Effect of photobiomodulation therapy on pain perception during anesthetic puncture of dental local anesthesia: A systematic review.

BACKGROUND: Local anesthetic puncture is often related to the experience of pain. This study aimed to systematically analyze the literature on changes in pain perception during the anesthetic puncture of dental local anesthesia after Photobiomodulation Therapy (PBMT). MATERIAL AND METHODS: An electronic search was performed in eight primary databases (Embase, LILACS, BBO, LIVIVO, MedLine via PubMed, SciELO, Scopus, and Web of Science) and three additional ones (EASY, Google Scholar, and OATD) to partially capture the "gray literature". The PICO strategy was used to identify randomized clinical trials evaluating the analgesic effect of PBMT in the anesthetic puncture site of dental local anesthesia compared to placebo or control groups, without restrictions on publication language and year. Two reviewers extracted the data and assessed the individual risk of bias of the eligible studies using the Cochrane Collaboration Risk of Bias Tool version 2.0. RESULTS: The electronic search found 3,485 records, of which eight met the eligibility criteria and were included in the qualitative synthesis. The studies were published from 2011 to 2022. None of the included studies had a low risk of bias. PBMT groups showed no significant difference in pain scores compared to placebo and control groups of most studies. CONCLUSION: Based on a low to very low certainty of evidence, PBMT seems to have no effect on pain perception during anesthetic puncture in patients undergoing dental local anesthesia.

Immune and metabolic challenges induce changes in pain sensation and related pathways in the hypothalamus.

The hypothalamic molecular processes participate in the regulation of the neuro-immune-endocrine system, including hormone, metabolite, chemokine circulation, and corresponding physiological and behavioral responses. RNA-sequencing profiles were analyzed to understand the effect of juvenile immune and metabolic distress 100 days after virally elicited maternal immune activation during gestation in pigs. Over 1,300 genes exhibited significant additive or interacting effects of gestational immune activation, juvenile distress, and sex. One-third of these genes presented multiple effects, emphasizing the complex interplay of these factors. Key functional categories enriched among affected genes included sensory perception of pain, steroidogenesis, prolactin, neuropeptide, and inflammatory signaling. These categories underscore the intricate relationship between gestational immune activation during gestation, distress, and the response of hypothalamic pathways to insults. These effects were sex-dependent for many genes, such as Prdm12, Oprd1, Isg20, Prl, Oxt, and Vip. The prevalence of differentially expressed genes annotated to proinflammatory and cell cycle processes suggests potential implications for synaptic plasticity and neuronal survival. The gene profiles affected by immune activation, distress, and sex pointed to the action of transcription factors SHOX2, STAT1, and REST. These findings underscore the importance of considering sex and postnatal challenges when studying causes of neurodevelopmental disorders and highlight the complexity of the "two-hit" hypothesis in understanding their etiology. Our study furthers the understanding of the intricate molecular responses in the hypothalamus to gestational immune activation and subsequent distress, shedding light on the sex-specific effects and the potential long-lasting consequences on pain perception, neuroendocrine regulation, and inflammatory processes.NEW & NOTEWORTHY The interaction of infection during gestation and insults later in life influences the molecular mechanisms in the hypothalamus that participate in pain sensation. The response of the hypothalamic transcriptome varies between sexes and can also affect synapses and immune signals. The findings from this study assist in the identification of agonists or antagonists that can guide pretranslational studies to ameliorate the effects of gestational insults interacting with postnatal challenges on physiological or behavioral disorders.

The prophylactic effect of photobiomodulation therapy on pain perception due to infiltration injection: a randomized clinical trial.

OBJECTIVES: Fear of pain in dentistry especially the injection involved in most of the processes has always been an important issue preventing the patients from consulting a dentist at the right time. This study aims to evaluate the effect of photobiomodulation therapy on reduction of pain in infiltration injection. MATERIALS AND METHODS: This trial is a crossover study including 30 patients. The patients are divided into two groups (laser therapy in the first period and placebo effect in the next period or vice versa with split-mouth design) using the covariate adaptive randomization method. All the patients received bilateral maxillary canine anesthesia in two periods performed with an ICT injection device (amount of anesthesia solution loaded: 1.8 mL) at a speed of 1 mL/min and a temperature of the solution of 37 °C. In each period, patients received either a prophylactic dose of 940-nm laser (500 mW, 10 J/cm2) or its placebo effect before the injection. The degree of pain perception after each sort of treatment is evaluated by both SEM (Sound, Eye, Motor, and Pain) and VAS (Visual Analogue Scale) scales. RESULTS: According to analysis, all the patients scored a VAS scale under 3 in the period they received intervention. Also considering the SEM scale, most of the patients scored 0 in the intervention period. No adverse effect was reported during or after the process. CONCLUSIONS: The study showed a significant effect of photobiomodulation on reducing pain perception during infiltration injection. CLINICAL RELEVANCE: This method can be useful in order to lower the pain for the patients consulting a dentist and therefore facilitate consulting at early stages of the dental issues. TRIAL REGISTRATION: The registration number (date) of the clinical trial in a Primary Registry in the WHO Registry Network is IR.ARAKMU.REC.1398.248(13/03/2020). The related URL is https://en.irct.ir/trial/45362 .

Electrostimulation of the white matter of the posterior insula and medial operculum: perception of vibrations, heat, and pain.

ABSTRACT: This study aimed to characterize the sensory responses observed when electrically stimulating the white matter surrounding the posterior insula and medial operculum (PIMO). We reviewed patients operated on under awake conditions for a glioma located in the temporoparietal junction. Patients' perceptions were retrieved from operative reports. Stimulation points were registered in the Montreal Neurological Institute template. A total of 12 stimulation points in 8 patients were analyzed. Painful sensations in the contralateral leg were reported (5 sites in 5 patients) when stimulating the white matter close to the parcel OP2/3 of the Glasser atlas. Pain had diverse qualities: burning, tingling, crushing, or electric shock. More laterally, in the white matter of OP1, pain and heat sensations in the upper part of the body were described (5 sites in 2 patients). Intermingled with these sites, vibration sensations were also reported (3 sites in 2 patients). Based on the tractograms of 44 subjects from the Human Connectome Project data set, we built a template of the pathways linking the thalamus to OP2/3 and OP1. Pain sites were located in the thalamo-OP2/3 and thalamo-OP1 tracts. Heat sites were located in the thalamo-OP1 tract. In the 227 awake surgeries performed for a tumor located outside of the PIMO region, no patients ever reported pain or heat sensations when stimulating the white matter. Thus, we propose that the thalamo-PIMO connections constitute the main cortical inputs for nociception and thermoception and emphasize that preserving these fibers is of utmost importance to prevent the postoperative onset of a debilitating insulo-opercular pain syndrome.

Suggestion Timing Moderates the Effects of Prior Pain Experiences on Pain Perception.

Two common elements in patient care are reoccurring painful events (eg, blood draws) and verbal suggestions from others for lessened pain. Research shows that verbal suggestions for lower pain can decrease subsequent pain perception from novel noxious stimuli, but it is less clear how these suggestions and prior painful experiences combine to influence the perception of a reoccurring painful event. The presented experiment tested the hypothesis that the order of these 2 factors influence pain perception for a reoccurring painful event. All participants (702 healthy college-student volunteers, 58% women, 85.5% White) experienced a novel painful event on one arm, then again on their other arm (now a familiar pain event). Participants who received the suggestion that they can tolerate more pain on the second arm relative to the first from the outset, before the initial pain event, perceived relatively less pain during the repeated event as compared to participants who received the same suggestion after the first painful event or no-suggestion (control). Given many pain events within medical contexts are, or become, familiar to patients, further researching the timing at which patients receive verbal suggestions for lower pain can inform practices to optimize the therapeutic, pain-reducing potential of such suggestions. PERSPECTIVE: Providing suggestions that a familiar pain event (ie, the second of 2) will be less painful than a prior event can reduce perceived pain for the familiar event depending on when it is presented. These findings can inform practices to optimize the therapeutic potential of verbal suggestions for reduced pain.

The impact of classical music on anxiety and pain perception during a thyroid fine needle aspiration biopsy.

AIM: To determine the impact of classical music on the anxiety and pain perception of patients who underwent thyroid fine-needle aspiration biopsy (TFNAB) for the first time. METHODS: In a prospective randomized controlled design, TFNAB patients were randomized into the intervention and control groups. The State Anxiety Inventory (SAI) before and after the procedure and the visual analog scale (VAS) after procedure were used for measuring anxiety and pain. RESULTS: A total of 82 patients were included. There was no significant difference between the music intervention group (n = 41) and control group (n = 41) in terms of age, gender, work status, highest education level, SAI score before TFNAB, and duration of the procedure (p > 0.05). It was observed that the anxiety level before TFNAB was higher in women in all patient groups (p = 0.009). While the SAI score decreased significantly in the music intervention group (Z = - 3.62, p < 0.001), there was no significant difference in the control group (Z = - 1.41, p = 0.157) after TFNAB. However, no significant difference was found in terms of VAS between two groups (p = 0.075). The duration of the TFNAB procedure was correlated with the change in the SAI score (r = 0.382, p < 0.001). CONCLUSION: This is the first study to examine the impact of music on patients' anxiety and pain perception during the TFNAB procedure. Despite the fact that classical music intervention did not decrease pain perception, it significantly reduced patient anxiety. Music is an easy-to-implement intervention that can be considered as an effective method for reducing patient anxiety during TFNAB.

Comparative study of two different computer-controlled local anesthesia injection systems in children: a randomized clinical trial.

PURPOSE: To compare pain perception associated with two computer-controlled local anesthesia devices, the WAND™ STA (Milestone Scientific Inc., Livingston, NJ, USA) and the Calaject (Rønvig dental MFG, Daugaard, Denmark) in young children. METHODS: A split-mouth randomized clinical trial comprising 30 patients, aged 6-12 years, received randomly, in two separate sessions, a local anesthesia injection in the maxillary using either the wand STA or the Calaject. Pain perception was evaluated using the patient's heart rate, an 11-point numerical scale (NRS), and the Sound, Eye, and Motor (SEM) body movements. Statistical difference was set at p = 0.05. Repeated measures analysis of variance were conducted to compare the mean pulse for Calaject and STA at different times. It was followed by univariate analysis and Bonferroni multiple comparisons tests. Wilcoxon tests were performed to compare NRS, SEM, and injection duration between Calaject and STA. RESULTS: There was no significant statistical difference between Calaject and STA in pulse rate before injection (p = 0.720), during injection (p = 0.767), and after injection (p = 0.757). The mean NRS score was significantly greater with STA in comparison with Calaject (p = 0.017). The mean SEM score was also significantly greater with STA in comparison with Calaject (p = 0.002). However, the mean duration was significantly longer with Calaject (p = 0.001). CONCLUSIONS: Calaject was more effective than STA in reducing pain perception associated with periapical injection in young children.

Dental pain perception and emotional changes: on the relationship between dental anxiety and olfaction.

BACKGROUND: The purpose of the study was to determine to what extent olfactory aromatherapy reduces the intensity of dental pain and the level of dental anxiety. It also attempted to corelate between olfactory aromatherapy, stages of dental visits, and various dental procedures. METHODS: Female patients were enrolled in a randomized controlled study. Olfactory aromatherapy was performed using lavender oils. Patients were randomly assigned to one of two groups: the lavender group, in which patients inhaled 2% lavender vapors, and the control group, in which patients inhaled water vapors. Pain score, anxiety score, and changes in vital signs were among the predictable variables. Anxiety and pain were assessed using the Modified Dental Anxiety Scale (MDAS), Speilberger State-Trait Anxiety Inventory (STAI), and visual analog scales (VAS). The vital signs were systolic (SBP) and diastolic (DBP), heart rate (HR), respiratory rate (RR), and oxygen saturation (Spo2). Variables were evaluated before inhalations, 20 min after inhalations, at the end of settings, and on the following day. RESULTS: Each group had 175 participants. Pain and anxiety scores were significantly reduced, and all vital signs improved, except for DBP. The MDAS, STAI, and pain scores are reduced by 3.4, 4.2, and 2.4 times, respectively, compared to the control group. Olfactory aromatherapy had the greatest impact during the phase of waiting rooms. CONCLUSION: When compared to the control group, olfactory aromatherapy reduces anxiety scores three to four times more. Pain perception is reduced by twice as much as in the control group. It also significantly reduces the anxiety associated with minor to moderately stressful dental procedures.

Effectiveness of low-level laser therapy in reducing pain perception of children during dental local anesthetic administration using laser acupuncture pen on the LI4 point: a randomized clinical trial.

PURPOSE: Laser acupuncture, a non-invasive variant of acupuncture, has been proven effective in the medical and dental fields. Hence, the present study aims to determine the effect of low-level laser therapy on the LI4 point, using a laser acupuncture pen, in reducing children's pain during local anesthetic (LA) administration. METHODS: Children in the age range of 8-12 years, in need of LA administration, were randomly assigned to two groups: Group I: laser acupuncture, Group II: control. For all the children, baseline simplified Modified Child Dental Anxiety Scale-Faces version (MCDAS(f)) was recorded, followed by laser acupuncture or standard care. Following the conventional protocol, LA was administered. The procedural pain was assessed using the Faces, Legs, Activity, Cry and Consolability scale (FLACC) and Faces Pain Scale-Revised (FPS-R). All the variations in pulse rate were recorded from baseline to the completion of LA administration. After the procedure, simplified MCDAS(f) was recorded one more time. The data were tabulated and analyzed statistically. RESULTS: A significant reduction in anxiety after LA administration, as observed in MCDAS(f) score, was noticed only in the laser acupuncture group. The pain scores, as reported in FPS-R, were low in children randomized to the laser group compared to the control. The FLACC pain scores also showed low values in the experimental group. CONCLUSION: Based on the study findings, within the limitations, low-level laser therapy using a laser acupuncture pen can reduce the pain perception of children undergoing LA administration and alleviate dental anxiety.

Local anesthesia with SleeperOne S4 computerized device vs traditional syringe and perceived pain in pediatric patients: a randomized clinical trial.

Local anesthesia is performed in dentistry before clinical procedures to avoid pain. Children can show fear at the sight of the needle and pain at its insertion. To make local anesthesia more comfortable, the use of computer-controlled local anesthetic delivery (CCLAD) systems has been developed to control the flow rate of the anesthetic solution injected through the needle. The aim of the present research is to evaluate and compare the discomfort felt by patients using a traditional syringe and the CCLAD system SleeperOne®, by considering pain, size sensation, bitterness, and vomit. 30 patients were included in the study and randomly assigned to traditional anesthesia or CCLAD. After injection, patients were assessed for the abovementioned outcomes. A Visual Analogue Scale (VAS) from 0 to 10 scores was used. As far as pain is concerned, statistically lower mean values were found in the Trial group (p < 0.05). Instead, concerning size, bitterness and vomit perceptions, no statistically significant differences were found between the groups (p > 0.05). Linear regressions were calculated considering technique, quadrant, dental arch, tooth, dentition, sex, and age as independent variables. The technique has shown to have a significant influence on pain (p < 0.05), with lower values for SleeperOne® device. Pain resulted significantly influenced by the type of dentition (p < 0.05), with higher scores for deciduous one. Moreover, perceived pain decreased with the increase of the age of patients (p < 0.05). At last, bitterness perception scores resulted to be higher for primary first molars (p < 0.05). SleeperOne® device seems to be a valid support for the reduction of pain related to anesthetic injection, especially in children. Further studies should evaluate CCLADs' uses combined with lidocaine preanesthetic as well as with conscious sedation through nitrous oxide in order to determine possible synergistic effects between these procedures.

Processing of sensory, painful and vestibular stimuli in the thalamus.

OBJECTIVES: The thalamus plays an important role in the mediation and integration of various stimuli (e.g., somatosensory, pain, and vestibular). Whether a stimulus-specific and topographic organization of the thalamic nuclei exists is still unknown. The aim of our study was to define a functional, in vivo map of multimodal sensory processing within the human thalamus. METHODS: Twenty healthy individuals (10 women, 21-34 years old) participated. Defined sensory stimuli were applied to both hands (innocuous touch, mechanical pain, and heat pain) and the vestibular organ (galvanic stimulation) during 3 T functional MRI. RESULTS: Bilateral thalamic activations could be detected for touch, mechanical pain, and vestibular stimulation within the left medio-dorsal and right anterior thalamus. Heat pain did not lead to thalamic activation at all. Stimuli applied to the left body side resulted in stronger activation patterns. Comparing an early with a late stimulation interval, the mentioned activation patterns were far more pronounced within the early stimulation interval. CONCLUSIONS: The right anterior and ventral-anterior nucleus and the left medio-dorsal nucleus appear to be important for the processing of multimodal sensory information. In addition, galvanic stimulation is processed more laterally compared to mechanical pain. The observed changes in activity within the thalamic nuclei depending on the stimulation interval suggest that the stimuli are processed in a thalamic network rather than a distinct nucleus. In particular, the vestibular network within the thalamus recruits bilateral nuclei, rendering the thalamus an important integrative structure for vestibular function.

A comparative study of pain perception during the microfocused ultrasound procedure between topical anesthesia and combined topical anesthesia with forced air cooling.

BACKGROUND: The experience of pain during microfocused ultrasound with visualization (MFU-V) treatment is common and crucial for dictating patient satisfaction and retention. OBJECTIVE: To compare the pain perception during the MFU-V procedure between two pain reduction methods (topical anesthesia alone versus combined topical anesthesia with forced air cooling). MATERIALS AND METHODS: This was a prospective, single-blinded, randomized controlled trial. A square area on the inner side of both arms of healthy volunteers was marked as an experimental site and randomly assigned to receive each pain reduction method: topical anesthesia or combined topical anesthesia with forced air cooling. Thereafter, MFU-V was performed with a 4.5 MHz, 4.5 mm transducer (10 lines, 0.9 J) followed by a 7 MHz, 3.0 mm transducer (10 lines, 0.3 J). The visual analog scale (VAS) for pain was measured immediately after 4.5 mm transducer (T1a), immediately after 3.0 mm transducer (T1b), and after the entire procedure (T2). RESULTS: Twenty-one participants with a mean (SD) age of 34.67 (±6.18) years were enrolled. The mean (±SD) pain score of combined topical anesthesia with forced air cooling-treated area was 5.40 (±1.64), 4.80 (±1.63), and 5.40 (±1.56) at T1a, T1b, and T2, respectively. The mean pain score for topical anesthesia-treated areas was 5.89 (±1.45), 5.00 (±1.72), and 5.76 (±1.67) at T1a, T1b, and T2, respectively. There were no statistically significant differences in the pain perception between the two methods. CONCLUSION: The addition of forced air cooling is not beneficial for pain reduction during the MFU-V procedure because its temperature reduction effect cannot be delivered to the deep parts of the skin, which is the target site of MFU-V.

Effect of a needle-free system versus traditional anesthesia on pain perception during palatal injections in children.

BACKGROUND: Needle-free injection systems can contribute to the prevention of needle-related pain during palatal infiltration anesthesia (PIA) in children. Research on this topic in children is required. AIM: The purpose of this clinical study was to evaluate the effectiveness and patient preference of a needle-free system versus traditional anesthesia (TA) on pain perception during PIA in children. DESIGN: The study was designed as a randomized, controlled crossover clinical study with 48 children aged 6-12 years requiring dental treatment with PIA in bilateral maxillary primary molars. TA was applied on one side and the Comfort-in™ injection system (CIS) on the other side in two separate sessions. Then, patient preference was recorded. The pain perception during PIA was evaluated using the Wong-Baker FACES Pain Rating Scale (PRS) and the Face, Legs, Activity, Cry, Consolability (FLACC) Scale. The data were analyzed for statistical significance (p < .05). RESULTS: There were statistically significant differences between the TA and the CIS according to the PRS and FLACC Scale scores. On both scales, significantly higher pain ratings were observed in the TA group during PIA (p < .001). There was a statistically significant difference in terms of patient preference (p < .001). Although 77.1% (n = 37) of the children preferred the CIS, 22.9% (n = 11) preferred the TA. Moreover, patient preference for the CIS was significantly higher in older children (p < .01). CONCLUSIONS: The application of a needle-free system during PIA ensured a decrease in pain perception in children.

Korsakoff syndrome and altered pain perception: a search of underlying neural mechanisms.

OBJECTIVES: Patients with Korsakoff syndrome (KS) may have a diminished pain perception. Information on KS and pain is scarce and limited to case descriptions. The present study is the first to investigate the underlying neural mechanisms of altered pain perception in patients with KS more systematically. METHODS: We conducted a literature search on neural correlates of pain perception in other neurocognitive disorders in which extensive research was done. RESULTS: The brain areas that are affected in KS showed considerable overlap with the neural correlates of pain perception in other neurocognitive disorders. We discussed which different aspects of disturbed pain perception could play a role within KS, based on distinct neural damage and brain areas involved in pain perception. CONCLUSIONS: Combining current knowledge, we hypothesize that diminished pain perception in KS may be related to lesioned neural connections between cerebral cortical networks and relays of mainly the thalamus, the periaqueductal gray, and possibly lower brain stem regions projecting to the cerebellum. Based on these neural correlates of altered pain perception, we assume that increased pain thresholds, inhibition of pain signals, and disturbed input to cerebral and cerebellar cortical areas involved in pain processing, all are candidate mechanisms in cases of diminished pain perception in KS. We recommend that clinicians need to be alert for somatic morbidity in patients with KS. Due to altered neural processing of nociceptive input the clinical symptoms of somatic morbidity may present differently (i.e. limited pain responses) and therefore are at risk of being missed.

Distraction With Virtual Reality Goggles in Paediatric Dental Treatment: A Randomised Controlled Trial.

AIM: The aim of this study was to examine whether screening content through virtual reality (VR) goggles can diminish pain perception during local anaesthesia administered using the inferior alveolar nerve block technique and rubber dam placement in routine paediatric dental treatment. MATERIALS AND METHODS: This is a crossover study of healthy 4- to 12-year-old children who were scheduled to receive local anaesthesia administered using the inferior alveolar nerve block technique and rubber dam placement in 2 visits. The participants were randomly assigned to undergo 1 treatment performed with Oculus GO VR goggles and the other treatment without. Pain was evaluated using the Wong-Baker FACES Pain Rating Scale and the Modified Behavioral Pain Scale (MBPS). RESULTS: The study group included 29 children with a mean age of 8.29 years (SD, 1.96). Whilst administering local anaesthesia, no significant difference was observed in the Wong-Baker FACES Pain Rating Scale and in MBPS movements between visits with and without the VR goggles. However, significantly lower pain perception was observed in the other parameters of MBPS when using the VR goggles: Face (P = .007) and Cry (P = .046). During placement of a rubber dam, significantly less pain was reported by the patients (P = .005) and observed by the assessor (Face [P = .005], Cry [P = .029], and Movement [P = 0.028]) when the VR goggles were used. CONCLUSIONS: VR can decrease pain perception during rubber dam placement in children, but it has limited benefit during administration of local anaesthesia.

Effectiveness of Aculief acupressure device on pain perception during local anesthesia in children: A double-blinded study.

AIM: The aim of this study was to evaluate the effect of the Aculief acupressure device on the reduction of pain during local anesthesia (LA) in children and to compare it with the cryotherapy technique. METHODOLOGY: 20 children of age group between 6 and 9 years, requiring pulpectomy or extraction bilaterally were chosen for the study. After ethical clearance and parental consent, children who were not experienced to prior local anesthesia were chosen for the study. A split-mouth study design was done to avoid bias, and children were divided into two groups. During the first visit cryotherapy application was done on any one side followed by the LA, and during the second visit Aculief acupressure application was done, which was followed by the LA. The objective and subjective evaluation of pain during the LA was carried out and analyzed. RESULTS: The objective perception of pain was evaluated using the Sound-Eye-Motor Scale by an observer who was blinded, and the subjective perception of pain by the Wong-Baker Faces Pain Rating Scale was evaluated by the child patient. The statistical analysis and comparison of values were done using the Wilcoxon signed-rank test. The pain during administration of LA was eliminated after the application of the Aculief acupressure device, and the results were superior to the cryotherapy technique. CONCLUSION: The Aculief acupressure device can be effectively used to eliminate pain perception while administering LA in children. It is a simple, safe, noninvasive, and effective device and is easy to perform.

Comparison of pain perception between computer-controlled local anesthetic delivery and the conventional syringe for inferior alveolar nerve block in children.

BACKGROUND: Local anesthesia (LA) is commonly used for pain control in clinical dental practice. However, it is often perceived as the most painful part of the treatment and the factor leading to the avoidance of dental care. Hence, research on better means of pain management is being conducted. OBJECTIVES: The aim of the study was to evaluate and compare pain perception using the No Pain III™ computer-controlled local anesthesia delivery (CCLAD) system and the conventional syringe, for inferior alveolar nerve block (IANB) in children. MATERIAL AND METHODS: Thirty children aged 6-12 years were included in the study. Children were randomly allocated into 2 groups by the flip of a coin. Group A received LA by conventional syringe and group B received LA by No Pain III™, on the contralateral side. Physiological parameters including blood pressure (BP), heart rate (HR) and respiratory rate (RR) were assessed at baseline, during the deposition and after the deposition of LA. A subjective evaluation of pain perception was assessed using the Wong-Baker FACES Pain Rating Scale (WBS). The measured values were subjected to statistical analysis. RESULTS: A statistically significant difference was observed between group A and group B for pain perception using the WBS, systolic BP and RR. CONCLUSIONS: The use of the No Pain III™ CCLAD system resulted in reduced pain perception and better acceptance when compared to the use of the conventional syringe, for IANB in children.

Impact of audible pops associated with spinal manipulation on perceived pain: a systematic review.

OBJECTIVES: An audible pop is the sound that can derive from an adjustment in spinal manipulative therapy and is often seen as an indicator of a successful treatment. A review conducted in 1998 concluded that there was little scientific evidence to support any therapeutic benefit derived from the audible pop. Since then, research methods have evolved considerably creating opportunities for new evidence to emerge. It was therefore timely to review the evidence. METHODS: The following electronic databases were searched for relevant studies pertaining to the impact of audible pops in spinal manipulative therapy: PubMed, Index to Chiropractic Literature (ICL), Cumulative Index to Nursing & Allied Health Literature (CINAHL) and Web-of-Science. The main outcome was pain. Two reviewers independently selected studies, extracted data, and assessed risk of bias and quality of the evidence using the Downs and Black checklist. Results of the included literature were synthesized into a systematic review. RESULTS: Five original research articles were included in the review, of which four were prospective cohort studies and one a randomized controlled trial. All studies reported similar results: regardless of the area of the spine manipulated or follow-up time, there was no evidence of improved pain outcomes associated with an audible pop. One study even reported a hypoalgesic effect to external pain stimuli after spinal manipulation, regardless of an audible pop. CONCLUSIONS: Whilst there is still no consensus among chiropractors on the association of an audible pop and pain outcomes in spinal manipulative therapy, knowledge about the audible pop has advanced. This review suggests that the presence or absence of an audible pop may not be important regarding pain outcomes with spinal manipulation.

Pain perception following computer-controlled versus conventional dental anesthesia: randomized controlled trial.

BACKGROUND: The administration of local anesthesia (LA) in dental practice requires an injection which is the leading cause of patients' fear and anxiety. Computer-controlled local anesthetic injector, designed to reduce the pain of performing local anesthesia by controlling the speed of injection. This single-blind randomised control trial aimed to compare the pain perception after computer-controlled local anesthesia (CCLA) and conventional LA. METHODS: Dental students were both test and operator group versus an experienced dentist as additional operator of the LA. Data were collected regarding gender, age, medical condition, smoking habits. Additionally, operator feedback about the handling, pain at insertion and during infiltration, excitement (Dental Anxiety Scale), and complications were assessed. RESULTS: Out of the 60 included participants, the majority were females (n = 41; 68.3%), medically healthy (n = 54; 90%), and did not receive medications (n = 54; 90%). While the participating students administered 62 (51.7%) injections, the experienced dentist administered 58 (48.3%) injections. The difference in pain perception on puncture between CCLA and conventional injections was not statistically significant (Sig. = 0.285); however, pain perception during injection was significantly different (Sig. = 0.029) between CCLA (1.65 ± 1.93) and conventional injections (2.49 ± 2.31). CONCLUSION: The professional experience influenced the pain perception while applying the LA. CCLA did not reduce pain on puncture significantly; however, pain perception during the injection was significantly reduced in the case of using CCLA devices compared to the conventional syringe.