Evaluation of the long-term stability of micro-screws under different loading protocols: a systematic review

Braz Oral Res. 2019 Jun 10:33:e046. doi: 10.1590/1807-3107bor-2019.vol33.0046.

Abstract

The aim of this systematic review was to investigate the association between the different factors of loading protocols and the long-term stability of micro-screws from biomechanical and histological viewpoints. Searches were performed on PubMed, Embase, Cochrane Library, Wanfang and CNKI databases for animal experiments comparing loading protocols and the long-term stability of micro-screws. Among 1011 detected papers, 16 studies met the eligibility criteria and were selected for analysis. Most studies showed medium methodological quality for evaluation of micro-screws' long-term stability. Five studies reported that loading would not destroy the long-term stability of micro-screws. Three studies indicated that low-intensity immediate loading or a 3-week minimal healing time was acceptable. Two studies reported that the loading magnitude was a controversial issue with regard to the micro-screws' long-term stability. Two studies suggested that counterclockwise loading could decrease the long-term stability of micro-screws. In conclusion, immediate loading below 100g force, healing time greater than 3 weeks, regular loading below 200g force and a clockwise direction of force supported the long-term stability of micro-screws. Further studies relating to the combination of varying loading conditions will be needed.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Bone Screws / standards*
  • Dental Implantation / instrumentation
  • Dental Implantation / methods*
  • Dental Implants / standards*
  • Equipment Design
  • Models, Animal
  • Orthodontic Anchorage Procedures / instrumentation
  • Orthodontic Anchorage Procedures / methods*
  • Reference Values
  • Reproducibility of Results
  • Time Factors
  • Treatment Outcome
  • Wound Healing

Substances

  • Dental Implants