implant stability quotient values. Mandibular cortical index evaluations should be considered before implant procedures, which may provide a presurgical treatment plan and may provide information about the mandibular bone quality.

Implant angulation: 2-year retrospective analysis on the influence of dental implant angle insertion on marginal bone resorption in maxillary and mandibular osseous onlay grafts.

The purpose of this study was to determine the existence of correlations between marginal peri-implant linear bone loss and the angulation of implants in maxillary and mandibular augmented areas over the course of a 2-year survey. Dependent variables described the sample of the present retrospective chart review. By using three-dimensional radiographs, input variables, describing the implant angulation (buccal-lingual angle [φ] and mesial-distal angle [θ]) were measured; outcome variables described survival rate and marginal bone resorption (MBR) around dental implants in autogenous grafts (10 maxillae and 14 mandibles). Pairwise comparisons and linear correlation coefficient were computed. The peri-implant MBR in maxillary buccal and palatal areas appeared less intensive in the presence of an increased angulation of an implant towards the palatal side. Minor MBR was recorded around mandibular dental implants positioned at a right angle and slightly angulated towards the mesial. Resorption in buccal areas may be less intensive as the angulation of placed implants increases towards the palatal area in the maxilla, whereas for the mandible, a greater inclination towards the lingual area could be negative. In the mandibular group, when the implant was slightly angulated in the direction of the distal area, bone resorption seemed to be more marked in the buccal area. In the planning of dental implant placement in reconstructed alveolar bone with autograft, the extremely unfavourable resorption at the buccal aspect should be considered; this marginal bone loss seemed to be very sensitive to the angulation of the dental implant.

The Midline Mandibular Lingual Canal: Importance in Implant Surgery

The study aims to determine if midline mandibular dental implants pose a risk for the midline lingual canal (MLC). Cone beam computed tomography was used to scan 122 mandibles (31 black males; 28 black females; 32 white males and 31 white females). Midsagittal sections in the reconstructed images were made. A measurement of 6 mm across bucco-lingually was delineated as the minimum dimensions for implant placement. In dentate cases with a bucco-lingual distance in excess of 6 mm, the measurement was across the apex of the socket to determine the bone dimension available below the socket for implant placement. From these markers a vertical line was dropped to the MLC to measure the available bone. The MLC was a consistent finding. A statistical significant difference in bone availability among the sexes and dentition pattern was found, indicating that midline implants in edentulous females posed a risk of injury to the vessels of the MLC. Implants in the position of lower central incisors are regarded as a safe procedure. Clinicians should however take note of the position of the midline mandibular lingual canal and approach this area with caution, especially if the alveolar ridge is to be reduced before implant placement.

Immediately Loaded Maxillary and Mandibular Dental Implants with Fixed CAD/CAM Prostheses Using a Flapless Surgical Approach: A Clinical Report

Immediate implant loading is a viable treatment method for selected cases. One of the greatest advantages of this method is the virtual surgery, which precedes the actual clinical treatment and eliminates any need for last minute decisions. The actual surgery time is decreased, since all steps are predetermined. Additionally, no flaps have to be elevated, resulting in preservation of periimplant soft tissues, vascularization of the underlying bone, fewer postoperative complications, and minimal patient discomfort. This article presents a clinical approach made possible due to the evolution of modern scanning techniques and appropriate software.

A study of effectiveness of midazolam sedation for prevention of myocardial arrhythmias in endosseous implant placement

The study aimed to assess electrocardiographic alterations during oral implant placement surgeries under local anesthesia (lidocaine chlorhydrate with epinephrine), using 15 mg of midazolam as an anxiolytic premedication. The study randomly selected 20 patients, aged 21-50 years old, requiring bilateral mandibular dental implants. Each patient was assessed using placebo on one side and midazolam on the contralateral side, with random, double-blinded distribution. The electrocardiogram recorded 12 static leads every 2 min, while D2 derivations were recorded continuously. No statistically significant differences were observed between the placebo and midazolam when analyzing the morphological behavior of the electrocardiographic wave and the presence of arrhythmias during the experiment. However, under sedation, assessment of the behavior of electrocardiographic parameters during different stages of the procedure revealed statistically significant differences (P<0.05) for heart rate, P-wave amplitude and duration of the RR and QTc intervals. The arrhythmias detected were considered low risk for patients without systemic alterations and were observed in 53.3% of patients. The most frequently occurring alterations were tachycardia, bradycardia, supraventricular and ventricular extrasystoles and blocked atrial extrasystole, which were similar for both placebo and midazolam, with the greatest incidence during the initial, incision and bone drilling stages. The use of 15 mg of midazolam made no difference compared with the placebo. The use of 15 mg of midazolam did not show an advantage in the incidence of arrhythmias The anxiolytic premedication does not prevent myocardial arrhythmias in endosseous implant placement. The clinical significance of the arrhythmias may not represent serious risks.

Postinsertion Pain in Region of Mandibular Dental Implants: A Case Report

This report describes the role of severe pain in failure of dental implants. A 27-year-old woman presented to the clinic to replace the missing mandibular right first molar and second premolar. A panoramic radiograph was taken, and a clinical examination was done. A decision was made to extract the mandibular right second molar, which had failing endodontics, and two dental implants were placed. Two days later, the patient reported severe pain in that area. Microscopic examination of the surgical specimen revealed longitudinal section of peripheral nerve in the implant site.

Immediate Loading of Dental Implants in the Anterior and Posterior Mandible: A Retrospective Study of 120 Cases

The objective of this retrospective study was to evaluate the overall success of immediately loaded implants in the mandible. This report focuses on immediately loaded anterior and posterior mandibular implants. A total of 979 patients received 2,904 mandibular dental implants placed from January 2007 to December 2008. One hundred sixty-one of the implants were placed anterior to the mental foramen, and 95 were placed posterior to the mental foramen. All immediately loaded implants were torque tested to 35 N-cm. All were provisionally restored the day of insertion. A total of 256 immediately loaded mandibular dental implants were placed in a 2-year period. Of the 256 immediately loaded implants, 252 integrated and were restored and 4 failed. Of the 4 failed implants, 3 were in the anterior mandible and the fourth was in the posterior mandible. All 4 were replaced, integrated, and have been restored. The survival rate for immediately loaded implants in the anterior mandible was 99.4%, and the survival rate in the posterior mandible was 97%. Immediately loaded implants have predictable clinical success in the anterior and posterior mandible.

A Prospective Follow-up Study of 44 Mandibular Immediately Loaded Implants Using Resonance Frequency Analysis: Preliminary 1-Year Results

This clinical study aimed to evaluate initial, 4-months, and 1-year stability of immediately loaded dental implants inserted according to a protocol of lower rehabilitation with prefabricated bars. The sample was composed of 11 edentulous patients. In each patient, 4 interforaminal implants were inserted. Immediately after implant installation, resonance frequency analysis (RFA) for each fixation was registered as well as after 4 months and 1 year with the prosthetic bar removed as it is a screwed system. The clinical implant survival rate was 100%. The RFA showed an increase in stability after 4 months from 64.09 +/- 6.48 to 64.31 +/- 4.96 and 1 year, 67.11 +/- 4.37. The analysis of variance showed a statistically significant result (P = 0.015) among implant stability quotient values for the different periods evaluated. Tukey test results showed statistically significant differences between 1-year results and the initial periods but there was no statistically significant difference between initial and 4-month results (P > 0.05). These preliminary 1-year results indicate that immediate loading of mandibular dental implants using the studied prefabricated bars protocol is a reliable treatment as it is in accordance with the results described in the literature for other similar techniques.

Five‐year evaluation of the influence of keratinized mucosa on peri‐implant soft‐tissue health and stability around implants supporting full‐arch mandibular fixed prostheses

The question of the importance of keratinized mucosa around dental implants for the prevention of peri-implant disease could not be answered in the relevant literature so far. To investigate the influence of peri-implant keratinized mucosa on long-term peri-implant soft-tissue health and stability over a period of 5 years. A total of 386 mandibular dental implants were placed in 73 completely edentulous patients, and subsequently restored with fixed full-arch prostheses. At prosthesis delivery (baseline) and after 3, 6, 12, 18, 24, 36, 48 and 60 months, modified plaque index (mPlI), modified sulcus bleeding index (mBI), distance between implant shoulder and mucosal margin (DIM) and width of peri-implant keratinized mucosa (KM) were recorded. Statistical analysis included multivariate logistic regression, multivariate ordinal logistic regression, generalized estimating equations and Bonferroni's correction. Fifty-eight patients with 307 implants completed the 5-year study. Statistically significantly higher plaque accumulation on lingual sites (mean mPlI 0.67, SD 0.85), bleeding tendencies on lingual sites (mean mBI 0.22, SD 0.53) and larger soft-tissue recession on buccal sites (mean DIM -0.69 mm, SD 1.11 mm) were found when the width of KM was <2 mm, compared to sites with>or=2 mm of KM (mean mPlI 0.40, SD 0.68, P=0.001; mean mBI 0.13, SD 0.41, P<0.01; mean DIM -0.08 mm, SD 0.86 mm, P<0.001). The width of keratinized mucosa had no effect on bleeding tendency or plaque accumulation on buccal sites (P>0.05). In patients exercising good oral hygiene and receiving regular implant maintenance therapy, implants with a reduced width of <2 mm of peri-implant keratinized mucosa were more prone to lingual plaque accumulation and bleeding as well as buccal soft-tissue recession over a period of 5 years.

PADOM: Device support the construction of a guide for positioning mandibular implants

Many authors agree on the importance of placing dental implants, like other prosthetic restorations, so that the occlusal forces are, ideally, directed along the long axis of the implant body. This helps to preserve the osseointegration and ensures even force distribution over the various supporting screw threads. The authors propose an innovative tool that allows the production of surgical templates, which can optimise the placement of mandibular dental implants, whilst also respecting established geometric and biomechanical concepts.