Height difference between the vestibular and palatal walls and palatal width: a cone beam computed tomography approach.

BACKGROUND: The objective of this study was to measure two parameters involved in tri-dimensional implant planning: the position of the buccal and palatal bone wall and the palatal thickness. METHODS: Cone beam computed tomography (CBCT) images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The height difference between the palatal and buccal walls was measured on the most coronal point of both walls. The thickness of the palatal wall was measured 2 mm from the most coronal point of the palatal wall. RESULTS: The mean values in the maxilla were 1.7 ± 0.9 mm for central and lateral incisors, 2.2 ± 1.7 mm for canines, 1.6 ± 0.9 mm for premolars and 1.9 ± 1.5 mm for molars. In the lower jaw, the mean values were 1.3 ± 0.8 mm for incisors, 1.7 ± 1.2 mm for canines, 2.3 ± 1.3 mm for premolars, and 2.6 ± 1.7 mm for molars. In the upper jaw, more than 55% of maxillary teeth (excluding second premolars and molars) presented mean height differences greater than 1 mm. In the mandible, more than 60% of incisors showed a buccal bone thickness of 1 mm from the apical to lingual aspect. All teeth except the second premolar presented a buccal wall located more than 1 mm more apically than the lingual bone wall. CONCLUSIONS: The buccal bone wall is located more apically (greater than 1 mm) than the palatal or lingual table in most of the cases assessed. The thickness of the palatal or lingual table is also less than 2 mm in the maxilla and mandible, except in the upper canines and premolars and the lower molars.

Relevant Design Aspects to Improve the Stability of Titanium Dental Implants.

Post-extractional implants and immediate loading protocols are becoming much more frequent in everyday clinical practice. Given the existing literature about tapered implants, the objective of this paper was to understand whether implant shape had a direct influence on the results of the insertion torque (IT) and implant stability quotient (ISQ). Seven tapered implant prototypes were developed and distributed into three groups and compared with a control cylindrical implant-VEGA by Klockner Implant System. The implants were inserted into bovine bone type III according to Lekholm and Zarb Classification. The sample size was n = 30 for the three groups. Final IT was measured with a torquemeter, and the ISQ was measured with Penguin Resonance Frequency Analysis (RFA). Modifications done to the Prototype I did not reveal higher values of the ISQ and IT when compared to VEGA. In the second group, when comparing the five prototypes (II-VI) with VEGA, it was seen that the values of the ISQ and IT were not always higher, but there were two values of the ISQ that were statistically significantly higher with the 4.0 mm diameter Prototypes II (76.3 ± 6.1) and IV (78 ± 3.7). Prototype VII was the one with higher and significant values of the ISQ and IT. In both diameters and in both variables, all differences were statistically significant enough to achieve the higher values of primary stability values (IT and ISQ). Given the limitations of this study, it can be concluded that when there is an increase of the diameter of the implant and body taper, there is an increase of the ISQ and IT, showing that the diameter of the implant is an important criteria to obtain higher values of primary stability.

Repeatability of the resonance frequency analysis values in implants with a new technology.

BACKGROUND: Assess the reliability (by means of reproducibility and repeatability) of the PenguinRFA system, analyse the ISQ values of different implant types and correlate the ISQ with the insertion torque during the placement of the implant. MATERIAL AND METHODS: 120 rough surface implants were placed in bovine bone (type II and III). The implants were divided into groups, according to its design. Once the implants were in place, the exact insertion torque was registered. Then, primary stability was measured by means of the resonance frequency analysis with the PenguinRFA and the Osstell ISQ devices. In each implant two transducers of each device were used. Three measurements were obtained with each transducer. RESULTS: The mean ISQ (implant stability quotient) of the whole sample is 67,70 ± 5,51. The Intraclass Correlation Coefficient (ICC) is 0,933 and 0,944 for transducers 1 and 2 respectively. The reproducibility is 0,906. The mean insertion torque is 24,54 ± 8,96N. The correlation between the ISQ and the insertion torque is 0,507 p<0,000 (MultiPeg 1) and 0,468 p<0,000 (MultiPeg 2) for bone type II and 0,533 p<0,801 (MultiPeg 1) and 0,193 p<0,140 (MultiPeg 2) for bone type III. CONCLUSIONS: The results of the present trial suggest that the PenguinRFA presents excellent reproducibility and repeatability, so it could be very useful in the monitoring of the stability of implants over time. Additionally, according to the results, the correlation between the IT and the RFA is low and there are no statistically significant differences in between implant types.

Thickness of the buccal bone wall and root angulation in the maxilla and mandible: an approach to cone beam computed tomography.

BACKGROUND: The objective of this paper is to anatomically describe the bone morphology in the maxillary and mandibular tooth areas, which might help in planning post-extraction implants. METHODS: CBCT images (Planmeca ProMax 3D) of 403 teeth (208 upper teeth and 195 lower teeth) were obtained from 49 patients referred to the Dental School of Seville from January to December 2014. The thickness of the facial wall was measured at the crest, point A, 4 mm below, point B, and at the apex, point C. The second parameter was the angle formed between the dental axis and the axis of the basal bone. RESULTS: A total of 403 teeth were measured. In the maxilla, 89.4% of incisors, 93.94% of canines, 78% of premolars and 70.5% of molars had a buccal bone wall thickness less than the ideal 2 mm. In the mandible, 73.5% of incisors, 49% of canines, 64% of premolars and 53% of molars had < 1 mm buccal bone thickness as measured at point B. The mean angulation in the maxilla was 11.67 ± 6.37° for incisors, 16.88 ± 7.93° for canines, 13.93 ± 8.6° for premolars, and 9.89 ± 4.8° for molars. In the mandible, the mean values were 10.63 ± 8.76° for incisors, 10.98 ± 7.36° for canines, 10.54 ± 5.82° for premolars and 16.19 ± 11.22° for molars. CONCLUSIONS: The high incidence of a buccal wall thickness of less than 2 mm in over 80% of the assessed sites indicates the need for additional regeneration procedures, and several locations may also require custom abutments to solve the angulation problems for screw-retained crowns.

Unravelling the effect of macro and microscopic design of dental implants on osseointegration: a randomised clinical study in minipigs.

Several dental implants are commercially available and new prototype design are constantly being fabricated. Nevertheless, it is still unclear what parameters of the design affect most the osseointegration of dental implants. The purpose of this study is to assess the effects of the microscopic and macroscopic design of dental implants in the osseointegration by comparing three macroscopic designs (Straumann tissue level (STD), essential cone (ECD) and prototype design (PD)) and six surface treatments. A total of 96 implants were placed in 12 minipigs. The implant stability quotient (ISQ), was assessed at the time of implantation, as well as at 2, 4 and 8 weeks. Histomorphometric and statistical analyses were conducted at the different sacrifice times, being 2, 4 and 8 weeks, to analyse the bone to implant contact (BIC), the bone area density (BAT) and the density of bone outside the thread region (ROI). The macroscopic design results showed higher ISQ values for the ECD, whereas the histomorphometric analysis showed higher ossoeintegration values for the STD. Regarding the microscopic design, both Sandblasted plus acid etching (hydrochloric/sulphuric acid) in a nitrogen atmosphere (SLActive) and Shot-blasted or bombarded with alumina particles and posterior alkaline immersion and thermal treatment (ContacTi) showed superior results in terms of osseointegration and reduced the osseointegration times from 8 weeks to 4 weeks compared to the other analysed surfaces. In conclusion, each of the macroscopic and microscopic designs need to be taken into account when designing novel dental implants to enhance the osseointegration process.

Comparative analysis of 2 resonance frequency measurement devices: Osstell Mentor and Osstell ISQ.

OBJECTIVE: Comparing reliability of Osstell Mentor and Osstell ISQ in implant stability measurement, and assessing whether their measurements are comparable. MATERIALS AND METHOD: Implant stability was measured with both devices on 58 implants in 15 patients. Six measurements were completed with each device with 2 different transducers (3 measurements with each transducer), that is, 12 measurements for each implant. RESULTS: Mean implant stability quotient (ISQ) value with Osstell ISQ was 72.59, 72.47, and 73.17 in the first measurements, respectively. With Osstell Mentor, the results were 72.43, 72.60, and 73.26, respectively; mean ranges were 3.37, 3.60, and 3.75, respectively. However, mean value with Osstell ISQ and Osstell Mentor was 72.87 and 72.04, respectively. The intraclass correlation coefficient was 0.98. This means an almost perfect degree of concordance between both devices. CONCLUSIONS: Resonance frequency analysis systems in Osstell Mentor and Osstell ISQ show almost perfect reproducibility and repeatability.

High prevalence of apical periodontitis amongst smokers in a sample of Spanish adults.

AIM: To study the prevalence of apical periodontitis in smoker and nonsmoker patients. METHODOLOGY: In a cross-sectional study, the records of 180 subjects, 109 smokers and 71 nonsmokers, were examined. All participants underwent a full-mouth radiographic survey incorporating 14 periapical radiographs. The periapical region of all teeth, excluding third molars, was examined. Periapical status was assessed using the Periapical Index score. Statistical analyses were conducted using the Cohen's Kappa test, analysis of variance and logistic regression. RESULTS: Apical periodontitis in at least one tooth was found in 74% of smokers and in 41% of nonsmokers (P < 0.01; odds ratio = 4.2; 95% C. I. = 2.2-7.9). Amongst smoker patients 5% of the teeth had apical periodontitis, whereas in nonsmoker subjects 3% of teeth were affected (P = 0.008; odds ratio = 1.5; 95% C. I. = 1.1-2.1). The percentage of root filled teeth in smoker and nonsmoker patients was 2.5% and 1.5%, respectively (P < 0.05; odds ratio = 1.7; C. I. 95% = 1.0-2.6). CONCLUSIONS: In this study population, smoking was significantly associated with a greater frequency of root canal treatment and with an increased prevalence of apical periodontitis.

Radiological assessment of periapical status using the periapical index: comparison of periapical radiography and digital panoramic radiography.

AIM: To compare the use of periapical radiographs and digital panoramic images displayed on monitor and glossy paper in the assessment of the periapical status of the teeth using the periapical index (PAI). METHODOLOGY: A total of 86 subjects were examined. All participants underwent a full-mouth radiographic survey (14 periapical radiographs) and a panoramic radiography. The periapical status, using the PAI score, of all appraised teeth was assessed. RESULTS: Periapical radiographs allowed the assessment of the periapical status of 87% of teeth using the PAI. On the contrary, digital radiography had a significantly reduced potential to allow assessment of the periapical status (P<0.01). Only 57.6% and 34.1% of teeth could be appraised using digital panoramic images displayed on monitor and glossy paper respectively (P<0.01). The total percentage of teeth with periapical pathosis was five fold higher when assessed with digital panoramic images displayed on glossy paper compared with periapical radiographs (P<0.01). CONCLUSIONS: Teeth were best viewed on periapical radiographs except maxillary second and third molars, which were better viewed in orthopantomograms. Orthopantomograms on screen were scorable more often than when on printed images. Apical periodontitis was scored more often on paper than on screen, and more often on screen than in periapical radiographs.

High prevalence of apical periodontitis amongst type 2 diabetic patients.

AIM: To study the prevalence of AP in patients with and without type 2 diabetes mellitus. METHODOLOGY: In a retrospective cohort study, the records of 38 subjects with diabetes and 32 control subjects were examined. All participants underwent a full-mouth radiographic survey incorporating 14 periapical radiographs. The periapical region of all teeth, excluding third molars, was examined. Periapical status was assessed using the periapical index score. Statistical analyses were conducted using the Cohen's kappa test, analysis of variance and logistic regression. RESULTS: Apical periodontitis in at least one tooth was found in 81.3% of diabetic patients and in 58% of control subjects (P = 0.040; OR = 3.2; 95% CI = 1.1-9.4). Amongst diabetic patients 7% of the teeth had AP, whereas in the control subjects 4% of teeth were affected (P = 0.007; OR = 1.8; 95% CI = 1.2-2.8). CONCLUSIONS: Type 2 diabetes mellitus is significantly associated with an increased prevalence of AP.

Periapical status and quality of root fillings and coronal restorations in an adult Spanish population.

AIM: To investigate the quality of root fillings and coronal restorations and their association with periapical status in an adult Spanish population. METHODOLOGY: A total of 180 subjects, aged 37.1 +/- 15.7 years, who presented as new patients at the Faculty of Dentistry, Seville, Spain, were examined. All participants underwent a full-mouth radiographic survey incorporating 14 periapical radiographs. The periapical region of all root filled teeth, excluding third molars, were examined. The technical quality of root fillings was evaluated in terms of length in relation to the root apex and lateral adaptation to the canal wall. Radiographic signs of overhang or open margins associated with coronal restorations were also evaluated. Periapical status was assessed using the Periapical Index score. Statistical analyses were conducted using the Cohen's kappa test and logistic regression. RESULTS: The total number of root filled teeth was 93, and 60 (64.5%) had apical periodontitis (AP). Presence of AP in root filled teeth was associated with inadequate adaptation of the filling (OR = 2.29; P = 0.06), inadequate length of the root filling (OR = 2.44; P = 0.048), and with poor radiographic quality of the coronal restoration (OR = 2.38; P = 0.054). Only 34.4% of the root fillings were adequate from a technical perspective. When both root fillings and coronal restorations were adequate the incidence of AP decreased to 31.3% (OR = 5.50; P < 0.01). CONCLUSIONS: The incidence of AP in root filled teeth was high. Many root fillings were technically unsatisfactory. Adequate root fillings and coronal restorations were associated with a lower incidence of AP; an adequate root filling had a more substantial impact on the outcome of treatment than the quality of the coronal restoration.

Prevalence of apical periodontitis and frequency of root-filled teeth in an adult Spanish population.

AIM: To estimate the prevalence of teeth with apical periodontitis (AP) and root-filled teeth in an adult Spanish population. METHODOLOGY: A total of 180 subjects, aged 37.1 +/- 15.7 years, presenting as new patients to the Faculty of Dentistry, Seville, Spain, were examined. All participants underwent a full-mouth radiographic survey (14 periapical radiographs). The frequency of root canal treatment and the periapical status of all teeth, using the periapical index (PAI) score, were assessed. An intraobserver agreement test on PAI scores produced a Cohen's kappa of 0.77 (substantial agreement). Results were analysed statistically using the Chi-square test. RESULTS: Apical periodontitis in one or several teeth was found in 110 subjects (61.1% prevalence), and 73 (40.6% prevalence) had at least one root-filled tooth. Among subjects with root-filled teeth, 48 (65.8%) had AP affecting at least one root-filled tooth. A total of 4453 teeth were examined, of these 186 (4.2%) had AP. The total number of root-filled teeth was 93 (2.1%), of which 60 (64.5%) had AP. Among non-root filled teeth, only 2.9% had AP. The prevalence of AP in connection with molar teeth was higher (5.5%) than for premolar (4.5%) and anterior teeth (3.2%; P < 0.01). More premolar and molar teeth were root-filled (2.8 and 2.7%, respectively) than anterior teeth (1.3%; P < 0.01). The prevalence of AP increased with age. CONCLUSIONS: The prevalence of AP in root-filled and untreated teeth, and the frequency of root-filled teeth were comparable to those reported in previous similar studies carried out in European countries. The prevalence of root-filled teeth with AP was found to be higher compared to that demonstrated in other epidemiological studies.