Dear editor
We read the article by Al-Shayyab1 with great interest, though we think that there is a methodical bias.
Usage of standard dental syringes with 27-gauge needles is not recommended for periodontal ligament (PDL) injections as they are very unlikely to achieve the correct pressure needed for successful single tooth anesthesia. In accordance with this, specialized syringes with short 30-gauge needles are commonly used all over the literature.2 The author addresses this in the “Discussion” section and writes that “a standard conventional dental syringe was used in the present study, not a special PDL syringe, since the former is readily available in the clinic and proves equally successful when a standard 27-gauge short needle was used,” citing Malamed from 1982 (a time during which the modern PDL syringes were not developed yet3) and Madan et al who write that “intraligamentary injection technique is equally effective when a standard 27-gauge needle is used”.4 The second assumption refers to the needle only, not the syringe. In addition, this needle issue is not proven by any reference or study. Therefore, one might come to the conclusion that PDL was not carried out correctly. Also, the authors did not evaluate pulp or tissue anesthesia and started the extraction procedure after a latency period of 5 minutes in all cases. In accordance with this, the success rates of the PDL injection cannot be given, but would be of interest.
Whereas for infiltration anesthesia, 1.8 mL was injected buccally and an additional 0.3 mL on the palatal side, PDL consisted of 0.2 mL on the mesial aspect of each root of the tooth. In accordance with this, one may consider this as infiltration with additional palatal nerve block. Besides, it is difficult to estimate how a mesial injection was possible, for example, for a three-rooted maxillary molar. How did the author approach the mesial side of the distal root? Normally, PDL is recommended at least in the mesiolingual and distolingual aspects. In addition, the newer literature shows that the injection PDL in four sites is significantly more successful than in two sites.5
In conclusion, the study of Al-Shayyab rather compares infiltration plus palatal block with a special, unusual and not suitable form of PDL. Therefore, from our point of view, generalization of the results should not be carried out, and further studies on conventional PDL in the maxilla are needed.
Footnotes
Disclosure
The authors report no conflicts of interest in this communication.
References
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