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Clinical Outcomes of Buffered vs. Non-Buffered Lidocaine

Comparison of Buffered vs. Non-Buffered Lidocaine Used in Dental and Oral Surgical Procedures: Clinical Outcomes

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02620683
Acronym
BUFFL
Enrollment
23
Registered
2015-12-03
Start date
2015-12-31
Completion date
2017-09-30
Last updated
2018-01-23

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anesthetics, Local, Blood Levels of Buffered vs Non-buffered Lidocaine

Keywords

lidocaine, jaw

Brief summary

Anecdotal reports suggest buffering lidocaine with epinephrine just before intraoral injection reduces time of onset, results in a deeper anesthetic effect, without the sting with injection from a low pH. Additional data are needed to establish clinical important outcomes such as the peak blood level of lidocaine as compared to the non-buffered drug combination. Clinical pilot studies are proposed as the start of a series of investigations to support or modify the use of the buffered anesthetic for intraoral procedures.

Detailed description

Specific Aims: Compare blood levels at 30min post injection mandibular block with buffered and non- buffered 2% lidocaine with 1/100k epinephrine. Assess outcomes (pain levels during and post-injection, and onset of anesthesia symptoms) after buffered and non-buffered oral administration of 2% lidocaine with 1/100k epinephrine. Assess possible topical anesthetic properties of buffered and non-buffered oral administration of 2% lidocaine with 1/100k epinephrine Hypotheses: No difference in peak blood levels exist between buffered and non-buffered intraoral injection of 2% lidocaine with 1/100k epinephrine. Injection of buffered local anesthetic will produce less discomfort for the subject as compared to the drug with a low pH. Buffered local anesthetic will not produce a topical anesthetic effect Study Time Frame: 6 months Month One IRB approvals. Recruit volunteers as subjects. Prepare case-books. Months Two-Three Clinical Study Months Four-Five Analyze Lab, QOL data Month Six Prepare Abstracts, Papers Methods: Blinded, Randomized Clinical Design Recruit subjects with IRB approved consent at UNC Target enrollment 24 subjects Subjects will serve as their own controls in a cross-over AB/BA study design which is uniform within sequences, uniform within periods, and balanced Sample size justification: Primary interest is estimation of effect size from pilot study. 24 subjects should be sufficient to provide data to assess whether a larger study is warranted and provide estimates for sample size calculation for larger studies. Vital signs recorded: 10 min before, during at 30min intervals and after post-anesthetic clinical signs disappear: targeted lower lip no longer numb. Randomized subjects to be injected alternatively with 4cc of buffered and 4cc non-buffered oral administration of 2% lidocaine with 1/100k epinephrine. SAS will be used to create randomization schedules: The randomization will be performed first to type of drug given with a balanced randomization (half subjects buffered; half to non-buffered) An OMS resident, Dr Phero, will administer the drugs in the OMS clinic. In week One each subject would receive anesthetic to block the inferior alveolar and lingual N; Halstead or Gow-Gates techniques. No Buccal N. block. At least a week later injections would involve the alternate local anesthetic combination. Venous blood samples would be drawn from the antecubital fossa 30min post oral injection and assayed for blood lidocaine levels Timed Assessment: pre, during injection, and post-anesthetic for Clinical Onset of Anesthesia Signs: subject reported molar area numbness and numb lower lip on ipsilateral injected side. Assessment for pain level on injection; modified Likert-type scale In addition at each clinic session an assessment of a topical anesthetic effect on contralateral lower lip with 5 drops of the injected drug placed on the clinically dry lower lip mucosa, Outcome yes/no. Data Collection: UNC OMS clinic Venous blood samples (10cc) will be drawn from the antecubital fossa 30min post oral injection. Timed assessment pre, during injection, and post-anesthetic clinical Signs: molar area anesthesia, incisor area anesthesia, and numb lower lip for topical Data Collection/Analysis: Data will be managed by study staff. Data collection forms and questionnaires for clinical data will be developed to use Teleform for direct scanning input into an ACCESS database. Similar forms have been used in previous studies. All databases are stored on a password protected School of Dentistry server with specific group assignment. SAS will be used for database management and statistical analysis. Descriptive statistics are used to verify correct entry through range and logical checks.

Interventions

DRUGLidocaine

See above

Sponsors

Dental Foundation of North Carolina, Inc.
CollaboratorOTHER
University of North Carolina, Chapel Hill
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Caregiver)

Eligibility

Sex/Gender
ALL
Age
18 Years to 30 Years
Healthy volunteers
Yes

Inclusion criteria

* Age 18-30 years * ASA I * Willingness to complete QOL instrument * Willingness to participate in two sessions

Exclusion criteria

* Allergy to lidocaine class of anesthetic drugs * Local anesthetic drug use in past week * Current symptoms teeth or oral mucosa

Design outcomes

Primary

MeasureTime frameDescription
Lidocaine Blood Levels 30 Minutes Post Injection30 minutes post injectionLidocaine blood levels were obtained 30 minutes post injection micro g/L The difference between injection type- 95% confidence intervals for the difference between injection types was calculated. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered, was performed using Wilcoxon rank sum tests with Proc NPAR1WAY (SAS v 9.3). Statistical significance was set as P \< 0.05 for all outcomes.

Secondary

MeasureTime frameDescription
Pain Intensity ScoresImmediately after lidocaine injectionPatients reported pain level immediately after injection of lidocaine via a Likert type scale where 1 = No Pain and 10 = Worst Pain Imaginable. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered was performed.
Number of Minutes to Anesthesia Symptoms of Lower LipPatient report of anesthesia symptom onset following injectionPatients were instructed to record the time when they experienced the initial indication of anesthesia signs in the lower lip. This was reported as the number of minutes following nerve block injection. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered was performed.
Topical Anesthesia Effect Contralateral Lower LipAt time of administrationInvestigator will administer 5-6 drops of the lidocaine to the contralateral lower lip and immediately ask if signs of numbness are present on the lip. Patients reported presence of numbness lower lip-Yes or No

Countries

United States

Participant flow

Recruitment details

Beginning in December 2015 23 subjects recruited for study conducted in the surgery clinic at UNC School of Dentistry

Pre-assignment details

No enrolled subjects excluded.

Participants by arm

ArmCount
All Study Participants
Subjects who were randomized to receive either Buffered or Non-Buffered Lidocaine
23
Total23

Baseline characteristics

CharacteristicAll Study Participants
Age, Categorical
<=18 years
0 Participants
Age, Categorical
>=65 years
0 Participants
Age, Categorical
Between 18 and 65 years
23 Participants
Age, Continuous21 years
Ethnicity (NIH/OMB)
Hispanic or Latino
0 Participants
Ethnicity (NIH/OMB)
Not Hispanic or Latino
23 Participants
Ethnicity (NIH/OMB)
Unknown or Not Reported
0 Participants
Region of Enrollment
United States
23 participants
Sex: Female, Male
Female
11 Participants
Sex: Female, Male
Male
12 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
0 / 230 / 23
other
Total, other adverse events
0 / 230 / 23
serious
Total, serious adverse events
0 / 230 / 23

Outcome results

Primary

Lidocaine Blood Levels 30 Minutes Post Injection

Lidocaine blood levels were obtained 30 minutes post injection micro g/L The difference between injection type- 95% confidence intervals for the difference between injection types was calculated. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered, was performed using Wilcoxon rank sum tests with Proc NPAR1WAY (SAS v 9.3). Statistical significance was set as P \< 0.05 for all outcomes.

Time frame: 30 minutes post injection

ArmMeasureGroupValue (MEAN)Dispersion
Buffered Lidocaine and Non-Buffered LidocaineLidocaine Blood Levels 30 Minutes Post Injectionbuffered lidocaine7.9 ug/LStandard Deviation 16.2
Buffered Lidocaine and Non-Buffered LidocaineLidocaine Blood Levels 30 Minutes Post Injectionnon-buffered lidocaine15.8 ug/LStandard Deviation 16.2
Comparison: The difference between injection type- 95% confidence intervals for the difference between injection types was calculated. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered, was performed using Wilcoxon signed rank tests (SAS v 9.3). Statistical significance was set as P \< 0.05 for all outcomes.p-value: 0.00695% CI: [-34.6, -5.86]Wilcoxon (Mann-Whitney)
Secondary

Number of Minutes to Anesthesia Symptoms of Lower Lip

Patients were instructed to record the time when they experienced the initial indication of anesthesia signs in the lower lip. This was reported as the number of minutes following nerve block injection. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered was performed.

Time frame: Patient report of anesthesia symptom onset following injection

ArmMeasureGroupValue (MEAN)Dispersion
Buffered Lidocaine and Non-Buffered LidocaineNumber of Minutes to Anesthesia Symptoms of Lower Lipbuffered lidocaine10.2 minutesStandard Deviation 16.1
Buffered Lidocaine and Non-Buffered LidocaineNumber of Minutes to Anesthesia Symptoms of Lower Lipnon-buffered lidocaine13.7 minutesStandard Deviation 16.1
Comparison: The difference between injection type- 95% confidence intervals for the difference between injection types was calculated. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered, was performed using Wilcoxon signed rank tests (SAS v 9.3). Statistical significance was set as P \< 0.05 for all outcomes.p-value: 0.2395% CI: [-4, 1]Wilcoxon (Mann-Whitney)
Secondary

Pain Intensity Scores

Patients reported pain level immediately after injection of lidocaine via a Likert type scale where 1 = No Pain and 10 = Worst Pain Imaginable. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered was performed.

Time frame: Immediately after lidocaine injection

ArmMeasureGroupValue (MEAN)Dispersion
Buffered Lidocaine and Non-Buffered LidocainePain Intensity Scoresbuffered lidocaine2.6 units on a scaleStandard Deviation 1.56
Buffered Lidocaine and Non-Buffered LidocainePain Intensity Scoresnon-buffered lidocaine3.0 units on a scaleStandard Deviation 2.2
Comparison: The difference between injection type- 95% confidence intervals for the difference between injection types was calculated. For the outcome variable, an assessment of treatment difference by subject, calculated as 1% Buffered minus 2% Non-Buffered, was performed using ProcTTEST (SAS v 9.3). Statistical significance was set as P \< 0.05 for all outcomes.p-value: 0.09695% CI: [-1.46, 0.13]t-test, 2 sided
Secondary

Topical Anesthesia Effect Contralateral Lower Lip

Investigator will administer 5-6 drops of the lidocaine to the contralateral lower lip and immediately ask if signs of numbness are present on the lip. Patients reported presence of numbness lower lip-Yes or No

Time frame: At time of administration

Population: Unable to administer in this fashion because Lidocaine would not remain on lip surface therefore data were not collected

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026