Primary stability of narrow-diameter dental implants with a multiple condensing thread design placed in bone with and without osteotomes: An in vitro study

Do dental implants installed in different types of bone (I, II, III, IV) have different success rates? A systematic review and meta-analysis

Purpose

The objective of this systematic review and meta-analysis was to evaluate the survival rate of implants installed in bone type IV (Lekholm and Zarb, 1995) compared to that of implants installed in bone types I, II, and III.

Material and methods

This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA) and was registered in the PROSPERO International Database of Systematic Reviews (CRD42021229775). The PubMed/MEDLINE, Scopus, and Cochrane databases were searched through July 2021. The PICO question was: "Dental implants installed in type IV bone have a lower success rate when compared to implants installed in type I bone, II and III?". The established inclusion criteria were: 1) controlled and randomized clinical trials (RCT), 2) prospective and retrospective studies with at least 10 participants with dental implants, and 3) patients with dental implants installed in bone tissue types I, II, III, and IV (Lekholm and Zarb, 1985). The minimum followup duration was 1 year.

Results

After searching the identified databases, 117 articles were selected for full reading and 68 were excluded. Thus, 49 studies were included for qualitative and quantitative analyses. The total number of participants included was 12,056, with a mean age of 41.56 years and 29,905 implants installed. Bone types I, II, and III exhibit a lower implant failure rate when compared to bone type IV.

Conclusion

Dental implants installed in bone types I, II, and III showed significantly higher survival rates than those installed in type IV. The bone type I success rate was not significantly different than that of type II; however, the success rate of bone type I and II was higher than that of type III.

Efficacy of indocyanine green and methylene blue mediated-photodynamic therapy on peri-implant outcomes among diabetics with peri-implant mucositis

BACKGROUND

This study aimed to assess the efficacy of indocyanine green (ICG)-mediated versus methylene blue (MB)-mediated photodynamic therapy (PDT) as an adjunct to conventional mechanical debridement (MD) on the peri‑implant clinical, radiographic, microbiological, and immunological outcomes among diabetics with peri‑implant mucositis (pi-M).

METHODS

For this 3-month follow-up study, diabetics having pi-M were randomly divided into 3 groups: group-I (n = 20) subjects received only MD; group-II (n = 20) participants received ICG-mediated adjunct PDT; and group-III (n = 20) subjects received MB-mediated adjunct PDT. Peri-implant clinical (i.e., plaque index [PI], bleeding on probing [BOP], probing depth [PD]), radiographic (crestal bone loss [CBL]), microbiological (Fusobacterium nucleatum [F. nucleatum], Tannerella forsythia [T. forsythia], Prevotella intermedia [P. intermedia], Porphyromonas gingivalis [P. gingivalis], Aggregatibacter actinomycetemcomitans [A. actinomycetemcomitans]), and immunological (interleukin [IL]-6, IL-1β, tumor necrosis factor-alpha [TNF-α]) outcomes were assessed at baseline and 3-month follow-up.

RESULTS

Mean changes between baseline and 3-month follow-up in peri‑implant clinico-radiographic parameters were significantly different between control (PI: 12.42±21.80%; BOP: 12.10±19.30%; PD: 0.45±0.41 mm; CBL: 1.10±1.02 mm) and test groups (ICG-mediated PDT [PI: 26.55±25.80%; BOP: 28.77±29.24%; PD: 0.84±0.62 mm; CBL: 1.98±1.85 mm] and MB-mediated PDT [PI: 27.24±26.15%; BOP: 27.71±28.16%; PD: 0.85±0.63 mm; CBL: 1.95±1.80 mm]), however comparable differences were observed in peri‑implant PI, BOP, PD, and CBL between group-II and group-III participants (p>0.05). The proportions of T. forsythia were significantly reduced in group-II (4.78 × 10⁴ colony-forming unit per milliliter [CFU/mL]) and group-III (4.76 × 10⁴ CFU/mL) as compared to group-I (-4.40 × 10³ CFU/mL) at 3-month follow-up (p = 0.02). No statistically significant differences were observed between the study groups regarding the proportions of the other assessed target bacterial species. For IL-6 (group-I: 210±108; group-II: 298±165; group-III: 277±121 pg/mL; p = 0.03), IL-1β (group-I: 101±95; group-II: 84±98; group-III: 86±74 pg/mL; p = 0.02), and TNF-α (group-I: 336±121; group-II: 385±210; group-III: 366±198 pg/mL; p = 0.03) peri‑implant sulcular fluid [PISF] levels, all three study groups demonstrated statistically significant reduction at 3-month follow-up.

CONCLUSIONS

ICG-mediated and MB-mediated adjunctive PDT showed statistically significant improvements in peri‑implant clinical, radiographic, microbiological, and immunological parameters as compared to conventional MD alone at 3-month follow-up among diabetics with pi-M. However, comparable outcomes were demonstrated by ICG-mediated and MB-mediated adjunctive PDT regarding the assessed peri‑implant parameters.

Comparison of photobiomodulation and photodynamic therapy as adjuncts to mechanical debridement for the treatment of peri-implantitis

BACKGROUND AND OBJECTIVE

The aim of this study was to compare the efficacy of photobiomodulation therapy (PBMT) and photodynamic therapy (PDT) as adjuncts to mechanical debridement (MD) for the treatment of peri-implantitis. The present study is based on the null hypothesis that there is no difference in the peri-implant inflammatory parameters (modified plaque index [mPI], modified gingival index [mGI], probing depth [PD]) and crestal bone loss (CBL) following MD either with PBMT or PDT in patients with peri-implantitis.

METHODS

Forty-nine patients with peri-implantitis were randomly categorized into three groups. In Groups 1 and 2, patients underwent MD with adjunct PBMT and PDT, respectively. In Group 3, patients underwent MD alone (controls). Peri-implant inflammatory parameters were measured at baseline and 3-months follow-up. P-values < 0.01 were considered statistically significant.

RESULTS

At baseline, peri-implant clinicoradiographic parameters were comparable in all groups. Compared with baseline, there was a significant reduction in mPI (P< 0.001), mGI (P< 0.001) and PD (P< 0.001) in Groups 1 and 2 at 3-months follow-up. In Group 3, there was no difference in the scores of mPI, mGI and PD at follow-up. At 3-months follow-up, there was no difference in mPI, mGI and PD among patients in Groups 1 and 2. The mPI (P< 0.001), mGI (P< 0.001) and PD (P< 0.001) were significantly higher in Group 3 than Groups 1 and 2. The CBL was comparable in all groups at follow-up.

CONCLUSION

PBMT and PDT seem to be useful adjuncts to MD for the treatment of peri-implant soft-tissue inflammation among patients with peri-implantitis.

Evaluation of the implant diameter on the initial-stability of narrow- and standard-diameter implants placed in simulated Type-I and Type-IV bone-blocks

Objective:

A comparison of the initial stability of narrow- and standard-diameter implants (SDIs) placed in Type-I and Type-IV bone-blocks is not yet reported. The aim was to evaluate in-vitro the influence of implant diameter on the initial stability of narrow- and standard-diameter implants (SDIs) placed in simulated Type-I and Type-IV bone-blocks.

Methods:

The present experimental in-vitro study was performed between July and September 2020 at the Specialist Dental Practice, Riyadh, Saudi Arabia. Narrow- and standard-diameter implants were placed 3-mm apart in simulated soft (Type-IV) and dense (Type-I) bone blocks by a trained and calibrated investigator. In groups A (Type-IV bone blocks) and B (Type-I bone blocks), implants were inserted using an insertion-torque and drilling-speed of 15-30 Ncm and 1000-1500 rpm, respectively with the implant collar at the crest of simulated bone blocks. In all samples, initial-stability was recorded using resonance frequency analysis (RFA). Sample-size estimation was done and group-comparisons were carried out. A P-value of 0.01 or less reflected statistical significance.

Results:

In Groups-A and -B, 44 (22 NDIs and 22 SDIs) and 44 (22 NDIs and 22 SDIs) were placed. In group-A, the mean RFA values for NDIs and SDIs were 68.5 ± 3.5 and 69.1 ± 2.4, respectively. In Group-B, the mean RFA values for NDIs and SDIs were 78.06 ± 9.6 and 75.3 ± 5.2. RFA values among NDIs and SDIs in groups A and B were similar.

Conclusion:

The NDIs and SDIs show comparable initial-stability when positioned in simulated Type-I and Type-IV bone blocks.

Influence of moderate cigarette-smoking on the peri-implant clinicoradiographic inflammatory parameters around cement- and screw-retained dental implants

The aim was to assess the influence of moderate cigarette-smoking on the clinical (bleeding on probing [BoP] and probing depth [PD]) and radiographic (crestal bone resorption [CBR]) around cement- and screw-retained dental implants at 5 years' follow-up. A questionnaire was used to collect information about age, gender, smoking history, duration of implants in function, jaw location of the implant, and daily toothbrushing and flossing. Peri-implant BoP, PD and CBR were measured in all groups. Group comparisons were performed using one-way analysis of variance and for multiple comparisons, the Bonferroni Post hoc adjustment test was performed. Level of significance was set at P<0.05. Forty-eight patients (25 smokers and 23 non-smokers) had cement-retained dental implants; and 48 (24 smokers and 24 non-smokers) had screw-retained dental implants. Among patients with cement and screw-retained dental implants, PD (P<0.05) and CBR (P<0.05) were significantly higher among smokers than non-smokers. The peri-implant sites that demonstrated BoP were statistically significantly higher among non-smokers (P<0.05) than smokers among patients with cement- and screw-retained dental implants. There was no statistically significant difference in peri-implant PD and CBR among smokers with cement- and screw-retained dental implants. Among non-smokers with cement and screw-retained dental implants, there was no statistically significant difference in BoP, PD and CBR. Cigarette-smoking is associated with an increased PD and CBR around cement- and screw-retained dental implants. Cigarette-smoking increases peri-implant soft tissue inflammation as well as loss of crestal bone and this relationship is independent of the type of implant retention protocol used.The author recommends that cement- and screw-retained dental implants are suitable for prosthesis restoration in non-smokers. Further studies on dual-smokers (individuals smoking cigarettes and other forms of tobacco products) are needed related to the clinicoradiographic inflammatory parameters around cement- and screw-retained dental implants.

Relationship between buccal alveolar bone thickness and crown-to-root dimensions around mandibular first and second molars: A cone-beam-computed tomography-based study

BACKGROUND

Assessment of buccal alveolar bone thickness (ABT) and crown-to-root dimensions are essential in implant density; therefore, three-dimensional evaluation of these parameters provides a superior visualization than conventional radiographs.

OBJECTIVE

The present cross-sectional cohort study aims to investigate the relationship between buccal ABT and crown-to-root dimensions around the mandibular first and second molars using cone-beam-computed tomography (CBCT).

METHODS

Initially, CBCT-based scans from 271 individuals were assessed. Based on the inclusion and exclusion criteria, 171 CBCT-based scans were excluded. In total, 100 CBCT-scans were included in the present investigation and processed for data extraction. On the mandibular first and second molars, the mesial and distal root lengths and mesiodistal diameter of the crowns were measured. The pulpal floor served as a reference point for assessment of root length. The buccal ABT was measured at the coronal, middle and apical one-third of the root. Statistical analysis was performed and the level of significance was set at P< 0.01. One-hundred CBCT-scans from 294 mandibular teeth (137 first molars and 157 second molars) were included. One hundred and eighty-nine and 105 teeth were from males and females, respectively.

RESULTS

The normality plot showed a normal data distribution. The mesiodistal crown width showed a weak yet significant correlation with mesial root length (r= 0.137), bone thickness at mesial apical third (r= 0.180), distal apical (r= 0.157) and distal coronal third (r= 0.161). Bone thickness at mesial, middle and apical third correlated significantly with one other (r= 0.786).

CONCLUSION

There is a direct correlation between the buccal ABT and tooth dimensions around the mandibular first and second molars.