The use of an artificial intelligence-driven novel tool for the evaluation of dental implants primary stability and immediate loading feasibility: an in vitro pilot study

PURPOSE

The primary aim of this study is to evaluate the correspondence between an Artificial Intelligence driven new tool prediction and the clinician's evaluation in the immediate loading suitability of curves recorded during implant insertion in an in vitro test. The secondary aim is to analyse peak insertion torque (pIT) and variable torque work (VTW) values of the implants used for the in vitro study.

MATERIAL AND METHODS

The study was performed on artificial bone blocks of solid rigid polyurethane without cortical layer with four different densities. Five types of implants with different macrogeometries were used. A total of 140 implants (7 implants of each type in the four polyurethane blocks) were inserted. Immediately after implant placement the insertion curves were classified by the operator as suitable or non-suitable for immediate loading. In a second moment the same curves were analyzed by the new AIT that classified them as belonging to YES or NO class. For each implant pIT and VTW were also recorded.

RESULTS

The correspondence between surgeon and AIT evaluation was 99,3% with only one false-negative reported by the algorithm analysis. The sensitivity resulted 98.95%, the specificity 100%, positive predictive value 100% and negative predictive value 97.8%. Mean pIT of the whole sample was 34.19 + 19.43 Ncm while mean VTW was 2266.89 + 1993.73 Ncm. Statistically significant differences were found between implant systems in the whole sample and when divided by polyurethane block density.

CONCLUSIONS

AIT showed a high level of accuracy in the prediction of immediate loading suitability of insertion curves examined. All the implants used in the in vitro test were able to reach good levels of primary stability, excluding when inserted in the less dense polyurethane block. Clinical studies conducted in larger samples and with more surgeons involved are necessary to confirm these results.

Primary Stability Evaluation of a Novel Tapered Implant Inserted in Low-Density Bone Sites: An In Vitro Study

Purpose: To evaluate primary stability of a new dental implant design in low-density bone sites, compare it with another implant design previously studied in the same bone density, and explore possible correlations between primary stability parameters. Materials and Methods: The study was carried out on fresh humid bovine bone classified as type III. The test group consisted of 30 DS Prime Taper implants (PT), and the control group consisted of 30 Astra Tech EV implants (EV). All the implants were inserted according to the protocol provided by the manufacturer. After placement, variable torque work (VTW), peak insertion torque (pIT), and resonance frequency analysis (RFA) were recorded. Results: Mann-Whitney test showed that the mean VTW and pIT were significantly higher in the test group PT compared to the control group EV; furthermore, statistical analysis showed that the mean RFA was slightly higher in the control group EV but without reaching statistical significance. Pearson correlation analysis showed a very strong positive correlation between pIT and VTW values in both groups; furthermore, it showed a positive correlation between pIT and RFA values and between VTW and RFA values again in both groups. Conclusion: The results showed that the novel tapered implants were able to reach good primary stability in low-density bone sites and that this was superior to parallel-walled implants when measured with VTW and pIT. Moreover, a statistically significant correlation was found between the three methods used to measure implant primary stability.

Influence of Stepped Osteotomy on Primary Stability of Implants Inserted in Low-Density Bone Sites: An In Vitro Study

PURPOSE

The aims of this study were to evaluate the ability of a stepped osteotomy to improve dental implant primary stability in low-density bone sites and to investigate possible correlations between primary stability parameters.

MATERIALS AND METHODS

The study was performed on fresh humid bovine bone classified as type III. The test group consisted of 30 Astra Tech EV implants inserted following the protocol provided by the manufacturer. The first control group consisted of 30 Astra Tech EV implants inserted in sites without the underpreparation of the apical portion. The second control group consisted of 30 Astra Tech TX implants inserted following the protocol provided by the manufacturer. Implant insertion was performed at the predetermined 30 rpm. The insertion torque data were recorded and exported as a curve; using a trapezoidal integration technique, the area underlying the curve was calculated: this area represents the variable torque work (VTW). Peak insertion torque (pIT) and resonance frequency analysis (RFA) were also recorded.

RESULTS

A Mann-Whitney test showed that the mean VTW was significantly higher in the test group compared with the first control and second control groups; furthermore, statistical analysis showed that pIT also was significantly higher in the test group compared with the first and second control groups. Analyzing RFA values, only the difference between the test group and second control group showed statistical significance. Pearson correlation analysis showed a very strong positive correlation between pIT and VTW values in all groups; furthermore, it showed a positive correlation between pIT and RFA values and between VTW and RFA values only in the test group.

CONCLUSION

Within the limitations of an in vitro study, the results show that stepped osteotomy can be a viable method to improve implant primary stability in low-density bone sites, and that, when a traditional osteotomy method is performed, RFA presents no correlation with pIT and VTW.

Marginal bone loss around implants with platform-switched Morse-cone connection: a radiographic cross-sectional study

OBJECTIVES

The aims of the present cross-sectional study are to evaluate the bone remodeling around Morse-cone implants placed subcrestally 1 year after loading and the prevalence of bone loss >0.5 mm after at least 3 years of loading.

MATERIAL AND METHODS

Subjects who underwent a radiographic check in 2013 with implants that had been in function for at least 3 years were considered for inclusion. The study population comprised of 145 subjects with a total of 523 implants. At the moment of insertion, all the implants were placed subcrestally from 1 to 3 mm as clinically measured. Radiographs taken at baseline, that is 1 year after loading (T0), and at the follow-up visit in 2013 (T1) were examined. The distance between the rim of the implant and the marginal bone level at mesial and distal aspects of each implant was determined and the mean bone loss calculated.

RESULTS

In the total sample, the mean bone loss occurred between baseline and 2013 examination was 0.42 ± 0.77 mm; at T1 424 implants presented the marginal bone level at the implant rim (78) or above it (346). On the other hand, 99 implants presented the rim above the bone crest. Fifty-one implants that at T1 presented the rim above the bone crest, and that between T0 and T1 had lost at least 0.5 mm, were considered losers: 10 implants lost up to 0.5 mm, 11 lost from 0.6 to 1 mm, 16 lost from 1.1 to 2 mm, and 14 lost more than 2 mm of bone. On a subject basis, 34 subjects (group A) with a total of 200 implant sites presented loser implants, while 111 subjects (group B) with 323 implants displayed non-loser implants.

CONCLUSIONS

Within the limits of a cross-sectional study, the results show that Morse-cone implants placed subcrestally in the vast majority of cases (89.9%) are able to maintain the bone crest at level of the rim or above it 1 year after loading. The incidence of loser sites (bone loss >0.5 mm) after at least 3 years of follow-up is 9.7% at implant level and 23.5% at patient level.

Development of a new implant primary stability parameter: insertion torque revisited

PURPOSE

The aims of the study are to introduce a new parameter to measure primary stability and to evaluate the possible correlations between this parameter and bone density, initial bone-to-implant contact (IBIC), Resonance Frequency Analysis (RFA), and peak insertion torque (IT).

MATERIAL AND METHODS

The study was performed on three different types of fresh humid bovine bone: type I, type II, and type III. A total of 90 XiVE implants (30 per bone type) were used; implant insertion was performed with a calibrated maximum torque of 70 Ncm at predetermined 30 rpm. The IT data were recorded and exported as a curve; using a trapezoidal integration technique, the area underlying the curve was calculated: this area represents the variable torque work (VTW). Furthermore, peak IT and RFA were recorded; finally IBIC was calculated from histological specimens.

RESULTS

Spearman correlation analysis of the entire sample reveals that VTW presents a significant (p < .01) positive correlation with bone density; a significant (p < .05) positive correlation with IBIC, and a significant (p < .01) positive correlation with all the other primary stability parameters. Spearman correlation analysis of the three different groups show that VTW presents a significant positive correlation with IT in all three types of bone; on the other hand, VTW shows a negative not significant correlation with RFA in bone I, a positive significant correlation in bone II, and a positive not significant correlation in bone III. Furthermore, VTW shows a negative significant correlation with IBIC in bone I and a positive significant correlation in bone II and III.

CONCLUSIONS

Within the limitations of an in vitro study, the VTW seems to be a promising parameter to measure implant primary stability.

Failure after closed traction of an unerupted maxillary permanent canine: Diagnosis and treatment planning

This report describes the treatment of a 13-year-old girl with unerupted maxillary permanent canines. It illustrates how recognizing an unexpected problem influenced the decision-making process. Despite 6 months of closed-eruption traction, the left canine had not erupted. However, the neighboring teeth were intruded, suggesting a diagnosis of canine ankylosis. When the site was surgically reopened, the wire chain used for the orthodontic traction appeared to be osseointegrated. It was renewed, and traction was applied for another 16 months, and the tooth was successfully brought into the arch. Bone tissue passing through the chain might have prevented forced eruption. In young patients with unerupted maxillary permanent canines, failure of closed traction can be attributed to ankylosis, and this accounts for tooth extraction as the treatment of choice. However, this clinical report suggests that additional measures might be warranted before the definitive diagnosis of ankylosis can be made and the tooth extracted.

Primary stability determination by means of insertion torque and RFA in a sample of 4,135 implants

OBJECTIVES

The aims of the present study are to evaluate the primary stability of a sample of 4,135 implants and to investigate the correlations between primary stability and mechanical characteristic of the implant and bone density at insertion time.

MATERIAL AND METHODS

The study was conducted from March 2002 to January 2009 at a private practice in Bologna (Italy). Patients were eligible for the study if they needed the insertion of single or multiple implants. Bone density, length, and diameter of each implant were recorded. During surgery for each implant, peak insertion torque (IT) was recorded; the resonance frequency analysis (RFA) values were also collected. Finally, it was recorded whether an implant was lost or removed at an early stage (within 6months from insertion surgery).

RESULTS

A total of 1,045 consecutive patients were included in the study. A total of 4,135 of implants were inserted. The sample presented 1,184 implants inserted in a postextractive site. The mean peak IT was 34.82±19.36. The mean RFA was 71.57±10.63 implant stability quotient. Spearman correlation analysis shows the presence of a weak positive correlation between IT and RFA. The statistical analysis shows a relevant dependency between IT and bone quality and a very weak dependency between RFA and bone quality. Again, the statistical analysis shows a quite weak correlation between length or diameter and IT, but it shows a relevant correlation between length and RFA. Postextractive implants presented a higher mean IT and a lower RFA compared with implants inserted in healed sites. Twenty-eight (0.7%) implants were considered to have failed and removed within 6months.

CONCLUSIONS

The results show that the implants studied obtain a good primary stability with a standard protocol. The IT and RFA appear as two independent features of primary stability. Data show that only IT is influenced by bone density as well as only RFA is correlated to the length of implants used. Finally, it is possible to obtain a good primary stability also in postextractive sites.

Determination of primary stability: a comparison of the surgeon's perception and objective measurements

PURPOSE

To evaluate the difference between the dental surgeon's perception of implant stability and the actual insertion torque and actual values obtained through resonance frequency analysis (RFA) during implant insertion surgery.

MATERIALS AND METHODS

One hundred fifty-two patients who needed one or more dental implants were selected. A total of 514 Xive implants was inserted. For all 514 implants, after insertion, the oral surgeon was asked to indicate the probable RFA values (implant stability quotient [ISQ]). For 483 implants, the surgeon was also asked to indicate the probable insertion torque values (N/cm). The actual values were then measured. The RFA and insertion torque values were grouped into low, medium, and high groups.

RESULTS

The mean perceived RFA was 72.2 +/- 9.8 ISQ. The mean actual RFA was 73.5 +/- 10.2 ISQ. This difference was statistically significant (P = .01). The mean perceived insertion torque was 39.1 +/- 20.1 Ncm. The mean actual insertion torque was 39.9 +/- 20.7 Ncm. The mean difference between actual and perceived ISQ values was -1 +/- 14.9, with a range from -60 to 59; the mean difference between actual and perceived insertion torque values was -1.3 +/- 9.9, with a range from -38 to 45.

CONCLUSIONS

Xive implants obtained good primary stability in many different clinical situations with a standard protocol. Primary stability is generally underestimated, especially in the presence of low or medium ISQ and torque values. The accuracy of primary stability prediction is not good enough to prevent mistakes when using an immediate loading technique; therefore, a more systematic use of objective measurements is encouraged.

Mandibular third molar removal in young patients: an evaluation of 2 different flap designs

PURPOSE

To evaluate the influence of 2 different flap designs on periodontal healing and postoperative complications, after inferior third molar removal in young patients.

PATIENTS AND METHODS

Twenty-four mandibular third molars were extracted from 12 patients with an average age of 16 years. Patients were included in the study when radiographs at the time of surgery showed that only the crown of the germ was formed. Each patient underwent 2 extractions, using a triangular flap on one side and an envelope flap on the other. Periodontal probing was recorded at the preoperative visit, and 7 days, 3 months, and 6 months after extraction. Postoperative complications were recorded using a questionnaire completed by the patient for the week after the extraction.

RESULTS

The examination performed 7 days after the extraction demonstrated a deeper probing depth in all teeth examined. This increase was statistically greater (P < .05) for the first and second molars when an envelope flap was used. After 3 months, the probing depths returned to preoperative values. No significant differences were seen between the 2 flap designs when postoperative complications were considered. The average operating time was 30.66 minutes with the triangular flap, versus 35.66 minutes with the envelope flap. This difference was not significant. After 6 months, the 2 flap designs resulted in no difference in periodontal healing or complications, but 30% of the surgical extractions resulted in a debilitating postoperative period for the patients treated.

CONCLUSIONS

Although we observed statistically significant differences in probing depth between triangular and envelope flaps 7 days after the extraction of third molars with no root development, this was not important from a clinical perspective, because periodontal healing at 3 and 6 months was comparable. We believe that this is also the case with the extraction of third molars with fully formed roots. Another important finding was the presence of a debilitating postoperative period in most of the patients who underwent extraction, contrary to the beliefs of many surgeons.

RFA values of implants placed in sinus grafted and nongrafted sites after 6 and 12 months

BACKGROUND

Maxillary sinus floor elevation surgery is widely used as a preimplantology method to permit implant insertion. Nevertheless, very few data are available about long-term stability of dental implants inserted in grafted sites.

PURPOSE

The aims of the present study were to evaluate the evolution of resonance frequency analysis (RFA) values at 6 and 12 months from the implant insertion in sinus grafted sites and nongrafted sites.

MATERIALS AND METHODS

In 14 patients, 80 Xive implants (Dentsply Friadent GmbH, Mannheim, Germany) were inserted. Sixty-three implants were inserted in a site previously treated with a sinus lift; 17 implants were inserted in healed or postextraction sites. For each implant diameter, length, bone density, insertion torque, and percentage of implant fixed to a nongrafted bone were recorded. RFA values at implant insertion after 6 and 12 months were recorded.

RESULTS

After 6 and 12 months, grafted sites showed higher RFA values than the control sites; after 12 months, the difference was statistically significant (.007). A statistically significant positive correlation was found between resonance frequency values and bone quality after 12 months (.05). No statistically significant correlation between RFA values and all the other variables considered was found.

CONCLUSIONS

Sites treated with sinus lift can offer good long-term stability. After 6 and 12 months, the geometric characteristics of the implant are no longer important to obtain high RFA values, and the bone-implant interface seems to be determinant.

Evaluation of factors influencing resonance frequency analysis values, at insertion surgery, of implants placed in sinus-augmented and nongrafted sites

BACKGROUND

The immediate loading technique requires a high primary stability. Resonance frequency analysis (RFA) has been proposed to assess this stability with a quantitative method.

PURPOSE

The aim of the present study was to evaluate if a good primary stability could be achieved in sites that had undergone a sinus augmentation procedure and also to evaluate the importance of different clinical factors in the determination of resonance frequency values at implant insertion.

MATERIALS AND METHODS

In 14 patients, 80 implants were inserted. Sixty-three implants were inserted in a site previously treated with a sinus augmentation procedure, while 17 implants were inserted in healed or postextraction sites. For each implant, diameter, length, bone density, insertion torque, RFA value, and percentage of implant fixed to a nongrafted bone were recorded.

RESULTS

Grafted sites showed high RFA values. A statistically significant positive correlation was found between resonance frequency values and implant diameter (p=0.007), implant length (p=0.02), diameter of the last bur used (p=0.01). No statistically significant correlation between RFA values and all the other variables considered was found.

CONCLUSIONS

Sites treated with sinus augmentation procedures can offer good primary stability after 6 months of healing. The length and diameter of the implants, together with the geometry of the implant used, are important to obtain high RFA values.

The Evolution of Buccal Gingival Recessions in a Student Population: A 5-Year Follow-Up

BACKGROUND

Data from cross-sectional studies revealed that gingival recession commonly occurred in subjects with a good standard of oral hygiene, but very little has been reported about longitudinal changes in the presence and extent of gingival recession in a similar sample of the population. The aim of this study was to follow up on the evolution of gingival recession at buccal tooth surfaces in a student population attending the fifth year at Bologna University Dental School who had been examined in a study 5 years earlier.

METHODS

The clinical examination involved assessment of the number of buccal surfaces with plaque and buccal gingival recession. Information about toothbrushing habits (brushing technique and frequency and toothbrush bristle stiffness) was collected in an interview.

RESULTS

The number of subjects with at least one recession and the total number of recessions had increased significantly. Comparing data from the baseline and the present study, no significant differences were observed for toothbrush type and frequency of toothbrushing, whereas the use of correct brushing techniques increased to 87% of the subjects.

CONCLUSION

The percentage of affected sites increased with the level of oral hygiene education, and this increase developed despite a reduction in the frequency of dangerous toothbrushing habits.

Gingival recession and toothbrushing in an Italian School of Dentistry: a pilot study

The aim of this pilot study was to evaluate the prevalence of gingival recession at buccal tooth surfaces in a student population of Bologna University Dental School. A total of 55 subjects, attending the 1st and 5th year of the course were examined. The clinical examination involved assessment of plaque, calculus, width of keratinized gingiva, buccal probing depth and buccal gingival recession. Information about toothbrushing behavior was collected in an interview. The multiple regression analysis showed that level of education (p=0.002), toothbrushing technique (p=0.013) and toothbrushing frequency (p=0.016) are significant contributors to gingival recession. Notwithstanding the limits of a preliminary study, a higher prevalence of buccal recession is observed in the final year students, which have also a significantly lower % of buccal surfaces with calculus (p=0.014). In addition, it clearly appears that there is the necessity to investigate other factors connected with toothbrushing (pressure, time, toothpaste quantity) in order to provide an oral hygiene education without undesired effects.